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* [RFC PATCH 00/15] rseq uapi and selftest updates
@ 2022-01-24 17:12 Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header Mathieu Desnoyers
                   ` (15 more replies)
  0 siblings, 16 replies; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Update the rseq selftests to adapt to the userspace ABI chosen by glibc
(will be released in February 2022). Provide a fallback implementation
to work with older glibc as well.

Remove broken 32-bit little/big endian accessor fields in rseq uapi.

Integrate various fixes gathered from librseq, including work-around for
known gcc and clang compiler bugs with asm goto.

The uplift to glibc's userspace ABI means we can now use %fs/%gs segment
selectors directly in the inline assembler for accesses to the rseq
thread area on x86.

Feedback is welcome,

Thanks,

Mathieu

Mathieu Desnoyers (15):
  selftests/rseq: introduce own copy of rseq uapi header
  rseq: Remove broken uapi field layout on 32-bit little endian
  selftests/rseq: Remove useless assignment to cpu variable
  selftests/rseq: Remove volatile from __rseq_abi
  selftests/rseq: Introduce rseq_get_abi() helper
  selftests/rseq: Introduce thread pointer getters
  selftests/rseq: Uplift rseq selftests for compatibility with
    glibc-2.35
  selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big
    endian
  selftests/rseq: Fix ppc32 missing instruction selection "u" and "x"
    for load/store
  selftests/rseq: Fix ppc32 offsets by using long rather than off_t
  selftests/rseq: Fix warnings about #if checks of undefined tokens
  selftests/rseq: Remove arm/mips asm goto compiler work-around
  selftests/rseq: Fix: work-around asm goto compiler bugs
  selftests/rseq: x86-64: use %fs segment selector for accessing rseq
    thread area
  selftests/rseq: x86-32: use %gs segment selector for accessing rseq
    thread area

 include/uapi/linux/rseq.h                     |  17 +-
 tools/testing/selftests/rseq/Makefile         |   2 +-
 .../selftests/rseq/basic_percpu_ops_test.c    |   2 +-
 tools/testing/selftests/rseq/compiler.h       |  30 +++
 tools/testing/selftests/rseq/param_test.c     |   8 +-
 tools/testing/selftests/rseq/rseq-abi.h       | 151 +++++++++++++
 tools/testing/selftests/rseq/rseq-arm.h       | 110 +++++-----
 tools/testing/selftests/rseq/rseq-arm64.h     |  79 +++++--
 .../rseq/rseq-generic-thread-pointer.h        |  25 +++
 tools/testing/selftests/rseq/rseq-mips.h      |  71 ++-----
 .../selftests/rseq/rseq-ppc-thread-pointer.h  |  30 +++
 tools/testing/selftests/rseq/rseq-ppc.h       | 128 +++++++----
 tools/testing/selftests/rseq/rseq-s390.h      |  55 +++--
 tools/testing/selftests/rseq/rseq-skip.h      |   2 +-
 .../selftests/rseq/rseq-thread-pointer.h      |  19 ++
 .../selftests/rseq/rseq-x86-thread-pointer.h  |  40 ++++
 tools/testing/selftests/rseq/rseq-x86.h       | 200 ++++++++++++------
 tools/testing/selftests/rseq/rseq.c           | 163 +++++++-------
 tools/testing/selftests/rseq/rseq.h           |  29 ++-
 19 files changed, 793 insertions(+), 368 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/compiler.h
 create mode 100644 tools/testing/selftests/rseq/rseq-abi.h
 create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h

-- 
2.17.1


^ permalink raw reply	[flat|nested] 40+ messages in thread

* [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian Mathieu Desnoyers
                   ` (14 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

The Linux kernel rseq uapi header has a broken layout for the
rseq_cs.ptr field on 32-bit little endian architectures. The entire
rseq_cs.ptr field is planned for removal, leaving only the 64-bit
rseq_cs.ptr64 field available.

Both glibc and librseq use their own copy of the Linux kernel uapi
header, where they introduce proper union fields to access to the 32-bit
low order bits of the rseq_cs pointer on 32-bit architectures.

Introduce a copy of the Linux kernel uapi headers in the Linux kernel
selftests.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-abi.h | 151 ++++++++++++++++++++++++
 tools/testing/selftests/rseq/rseq.c     |  14 +--
 tools/testing/selftests/rseq/rseq.h     |  10 +-
 3 files changed, 161 insertions(+), 14 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/rseq-abi.h

diff --git a/tools/testing/selftests/rseq/rseq-abi.h b/tools/testing/selftests/rseq/rseq-abi.h
new file mode 100644
index 000000000000..a8c44d9af71f
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-abi.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef _RSEQ_ABI_H
+#define _RSEQ_ABI_H
+
+/*
+ * rseq-abi.h
+ *
+ * Restartable sequences system call API
+ *
+ * Copyright (c) 2015-2022 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+enum rseq_abi_cpu_id_state {
+	RSEQ_ABI_CPU_ID_UNINITIALIZED			= -1,
+	RSEQ_ABI_CPU_ID_REGISTRATION_FAILED		= -2,
+};
+
+enum rseq_abi_flags {
+	RSEQ_ABI_FLAG_UNREGISTER = (1 << 0),
+};
+
+enum rseq_abi_cs_flags_bit {
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT	= 0,
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT	= 1,
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT	= 2,
+};
+
+enum rseq_abi_cs_flags {
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT),
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT),
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT),
+};
+
+/*
+ * struct rseq_abi_cs is aligned on 4 * 8 bytes to ensure it is always
+ * contained within a single cache-line. It is usually declared as
+ * link-time constant data.
+ */
+struct rseq_abi_cs {
+	/* Version of this structure. */
+	__u32 version;
+	/* enum rseq_abi_cs_flags */
+	__u32 flags;
+	__u64 start_ip;
+	/* Offset from start_ip. */
+	__u64 post_commit_offset;
+	__u64 abort_ip;
+} __attribute__((aligned(4 * sizeof(__u64))));
+
+/*
+ * struct rseq_abi is aligned on 4 * 8 bytes to ensure it is always
+ * contained within a single cache-line.
+ *
+ * A single struct rseq_abi per thread is allowed.
+ */
+struct rseq_abi {
+	/*
+	 * Restartable sequences cpu_id_start field. Updated by the
+	 * kernel. Read by user-space with single-copy atomicity
+	 * semantics. This field should only be read by the thread which
+	 * registered this data structure. Aligned on 32-bit. Always
+	 * contains a value in the range of possible CPUs, although the
+	 * value may not be the actual current CPU (e.g. if rseq is not
+	 * initialized). This CPU number value should always be compared
+	 * against the value of the cpu_id field before performing a rseq
+	 * commit or returning a value read from a data structure indexed
+	 * using the cpu_id_start value.
+	 */
+	__u32 cpu_id_start;
+	/*
+	 * Restartable sequences cpu_id field. Updated by the kernel.
+	 * Read by user-space with single-copy atomicity semantics. This
+	 * field should only be read by the thread which registered this
+	 * data structure. Aligned on 32-bit. Values
+	 * RSEQ_CPU_ID_UNINITIALIZED and RSEQ_CPU_ID_REGISTRATION_FAILED
+	 * have a special semantic: the former means "rseq uninitialized",
+	 * and latter means "rseq initialization failed". This value is
+	 * meant to be read within rseq critical sections and compared
+	 * with the cpu_id_start value previously read, before performing
+	 * the commit instruction, or read and compared with the
+	 * cpu_id_start value before returning a value loaded from a data
+	 * structure indexed using the cpu_id_start value.
+	 */
+	__u32 cpu_id;
+	/*
+	 * Restartable sequences rseq_cs field.
+	 *
+	 * Contains NULL when no critical section is active for the current
+	 * thread, or holds a pointer to the currently active struct rseq_cs.
+	 *
+	 * Updated by user-space, which sets the address of the currently
+	 * active rseq_cs at the beginning of assembly instruction sequence
+	 * block, and set to NULL by the kernel when it restarts an assembly
+	 * instruction sequence block, as well as when the kernel detects that
+	 * it is preempting or delivering a signal outside of the range
+	 * targeted by the rseq_cs. Also needs to be set to NULL by user-space
+	 * before reclaiming memory that contains the targeted struct rseq_cs.
+	 *
+	 * Read and set by the kernel. Set by user-space with single-copy
+	 * atomicity semantics. This field should only be updated by the
+	 * thread which registered this data structure. Aligned on 64-bit.
+	 */
+	union {
+		__u64 ptr64;
+
+		/*
+		 * The "arch" field provides architecture accessor for
+		 * the ptr field based on architecture pointer size and
+		 * endianness.
+		 */
+		struct {
+#ifdef __LP64__
+			__u64 ptr;
+#elif defined(__BYTE_ORDER) ? (__BYTE_ORDER == __BIG_ENDIAN) : defined(__BIG_ENDIAN)
+			__u32 padding;		/* Initialized to zero. */
+			__u32 ptr;
+#else
+			__u32 ptr;
+			__u32 padding;		/* Initialized to zero. */
+#endif
+		} arch;
+	} rseq_cs;
+
+	/*
+	 * Restartable sequences flags field.
+	 *
+	 * This field should only be updated by the thread which
+	 * registered this data structure. Read by the kernel.
+	 * Mainly used for single-stepping through rseq critical sections
+	 * with debuggers.
+	 *
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT
+	 *     Inhibit instruction sequence block restart on preemption
+	 *     for this thread.
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL
+	 *     Inhibit instruction sequence block restart on signal
+	 *     delivery for this thread.
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE
+	 *     Inhibit instruction sequence block restart on migration for
+	 *     this thread.
+	 */
+	__u32 flags;
+} __attribute__((aligned(4 * sizeof(__u64))));
+
+#endif /* _RSEQ_ABI_H */
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index fb440dfca158..bfe1b2692ffc 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -30,8 +30,8 @@
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread volatile struct rseq __rseq_abi = {
-	.cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
+__thread volatile struct rseq_abi __rseq_abi = {
+	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
 };
 
 /*
@@ -66,7 +66,7 @@ static void signal_restore(sigset_t oldset)
 		abort();
 }
 
-static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len,
+static int sys_rseq(volatile struct rseq_abi *rseq_abi, uint32_t rseq_len,
 		    int flags, uint32_t sig)
 {
 	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
@@ -86,13 +86,13 @@ int rseq_register_current_thread(void)
 	}
 	if (__rseq_refcount++)
 		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), 0, RSEQ_SIG);
 	if (!rc) {
 		assert(rseq_current_cpu_raw() >= 0);
 		goto end;
 	}
 	if (errno != EBUSY)
-		__rseq_abi.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
+		__rseq_abi.cpu_id = RSEQ_ABI_CPU_ID_REGISTRATION_FAILED;
 	ret = -1;
 	__rseq_refcount--;
 end:
@@ -114,8 +114,8 @@ int rseq_unregister_current_thread(void)
 	}
 	if (--__rseq_refcount)
 		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq),
-		      RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi),
+		      RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
 	if (!rc)
 		goto end;
 	__rseq_refcount = 1;
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 3f63eb362b92..cb6bbc53b586 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -16,7 +16,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <linux/rseq.h>
+#include "rseq-abi.h"
 
 /*
  * Empty code injection macros, override when testing.
@@ -43,7 +43,7 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread volatile struct rseq __rseq_abi;
+extern __thread volatile struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
@@ -139,11 +139,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-#ifdef __LP64__
-	__rseq_abi.rseq_cs.ptr = 0;
-#else
-	__rseq_abi.rseq_cs.ptr.ptr32 = 0;
-#endif
+	__rseq_abi.rseq_cs.arch.ptr = 0;
 }
 
 /*
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-01-25 12:21   ` Christian Brauner
  2022-01-24 17:12 ` [RFC PATCH 03/15] selftests/rseq: Remove useless assignment to cpu variable Mathieu Desnoyers
                   ` (13 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers, Florian Weimer,
	Andy Lutomirski, Dave Watson, Andrew Morton, Russell King,
	Andi Kleen, Christian Brauner, Ben Maurer, Steven Rostedt,
	Josh Triplett, Linus Torvalds, Catalin Marinas, Will Deacon,
	Michael Kerrisk, Joel Fernandes

The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
entirely wrong on 32-bit little endian: a preprocessor logic mistake
wrongly uses the big endian field layout on 32-bit little endian
architectures.

Fortunately, those ptr32 accessors were never used within the kernel,
and only meant as a convenience for user-space.

Remove those and only leave the "ptr64" union field, as this is the only
thing really needed to express the ABI. Document how 32-bit
architectures are meant to interact with this "ptr64" union field.

Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
---
 include/uapi/linux/rseq.h | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index 9a402fdb60e9..31290f2424a7 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -105,22 +105,13 @@ struct rseq {
 	 * Read and set by the kernel. Set by user-space with single-copy
 	 * atomicity semantics. This field should only be updated by the
 	 * thread which registered this data structure. Aligned on 64-bit.
+	 *
+	 * 32-bit architectures should update the low order bits of the
+	 * rseq_cs.ptr64 field, leaving the high order bits initialized
+	 * to 0.
 	 */
 	union {
 		__u64 ptr64;
-#ifdef __LP64__
-		__u64 ptr;
-#else
-		struct {
-#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined(__BIG_ENDIAN)
-			__u32 padding;		/* Initialized to zero. */
-			__u32 ptr32;
-#else /* LITTLE */
-			__u32 ptr32;
-			__u32 padding;		/* Initialized to zero. */
-#endif /* ENDIAN */
-		} ptr;
-#endif
 	} rseq_cs;
 
 	/*
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 03/15] selftests/rseq: Remove useless assignment to cpu variable
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 04/15] selftests/rseq: Remove volatile from __rseq_abi Mathieu Desnoyers
                   ` (12 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/param_test.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 699ad5f93c34..cc2cfc1da938 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -368,9 +368,7 @@ void *test_percpu_spinlock_thread(void *arg)
 		abort();
 	reps = thread_data->reps;
 	for (i = 0; i < reps; i++) {
-		int cpu = rseq_cpu_start();
-
-		cpu = rseq_this_cpu_lock(&data->lock);
+		int cpu = rseq_this_cpu_lock(&data->lock);
 		data->c[cpu].count++;
 		rseq_percpu_unlock(&data->lock, cpu);
 #ifndef BENCHMARK
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 04/15] selftests/rseq: Remove volatile from __rseq_abi
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (2 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 03/15] selftests/rseq: Remove useless assignment to cpu variable Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 05/15] selftests/rseq: Introduce rseq_get_abi() helper Mathieu Desnoyers
                   ` (11 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

All accesses to the __rseq_abi fields are volatile, but remove the
volatile from the TLS variable declaration, otherwise we are stuck with
volatile for the upcoming rseq_get_abi() helper.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq.c | 4 ++--
 tools/testing/selftests/rseq/rseq.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index bfe1b2692ffc..1f905b60728a 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -30,7 +30,7 @@
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread volatile struct rseq_abi __rseq_abi = {
+__thread struct rseq_abi __rseq_abi = {
 	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
 };
 
@@ -92,7 +92,7 @@ int rseq_register_current_thread(void)
 		goto end;
 	}
 	if (errno != EBUSY)
-		__rseq_abi.cpu_id = RSEQ_ABI_CPU_ID_REGISTRATION_FAILED;
+		RSEQ_WRITE_ONCE(__rseq_abi.cpu_id, RSEQ_ABI_CPU_ID_REGISTRATION_FAILED);
 	ret = -1;
 	__rseq_refcount--;
 end:
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index cb6bbc53b586..d580f8e9c001 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -43,7 +43,7 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread volatile struct rseq_abi __rseq_abi;
+extern __thread struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
@@ -139,7 +139,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-	__rseq_abi.rseq_cs.arch.ptr = 0;
+	RSEQ_WRITE_ONCE(__rseq_abi.rseq_cs.arch.ptr, 0);
 }
 
 /*
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 05/15] selftests/rseq: Introduce rseq_get_abi() helper
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (3 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 04/15] selftests/rseq: Remove volatile from __rseq_abi Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 06/15] selftests/rseq: Introduce thread pointer getters Mathieu Desnoyers
                   ` (10 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer, rather than through an actual
Thread-Local Storage (TLS) variable, as the kernel selftests initially
expected.

Introduce a rseq_get_abi() helper, initially using the __rseq_abi
TLS variable, in preparation for changing this userspace ABI for one
which is compatible with glibc-2.35.

Note that the __rseq_abi TLS and glibc-2.35's ABI for per-thread data
cannot actively coexist in a process, because the kernel supports only
a single rseq registration per thread.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-arm.h   | 32 +++++++++++------------
 tools/testing/selftests/rseq/rseq-arm64.h | 32 +++++++++++------------
 tools/testing/selftests/rseq/rseq-mips.h  | 32 +++++++++++------------
 tools/testing/selftests/rseq/rseq-ppc.h   | 32 +++++++++++------------
 tools/testing/selftests/rseq/rseq-s390.h  | 24 ++++++++---------
 tools/testing/selftests/rseq/rseq-x86.h   | 30 ++++++++++-----------
 tools/testing/selftests/rseq/rseq.h       | 11 +++++---
 7 files changed, 99 insertions(+), 94 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 5943c816c07c..6716540e17c6 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -185,8 +185,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -255,8 +255,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -316,8 +316,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -381,8 +381,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -457,8 +457,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -537,8 +537,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -657,8 +657,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -782,8 +782,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 200dae9e4208..b9d9b3aa6e9b 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -230,8 +230,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -287,8 +287,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expectnot]		"r" (expectnot),
 		  [load]		"Qo" (*load),
@@ -337,8 +337,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [count]		"r" (count)
 		  RSEQ_INJECT_INPUT
@@ -388,8 +388,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -447,8 +447,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -508,8 +508,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [v2]			"Qo" (*v2),
@@ -569,8 +569,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -629,8 +629,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index e989e7c14b09..2b1f5bd95268 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -190,8 +190,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -258,8 +258,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -319,8 +319,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -382,8 +382,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -456,8 +456,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -532,8 +532,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -649,8 +649,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -771,8 +771,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 76be90196fe4..2e6b7572ba08 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -235,8 +235,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -301,8 +301,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -359,8 +359,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -419,8 +419,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -489,8 +489,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -560,8 +560,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -635,8 +635,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -711,8 +711,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 8ef94ad1cbb4..b906e044d2a3 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -165,8 +165,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -233,8 +233,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -288,8 +288,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -347,8 +347,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -426,8 +426,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -534,8 +534,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 640411518e46..1d9fa0516e53 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -141,7 +141,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -207,7 +207,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -258,7 +258,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"er" (count)
@@ -314,7 +314,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, off_t off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [ptr]			"m" (*ptr),
 		  [off]			"er" (off),
@@ -372,7 +372,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -449,7 +449,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -555,7 +555,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -719,7 +719,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -785,7 +785,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -836,7 +836,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"ir" (count)
@@ -894,7 +894,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"m" (newv2),
@@ -962,7 +962,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -1032,7 +1032,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -1142,7 +1142,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
@@ -1255,7 +1255,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index d580f8e9c001..ca668a2af172 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -46,6 +46,11 @@
 extern __thread struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
+static inline struct rseq_abi *rseq_get_abi(void)
+{
+	return &__rseq_abi;
+}
+
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
 #define rseq_unlikely(x)	__builtin_expect(!!(x), 0)
 #define rseq_barrier()		__asm__ __volatile__("" : : : "memory")
@@ -108,7 +113,7 @@ int32_t rseq_fallback_current_cpu(void);
  */
 static inline int32_t rseq_current_cpu_raw(void)
 {
-	return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id);
+	return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id);
 }
 
 /*
@@ -124,7 +129,7 @@ static inline int32_t rseq_current_cpu_raw(void)
  */
 static inline uint32_t rseq_cpu_start(void)
 {
-	return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start);
+	return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id_start);
 }
 
 static inline uint32_t rseq_current_cpu(void)
@@ -139,7 +144,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-	RSEQ_WRITE_ONCE(__rseq_abi.rseq_cs.arch.ptr, 0);
+	RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);
 }
 
 /*
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 06/15] selftests/rseq: Introduce thread pointer getters
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (4 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 05/15] selftests/rseq: Introduce rseq_get_abi() helper Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 07/15] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35 Mathieu Desnoyers
                   ` (9 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer.

The toolchains do not implement accessing the thread pointer on all
architectures. Provide thread pointer getters for ppc and x86 which
lack (or lacked until recently) toolchain support.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 .../rseq/rseq-generic-thread-pointer.h        | 25 ++++++++++++
 .../selftests/rseq/rseq-ppc-thread-pointer.h  | 30 ++++++++++++++
 .../selftests/rseq/rseq-thread-pointer.h      | 19 +++++++++
 .../selftests/rseq/rseq-x86-thread-pointer.h  | 40 +++++++++++++++++++
 4 files changed, 114 insertions(+)
 create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h

diff --git a/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h b/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
new file mode 100644
index 000000000000..38c584661571
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-generic-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_GENERIC_THREAD_POINTER
+#define _RSEQ_GENERIC_THREAD_POINTER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Use gcc builtin thread pointer. */
+static inline void *rseq_thread_pointer(void)
+{
+	return __builtin_thread_pointer();
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h b/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
new file mode 100644
index 000000000000..263eee84fb76
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-ppc-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_PPC_THREAD_POINTER
+#define _RSEQ_PPC_THREAD_POINTER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static inline void *rseq_thread_pointer(void)
+{
+#ifdef __powerpc64__
+	register void *__result asm ("r13");
+#else
+	register void *__result asm ("r2");
+#endif
+	asm ("" : "=r" (__result));
+	return __result;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-thread-pointer.h b/tools/testing/selftests/rseq/rseq-thread-pointer.h
new file mode 100644
index 000000000000..977c25d758b2
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-thread-pointer.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_THREAD_POINTER
+#define _RSEQ_THREAD_POINTER
+
+#if defined(__x86_64__) || defined(__i386__)
+#include "rseq-x86-thread-pointer.h"
+#elif defined(__PPC__)
+#include "rseq-ppc-thread-pointer.h"
+#else
+#include "rseq-generic-thread-pointer.h"
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
new file mode 100644
index 000000000000..d3133587d996
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-x86-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_X86_THREAD_POINTER
+#define _RSEQ_X86_THREAD_POINTER
+
+#include <features.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if __GNUC_PREREQ (11, 1)
+static inline void *rseq_thread_pointer(void)
+{
+	return __builtin_thread_pointer();
+}
+#else
+static inline void *rseq_thread_pointer(void)
+{
+	void *__result;
+
+# ifdef __x86_64__
+	__asm__ ("mov %%fs:0, %0" : "=r" (__result));
+# else
+	__asm__ ("mov %%gs:0, %0" : "=r" (__result));
+# endif
+	return __result;
+}
+#endif /* !GCC 11 */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 07/15] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (5 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 06/15] selftests/rseq: Introduce thread pointer getters Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 08/15] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian Mathieu Desnoyers
                   ` (8 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

glibc-2.35 (upcoming release date 2022-02-01) exposes the rseq per-thread
data in the TCB, accessible at an offset from the thread pointer, rather
than through an actual Thread-Local Storage (TLS) variable, as the
Linux kernel selftests initially expected.

The __rseq_abi TLS and glibc-2.35's ABI for per-thread data cannot
actively coexist in a process, because the kernel supports only a single
rseq registration per thread.

Here is the scheme introduced to ensure selftests can work both with an
older glibc and with glibc-2.35+:

- librseq exposes its own "rseq_offset, rseq_size, rseq_flags" ABI.

- librseq queries for glibc rseq ABI (__rseq_offset, __rseq_size,
  __rseq_flags) using dlsym() in a librseq library constructor. If those
  are found, copy their values into rseq_offset, rseq_size, and
  rseq_flags.

- Else, if those glibc symbols are not found, handle rseq registration
  from librseq and use its own IE-model TLS to implement the rseq ABI
  per-thread storage.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/Makefile |   2 +-
 tools/testing/selftests/rseq/rseq.c   | 161 ++++++++++++--------------
 tools/testing/selftests/rseq/rseq.h   |  13 ++-
 3 files changed, 88 insertions(+), 88 deletions(-)

diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile
index 2af9d39a9716..215e1067f037 100644
--- a/tools/testing/selftests/rseq/Makefile
+++ b/tools/testing/selftests/rseq/Makefile
@@ -6,7 +6,7 @@ endif
 
 CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L$(OUTPUT) -Wl,-rpath=./ \
 	  $(CLANG_FLAGS)
-LDLIBS += -lpthread
+LDLIBS += -lpthread -ldl
 
 # Own dependencies because we only want to build against 1st prerequisite, but
 # still track changes to header files and depend on shared object.
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 1f905b60728a..07ba0d463a96 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -26,130 +26,123 @@
 #include <assert.h>
 #include <signal.h>
 #include <limits.h>
+#include <dlfcn.h>
 
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread struct rseq_abi __rseq_abi = {
-	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
-};
+static const int *libc_rseq_offset_p;
+static const unsigned int *libc_rseq_size_p;
+static const unsigned int *libc_rseq_flags_p;
 
-/*
- * Shared with other libraries. This library may take rseq ownership if it is
- * still 0 when executing the library constructor. Set to 1 by library
- * constructor when handling rseq. Set to 0 in destructor if handling rseq.
- */
-int __rseq_handled;
+/* Offset from the thread pointer to the rseq area.  */
+int rseq_offset;
+
+/* Size of the registered rseq area.  0 if the registration was
+   unsuccessful.  */
+unsigned int rseq_size = -1U;
+
+/* Flags used during rseq registration.  */
+unsigned int rseq_flags;
 
-/* Whether this library have ownership of rseq registration. */
 static int rseq_ownership;
 
-static __thread volatile uint32_t __rseq_refcount;
+static
+__thread struct rseq_abi __rseq_abi __attribute__((tls_model("initial-exec"))) = {
+	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
+};
 
-static void signal_off_save(sigset_t *oldset)
+static int sys_rseq(struct rseq_abi *rseq_abi, uint32_t rseq_len,
+		    int flags, uint32_t sig)
 {
-	sigset_t set;
-	int ret;
-
-	sigfillset(&set);
-	ret = pthread_sigmask(SIG_BLOCK, &set, oldset);
-	if (ret)
-		abort();
+	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
 }
 
-static void signal_restore(sigset_t oldset)
+int rseq_available(void)
 {
-	int ret;
+	int rc;
 
-	ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
-	if (ret)
+	rc = sys_rseq(NULL, 0, 0, 0);
+	if (rc != -1)
 		abort();
-}
-
-static int sys_rseq(volatile struct rseq_abi *rseq_abi, uint32_t rseq_len,
-		    int flags, uint32_t sig)
-{
-	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
+	switch (errno) {
+	case ENOSYS:
+		return 0;
+	case EINVAL:
+		return 1;
+	default:
+		abort();
+	}
 }
 
 int rseq_register_current_thread(void)
 {
-	int rc, ret = 0;
-	sigset_t oldset;
+	int rc;
 
-	if (!rseq_ownership)
+	if (!rseq_ownership) {
+		/* Treat libc's ownership as a successful registration. */
 		return 0;
-	signal_off_save(&oldset);
-	if (__rseq_refcount == UINT_MAX) {
-		ret = -1;
-		goto end;
 	}
-	if (__rseq_refcount++)
-		goto end;
 	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), 0, RSEQ_SIG);
-	if (!rc) {
-		assert(rseq_current_cpu_raw() >= 0);
-		goto end;
-	}
-	if (errno != EBUSY)
-		RSEQ_WRITE_ONCE(__rseq_abi.cpu_id, RSEQ_ABI_CPU_ID_REGISTRATION_FAILED);
-	ret = -1;
-	__rseq_refcount--;
-end:
-	signal_restore(oldset);
-	return ret;
+	if (rc)
+		return -1;
+	assert(rseq_current_cpu_raw() >= 0);
+	return 0;
 }
 
 int rseq_unregister_current_thread(void)
 {
-	int rc, ret = 0;
-	sigset_t oldset;
+	int rc;
 
-	if (!rseq_ownership)
+	if (!rseq_ownership) {
+		/* Treat libc's ownership as a successful unregistration. */
 		return 0;
-	signal_off_save(&oldset);
-	if (!__rseq_refcount) {
-		ret = -1;
-		goto end;
 	}
-	if (--__rseq_refcount)
-		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi),
-		      RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
-	if (!rc)
-		goto end;
-	__rseq_refcount = 1;
-	ret = -1;
-end:
-	signal_restore(oldset);
-	return ret;
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
+	if (rc)
+		return -1;
+	return 0;
 }
 
-int32_t rseq_fallback_current_cpu(void)
+static __attribute__((constructor))
+void rseq_init(void)
 {
-	int32_t cpu;
-
-	cpu = sched_getcpu();
-	if (cpu < 0) {
-		perror("sched_getcpu()");
-		abort();
+	libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");
+	libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");
+	libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");
+	if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p) {
+		/* rseq registration owned by glibc */
+		rseq_offset = *libc_rseq_offset_p;
+		rseq_size = *libc_rseq_size_p;
+		rseq_flags = *libc_rseq_flags_p;
+		return;
 	}
-	return cpu;
-}
-
-void __attribute__((constructor)) rseq_init(void)
-{
-	/* Check whether rseq is handled by another library. */
-	if (__rseq_handled)
+	if (!rseq_available())
 		return;
-	__rseq_handled = 1;
 	rseq_ownership = 1;
+	rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
+	rseq_size = sizeof(struct rseq_abi);
+	rseq_flags = 0;
 }
 
-void __attribute__((destructor)) rseq_fini(void)
+static __attribute__((destructor))
+void rseq_exit(void)
 {
 	if (!rseq_ownership)
 		return;
-	__rseq_handled = 0;
+	rseq_offset = 0;
+	rseq_size = -1U;
 	rseq_ownership = 0;
 }
+
+int32_t rseq_fallback_current_cpu(void)
+{
+	int32_t cpu;
+
+	cpu = sched_getcpu();
+	if (cpu < 0) {
+		perror("sched_getcpu()");
+		abort();
+	}
+	return cpu;
+}
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index ca668a2af172..17531ccd3090 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -43,12 +43,19 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread struct rseq_abi __rseq_abi;
-extern int __rseq_handled;
+#include "rseq-thread-pointer.h"
+
+/* Offset from the thread pointer to the rseq area.  */
+extern int rseq_offset;
+/* Size of the registered rseq area.  0 if the registration was
+   unsuccessful.  */
+extern unsigned int rseq_size;
+/* Flags used during rseq registration.  */
+extern unsigned int rseq_flags;
 
 static inline struct rseq_abi *rseq_get_abi(void)
 {
-	return &__rseq_abi;
+	return (struct rseq_abi *) ((uintptr_t) rseq_thread_pointer() + rseq_offset);
 }
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 08/15] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (6 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 07/15] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35 Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 09/15] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store Mathieu Desnoyers
                   ` (7 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

ppc32 incorrectly uses padding as rseq_cs pointer field. Fix this by
using the rseq_cs.arch.ptr field.

Use this field across all architectures.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-arm.h   | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-arm64.h | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-mips.h  | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-ppc.h   | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-s390.h  | 12 ++++++------
 5 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 6716540e17c6..5f567b3b40f2 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -186,7 +186,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -256,7 +256,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -317,7 +317,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -382,7 +382,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -458,7 +458,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -538,7 +538,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -658,7 +658,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -783,7 +783,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index b9d9b3aa6e9b..d0f2b7feee94 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -231,7 +231,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -288,7 +288,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expectnot]		"r" (expectnot),
 		  [load]		"Qo" (*load),
@@ -338,7 +338,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [count]		"r" (count)
 		  RSEQ_INJECT_INPUT
@@ -389,7 +389,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -448,7 +448,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -509,7 +509,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [v2]			"Qo" (*v2),
@@ -570,7 +570,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -630,7 +630,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 2b1f5bd95268..6df54273825d 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -191,7 +191,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -259,7 +259,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -320,7 +320,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -383,7 +383,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -457,7 +457,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -533,7 +533,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -650,7 +650,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -772,7 +772,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 2e6b7572ba08..c4ba1375285d 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -236,7 +236,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -302,7 +302,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -360,7 +360,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -420,7 +420,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -490,7 +490,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -561,7 +561,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -636,7 +636,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -712,7 +712,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index b906e044d2a3..9927021f8bd0 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -166,7 +166,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -234,7 +234,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -289,7 +289,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -348,7 +348,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -427,7 +427,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -535,7 +535,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 09/15] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (7 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 08/15] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 10/15] selftests/rseq: Fix ppc32 offsets by using long rather than off_t Mathieu Desnoyers
                   ` (6 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Building the rseq basic test  with
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
Target: powerpc-linux-gnu

leads to these errors:

/tmp/ccieEWxU.s: Assembler messages:
/tmp/ccieEWxU.s:118: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:118: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:121: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:121: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:626: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:626: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:629: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:629: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:735: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:735: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:738: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:738: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:741: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:741: Error: junk at end of line: `,8'
Makefile:581: recipe for target 'basic_percpu_ops_test.o' failed

Based on discussion with Linux powerpc maintainers and review of
the use of the "m" operand in powerpc kernel code, add the missing
%Un%Xn (where n is operand number) to the lwz, stw, ld, and std
instructions when used with "m" operands.

Using "WORD" to mean either a 32-bit or 64-bit type depending on
the architecture is misleading. The term "WORD" really means a
32-bit type in both 32-bit and 64-bit powerpc assembler. The intent
here is to wrap load/store to intptr_t into common macros for both
32-bit and 64-bit.

Rename the macros with a RSEQ_ prefix, and use the terms "INT"
for always 32-bit type, and "LONG" for architecture bitness-sized
type.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-ppc.h | 55 +++++++++++++------------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index c4ba1375285d..87befda47ba4 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -47,10 +47,13 @@ do {									\
 
 #ifdef __PPC64__
 
-#define STORE_WORD	"std "
-#define LOAD_WORD	"ld "
-#define LOADX_WORD	"ldx "
-#define CMP_WORD	"cmpd "
+#define RSEQ_STORE_LONG(arg)	"std%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"ld%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"ldx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpd "
+#define RSEQ_CMP_LONG_INT	"cmpdi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
@@ -89,10 +92,13 @@ do {									\
 
 #else /* #ifdef __PPC64__ */
 
-#define STORE_WORD	"stw "
-#define LOAD_WORD	"lwz "
-#define LOADX_WORD	"lwzx "
-#define CMP_WORD	"cmpw "
+#define RSEQ_STORE_LONG(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	RSEQ_STORE_LONG(arg)					/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	RSEQ_LOAD_LONG(arg)					/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"lwzx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpw "
+#define RSEQ_CMP_LONG_INT	"cmpwi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
@@ -125,7 +131,7 @@ do {									\
 		RSEQ_INJECT_ASM(1)						\
 		"lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t"			\
 		"addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t"		\
-		"stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t"			\
+		RSEQ_STORE_INT(rseq_cs) "%%r17, %[" __rseq_str(rseq_cs) "]\n\t"	\
 		__rseq_str(label) ":\n\t"
 
 #endif /* #ifdef __PPC64__ */
@@ -136,7 +142,7 @@ do {									\
 
 #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)			\
 		RSEQ_INJECT_ASM(2)						\
-		"lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t"		\
+		RSEQ_LOAD_INT(current_cpu_id) "%%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
 		"cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
@@ -153,25 +159,25 @@ do {									\
  * 	RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
  */
 #define RSEQ_ASM_OP_CMPEQ(var, expect, label)					\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_CMPNE(var, expectnot, label)				\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
 		"beq- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_STORE(value, var)						\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
 
 /* Load @var to r17 */
 #define RSEQ_ASM_OP_R_LOAD(var)							\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Store r17 to @var */
 #define RSEQ_ASM_OP_R_STORE(var)						\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Add @count to r17 */
 #define RSEQ_ASM_OP_R_ADD(count)						\
@@ -179,11 +185,11 @@ do {									\
 
 /* Load (r17 + voffp) to r17 */
 #define RSEQ_ASM_OP_R_LOADX(voffp)						\
-		LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
+		RSEQ_LOADX_LONG "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
 
 /* TODO: implement a faster memcpy. */
 #define RSEQ_ASM_OP_R_MEMCPY() \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"beq 333f\n\t" \
 		"addi %%r20, %%r20, -1\n\t" \
 		"addi %%r21, %%r21, -1\n\t" \
@@ -191,16 +197,16 @@ do {									\
 		"lbzu %%r18, 1(%%r20)\n\t" \
 		"stbu %%r18, 1(%%r21)\n\t" \
 		"addi %%r19, %%r19, -1\n\t" \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"bne 222b\n\t" \
 		"333:\n\t" \
 
 #define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label)			\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"			\
 		__rseq_str(post_commit_label) ":\n\t"
 
 #define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label)			\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
 		__rseq_str(post_commit_label) ":\n\t"
 
 static inline __attribute__((always_inline))
@@ -743,9 +749,4 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 #endif
 }
 
-#undef STORE_WORD
-#undef LOAD_WORD
-#undef LOADX_WORD
-#undef CMP_WORD
-
 #endif /* !RSEQ_SKIP_FASTPATH */
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 10/15] selftests/rseq: Fix ppc32 offsets by using long rather than off_t
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (8 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 09/15] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 11/15] selftests/rseq: Fix warnings about #if checks of undefined tokens Mathieu Desnoyers
                   ` (5 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

The semantic of off_t is for file offsets. We mean to use it as an
offset from a pointer. We really expect it to fit in a single register,
and not use a 64-bit type on 32-bit architectures.

Fix runtime issues on ppc32 where the offset is always 0 due to
inconsistency between the argument type (off_t -> 64-bit) and type
expected by the inline assembler (32-bit).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/basic_percpu_ops_test.c | 2 +-
 tools/testing/selftests/rseq/param_test.c            | 2 +-
 tools/testing/selftests/rseq/rseq-arm.h              | 2 +-
 tools/testing/selftests/rseq/rseq-arm64.h            | 2 +-
 tools/testing/selftests/rseq/rseq-mips.h             | 2 +-
 tools/testing/selftests/rseq/rseq-ppc.h              | 2 +-
 tools/testing/selftests/rseq/rseq-s390.h             | 2 +-
 tools/testing/selftests/rseq/rseq-skip.h             | 2 +-
 tools/testing/selftests/rseq/rseq-x86.h              | 6 +++---
 9 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/rseq/basic_percpu_ops_test.c b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
index b953a52ff706..517756afc2a4 100644
--- a/tools/testing/selftests/rseq/basic_percpu_ops_test.c
+++ b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
@@ -167,7 +167,7 @@ struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
 	for (;;) {
 		struct percpu_list_node *head;
 		intptr_t *targetptr, expectnot, *load;
-		off_t offset;
+		long offset;
 		int ret, cpu;
 
 		cpu = rseq_cpu_start();
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index cc2cfc1da938..335c290b39e7 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -549,7 +549,7 @@ struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
 	for (;;) {
 		struct percpu_list_node *head;
 		intptr_t *targetptr, expectnot, *load;
-		off_t offset;
+		long offset;
 		int ret;
 
 		cpu = rseq_cpu_start();
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 5f567b3b40f2..ae476af70152 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -217,7 +217,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index d0f2b7feee94..7806817062c2 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -259,7 +259,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 6df54273825d..0d1d9255da70 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -222,7 +222,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 87befda47ba4..aa18c0eabf40 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -270,7 +270,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 9927021f8bd0..0f523b3ecdef 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -198,7 +198,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-skip.h b/tools/testing/selftests/rseq/rseq-skip.h
index 72750b5905a9..7b53dac1fcdd 100644
--- a/tools/testing/selftests/rseq/rseq-skip.h
+++ b/tools/testing/selftests/rseq/rseq-skip.h
@@ -13,7 +13,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	return -1;
 }
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 1d9fa0516e53..0ee6c041d4be 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -172,7 +172,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
@@ -286,7 +286,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
  *  *pval += inc;
  */
 static inline __attribute__((always_inline))
-int rseq_offset_deref_addv(intptr_t *ptr, off_t off, intptr_t inc, int cpu)
+int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
@@ -750,7 +750,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 11/15] selftests/rseq: Fix warnings about #if checks of undefined tokens
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (9 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 10/15] selftests/rseq: Fix ppc32 offsets by using long rather than off_t Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 12/15] selftests/rseq: Remove arm/mips asm goto compiler work-around Mathieu Desnoyers
                   ` (4 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/param_test.c | 2 +-
 tools/testing/selftests/rseq/rseq-x86.h   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 335c290b39e7..da23c22d5882 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -161,7 +161,7 @@ unsigned int yield_mod_cnt, nr_abort;
 	"	cbnz	" INJECT_ASM_REG ", 222b\n"			\
 	"333:\n"
 
-#elif __PPC__
+#elif defined(__PPC__)
 
 #define RSEQ_INJECT_INPUT \
 	, [loop_cnt_1]"m"(loop_cnt[1]) \
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 0ee6c041d4be..e444563c6999 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -600,7 +600,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 #endif /* !RSEQ_SKIP_FASTPATH */
 
-#elif __i386__
+#elif defined(__i386__)
 
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc")
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 12/15] selftests/rseq: Remove arm/mips asm goto compiler work-around
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (10 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 11/15] selftests/rseq: Fix warnings about #if checks of undefined tokens Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 13/15] selftests/rseq: Fix: work-around asm goto compiler bugs Mathieu Desnoyers
                   ` (3 subsequent siblings)
  15 siblings, 0 replies; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

The arm and mips work-around for asm goto size guess issues are not
properly documented, and lack reference to specific compiler versions,
upstream compiler bug tracker entry, and reproducer.

I can only find a loosely documented patch in my original LKML rseq post
refering to gcc < 7 on ARM, but it does not appear to be sufficient to
track the exact issue. Also, I am not sure MIPS really has the same
limitation.

Therefore, remove the work-around until we can properly document this.

Link: https://lore.kernel.org/lkml/20171121141900.18471-17-mathieu.desnoyers@efficios.com/
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-arm.h  | 37 ------------------------
 tools/testing/selftests/rseq/rseq-mips.h | 37 ------------------------
 2 files changed, 74 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index ae476af70152..64c3a622107b 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -147,14 +147,11 @@ do {									\
 		teardown						\
 		"b %l[" __rseq_str(cmpfail_label) "]\n\t"
 
-#define rseq_workaround_gcc_asm_size_guess()	__asm__ __volatile__("")
-
 static inline __attribute__((always_inline))
 int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -198,14 +195,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -221,7 +215,6 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -270,14 +263,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -292,7 +282,6 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 #ifdef RSEQ_COMPARE_TWICE
@@ -328,10 +317,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
@@ -347,7 +334,6 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -398,14 +384,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -422,7 +405,6 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -474,14 +456,11 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -498,7 +477,6 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -554,14 +532,11 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -582,7 +557,6 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -678,21 +652,16 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("cpu_id comparison failed");
 error2:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -706,7 +675,6 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -803,21 +771,16 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("cpu_id comparison failed");
 error2:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 0d1d9255da70..878739fae2fd 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -154,14 +154,11 @@ do {									\
 		teardown \
 		"b %l[" __rseq_str(cmpfail_label) "]\n\t"
 
-#define rseq_workaround_gcc_asm_size_guess()	__asm__ __volatile__("")
-
 static inline __attribute__((always_inline))
 int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -203,14 +200,11 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -226,7 +220,6 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -273,14 +266,11 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -295,7 +285,6 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 #ifdef RSEQ_COMPARE_TWICE
@@ -331,10 +320,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
@@ -350,7 +337,6 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -399,14 +385,11 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -423,7 +406,6 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -473,14 +455,11 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -497,7 +476,6 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 {
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -549,14 +527,11 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
@@ -577,7 +552,6 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -670,21 +644,16 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("cpu_id comparison failed");
 error2:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -698,7 +667,6 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 	RSEQ_INJECT_C(9)
 
-	rseq_workaround_gcc_asm_size_guess();
 	__asm__ __volatile__ goto (
 		RSEQ_ASM_DEFINE_TABLE(9, 1f, 2f, 4f) /* start, commit, abort */
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[cmpfail])
@@ -792,21 +760,16 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-	rseq_workaround_gcc_asm_size_guess();
 	return 0;
 abort:
-	rseq_workaround_gcc_asm_size_guess();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
-	rseq_workaround_gcc_asm_size_guess();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("cpu_id comparison failed");
 error2:
-	rseq_workaround_gcc_asm_size_guess();
 	rseq_bug("expected value comparison failed");
 #endif
 }
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 13/15] selftests/rseq: Fix: work-around asm goto compiler bugs
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (11 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 12/15] selftests/rseq: Remove arm/mips asm goto compiler work-around Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 14/15] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area Mathieu Desnoyers
                   ` (2 subsequent siblings)
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

gcc and clang each have their own compiler bugs with respect to asm
goto. Implement a work-around for compiler versions known to have those
bugs.

gcc prior to 4.8.2 miscompiles asm goto.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

gcc prior to 8.1.0 miscompiles asm goto at O1.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908

clang prior to version 13.0.1 miscompiles asm goto at O2.
https://github.com/llvm/llvm-project/issues/52735

Work around these issues by adding a volatile inline asm with
memory clobber in the fallthrough after the asm goto and at each
label target.  Emit this for all compilers in case other similar
issues are found in the future.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/compiler.h   | 30 ++++++++++
 tools/testing/selftests/rseq/rseq-arm.h   | 39 +++++++++++++
 tools/testing/selftests/rseq/rseq-arm64.h | 45 +++++++++++++--
 tools/testing/selftests/rseq/rseq-ppc.h   | 39 +++++++++++++
 tools/testing/selftests/rseq/rseq-s390.h  | 29 ++++++++++
 tools/testing/selftests/rseq/rseq-x86.h   | 68 +++++++++++++++++++++++
 tools/testing/selftests/rseq/rseq.h       |  1 +
 7 files changed, 245 insertions(+), 6 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/compiler.h

diff --git a/tools/testing/selftests/rseq/compiler.h b/tools/testing/selftests/rseq/compiler.h
new file mode 100644
index 000000000000..876eb6a7f75b
--- /dev/null
+++ b/tools/testing/selftests/rseq/compiler.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq/compiler.h
+ *
+ * Work-around asm goto compiler bugs.
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef RSEQ_COMPILER_H
+#define RSEQ_COMPILER_H
+
+/*
+ * gcc prior to 4.8.2 miscompiles asm goto.
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
+ *
+ * gcc prior to 8.1.0 miscompiles asm goto at O1.
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908
+ *
+ * clang prior to version 13.0.1 miscompiles asm goto at O2.
+ * https://github.com/llvm/llvm-project/issues/52735
+ *
+ * Work around these issues by adding a volatile inline asm with
+ * memory clobber in the fallthrough after the asm goto and at each
+ * label target.  Emit this for all compilers in case other similar
+ * issues are found in the future.
+ */
+#define rseq_after_asm_goto()	asm volatile ("" : : : "memory")
+
+#endif  /* RSEQ_COMPILER_H_ */
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 64c3a622107b..893a11eca9d5 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -195,16 +195,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -263,16 +268,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -317,12 +327,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -384,16 +397,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -456,16 +474,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -532,18 +555,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -652,16 +681,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -771,16 +805,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 7806817062c2..cbe190a4d005 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -242,17 +242,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -300,16 +304,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -348,12 +357,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -402,17 +414,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -461,17 +477,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -522,19 +542,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -584,17 +609,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -644,17 +673,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index aa18c0eabf40..bab8e0b9fb11 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -254,16 +254,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -322,16 +327,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -378,12 +388,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -442,16 +455,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -512,16 +530,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -583,18 +606,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -659,16 +688,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -735,16 +769,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 0f523b3ecdef..4e6dc5f0cb42 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -178,16 +178,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -248,16 +253,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -301,12 +311,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -364,16 +377,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -443,18 +461,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -555,16 +579,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index e444563c6999..4ab2e74811ab 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -152,16 +152,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -220,16 +225,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -269,12 +279,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -387,16 +400,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -464,18 +482,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -574,16 +598,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -730,16 +759,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -798,16 +832,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -847,12 +886,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -909,16 +951,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -977,16 +1024,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 
@@ -1047,18 +1099,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -1161,16 +1219,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -1274,16 +1337,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 17531ccd3090..6bd0ac466b4a 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "rseq-abi.h"
+#include "compiler.h"
 
 /*
  * Empty code injection macros, override when testing.
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 14/15] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (12 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 13/15] selftests/rseq: Fix: work-around asm goto compiler bugs Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-24 17:12 ` [RFC PATCH 15/15] selftests/rseq: x86-32: use %gs " Mathieu Desnoyers
  2022-01-27 15:46 ` [RFC PATCH 00/15] rseq uapi and selftest updates Peter Zijlstra
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %fs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-x86.h | 58 +++++++++++++------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 4ab2e74811ab..29769664edaa 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -28,6 +28,8 @@
 
 #ifdef __x86_64__
 
+#define RSEQ_ASM_TP_SEGMENT	%%fs
+
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc")
 #define rseq_smp_rmb()	rseq_barrier()
@@ -123,14 +125,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -141,7 +143,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -189,15 +191,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movq %[v], %%rbx\n\t"
 		"cmpq %%rbx, %[expectnot]\n\t"
 		"je %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movq %[v], %%rbx\n\t"
 		"cmpq %%rbx, %[expectnot]\n\t"
 		"je %l[error2]\n\t"
@@ -212,7 +214,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -255,11 +257,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* final store */
 		"addq %[count], %[v]\n\t"
@@ -268,7 +270,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"er" (count)
@@ -309,11 +311,11 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* get p+v */
 		"movq %[ptr], %%rbx\n\t"
@@ -327,7 +329,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [ptr]			"m" (*ptr),
 		  [off]			"er" (off),
@@ -364,14 +366,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -385,7 +387,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -444,8 +446,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
@@ -454,7 +456,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(5)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 		"cmpq %[v2], %[expect2]\n\t"
@@ -467,7 +469,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -524,14 +526,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"movq %[dst], %[rseq_scratch1]\n\t"
 		"movq %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz 7f\n\t"
 #endif
@@ -579,7 +581,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [RFC PATCH 15/15] selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (13 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 14/15] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area Mathieu Desnoyers
@ 2022-01-24 17:12 ` Mathieu Desnoyers
  2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  2022-01-27 15:46 ` [RFC PATCH 00/15] rseq uapi and selftest updates Peter Zijlstra
  15 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-24 17:12 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: linux-kernel, Peter Zijlstra, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers

Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %gs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---
 tools/testing/selftests/rseq/rseq-x86.h | 66 +++++++++++++------------
 1 file changed, 34 insertions(+), 32 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 29769664edaa..f704d3664327 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -633,6 +633,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 #elif defined(__i386__)
 
+#define RSEQ_ASM_TP_SEGMENT	%%gs
+
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc")
 #define rseq_smp_rmb()	\
@@ -732,14 +734,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -750,7 +752,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -798,15 +800,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[v], %%ebx\n\t"
 		"cmpl %%ebx, %[expectnot]\n\t"
 		"je %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movl %[v], %%ebx\n\t"
 		"cmpl %%ebx, %[expectnot]\n\t"
 		"je %l[error2]\n\t"
@@ -821,7 +823,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -864,11 +866,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* final store */
 		"addl %[count], %[v]\n\t"
@@ -877,7 +879,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"ir" (count)
@@ -916,14 +918,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -938,7 +940,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"m" (newv2),
@@ -987,15 +989,15 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %[v], %%eax\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movl %[expect], %%eax\n\t"
 		"cmpl %[v], %%eax\n\t"
 		"jnz %l[error2]\n\t"
@@ -1011,7 +1013,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -1062,8 +1064,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
@@ -1072,7 +1074,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(5)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 		"cmpl %[expect2], %[v2]\n\t"
@@ -1086,7 +1088,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -1144,15 +1146,15 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"movl %[dst], %[rseq_scratch1]\n\t"
 		"movl %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 7f\n\t"
@@ -1202,7 +1204,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
@@ -1261,15 +1263,15 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"movl %[dst], %[rseq_scratch1]\n\t"
 		"movl %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 7f\n\t"
@@ -1320,7 +1322,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-24 17:12 ` [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian Mathieu Desnoyers
@ 2022-01-25 12:21   ` Christian Brauner
  2022-01-25 14:41     ` Mathieu Desnoyers
  0 siblings, 1 reply; 40+ messages in thread
From: Christian Brauner @ 2022-01-25 12:21 UTC (permalink / raw)
  To: Mathieu Desnoyers
  Cc: Thomas Gleixner, linux-kernel, Peter Zijlstra, Paul E . McKenney,
	Boqun Feng, H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

On Mon, Jan 24, 2022 at 12:12:40PM -0500, Mathieu Desnoyers wrote:
> The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
> entirely wrong on 32-bit little endian: a preprocessor logic mistake
> wrongly uses the big endian field layout on 32-bit little endian
> architectures.
> 
> Fortunately, those ptr32 accessors were never used within the kernel,
> and only meant as a convenience for user-space.
> 
> Remove those and only leave the "ptr64" union field, as this is the only
> thing really needed to express the ABI. Document how 32-bit
> architectures are meant to interact with this "ptr64" union field.
> 
> Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes")
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Florian Weimer <fw@deneb.enyo.de>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-api@vger.kernel.org
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Dave Watson <davejwatson@fb.com>
> Cc: Paul Turner <pjt@google.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: "H . Peter Anvin" <hpa@zytor.com>
> Cc: Andi Kleen <andi@firstfloor.org>
> Cc: Christian Brauner <christian.brauner@ubuntu.com>
> Cc: Ben Maurer <bmaurer@fb.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
> Cc: Joel Fernandes <joelaf@google.com>
> Cc: Paul E. McKenney <paulmck@kernel.org>
> ---
>  include/uapi/linux/rseq.h | 17 ++++-------------
>  1 file changed, 4 insertions(+), 13 deletions(-)
> 
> diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
> index 9a402fdb60e9..31290f2424a7 100644
> --- a/include/uapi/linux/rseq.h
> +++ b/include/uapi/linux/rseq.h
> @@ -105,22 +105,13 @@ struct rseq {
>  	 * Read and set by the kernel. Set by user-space with single-copy
>  	 * atomicity semantics. This field should only be updated by the
>  	 * thread which registered this data structure. Aligned on 64-bit.
> +	 *
> +	 * 32-bit architectures should update the low order bits of the
> +	 * rseq_cs.ptr64 field, leaving the high order bits initialized
> +	 * to 0.
>  	 */
>  	union {

A bit unfortunate we seem to have to keep the union around even though
it's just one field now.

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-25 12:21   ` Christian Brauner
@ 2022-01-25 14:41     ` Mathieu Desnoyers
  2022-01-25 19:00       ` Mathieu Desnoyers
  0 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-25 14:41 UTC (permalink / raw)
  To: Christian Brauner
  Cc: Thomas Gleixner, linux-kernel, Peter Zijlstra, paulmck,
	Boqun Feng, H. Peter Anvin, Paul Turner, linux-api, shuah,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

----- On Jan 25, 2022, at 7:21 AM, Christian Brauner brauner@kernel.org wrote:

> On Mon, Jan 24, 2022 at 12:12:40PM -0500, Mathieu Desnoyers wrote:
>> The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
>> entirely wrong on 32-bit little endian: a preprocessor logic mistake
>> wrongly uses the big endian field layout on 32-bit little endian
>> architectures.
>> 
>> Fortunately, those ptr32 accessors were never used within the kernel,
>> and only meant as a convenience for user-space.
>> 
>> Remove those and only leave the "ptr64" union field, as this is the only
>> thing really needed to express the ABI. Document how 32-bit
>> architectures are meant to interact with this "ptr64" union field.
>> 
>> Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update
>> includes")
>> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
>> Cc: Florian Weimer <fw@deneb.enyo.de>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: linux-api@vger.kernel.org
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Boqun Feng <boqun.feng@gmail.com>
>> Cc: Andy Lutomirski <luto@amacapital.net>
>> Cc: Dave Watson <davejwatson@fb.com>
>> Cc: Paul Turner <pjt@google.com>
>> Cc: Andrew Morton <akpm@linux-foundation.org>
>> Cc: Russell King <linux@arm.linux.org.uk>
>> Cc: "H . Peter Anvin" <hpa@zytor.com>
>> Cc: Andi Kleen <andi@firstfloor.org>
>> Cc: Christian Brauner <christian.brauner@ubuntu.com>
>> Cc: Ben Maurer <bmaurer@fb.com>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Cc: Josh Triplett <josh@joshtriplett.org>
>> Cc: Linus Torvalds <torvalds@linux-foundation.org>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will.deacon@arm.com>
>> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
>> Cc: Joel Fernandes <joelaf@google.com>
>> Cc: Paul E. McKenney <paulmck@kernel.org>
>> ---
>>  include/uapi/linux/rseq.h | 17 ++++-------------
>>  1 file changed, 4 insertions(+), 13 deletions(-)
>> 
>> diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
>> index 9a402fdb60e9..31290f2424a7 100644
>> --- a/include/uapi/linux/rseq.h
>> +++ b/include/uapi/linux/rseq.h
>> @@ -105,22 +105,13 @@ struct rseq {
>>  	 * Read and set by the kernel. Set by user-space with single-copy
>>  	 * atomicity semantics. This field should only be updated by the
>>  	 * thread which registered this data structure. Aligned on 64-bit.
>> +	 *
>> +	 * 32-bit architectures should update the low order bits of the
>> +	 * rseq_cs.ptr64 field, leaving the high order bits initialized
>> +	 * to 0.
>>  	 */
>>  	union {
> 
> A bit unfortunate we seem to have to keep the union around even though
> it's just one field now.

Well, as far as the user-space projects that I know of which use rseq
are concerned (glibc, librseq, tcmalloc), those end up with their own
copy of the uapi header anyway to deal with the big/little endian field
on 32-bit. So I'm very much open to remove the union if we accept that
this uapi header is really just meant to express the ABI and is not
expected to be used as an API by user-space.

That would mean we also bring a uapi header copy into the kernel
rseq selftests as well to minimize the gap between librseq and
the kernel sefltests (the kernel sefltests pretty much include a
copy of librseq for convenience. librseq is maintained out of tree).

Thoughts ?

Thanks,

Mathieu


-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-25 14:41     ` Mathieu Desnoyers
@ 2022-01-25 19:00       ` Mathieu Desnoyers
  2022-01-26  8:03         ` Christian Brauner
  2022-01-26 17:16         ` David Laight
  0 siblings, 2 replies; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-25 19:00 UTC (permalink / raw)
  To: Christian Brauner
  Cc: Thomas Gleixner, linux-kernel, Peter Zijlstra, paulmck,
	Boqun Feng, H. Peter Anvin, Paul Turner, linux-api, shuah,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

----- On Jan 25, 2022, at 9:41 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:

> ----- On Jan 25, 2022, at 7:21 AM, Christian Brauner brauner@kernel.org wrote:
[...]
>>>  include/uapi/linux/rseq.h | 17 ++++-------------
[...]
>>>  	union {
>> 
>> A bit unfortunate we seem to have to keep the union around even though
>> it's just one field now.
> 
> Well, as far as the user-space projects that I know of which use rseq
> are concerned (glibc, librseq, tcmalloc), those end up with their own
> copy of the uapi header anyway to deal with the big/little endian field
> on 32-bit. So I'm very much open to remove the union if we accept that
> this uapi header is really just meant to express the ABI and is not
> expected to be used as an API by user-space.
> 
> That would mean we also bring a uapi header copy into the kernel
> rseq selftests as well to minimize the gap between librseq and
> the kernel sefltests (the kernel sefltests pretty much include a
> copy of librseq for convenience. librseq is maintained out of tree).
> 
> Thoughts ?

Actually, if we go ahead and remove the union, and replace:

struct rseq {
  union {
    __u64 ptr64;
  } rseq_cs;
[...]
} v;

by:

struct rseq {
  __u64 rseq_cs;
} v;

expressions such as these are unchanged:

- sizeof(v.rseq_cs),
- &v.rseq_cs,
- __alignof__(v.rseq_cs),
- offsetof(struct rseq, rseq_cs).

So users of the uapi rseq.h (as an API) can still use rseq_abi->rseq_cs before
and after the change.

Based on this, I am inclined to remove the union, and just make the rseq_cs field
a __u64.

Any objections ?

Thanks,

Mathieu


> 
> Thanks,
> 
> Mathieu
> 
> 
> --
> Mathieu Desnoyers
> EfficiOS Inc.
> http://www.efficios.com

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-25 19:00       ` Mathieu Desnoyers
@ 2022-01-26  8:03         ` Christian Brauner
  2022-01-26 11:00           ` Florian Weimer
  2022-01-26 17:16         ` David Laight
  1 sibling, 1 reply; 40+ messages in thread
From: Christian Brauner @ 2022-01-26  8:03 UTC (permalink / raw)
  To: Mathieu Desnoyers
  Cc: Thomas Gleixner, linux-kernel, Peter Zijlstra, paulmck,
	Boqun Feng, H. Peter Anvin, Paul Turner, linux-api, shuah,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

On Tue, Jan 25, 2022 at 02:00:48PM -0500, Mathieu Desnoyers wrote:
> ----- On Jan 25, 2022, at 9:41 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
> 
> > ----- On Jan 25, 2022, at 7:21 AM, Christian Brauner brauner@kernel.org wrote:
> [...]
> >>>  include/uapi/linux/rseq.h | 17 ++++-------------
> [...]
> >>>  	union {
> >> 
> >> A bit unfortunate we seem to have to keep the union around even though
> >> it's just one field now.
> > 
> > Well, as far as the user-space projects that I know of which use rseq
> > are concerned (glibc, librseq, tcmalloc), those end up with their own
> > copy of the uapi header anyway to deal with the big/little endian field
> > on 32-bit. So I'm very much open to remove the union if we accept that
> > this uapi header is really just meant to express the ABI and is not
> > expected to be used as an API by user-space.
> > 
> > That would mean we also bring a uapi header copy into the kernel
> > rseq selftests as well to minimize the gap between librseq and
> > the kernel sefltests (the kernel sefltests pretty much include a
> > copy of librseq for convenience. librseq is maintained out of tree).
> > 
> > Thoughts ?
> 
> Actually, if we go ahead and remove the union, and replace:
> 
> struct rseq {
>   union {
>     __u64 ptr64;
>   } rseq_cs;
> [...]
> } v;
> 
> by:
> 
> struct rseq {
>   __u64 rseq_cs;
> } v;
> 
> expressions such as these are unchanged:
> 
> - sizeof(v.rseq_cs),
> - &v.rseq_cs,
> - __alignof__(v.rseq_cs),
> - offsetof(struct rseq, rseq_cs).
> 
> So users of the uapi rseq.h (as an API) can still use rseq_abi->rseq_cs before
> and after the change.
> 
> Based on this, I am inclined to remove the union, and just make the rseq_cs field
> a __u64.
> 
> Any objections ?

I do like it fwiw. But since I haven't been heavily involved in the
userspace usage of this I can't speak confidently to the regression
potential of a change like this. But I would think that we should risk
it instead of dragging a pointless union around forever.

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-26  8:03         ` Christian Brauner
@ 2022-01-26 11:00           ` Florian Weimer
  0 siblings, 0 replies; 40+ messages in thread
From: Florian Weimer @ 2022-01-26 11:00 UTC (permalink / raw)
  To: Christian Brauner
  Cc: Mathieu Desnoyers, Thomas Gleixner, linux-kernel, Peter Zijlstra,
	paulmck, Boqun Feng, H. Peter Anvin, Paul Turner, linux-api,
	shuah, linux-kselftest, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

* Christian Brauner:

> On Tue, Jan 25, 2022 at 02:00:48PM -0500, Mathieu Desnoyers wrote:
>> So users of the uapi rseq.h (as an API) can still use
>> rseq_abi->rseq_cs before and after the change.
>> 
>> Based on this, I am inclined to remove the union, and just make the
>> rseq_cs field a __u64.
>> 
>> Any objections ?
>
> I do like it fwiw. But since I haven't been heavily involved in the
> userspace usage of this I can't speak confidently to the regression
> potential of a change like this. But I would think that we should risk
> it instead of dragging a pointless union around forever.

I don't think glibc needs changes for this, it will keep building just
fine.  We'll need to adjust the included kernel header fragment that
could be used by applications in some corner cases, but that's it.

^ permalink raw reply	[flat|nested] 40+ messages in thread

* RE: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-25 19:00       ` Mathieu Desnoyers
  2022-01-26  8:03         ` Christian Brauner
@ 2022-01-26 17:16         ` David Laight
  2022-01-26 18:59           ` Mathieu Desnoyers
  1 sibling, 1 reply; 40+ messages in thread
From: David Laight @ 2022-01-26 17:16 UTC (permalink / raw)
  To: 'Mathieu Desnoyers', Christian Brauner
  Cc: Thomas Gleixner, linux-kernel, Peter Zijlstra, paulmck,
	Boqun Feng, H. Peter Anvin, Paul Turner, linux-api, shuah,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

From: Mathieu Desnoyers
> Sent: 25 January 2022 19:01
> 
> ----- On Jan 25, 2022, at 9:41 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
> 
> > ----- On Jan 25, 2022, at 7:21 AM, Christian Brauner brauner@kernel.org wrote:
> [...]
> >>>  include/uapi/linux/rseq.h | 17 ++++-------------
> [...]
> >>>  	union {
> >>
> >> A bit unfortunate we seem to have to keep the union around even though
> >> it's just one field now.
> >
> > Well, as far as the user-space projects that I know of which use rseq
> > are concerned (glibc, librseq, tcmalloc), those end up with their own
> > copy of the uapi header anyway to deal with the big/little endian field
> > on 32-bit. So I'm very much open to remove the union if we accept that
> > this uapi header is really just meant to express the ABI and is not
> > expected to be used as an API by user-space.
> >
> > That would mean we also bring a uapi header copy into the kernel
> > rseq selftests as well to minimize the gap between librseq and
> > the kernel sefltests (the kernel sefltests pretty much include a
> > copy of librseq for convenience. librseq is maintained out of tree).
> >
> > Thoughts ?
> 
> Actually, if we go ahead and remove the union, and replace:
> 
> struct rseq {
>   union {
>     __u64 ptr64;
>   } rseq_cs;
> [...]
> } v;
> 
> by:
> 
> struct rseq {
>   __u64 rseq_cs;
> } v;
> 
> expressions such as these are unchanged:
> 
> - sizeof(v.rseq_cs),
> - &v.rseq_cs,
> - __alignof__(v.rseq_cs),
> - offsetof(struct rseq, rseq_cs).
> 
> So users of the uapi rseq.h (as an API) can still use rseq_abi->rseq_cs before
> and after the change.

But:
	v.rseq_cs.ptr_64 = (uintptr_t)&foo;
is broken.

> Based on this, I am inclined to remove the union, and just make the rseq_cs field
> a __u64.

It really is a shame that you can't do:
	void   *rseq_cs __attribute__((size(8)));
and have the compiler just DTRT on 32bit systems.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-26 17:16         ` David Laight
@ 2022-01-26 18:59           ` Mathieu Desnoyers
  2022-01-27 15:27             ` [RFC PATCH v2] " Mathieu Desnoyers
  0 siblings, 1 reply; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-26 18:59 UTC (permalink / raw)
  To: David Laight
  Cc: Christian Brauner, Thomas Gleixner, linux-kernel, Peter Zijlstra,
	paulmck, Boqun Feng, H. Peter Anvin, Paul Turner, linux-api,
	shuah, linux-kselftest, Florian Weimer, Andy Lutomirski,
	Dave Watson, Andrew Morton, Russell King, Andi Kleen,
	Christian Brauner, Ben Maurer, rostedt, Josh Triplett,
	Linus Torvalds, Catalin Marinas, Will Deacon, Michael Kerrisk,
	Joel Fernandes

----- On Jan 26, 2022, at 12:16 PM, David Laight David.Laight@ACULAB.COM wrote:

> From: Mathieu Desnoyers
>> Sent: 25 January 2022 19:01
>> 
>> ----- On Jan 25, 2022, at 9:41 AM, Mathieu Desnoyers
>> mathieu.desnoyers@efficios.com wrote:
>> 
>> > ----- On Jan 25, 2022, at 7:21 AM, Christian Brauner brauner@kernel.org wrote:
>> [...]
>> >>>  include/uapi/linux/rseq.h | 17 ++++-------------
>> [...]
>> >>>  	union {
>> >>
>> >> A bit unfortunate we seem to have to keep the union around even though
>> >> it's just one field now.
>> >
>> > Well, as far as the user-space projects that I know of which use rseq
>> > are concerned (glibc, librseq, tcmalloc), those end up with their own
>> > copy of the uapi header anyway to deal with the big/little endian field
>> > on 32-bit. So I'm very much open to remove the union if we accept that
>> > this uapi header is really just meant to express the ABI and is not
>> > expected to be used as an API by user-space.
>> >
>> > That would mean we also bring a uapi header copy into the kernel
>> > rseq selftests as well to minimize the gap between librseq and
>> > the kernel sefltests (the kernel sefltests pretty much include a
>> > copy of librseq for convenience. librseq is maintained out of tree).
>> >
>> > Thoughts ?
>> 
>> Actually, if we go ahead and remove the union, and replace:
>> 
>> struct rseq {
>>   union {
>>     __u64 ptr64;
>>   } rseq_cs;
>> [...]
>> } v;
>> 
>> by:
>> 
>> struct rseq {
>>   __u64 rseq_cs;
>> } v;
>> 
>> expressions such as these are unchanged:
>> 
>> - sizeof(v.rseq_cs),
>> - &v.rseq_cs,
>> - __alignof__(v.rseq_cs),
>> - offsetof(struct rseq, rseq_cs).
>> 
>> So users of the uapi rseq.h (as an API) can still use rseq_abi->rseq_cs before
>> and after the change.
> 
> But:
>	v.rseq_cs.ptr_64 = (uintptr_t)&foo;
> is broken.

True. But v.rseq_cs.ptr (on 64-bit) and v.rseq_cs.ptr.ptr32 (on 32-bit) are also
broken with the planned field removal. So how is the v.rseq_cs_ptr64 situation
different ?

My thinking here is that it does not matter if we break compilation for some
users of the uapi as an API as long as the ABI stays the same, especially
considering that all known users implement their own copy of the header.

I suspect that as far as the API is concerned, it is nice that we have at least
one way to access the field which works both before and after the change.
Simply using "v.rseq_cs" works both before/after for all use-cases that seem
to matter here.

> 
>> Based on this, I am inclined to remove the union, and just make the rseq_cs
>> field
>> a __u64.
> 
> It really is a shame that you can't do:
>	void   *rseq_cs __attribute__((size(8)));
> and have the compiler just DTRT on 32bit systems.

Indeed, the "size" directive appears to be ignored by the compiler.

Thanks,

Mathieu

> 
>	David
> 
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT,
> UK
> Registration No: 1397386 (Wales)

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

^ permalink raw reply	[flat|nested] 40+ messages in thread

* [RFC PATCH v2] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-26 18:59           ` Mathieu Desnoyers
@ 2022-01-27 15:27             ` Mathieu Desnoyers
  2022-01-28  8:52               ` Christian Brauner
  2022-02-03 14:33               ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  0 siblings, 2 replies; 40+ messages in thread
From: Mathieu Desnoyers @ 2022-01-27 15:27 UTC (permalink / raw)
  To: Peter Zijlstra
  Cc: linux-kernel, Thomas Gleixner, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Mathieu Desnoyers, Florian Weimer,
	Andy Lutomirski, Dave Watson, Andrew Morton, Russell King,
	Andi Kleen, Christian Brauner, Ben Maurer, Steven Rostedt,
	Josh Triplett, Linus Torvalds, Catalin Marinas, Will Deacon,
	Michael Kerrisk, Joel Fernandes

The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
entirely wrong on 32-bit little endian: a preprocessor logic mistake
wrongly uses the big endian field layout on 32-bit little endian
architectures.

Fortunately, those ptr32 accessors were never used within the kernel,
and only meant as a convenience for user-space.

Remove those and replace the whole rseq_cs union by a __u64 type, as
this is the only thing really needed to express the ABI. Document how
32-bit architectures are meant to interact with this field.

Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Florian Weimer <fw@deneb.enyo.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
---
 include/uapi/linux/rseq.h | 20 ++++----------------
 kernel/rseq.c             |  8 ++++----
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index 9a402fdb60e9..77ee207623a9 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -105,23 +105,11 @@ struct rseq {
 	 * Read and set by the kernel. Set by user-space with single-copy
 	 * atomicity semantics. This field should only be updated by the
 	 * thread which registered this data structure. Aligned on 64-bit.
+	 *
+	 * 32-bit architectures should update the low order bits of the
+	 * rseq_cs field, leaving the high order bits initialized to 0.
 	 */
-	union {
-		__u64 ptr64;
-#ifdef __LP64__
-		__u64 ptr;
-#else
-		struct {
-#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined(__BIG_ENDIAN)
-			__u32 padding;		/* Initialized to zero. */
-			__u32 ptr32;
-#else /* LITTLE */
-			__u32 ptr32;
-			__u32 padding;		/* Initialized to zero. */
-#endif /* ENDIAN */
-		} ptr;
-#endif
-	} rseq_cs;
+	__u64 rseq_cs;
 
 	/*
 	 * Restartable sequences flags field.
diff --git a/kernel/rseq.c b/kernel/rseq.c
index 6d45ac3dae7f..97ac20b4f738 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -128,10 +128,10 @@ static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
 	int ret;
 
 #ifdef CONFIG_64BIT
-	if (get_user(ptr, &t->rseq->rseq_cs.ptr64))
+	if (get_user(ptr, &t->rseq->rseq_cs))
 		return -EFAULT;
 #else
-	if (copy_from_user(&ptr, &t->rseq->rseq_cs.ptr64, sizeof(ptr)))
+	if (copy_from_user(&ptr, &t->rseq->rseq_cs, sizeof(ptr)))
 		return -EFAULT;
 #endif
 	if (!ptr) {
@@ -217,9 +217,9 @@ static int clear_rseq_cs(struct task_struct *t)
 	 * Set rseq_cs to NULL.
 	 */
 #ifdef CONFIG_64BIT
-	return put_user(0UL, &t->rseq->rseq_cs.ptr64);
+	return put_user(0UL, &t->rseq->rseq_cs);
 #else
-	if (clear_user(&t->rseq->rseq_cs.ptr64, sizeof(t->rseq->rseq_cs.ptr64)))
+	if (clear_user(&t->rseq->rseq_cs, sizeof(t->rseq->rseq_cs)))
 		return -EFAULT;
 	return 0;
 #endif
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH 00/15] rseq uapi and selftest updates
  2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
                   ` (14 preceding siblings ...)
  2022-01-24 17:12 ` [RFC PATCH 15/15] selftests/rseq: x86-32: use %gs " Mathieu Desnoyers
@ 2022-01-27 15:46 ` Peter Zijlstra
  15 siblings, 0 replies; 40+ messages in thread
From: Peter Zijlstra @ 2022-01-27 15:46 UTC (permalink / raw)
  To: Mathieu Desnoyers
  Cc: Thomas Gleixner, linux-kernel, Paul E . McKenney, Boqun Feng,
	H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest

On Mon, Jan 24, 2022 at 12:12:38PM -0500, Mathieu Desnoyers wrote:
> Mathieu Desnoyers (15):
>   selftests/rseq: introduce own copy of rseq uapi header
>   rseq: Remove broken uapi field layout on 32-bit little endian
>   selftests/rseq: Remove useless assignment to cpu variable
>   selftests/rseq: Remove volatile from __rseq_abi
>   selftests/rseq: Introduce rseq_get_abi() helper
>   selftests/rseq: Introduce thread pointer getters
>   selftests/rseq: Uplift rseq selftests for compatibility with
>     glibc-2.35
>   selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big
>     endian
>   selftests/rseq: Fix ppc32 missing instruction selection "u" and "x"
>     for load/store
>   selftests/rseq: Fix ppc32 offsets by using long rather than off_t
>   selftests/rseq: Fix warnings about #if checks of undefined tokens
>   selftests/rseq: Remove arm/mips asm goto compiler work-around
>   selftests/rseq: Fix: work-around asm goto compiler bugs
>   selftests/rseq: x86-64: use %fs segment selector for accessing rseq
>     thread area
>   selftests/rseq: x86-32: use %gs segment selector for accessing rseq
>     thread area

Thanks, I'll go stick then in sched/core.

^ permalink raw reply	[flat|nested] 40+ messages in thread

* Re: [RFC PATCH v2] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-27 15:27             ` [RFC PATCH v2] " Mathieu Desnoyers
@ 2022-01-28  8:52               ` Christian Brauner
  2022-02-03 14:33               ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
  1 sibling, 0 replies; 40+ messages in thread
From: Christian Brauner @ 2022-01-28  8:52 UTC (permalink / raw)
  To: Mathieu Desnoyers
  Cc: Peter Zijlstra, linux-kernel, Thomas Gleixner, Paul E . McKenney,
	Boqun Feng, H . Peter Anvin, Paul Turner, linux-api, Shuah Khan,
	linux-kselftest, Florian Weimer, Andy Lutomirski, Dave Watson,
	Andrew Morton, Russell King, Andi Kleen, Christian Brauner,
	Ben Maurer, Steven Rostedt, Josh Triplett, Linus Torvalds,
	Catalin Marinas, Will Deacon, Michael Kerrisk, Joel Fernandes

On Thu, Jan 27, 2022 at 10:27:20AM -0500, Mathieu Desnoyers wrote:
> The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
> entirely wrong on 32-bit little endian: a preprocessor logic mistake
> wrongly uses the big endian field layout on 32-bit little endian
> architectures.
> 
> Fortunately, those ptr32 accessors were never used within the kernel,
> and only meant as a convenience for user-space.
> 
> Remove those and replace the whole rseq_cs union by a __u64 type, as
> this is the only thing really needed to express the ABI. Document how
> 32-bit architectures are meant to interact with this field.
> 
> Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes")
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Florian Weimer <fw@deneb.enyo.de>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: linux-api@vger.kernel.org
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Boqun Feng <boqun.feng@gmail.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Dave Watson <davejwatson@fb.com>
> Cc: Paul Turner <pjt@google.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Russell King <linux@arm.linux.org.uk>
> Cc: "H . Peter Anvin" <hpa@zytor.com>
> Cc: Andi Kleen <andi@firstfloor.org>
> Cc: Christian Brauner <christian.brauner@ubuntu.com>
> Cc: Ben Maurer <bmaurer@fb.com>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Josh Triplett <josh@joshtriplett.org>
> Cc: Linus Torvalds <torvalds@linux-foundation.org>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Michael Kerrisk <mtk.manpages@gmail.com>
> Cc: Joel Fernandes <joelaf@google.com>
> Cc: Paul E. McKenney <paulmck@kernel.org>
> ---

Looks way cleaner now! Fwiw,
Acked-by: Christian Brauner <brauner@kernel.org>

>  include/uapi/linux/rseq.h | 20 ++++----------------
>  kernel/rseq.c             |  8 ++++----
>  2 files changed, 8 insertions(+), 20 deletions(-)
> 
> diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
> index 9a402fdb60e9..77ee207623a9 100644
> --- a/include/uapi/linux/rseq.h
> +++ b/include/uapi/linux/rseq.h
> @@ -105,23 +105,11 @@ struct rseq {
>  	 * Read and set by the kernel. Set by user-space with single-copy
>  	 * atomicity semantics. This field should only be updated by the
>  	 * thread which registered this data structure. Aligned on 64-bit.
> +	 *
> +	 * 32-bit architectures should update the low order bits of the
> +	 * rseq_cs field, leaving the high order bits initialized to 0.
>  	 */
> -	union {
> -		__u64 ptr64;
> -#ifdef __LP64__
> -		__u64 ptr;
> -#else
> -		struct {
> -#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined(__BIG_ENDIAN)
> -			__u32 padding;		/* Initialized to zero. */
> -			__u32 ptr32;
> -#else /* LITTLE */
> -			__u32 ptr32;
> -			__u32 padding;		/* Initialized to zero. */
> -#endif /* ENDIAN */
> -		} ptr;
> -#endif
> -	} rseq_cs;
> +	__u64 rseq_cs;
>  
>  	/*
>  	 * Restartable sequences flags field.
> diff --git a/kernel/rseq.c b/kernel/rseq.c
> index 6d45ac3dae7f..97ac20b4f738 100644
> --- a/kernel/rseq.c
> +++ b/kernel/rseq.c
> @@ -128,10 +128,10 @@ static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
>  	int ret;
>  
>  #ifdef CONFIG_64BIT
> -	if (get_user(ptr, &t->rseq->rseq_cs.ptr64))
> +	if (get_user(ptr, &t->rseq->rseq_cs))
>  		return -EFAULT;
>  #else
> -	if (copy_from_user(&ptr, &t->rseq->rseq_cs.ptr64, sizeof(ptr)))
> +	if (copy_from_user(&ptr, &t->rseq->rseq_cs, sizeof(ptr)))
>  		return -EFAULT;
>  #endif
>  	if (!ptr) {
> @@ -217,9 +217,9 @@ static int clear_rseq_cs(struct task_struct *t)
>  	 * Set rseq_cs to NULL.
>  	 */
>  #ifdef CONFIG_64BIT
> -	return put_user(0UL, &t->rseq->rseq_cs.ptr64);
> +	return put_user(0UL, &t->rseq->rseq_cs);
>  #else
> -	if (clear_user(&t->rseq->rseq_cs.ptr64, sizeof(t->rseq->rseq_cs.ptr64)))
> +	if (clear_user(&t->rseq->rseq_cs, sizeof(t->rseq->rseq_cs)))
>  		return -EFAULT;
>  	return 0;
>  #endif
> -- 
> 2.17.1
> 

^ permalink raw reply	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area
  2022-01-24 17:12 ` [RFC PATCH 15/15] selftests/rseq: x86-32: use %gs " Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     127b6429d235ab7c358223bbfd8a8b8d8cc799b6
Gitweb:        https://git.kernel.org/tip/127b6429d235ab7c358223bbfd8a8b8d8cc799b6
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:53 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:37 +01:00

selftests/rseq: x86-32: use %gs segment selector for accessing rseq thread area

Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %gs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-16-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-x86.h | 66 ++++++++++++------------
 1 file changed, 34 insertions(+), 32 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 2976966..f704d36 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -633,6 +633,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 #elif defined(__i386__)
 
+#define RSEQ_ASM_TP_SEGMENT	%%gs
+
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc")
 #define rseq_smp_rmb()	\
@@ -732,14 +734,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -750,7 +752,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -798,15 +800,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[v], %%ebx\n\t"
 		"cmpl %%ebx, %[expectnot]\n\t"
 		"je %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movl %[v], %%ebx\n\t"
 		"cmpl %%ebx, %[expectnot]\n\t"
 		"je %l[error2]\n\t"
@@ -821,7 +823,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -864,11 +866,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* final store */
 		"addl %[count], %[v]\n\t"
@@ -877,7 +879,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"ir" (count)
@@ -916,14 +918,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -938,7 +940,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"m" (newv2),
@@ -987,15 +989,15 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %[v], %%eax\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movl %[expect], %%eax\n\t"
 		"cmpl %[v], %%eax\n\t"
 		"jnz %l[error2]\n\t"
@@ -1011,7 +1013,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -1062,8 +1064,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
@@ -1072,7 +1074,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(5)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpl %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 		"cmpl %[expect2], %[v2]\n\t"
@@ -1086,7 +1088,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -1144,15 +1146,15 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"movl %[dst], %[rseq_scratch1]\n\t"
 		"movl %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 7f\n\t"
@@ -1202,7 +1204,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
@@ -1261,15 +1263,15 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"movl %[dst], %[rseq_scratch1]\n\t"
 		"movl %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"movl %[expect], %%eax\n\t"
 		"cmpl %%eax, %[v]\n\t"
 		"jnz 7f\n\t"
@@ -1320,7 +1322,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" (rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area
  2022-01-24 17:12 ` [RFC PATCH 14/15] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     4e15bb766b6c6e963a4d33629034d0ec3b7637df
Gitweb:        https://git.kernel.org/tip/4e15bb766b6c6e963a4d33629034d0ec3b7637df
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:52 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:37 +01:00

selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area

Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %fs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-15-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-x86.h | 58 ++++++++++++------------
 1 file changed, 30 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 4ab2e74..2976966 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -28,6 +28,8 @@
 
 #ifdef __x86_64__
 
+#define RSEQ_ASM_TP_SEGMENT	%%fs
+
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%rsp)" ::: "memory", "cc")
 #define rseq_smp_rmb()	rseq_barrier()
@@ -123,14 +125,14 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -141,7 +143,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -189,15 +191,15 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"movq %[v], %%rbx\n\t"
 		"cmpq %%rbx, %[expectnot]\n\t"
 		"je %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"movq %[v], %%rbx\n\t"
 		"cmpq %%rbx, %[expectnot]\n\t"
 		"je %l[error2]\n\t"
@@ -212,7 +214,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -255,11 +257,11 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* final store */
 		"addq %[count], %[v]\n\t"
@@ -268,7 +270,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"er" (count)
@@ -309,11 +311,11 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error1])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 #endif
 		/* get p+v */
 		"movq %[ptr], %%rbx\n\t"
@@ -327,7 +329,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [ptr]			"m" (*ptr),
 		  [off]			"er" (off),
@@ -364,14 +366,14 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error2])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 #endif
@@ -385,7 +387,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -444,8 +446,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_EXIT_POINT(1f, %l[error3])
 #endif
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[cmpfail]\n\t"
@@ -454,7 +456,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"jnz %l[cmpfail]\n\t"
 		RSEQ_INJECT_ASM(5)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), %l[error1])
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), %l[error1])
 		"cmpq %[v], %[expect]\n\t"
 		"jnz %l[error2]\n\t"
 		"cmpq %[v2], %[expect2]\n\t"
@@ -467,7 +469,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -524,14 +526,14 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"movq %[dst], %[rseq_scratch1]\n\t"
 		"movq %[len], %[rseq_scratch2]\n\t"
 		/* Start rseq by storing table entry pointer into rseq_cs. */
-		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_CS_OFFSET(%[rseq_abi]))
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 4f)
+		RSEQ_ASM_STORE_RSEQ_CS(1, 3b, RSEQ_ASM_TP_SEGMENT:RSEQ_CS_OFFSET(%[rseq_offset]))
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 4f)
 		RSEQ_INJECT_ASM(3)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz 5f\n\t"
 		RSEQ_INJECT_ASM(4)
 #ifdef RSEQ_COMPARE_TWICE
-		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_CPU_ID_OFFSET(%[rseq_abi]), 6f)
+		RSEQ_ASM_CMP_CPU_ID(cpu_id, RSEQ_ASM_TP_SEGMENT:RSEQ_CPU_ID_OFFSET(%[rseq_offset]), 6f)
 		"cmpq %[v], %[expect]\n\t"
 		"jnz 7f\n\t"
 #endif
@@ -579,7 +581,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (rseq_get_abi()),
+		  [rseq_offset]		"r" ((long)rseq_offset),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Fix: work-around asm goto compiler bugs
  2022-01-24 17:12 ` [RFC PATCH 13/15] selftests/rseq: Fix: work-around asm goto compiler bugs Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     b53823fb2ef854222853be164f3b1e815f315144
Gitweb:        https://git.kernel.org/tip/b53823fb2ef854222853be164f3b1e815f315144
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:51 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:37 +01:00

selftests/rseq: Fix: work-around asm goto compiler bugs

gcc and clang each have their own compiler bugs with respect to asm
goto. Implement a work-around for compiler versions known to have those
bugs.

gcc prior to 4.8.2 miscompiles asm goto.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

gcc prior to 8.1.0 miscompiles asm goto at O1.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908

clang prior to version 13.0.1 miscompiles asm goto at O2.
https://github.com/llvm/llvm-project/issues/52735

Work around these issues by adding a volatile inline asm with
memory clobber in the fallthrough after the asm goto and at each
label target.  Emit this for all compilers in case other similar
issues are found in the future.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-14-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/compiler.h   | 30 ++++++++++-
 tools/testing/selftests/rseq/rseq-arm.h   | 39 +++++++++++++-
 tools/testing/selftests/rseq/rseq-arm64.h | 45 +++++++++++++--
 tools/testing/selftests/rseq/rseq-ppc.h   | 39 +++++++++++++-
 tools/testing/selftests/rseq/rseq-s390.h  | 29 +++++++++-
 tools/testing/selftests/rseq/rseq-x86.h   | 68 ++++++++++++++++++++++-
 tools/testing/selftests/rseq/rseq.h       |  1 +-
 7 files changed, 245 insertions(+), 6 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/compiler.h

diff --git a/tools/testing/selftests/rseq/compiler.h b/tools/testing/selftests/rseq/compiler.h
new file mode 100644
index 0000000..876eb6a
--- /dev/null
+++ b/tools/testing/selftests/rseq/compiler.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq/compiler.h
+ *
+ * Work-around asm goto compiler bugs.
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef RSEQ_COMPILER_H
+#define RSEQ_COMPILER_H
+
+/*
+ * gcc prior to 4.8.2 miscompiles asm goto.
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
+ *
+ * gcc prior to 8.1.0 miscompiles asm goto at O1.
+ * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908
+ *
+ * clang prior to version 13.0.1 miscompiles asm goto at O2.
+ * https://github.com/llvm/llvm-project/issues/52735
+ *
+ * Work around these issues by adding a volatile inline asm with
+ * memory clobber in the fallthrough after the asm goto and at each
+ * label target.  Emit this for all compilers in case other similar
+ * issues are found in the future.
+ */
+#define rseq_after_asm_goto()	asm volatile ("" : : : "memory")
+
+#endif  /* RSEQ_COMPILER_H_ */
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 64c3a62..893a11e 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -195,16 +195,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -263,16 +268,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -317,12 +327,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -384,16 +397,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -456,16 +474,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -532,18 +555,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -652,16 +681,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -771,16 +805,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 7806817..cbe190a 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -242,17 +242,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -300,16 +304,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -348,12 +357,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -402,17 +414,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -461,17 +477,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -522,19 +542,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -584,17 +609,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -644,17 +673,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
-
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index aa18c0e..bab8e0b 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -254,16 +254,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -322,16 +327,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -378,12 +388,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -442,16 +455,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -512,16 +530,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -583,18 +606,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -659,16 +688,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -735,16 +769,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 0f523b3..4e6dc5f 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -178,16 +178,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -248,16 +253,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -301,12 +311,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -364,16 +377,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -443,18 +461,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -555,16 +579,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index e444563..4ab2e74 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -152,16 +152,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -220,16 +225,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -269,12 +279,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -387,16 +400,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -464,18 +482,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -574,16 +598,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -730,16 +759,21 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -798,16 +832,21 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -847,12 +886,15 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		  , error1
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 #endif
 }
@@ -909,16 +951,21 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -977,16 +1024,21 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 
@@ -1047,18 +1099,24 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2, error3
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("1st expected value comparison failed");
 error3:
+	rseq_after_asm_goto();
 	rseq_bug("2nd expected value comparison failed");
 #endif
 }
@@ -1161,16 +1219,21 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
@@ -1274,16 +1337,21 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		  , error1, error2
 #endif
 	);
+	rseq_after_asm_goto();
 	return 0;
 abort:
+	rseq_after_asm_goto();
 	RSEQ_INJECT_FAILED
 	return -1;
 cmpfail:
+	rseq_after_asm_goto();
 	return 1;
 #ifdef RSEQ_COMPARE_TWICE
 error1:
+	rseq_after_asm_goto();
 	rseq_bug("cpu_id comparison failed");
 error2:
+	rseq_after_asm_goto();
 	rseq_bug("expected value comparison failed");
 #endif
 }
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 17531cc..6bd0ac4 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -17,6 +17,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include "rseq-abi.h"
+#include "compiler.h"
 
 /*
  * Empty code injection macros, override when testing.

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Fix warnings about #if checks of undefined tokens
  2022-01-24 17:12 ` [RFC PATCH 11/15] selftests/rseq: Fix warnings about #if checks of undefined tokens Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     d7ed99ade3e62b755584eea07b4e499e79240527
Gitweb:        https://git.kernel.org/tip/d7ed99ade3e62b755584eea07b4e499e79240527
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:49 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:36 +01:00

selftests/rseq: Fix warnings about #if checks of undefined tokens

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-12-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/param_test.c | 2 +-
 tools/testing/selftests/rseq/rseq-x86.h   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 335c290..da23c22 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -161,7 +161,7 @@ unsigned int yield_mod_cnt, nr_abort;
 	"	cbnz	" INJECT_ASM_REG ", 222b\n"			\
 	"333:\n"
 
-#elif __PPC__
+#elif defined(__PPC__)
 
 #define RSEQ_INJECT_INPUT \
 	, [loop_cnt_1]"m"(loop_cnt[1]) \
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 0ee6c04..e444563 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -600,7 +600,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 
 #endif /* !RSEQ_SKIP_FASTPATH */
 
-#elif __i386__
+#elif defined(__i386__)
 
 #define rseq_smp_mb()	\
 	__asm__ __volatile__ ("lock; addl $0,-128(%%esp)" ::: "memory", "cc")

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Fix ppc32 offsets by using long rather than off_t
  2022-01-24 17:12 ` [RFC PATCH 10/15] selftests/rseq: Fix ppc32 offsets by using long rather than off_t Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     26dc8a6d8e11552f3b797b5aafe01071ca32d692
Gitweb:        https://git.kernel.org/tip/26dc8a6d8e11552f3b797b5aafe01071ca32d692
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:48 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:36 +01:00

selftests/rseq: Fix ppc32 offsets by using long rather than off_t

The semantic of off_t is for file offsets. We mean to use it as an
offset from a pointer. We really expect it to fit in a single register,
and not use a 64-bit type on 32-bit architectures.

Fix runtime issues on ppc32 where the offset is always 0 due to
inconsistency between the argument type (off_t -> 64-bit) and type
expected by the inline assembler (32-bit).

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-11-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/basic_percpu_ops_test.c | 2 +-
 tools/testing/selftests/rseq/param_test.c            | 2 +-
 tools/testing/selftests/rseq/rseq-arm.h              | 2 +-
 tools/testing/selftests/rseq/rseq-arm64.h            | 2 +-
 tools/testing/selftests/rseq/rseq-mips.h             | 2 +-
 tools/testing/selftests/rseq/rseq-ppc.h              | 2 +-
 tools/testing/selftests/rseq/rseq-s390.h             | 2 +-
 tools/testing/selftests/rseq/rseq-skip.h             | 2 +-
 tools/testing/selftests/rseq/rseq-x86.h              | 6 +++---
 9 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/rseq/basic_percpu_ops_test.c b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
index b953a52..517756a 100644
--- a/tools/testing/selftests/rseq/basic_percpu_ops_test.c
+++ b/tools/testing/selftests/rseq/basic_percpu_ops_test.c
@@ -167,7 +167,7 @@ struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
 	for (;;) {
 		struct percpu_list_node *head;
 		intptr_t *targetptr, expectnot, *load;
-		off_t offset;
+		long offset;
 		int ret, cpu;
 
 		cpu = rseq_cpu_start();
diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index cc2cfc1..335c290 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -549,7 +549,7 @@ struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
 	for (;;) {
 		struct percpu_list_node *head;
 		intptr_t *targetptr, expectnot, *load;
-		off_t offset;
+		long offset;
 		int ret;
 
 		cpu = rseq_cpu_start();
diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 5f567b3..ae476af 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -217,7 +217,7 @@ error2:
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index d0f2b7f..7806817 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -259,7 +259,7 @@ error2:
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 6df5427..0d1d925 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -222,7 +222,7 @@ error2:
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 87befda..aa18c0e 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -270,7 +270,7 @@ error2:
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 9927021..0f523b3 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -198,7 +198,7 @@ error2:
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
diff --git a/tools/testing/selftests/rseq/rseq-skip.h b/tools/testing/selftests/rseq/rseq-skip.h
index 72750b5..7b53dac 100644
--- a/tools/testing/selftests/rseq/rseq-skip.h
+++ b/tools/testing/selftests/rseq/rseq-skip.h
@@ -13,7 +13,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	return -1;
 }
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 1d9fa05..0ee6c04 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -172,7 +172,7 @@ error2:
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
@@ -286,7 +286,7 @@ error1:
  *  *pval += inc;
  */
 static inline __attribute__((always_inline))
-int rseq_offset_deref_addv(intptr_t *ptr, off_t off, intptr_t inc, int cpu)
+int rseq_offset_deref_addv(intptr_t *ptr, long off, intptr_t inc, int cpu)
 {
 	RSEQ_INJECT_C(9)
 
@@ -750,7 +750,7 @@ error2:
  */
 static inline __attribute__((always_inline))
 int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
-			       off_t voffp, intptr_t *load, int cpu)
+			       long voffp, intptr_t *load, int cpu)
 {
 	RSEQ_INJECT_C(9)
 

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store
  2022-01-24 17:12 ` [RFC PATCH 09/15] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     de6b52a21420a18dc8a36438d581efd1313d5fe3
Gitweb:        https://git.kernel.org/tip/de6b52a21420a18dc8a36438d581efd1313d5fe3
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:47 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:36 +01:00

selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store

Building the rseq basic test  with
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
Target: powerpc-linux-gnu

leads to these errors:

/tmp/ccieEWxU.s: Assembler messages:
/tmp/ccieEWxU.s:118: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:118: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:121: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:121: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:626: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:626: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:629: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:629: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:735: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:735: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:738: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:738: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:741: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:741: Error: junk at end of line: `,8'
Makefile:581: recipe for target 'basic_percpu_ops_test.o' failed

Based on discussion with Linux powerpc maintainers and review of
the use of the "m" operand in powerpc kernel code, add the missing
%Un%Xn (where n is operand number) to the lwz, stw, ld, and std
instructions when used with "m" operands.

Using "WORD" to mean either a 32-bit or 64-bit type depending on
the architecture is misleading. The term "WORD" really means a
32-bit type in both 32-bit and 64-bit powerpc assembler. The intent
here is to wrap load/store to intptr_t into common macros for both
32-bit and 64-bit.

Rename the macros with a RSEQ_ prefix, and use the terms "INT"
for always 32-bit type, and "LONG" for architecture bitness-sized
type.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-10-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-ppc.h | 55 ++++++++++++------------
 1 file changed, 28 insertions(+), 27 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index c4ba137..87befda 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -47,10 +47,13 @@ do {									\
 
 #ifdef __PPC64__
 
-#define STORE_WORD	"std "
-#define LOAD_WORD	"ld "
-#define LOADX_WORD	"ldx "
-#define CMP_WORD	"cmpd "
+#define RSEQ_STORE_LONG(arg)	"std%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"ld%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"ldx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpd "
+#define RSEQ_CMP_LONG_INT	"cmpdi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
@@ -89,10 +92,13 @@ do {									\
 
 #else /* #ifdef __PPC64__ */
 
-#define STORE_WORD	"stw "
-#define LOAD_WORD	"lwz "
-#define LOADX_WORD	"lwzx "
-#define CMP_WORD	"cmpw "
+#define RSEQ_STORE_LONG(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	RSEQ_STORE_LONG(arg)					/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	RSEQ_LOAD_LONG(arg)					/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"lwzx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpw "
+#define RSEQ_CMP_LONG_INT	"cmpwi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
@@ -125,7 +131,7 @@ do {									\
 		RSEQ_INJECT_ASM(1)						\
 		"lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t"			\
 		"addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t"		\
-		"stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t"			\
+		RSEQ_STORE_INT(rseq_cs) "%%r17, %[" __rseq_str(rseq_cs) "]\n\t"	\
 		__rseq_str(label) ":\n\t"
 
 #endif /* #ifdef __PPC64__ */
@@ -136,7 +142,7 @@ do {									\
 
 #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)			\
 		RSEQ_INJECT_ASM(2)						\
-		"lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t"		\
+		RSEQ_LOAD_INT(current_cpu_id) "%%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
 		"cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
@@ -153,25 +159,25 @@ do {									\
  * 	RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
  */
 #define RSEQ_ASM_OP_CMPEQ(var, expect, label)					\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_CMPNE(var, expectnot, label)				\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
 		"beq- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_STORE(value, var)						\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
 
 /* Load @var to r17 */
 #define RSEQ_ASM_OP_R_LOAD(var)							\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Store r17 to @var */
 #define RSEQ_ASM_OP_R_STORE(var)						\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Add @count to r17 */
 #define RSEQ_ASM_OP_R_ADD(count)						\
@@ -179,11 +185,11 @@ do {									\
 
 /* Load (r17 + voffp) to r17 */
 #define RSEQ_ASM_OP_R_LOADX(voffp)						\
-		LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
+		RSEQ_LOADX_LONG "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
 
 /* TODO: implement a faster memcpy. */
 #define RSEQ_ASM_OP_R_MEMCPY() \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"beq 333f\n\t" \
 		"addi %%r20, %%r20, -1\n\t" \
 		"addi %%r21, %%r21, -1\n\t" \
@@ -191,16 +197,16 @@ do {									\
 		"lbzu %%r18, 1(%%r20)\n\t" \
 		"stbu %%r18, 1(%%r21)\n\t" \
 		"addi %%r19, %%r19, -1\n\t" \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"bne 222b\n\t" \
 		"333:\n\t" \
 
 #define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label)			\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"			\
 		__rseq_str(post_commit_label) ":\n\t"
 
 #define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label)			\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
 		__rseq_str(post_commit_label) ":\n\t"
 
 static inline __attribute__((always_inline))
@@ -743,9 +749,4 @@ error2:
 #endif
 }
 
-#undef STORE_WORD
-#undef LOAD_WORD
-#undef LOADX_WORD
-#undef CMP_WORD
-
 #endif /* !RSEQ_SKIP_FASTPATH */

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian
  2022-01-24 17:12 ` [RFC PATCH 08/15] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     24d1136a29da5953de5c0cbc6c83eb62a1e0bf14
Gitweb:        https://git.kernel.org/tip/24d1136a29da5953de5c0cbc6c83eb62a1e0bf14
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:46 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:35 +01:00

selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian

ppc32 incorrectly uses padding as rseq_cs pointer field. Fix this by
using the rseq_cs.arch.ptr field.

Use this field across all architectures.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-9-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-arm.h   | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-arm64.h | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-mips.h  | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-ppc.h   | 16 ++++++++--------
 tools/testing/selftests/rseq/rseq-s390.h  | 12 ++++++------
 5 files changed, 38 insertions(+), 38 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 6716540..5f567b3 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -186,7 +186,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -256,7 +256,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -317,7 +317,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -382,7 +382,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -458,7 +458,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -538,7 +538,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -658,7 +658,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -783,7 +783,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index b9d9b3a..d0f2b7f 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -231,7 +231,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -288,7 +288,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expectnot]		"r" (expectnot),
 		  [load]		"Qo" (*load),
@@ -338,7 +338,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [count]		"r" (count)
 		  RSEQ_INJECT_INPUT
@@ -389,7 +389,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -448,7 +448,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -509,7 +509,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [v2]			"Qo" (*v2),
@@ -570,7 +570,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -630,7 +630,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index 2b1f5bd..6df5427 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -191,7 +191,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -259,7 +259,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -320,7 +320,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -383,7 +383,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -457,7 +457,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -533,7 +533,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -650,7 +650,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -772,7 +772,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 2e6b757..c4ba137 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -236,7 +236,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -302,7 +302,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -360,7 +360,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -420,7 +420,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -490,7 +490,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -561,7 +561,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -636,7 +636,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -712,7 +712,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index b906e04..9927021 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -166,7 +166,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -234,7 +234,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -289,7 +289,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -348,7 +348,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -427,7 +427,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -535,7 +535,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
 		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
-		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs.arch.ptr),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35
  2022-01-24 17:12 ` [RFC PATCH 07/15] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35 Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     233e667e1ae3e348686bd9dd0172e62a09d852e1
Gitweb:        https://git.kernel.org/tip/233e667e1ae3e348686bd9dd0172e62a09d852e1
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:45 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:35 +01:00

selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35

glibc-2.35 (upcoming release date 2022-02-01) exposes the rseq per-thread
data in the TCB, accessible at an offset from the thread pointer, rather
than through an actual Thread-Local Storage (TLS) variable, as the
Linux kernel selftests initially expected.

The __rseq_abi TLS and glibc-2.35's ABI for per-thread data cannot
actively coexist in a process, because the kernel supports only a single
rseq registration per thread.

Here is the scheme introduced to ensure selftests can work both with an
older glibc and with glibc-2.35+:

- librseq exposes its own "rseq_offset, rseq_size, rseq_flags" ABI.

- librseq queries for glibc rseq ABI (__rseq_offset, __rseq_size,
  __rseq_flags) using dlsym() in a librseq library constructor. If those
  are found, copy their values into rseq_offset, rseq_size, and
  rseq_flags.

- Else, if those glibc symbols are not found, handle rseq registration
  from librseq and use its own IE-model TLS to implement the rseq ABI
  per-thread storage.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-8-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/Makefile |   2 +-
 tools/testing/selftests/rseq/rseq.c   | 161 +++++++++++--------------
 tools/testing/selftests/rseq/rseq.h   |  13 +-
 3 files changed, 88 insertions(+), 88 deletions(-)

diff --git a/tools/testing/selftests/rseq/Makefile b/tools/testing/selftests/rseq/Makefile
index 2af9d39..215e106 100644
--- a/tools/testing/selftests/rseq/Makefile
+++ b/tools/testing/selftests/rseq/Makefile
@@ -6,7 +6,7 @@ endif
 
 CFLAGS += -O2 -Wall -g -I./ -I../../../../usr/include/ -L$(OUTPUT) -Wl,-rpath=./ \
 	  $(CLANG_FLAGS)
-LDLIBS += -lpthread
+LDLIBS += -lpthread -ldl
 
 # Own dependencies because we only want to build against 1st prerequisite, but
 # still track changes to header files and depend on shared object.
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index 1f905b6..07ba0d4 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -26,130 +26,123 @@
 #include <assert.h>
 #include <signal.h>
 #include <limits.h>
+#include <dlfcn.h>
 
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread struct rseq_abi __rseq_abi = {
-	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
-};
+static const int *libc_rseq_offset_p;
+static const unsigned int *libc_rseq_size_p;
+static const unsigned int *libc_rseq_flags_p;
 
-/*
- * Shared with other libraries. This library may take rseq ownership if it is
- * still 0 when executing the library constructor. Set to 1 by library
- * constructor when handling rseq. Set to 0 in destructor if handling rseq.
- */
-int __rseq_handled;
+/* Offset from the thread pointer to the rseq area.  */
+int rseq_offset;
+
+/* Size of the registered rseq area.  0 if the registration was
+   unsuccessful.  */
+unsigned int rseq_size = -1U;
+
+/* Flags used during rseq registration.  */
+unsigned int rseq_flags;
 
-/* Whether this library have ownership of rseq registration. */
 static int rseq_ownership;
 
-static __thread volatile uint32_t __rseq_refcount;
+static
+__thread struct rseq_abi __rseq_abi __attribute__((tls_model("initial-exec"))) = {
+	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
+};
 
-static void signal_off_save(sigset_t *oldset)
+static int sys_rseq(struct rseq_abi *rseq_abi, uint32_t rseq_len,
+		    int flags, uint32_t sig)
 {
-	sigset_t set;
-	int ret;
-
-	sigfillset(&set);
-	ret = pthread_sigmask(SIG_BLOCK, &set, oldset);
-	if (ret)
-		abort();
+	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
 }
 
-static void signal_restore(sigset_t oldset)
+int rseq_available(void)
 {
-	int ret;
+	int rc;
 
-	ret = pthread_sigmask(SIG_SETMASK, &oldset, NULL);
-	if (ret)
+	rc = sys_rseq(NULL, 0, 0, 0);
+	if (rc != -1)
 		abort();
-}
-
-static int sys_rseq(volatile struct rseq_abi *rseq_abi, uint32_t rseq_len,
-		    int flags, uint32_t sig)
-{
-	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
+	switch (errno) {
+	case ENOSYS:
+		return 0;
+	case EINVAL:
+		return 1;
+	default:
+		abort();
+	}
 }
 
 int rseq_register_current_thread(void)
 {
-	int rc, ret = 0;
-	sigset_t oldset;
+	int rc;
 
-	if (!rseq_ownership)
+	if (!rseq_ownership) {
+		/* Treat libc's ownership as a successful registration. */
 		return 0;
-	signal_off_save(&oldset);
-	if (__rseq_refcount == UINT_MAX) {
-		ret = -1;
-		goto end;
 	}
-	if (__rseq_refcount++)
-		goto end;
 	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), 0, RSEQ_SIG);
-	if (!rc) {
-		assert(rseq_current_cpu_raw() >= 0);
-		goto end;
-	}
-	if (errno != EBUSY)
-		RSEQ_WRITE_ONCE(__rseq_abi.cpu_id, RSEQ_ABI_CPU_ID_REGISTRATION_FAILED);
-	ret = -1;
-	__rseq_refcount--;
-end:
-	signal_restore(oldset);
-	return ret;
+	if (rc)
+		return -1;
+	assert(rseq_current_cpu_raw() >= 0);
+	return 0;
 }
 
 int rseq_unregister_current_thread(void)
 {
-	int rc, ret = 0;
-	sigset_t oldset;
+	int rc;
 
-	if (!rseq_ownership)
+	if (!rseq_ownership) {
+		/* Treat libc's ownership as a successful unregistration. */
 		return 0;
-	signal_off_save(&oldset);
-	if (!__rseq_refcount) {
-		ret = -1;
-		goto end;
 	}
-	if (--__rseq_refcount)
-		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi),
-		      RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
-	if (!rc)
-		goto end;
-	__rseq_refcount = 1;
-	ret = -1;
-end:
-	signal_restore(oldset);
-	return ret;
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
+	if (rc)
+		return -1;
+	return 0;
 }
 
-int32_t rseq_fallback_current_cpu(void)
+static __attribute__((constructor))
+void rseq_init(void)
 {
-	int32_t cpu;
-
-	cpu = sched_getcpu();
-	if (cpu < 0) {
-		perror("sched_getcpu()");
-		abort();
+	libc_rseq_offset_p = dlsym(RTLD_NEXT, "__rseq_offset");
+	libc_rseq_size_p = dlsym(RTLD_NEXT, "__rseq_size");
+	libc_rseq_flags_p = dlsym(RTLD_NEXT, "__rseq_flags");
+	if (libc_rseq_size_p && libc_rseq_offset_p && libc_rseq_flags_p) {
+		/* rseq registration owned by glibc */
+		rseq_offset = *libc_rseq_offset_p;
+		rseq_size = *libc_rseq_size_p;
+		rseq_flags = *libc_rseq_flags_p;
+		return;
 	}
-	return cpu;
-}
-
-void __attribute__((constructor)) rseq_init(void)
-{
-	/* Check whether rseq is handled by another library. */
-	if (__rseq_handled)
+	if (!rseq_available())
 		return;
-	__rseq_handled = 1;
 	rseq_ownership = 1;
+	rseq_offset = (void *)&__rseq_abi - rseq_thread_pointer();
+	rseq_size = sizeof(struct rseq_abi);
+	rseq_flags = 0;
 }
 
-void __attribute__((destructor)) rseq_fini(void)
+static __attribute__((destructor))
+void rseq_exit(void)
 {
 	if (!rseq_ownership)
 		return;
-	__rseq_handled = 0;
+	rseq_offset = 0;
+	rseq_size = -1U;
 	rseq_ownership = 0;
 }
+
+int32_t rseq_fallback_current_cpu(void)
+{
+	int32_t cpu;
+
+	cpu = sched_getcpu();
+	if (cpu < 0) {
+		perror("sched_getcpu()");
+		abort();
+	}
+	return cpu;
+}
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index ca668a2..17531cc 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -43,12 +43,19 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread struct rseq_abi __rseq_abi;
-extern int __rseq_handled;
+#include "rseq-thread-pointer.h"
+
+/* Offset from the thread pointer to the rseq area.  */
+extern int rseq_offset;
+/* Size of the registered rseq area.  0 if the registration was
+   unsuccessful.  */
+extern unsigned int rseq_size;
+/* Flags used during rseq registration.  */
+extern unsigned int rseq_flags;
 
 static inline struct rseq_abi *rseq_get_abi(void)
 {
-	return &__rseq_abi;
+	return (struct rseq_abi *) ((uintptr_t) rseq_thread_pointer() + rseq_offset);
 }
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Introduce thread pointer getters
  2022-01-24 17:12 ` [RFC PATCH 06/15] selftests/rseq: Introduce thread pointer getters Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     886ddfba933f5ce9d76c278165d834d114ba4ffc
Gitweb:        https://git.kernel.org/tip/886ddfba933f5ce9d76c278165d834d114ba4ffc
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:44 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:35 +01:00

selftests/rseq: Introduce thread pointer getters

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer.

The toolchains do not implement accessing the thread pointer on all
architectures. Provide thread pointer getters for ppc and x86 which
lack (or lacked until recently) toolchain support.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-7-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h | 25 ++++-
 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h     | 30 +++++-
 tools/testing/selftests/rseq/rseq-thread-pointer.h         | 19 +++-
 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h     | 40 +++++++-
 4 files changed, 114 insertions(+)
 create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h
 create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h

diff --git a/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h b/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
new file mode 100644
index 0000000..38c5846
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-generic-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_GENERIC_THREAD_POINTER
+#define _RSEQ_GENERIC_THREAD_POINTER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Use gcc builtin thread pointer. */
+static inline void *rseq_thread_pointer(void)
+{
+	return __builtin_thread_pointer();
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h b/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
new file mode 100644
index 0000000..263eee8
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-ppc-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_PPC_THREAD_POINTER
+#define _RSEQ_PPC_THREAD_POINTER
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+static inline void *rseq_thread_pointer(void)
+{
+#ifdef __powerpc64__
+	register void *__result asm ("r13");
+#else
+	register void *__result asm ("r2");
+#endif
+	asm ("" : "=r" (__result));
+	return __result;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-thread-pointer.h b/tools/testing/selftests/rseq/rseq-thread-pointer.h
new file mode 100644
index 0000000..977c25d
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-thread-pointer.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_THREAD_POINTER
+#define _RSEQ_THREAD_POINTER
+
+#if defined(__x86_64__) || defined(__i386__)
+#include "rseq-x86-thread-pointer.h"
+#elif defined(__PPC__)
+#include "rseq-ppc-thread-pointer.h"
+#else
+#include "rseq-generic-thread-pointer.h"
+#endif
+
+#endif
diff --git a/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
new file mode 100644
index 0000000..d313358
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */
+/*
+ * rseq-x86-thread-pointer.h
+ *
+ * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _RSEQ_X86_THREAD_POINTER
+#define _RSEQ_X86_THREAD_POINTER
+
+#include <features.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if __GNUC_PREREQ (11, 1)
+static inline void *rseq_thread_pointer(void)
+{
+	return __builtin_thread_pointer();
+}
+#else
+static inline void *rseq_thread_pointer(void)
+{
+	void *__result;
+
+# ifdef __x86_64__
+	__asm__ ("mov %%fs:0, %0" : "=r" (__result));
+# else
+	__asm__ ("mov %%gs:0, %0" : "=r" (__result));
+# endif
+	return __result;
+}
+#endif /* !GCC 11 */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Introduce rseq_get_abi() helper
  2022-01-24 17:12 ` [RFC PATCH 05/15] selftests/rseq: Introduce rseq_get_abi() helper Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     e546cd48ccc456074ddb8920732aef4af65d7ca7
Gitweb:        https://git.kernel.org/tip/e546cd48ccc456074ddb8920732aef4af65d7ca7
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:43 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:35 +01:00

selftests/rseq: Introduce rseq_get_abi() helper

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer, rather than through an actual
Thread-Local Storage (TLS) variable, as the kernel selftests initially
expected.

Introduce a rseq_get_abi() helper, initially using the __rseq_abi
TLS variable, in preparation for changing this userspace ABI for one
which is compatible with glibc-2.35.

Note that the __rseq_abi TLS and glibc-2.35's ABI for per-thread data
cannot actively coexist in a process, because the kernel supports only
a single rseq registration per thread.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-6-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-arm.h   | 32 +++++++++++-----------
 tools/testing/selftests/rseq/rseq-arm64.h | 32 +++++++++++-----------
 tools/testing/selftests/rseq/rseq-mips.h  | 32 +++++++++++-----------
 tools/testing/selftests/rseq/rseq-ppc.h   | 32 +++++++++++-----------
 tools/testing/selftests/rseq/rseq-s390.h  | 24 ++++++++---------
 tools/testing/selftests/rseq/rseq-x86.h   | 30 ++++++++++-----------
 tools/testing/selftests/rseq/rseq.h       | 11 +++++---
 7 files changed, 99 insertions(+), 94 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq-arm.h b/tools/testing/selftests/rseq/rseq-arm.h
index 5943c81..6716540 100644
--- a/tools/testing/selftests/rseq/rseq-arm.h
+++ b/tools/testing/selftests/rseq/rseq-arm.h
@@ -185,8 +185,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -255,8 +255,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -316,8 +316,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -381,8 +381,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -457,8 +457,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -537,8 +537,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -657,8 +657,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -782,8 +782,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-arm64.h b/tools/testing/selftests/rseq/rseq-arm64.h
index 200dae9..b9d9b3a 100644
--- a/tools/testing/selftests/rseq/rseq-arm64.h
+++ b/tools/testing/selftests/rseq/rseq-arm64.h
@@ -230,8 +230,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -287,8 +287,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expectnot]		"r" (expectnot),
 		  [load]		"Qo" (*load),
@@ -337,8 +337,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [count]		"r" (count)
 		  RSEQ_INJECT_INPUT
@@ -388,8 +388,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -447,8 +447,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -508,8 +508,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"Qo" (*v),
 		  [expect]		"r" (expect),
 		  [v2]			"Qo" (*v2),
@@ -569,8 +569,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
@@ -629,8 +629,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"Qo" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"Qo" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [expect]		"r" (expect),
 		  [v]			"Qo" (*v),
 		  [newv]		"r" (newv),
diff --git a/tools/testing/selftests/rseq/rseq-mips.h b/tools/testing/selftests/rseq/rseq-mips.h
index e989e7c..2b1f5bd 100644
--- a/tools/testing/selftests/rseq/rseq-mips.h
+++ b/tools/testing/selftests/rseq/rseq-mips.h
@@ -190,8 +190,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -258,8 +258,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -319,8 +319,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [count]		"Ir" (count)
 		  RSEQ_INJECT_INPUT
@@ -382,8 +382,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -456,8 +456,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -532,8 +532,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		"5:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -649,8 +649,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -771,8 +771,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		"8:\n\t"
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-ppc.h b/tools/testing/selftests/rseq/rseq-ppc.h
index 76be901..2e6b757 100644
--- a/tools/testing/selftests/rseq/rseq-ppc.h
+++ b/tools/testing/selftests/rseq/rseq-ppc.h
@@ -235,8 +235,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -301,8 +301,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -359,8 +359,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -419,8 +419,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -489,8 +489,8 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -560,8 +560,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -635,8 +635,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -711,8 +711,8 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-s390.h b/tools/testing/selftests/rseq/rseq-s390.h
index 8ef94ad..b906e04 100644
--- a/tools/testing/selftests/rseq/rseq-s390.h
+++ b/tools/testing/selftests/rseq/rseq-s390.h
@@ -165,8 +165,8 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -233,8 +233,8 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -288,8 +288,8 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"r" (count)
@@ -347,8 +347,8 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -426,8 +426,8 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -534,8 +534,8 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [current_cpu_id]	"m" (__rseq_abi.cpu_id),
-		  [rseq_cs]		"m" (__rseq_abi.rseq_cs),
+		  [current_cpu_id]	"m" (rseq_get_abi()->cpu_id),
+		  [rseq_cs]		"m" (rseq_get_abi()->rseq_cs),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
diff --git a/tools/testing/selftests/rseq/rseq-x86.h b/tools/testing/selftests/rseq/rseq-x86.h
index 6404115..1d9fa05 100644
--- a/tools/testing/selftests/rseq/rseq-x86.h
+++ b/tools/testing/selftests/rseq/rseq-x86.h
@@ -141,7 +141,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -207,7 +207,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -258,7 +258,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"er" (count)
@@ -314,7 +314,7 @@ int rseq_offset_deref_addv(intptr_t *ptr, off_t off, intptr_t inc, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [ptr]			"m" (*ptr),
 		  [off]			"er" (off),
@@ -372,7 +372,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -449,7 +449,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -555,7 +555,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
@@ -719,7 +719,7 @@ int rseq_cmpeqv_storev(intptr_t *v, intptr_t expect, intptr_t newv, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  [v]			"m" (*v),
 		  [expect]		"r" (expect),
 		  [newv]		"r" (newv)
@@ -785,7 +785,7 @@ int rseq_cmpnev_storeoffp_load(intptr_t *v, intptr_t expectnot,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expectnot]		"r" (expectnot),
@@ -836,7 +836,7 @@ int rseq_addv(intptr_t *v, intptr_t count, int cpu)
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [count]		"ir" (count)
@@ -894,7 +894,7 @@ int rseq_cmpeqv_trystorev_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"m" (newv2),
@@ -962,7 +962,7 @@ int rseq_cmpeqv_trystorev_storev_release(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* try store input */
 		  [v2]			"m" (*v2),
 		  [newv2]		"r" (newv2),
@@ -1032,7 +1032,7 @@ int rseq_cmpeqv_cmpeqv_storev(intptr_t *v, intptr_t expect,
 		RSEQ_ASM_DEFINE_ABORT(4, "", abort)
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* cmp2 input */
 		  [v2]			"m" (*v2),
 		  [expect2]		"r" (expect2),
@@ -1142,7 +1142,7 @@ int rseq_cmpeqv_trymemcpy_storev(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
@@ -1255,7 +1255,7 @@ int rseq_cmpeqv_trymemcpy_storev_release(intptr_t *v, intptr_t expect,
 #endif
 		: /* gcc asm goto does not allow outputs */
 		: [cpu_id]		"r" (cpu),
-		  [rseq_abi]		"r" (&__rseq_abi),
+		  [rseq_abi]		"r" (rseq_get_abi()),
 		  /* final store input */
 		  [v]			"m" (*v),
 		  [expect]		"m" (expect),
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index d580f8e..ca668a2 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -46,6 +46,11 @@
 extern __thread struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
+static inline struct rseq_abi *rseq_get_abi(void)
+{
+	return &__rseq_abi;
+}
+
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
 #define rseq_unlikely(x)	__builtin_expect(!!(x), 0)
 #define rseq_barrier()		__asm__ __volatile__("" : : : "memory")
@@ -108,7 +113,7 @@ int32_t rseq_fallback_current_cpu(void);
  */
 static inline int32_t rseq_current_cpu_raw(void)
 {
-	return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id);
+	return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id);
 }
 
 /*
@@ -124,7 +129,7 @@ static inline int32_t rseq_current_cpu_raw(void)
  */
 static inline uint32_t rseq_cpu_start(void)
 {
-	return RSEQ_ACCESS_ONCE(__rseq_abi.cpu_id_start);
+	return RSEQ_ACCESS_ONCE(rseq_get_abi()->cpu_id_start);
 }
 
 static inline uint32_t rseq_current_cpu(void)
@@ -139,7 +144,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-	RSEQ_WRITE_ONCE(__rseq_abi.rseq_cs.arch.ptr, 0);
+	RSEQ_WRITE_ONCE(rseq_get_abi()->rseq_cs.arch.ptr, 0);
 }
 
 /*

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Remove volatile from __rseq_abi
  2022-01-24 17:12 ` [RFC PATCH 04/15] selftests/rseq: Remove volatile from __rseq_abi Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     94b80a19ebfe347a01301d750040a61c38200e2b
Gitweb:        https://git.kernel.org/tip/94b80a19ebfe347a01301d750040a61c38200e2b
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:42 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:34 +01:00

selftests/rseq: Remove volatile from __rseq_abi

This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.

All accesses to the __rseq_abi fields are volatile, but remove the
volatile from the TLS variable declaration, otherwise we are stuck with
volatile for the upcoming rseq_get_abi() helper.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-5-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq.c | 4 ++--
 tools/testing/selftests/rseq/rseq.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index bfe1b26..1f905b6 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -30,7 +30,7 @@
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread volatile struct rseq_abi __rseq_abi = {
+__thread struct rseq_abi __rseq_abi = {
 	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
 };
 
@@ -92,7 +92,7 @@ int rseq_register_current_thread(void)
 		goto end;
 	}
 	if (errno != EBUSY)
-		__rseq_abi.cpu_id = RSEQ_ABI_CPU_ID_REGISTRATION_FAILED;
+		RSEQ_WRITE_ONCE(__rseq_abi.cpu_id, RSEQ_ABI_CPU_ID_REGISTRATION_FAILED);
 	ret = -1;
 	__rseq_refcount--;
 end:
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index cb6bbc5..d580f8e 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -43,7 +43,7 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread volatile struct rseq_abi __rseq_abi;
+extern __thread struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
@@ -139,7 +139,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-	__rseq_abi.rseq_cs.arch.ptr = 0;
+	RSEQ_WRITE_ONCE(__rseq_abi.rseq_cs.arch.ptr, 0);
 }
 
 /*

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: Remove useless assignment to cpu variable
  2022-01-24 17:12 ` [RFC PATCH 03/15] selftests/rseq: Remove useless assignment to cpu variable Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     930378d056eac2c96407b02aafe4938d0ac9cc37
Gitweb:        https://git.kernel.org/tip/930378d056eac2c96407b02aafe4938d0ac9cc37
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:41 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:34 +01:00

selftests/rseq: Remove useless assignment to cpu variable

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-4-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/param_test.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/tools/testing/selftests/rseq/param_test.c b/tools/testing/selftests/rseq/param_test.c
index 699ad5f..cc2cfc1 100644
--- a/tools/testing/selftests/rseq/param_test.c
+++ b/tools/testing/selftests/rseq/param_test.c
@@ -368,9 +368,7 @@ void *test_percpu_spinlock_thread(void *arg)
 		abort();
 	reps = thread_data->reps;
 	for (i = 0; i < reps; i++) {
-		int cpu = rseq_cpu_start();
-
-		cpu = rseq_this_cpu_lock(&data->lock);
+		int cpu = rseq_this_cpu_lock(&data->lock);
 		data->c[cpu].count++;
 		rseq_percpu_unlock(&data->lock, cpu);
 #ifndef BENCHMARK

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] rseq: Remove broken uapi field layout on 32-bit little endian
  2022-01-27 15:27             ` [RFC PATCH v2] " Mathieu Desnoyers
  2022-01-28  8:52               ` Christian Brauner
@ 2022-02-03 14:33               ` tip-bot2 for Mathieu Desnoyers
  1 sibling, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     bfdf4e6208051ed7165b2e92035b4bf11f43eb63
Gitweb:        https://git.kernel.org/tip/bfdf4e6208051ed7165b2e92035b4bf11f43eb63
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Thu, 27 Jan 2022 10:27:20 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:34 +01:00

rseq: Remove broken uapi field layout on 32-bit little endian

The rseq rseq_cs.ptr.{ptr32,padding} uapi endianness handling is
entirely wrong on 32-bit little endian: a preprocessor logic mistake
wrongly uses the big endian field layout on 32-bit little endian
architectures.

Fortunately, those ptr32 accessors were never used within the kernel,
and only meant as a convenience for user-space.

Remove those and replace the whole rseq_cs union by a __u64 type, as
this is the only thing really needed to express the ABI. Document how
32-bit architectures are meant to interact with this field.

Fixes: ec9c82e03a74 ("rseq: uapi: Declare rseq_cs field as union, update includes")
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220127152720.25898-1-mathieu.desnoyers@efficios.com
---
 include/uapi/linux/rseq.h | 20 ++++----------------
 kernel/rseq.c             |  8 ++++----
 2 files changed, 8 insertions(+), 20 deletions(-)

diff --git a/include/uapi/linux/rseq.h b/include/uapi/linux/rseq.h
index 9a402fd..77ee207 100644
--- a/include/uapi/linux/rseq.h
+++ b/include/uapi/linux/rseq.h
@@ -105,23 +105,11 @@ struct rseq {
 	 * Read and set by the kernel. Set by user-space with single-copy
 	 * atomicity semantics. This field should only be updated by the
 	 * thread which registered this data structure. Aligned on 64-bit.
+	 *
+	 * 32-bit architectures should update the low order bits of the
+	 * rseq_cs field, leaving the high order bits initialized to 0.
 	 */
-	union {
-		__u64 ptr64;
-#ifdef __LP64__
-		__u64 ptr;
-#else
-		struct {
-#if (defined(__BYTE_ORDER) && (__BYTE_ORDER == __BIG_ENDIAN)) || defined(__BIG_ENDIAN)
-			__u32 padding;		/* Initialized to zero. */
-			__u32 ptr32;
-#else /* LITTLE */
-			__u32 ptr32;
-			__u32 padding;		/* Initialized to zero. */
-#endif /* ENDIAN */
-		} ptr;
-#endif
-	} rseq_cs;
+	__u64 rseq_cs;
 
 	/*
 	 * Restartable sequences flags field.
diff --git a/kernel/rseq.c b/kernel/rseq.c
index 6d45ac3..97ac20b 100644
--- a/kernel/rseq.c
+++ b/kernel/rseq.c
@@ -128,10 +128,10 @@ static int rseq_get_rseq_cs(struct task_struct *t, struct rseq_cs *rseq_cs)
 	int ret;
 
 #ifdef CONFIG_64BIT
-	if (get_user(ptr, &t->rseq->rseq_cs.ptr64))
+	if (get_user(ptr, &t->rseq->rseq_cs))
 		return -EFAULT;
 #else
-	if (copy_from_user(&ptr, &t->rseq->rseq_cs.ptr64, sizeof(ptr)))
+	if (copy_from_user(&ptr, &t->rseq->rseq_cs, sizeof(ptr)))
 		return -EFAULT;
 #endif
 	if (!ptr) {
@@ -217,9 +217,9 @@ static int clear_rseq_cs(struct task_struct *t)
 	 * Set rseq_cs to NULL.
 	 */
 #ifdef CONFIG_64BIT
-	return put_user(0UL, &t->rseq->rseq_cs.ptr64);
+	return put_user(0UL, &t->rseq->rseq_cs);
 #else
-	if (clear_user(&t->rseq->rseq_cs.ptr64, sizeof(t->rseq->rseq_cs.ptr64)))
+	if (clear_user(&t->rseq->rseq_cs, sizeof(t->rseq->rseq_cs)))
 		return -EFAULT;
 	return 0;
 #endif

^ permalink raw reply related	[flat|nested] 40+ messages in thread

* [tip: sched/core] selftests/rseq: introduce own copy of rseq uapi header
  2022-01-24 17:12 ` [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header Mathieu Desnoyers
@ 2022-02-03 14:33   ` tip-bot2 for Mathieu Desnoyers
  0 siblings, 0 replies; 40+ messages in thread
From: tip-bot2 for Mathieu Desnoyers @ 2022-02-03 14:33 UTC (permalink / raw)
  To: linux-tip-commits
  Cc: Mathieu Desnoyers, Peter Zijlstra (Intel), x86, linux-kernel

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     5c105d55a9dc9e01535116ccfc26e703168a574f
Gitweb:        https://git.kernel.org/tip/5c105d55a9dc9e01535116ccfc26e703168a574f
Author:        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
AuthorDate:    Mon, 24 Jan 2022 12:12:39 -05:00
Committer:     Peter Zijlstra <peterz@infradead.org>
CommitterDate: Wed, 02 Feb 2022 13:11:33 +01:00

selftests/rseq: introduce own copy of rseq uapi header

The Linux kernel rseq uapi header has a broken layout for the
rseq_cs.ptr field on 32-bit little endian architectures. The entire
rseq_cs.ptr field is planned for removal, leaving only the 64-bit
rseq_cs.ptr64 field available.

Both glibc and librseq use their own copy of the Linux kernel uapi
header, where they introduce proper union fields to access to the 32-bit
low order bits of the rseq_cs pointer on 32-bit architectures.

Introduce a copy of the Linux kernel uapi headers in the Linux kernel
selftests.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-2-mathieu.desnoyers@efficios.com
---
 tools/testing/selftests/rseq/rseq-abi.h | 151 +++++++++++++++++++++++-
 tools/testing/selftests/rseq/rseq.c     |  14 +-
 tools/testing/selftests/rseq/rseq.h     |  10 +--
 3 files changed, 161 insertions(+), 14 deletions(-)
 create mode 100644 tools/testing/selftests/rseq/rseq-abi.h

diff --git a/tools/testing/selftests/rseq/rseq-abi.h b/tools/testing/selftests/rseq/rseq-abi.h
new file mode 100644
index 0000000..a8c44d9
--- /dev/null
+++ b/tools/testing/selftests/rseq/rseq-abi.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+#ifndef _RSEQ_ABI_H
+#define _RSEQ_ABI_H
+
+/*
+ * rseq-abi.h
+ *
+ * Restartable sequences system call API
+ *
+ * Copyright (c) 2015-2022 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+enum rseq_abi_cpu_id_state {
+	RSEQ_ABI_CPU_ID_UNINITIALIZED			= -1,
+	RSEQ_ABI_CPU_ID_REGISTRATION_FAILED		= -2,
+};
+
+enum rseq_abi_flags {
+	RSEQ_ABI_FLAG_UNREGISTER = (1 << 0),
+};
+
+enum rseq_abi_cs_flags_bit {
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT	= 0,
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT	= 1,
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT	= 2,
+};
+
+enum rseq_abi_cs_flags {
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT),
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT),
+	RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE	=
+		(1U << RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT),
+};
+
+/*
+ * struct rseq_abi_cs is aligned on 4 * 8 bytes to ensure it is always
+ * contained within a single cache-line. It is usually declared as
+ * link-time constant data.
+ */
+struct rseq_abi_cs {
+	/* Version of this structure. */
+	__u32 version;
+	/* enum rseq_abi_cs_flags */
+	__u32 flags;
+	__u64 start_ip;
+	/* Offset from start_ip. */
+	__u64 post_commit_offset;
+	__u64 abort_ip;
+} __attribute__((aligned(4 * sizeof(__u64))));
+
+/*
+ * struct rseq_abi is aligned on 4 * 8 bytes to ensure it is always
+ * contained within a single cache-line.
+ *
+ * A single struct rseq_abi per thread is allowed.
+ */
+struct rseq_abi {
+	/*
+	 * Restartable sequences cpu_id_start field. Updated by the
+	 * kernel. Read by user-space with single-copy atomicity
+	 * semantics. This field should only be read by the thread which
+	 * registered this data structure. Aligned on 32-bit. Always
+	 * contains a value in the range of possible CPUs, although the
+	 * value may not be the actual current CPU (e.g. if rseq is not
+	 * initialized). This CPU number value should always be compared
+	 * against the value of the cpu_id field before performing a rseq
+	 * commit or returning a value read from a data structure indexed
+	 * using the cpu_id_start value.
+	 */
+	__u32 cpu_id_start;
+	/*
+	 * Restartable sequences cpu_id field. Updated by the kernel.
+	 * Read by user-space with single-copy atomicity semantics. This
+	 * field should only be read by the thread which registered this
+	 * data structure. Aligned on 32-bit. Values
+	 * RSEQ_CPU_ID_UNINITIALIZED and RSEQ_CPU_ID_REGISTRATION_FAILED
+	 * have a special semantic: the former means "rseq uninitialized",
+	 * and latter means "rseq initialization failed". This value is
+	 * meant to be read within rseq critical sections and compared
+	 * with the cpu_id_start value previously read, before performing
+	 * the commit instruction, or read and compared with the
+	 * cpu_id_start value before returning a value loaded from a data
+	 * structure indexed using the cpu_id_start value.
+	 */
+	__u32 cpu_id;
+	/*
+	 * Restartable sequences rseq_cs field.
+	 *
+	 * Contains NULL when no critical section is active for the current
+	 * thread, or holds a pointer to the currently active struct rseq_cs.
+	 *
+	 * Updated by user-space, which sets the address of the currently
+	 * active rseq_cs at the beginning of assembly instruction sequence
+	 * block, and set to NULL by the kernel when it restarts an assembly
+	 * instruction sequence block, as well as when the kernel detects that
+	 * it is preempting or delivering a signal outside of the range
+	 * targeted by the rseq_cs. Also needs to be set to NULL by user-space
+	 * before reclaiming memory that contains the targeted struct rseq_cs.
+	 *
+	 * Read and set by the kernel. Set by user-space with single-copy
+	 * atomicity semantics. This field should only be updated by the
+	 * thread which registered this data structure. Aligned on 64-bit.
+	 */
+	union {
+		__u64 ptr64;
+
+		/*
+		 * The "arch" field provides architecture accessor for
+		 * the ptr field based on architecture pointer size and
+		 * endianness.
+		 */
+		struct {
+#ifdef __LP64__
+			__u64 ptr;
+#elif defined(__BYTE_ORDER) ? (__BYTE_ORDER == __BIG_ENDIAN) : defined(__BIG_ENDIAN)
+			__u32 padding;		/* Initialized to zero. */
+			__u32 ptr;
+#else
+			__u32 ptr;
+			__u32 padding;		/* Initialized to zero. */
+#endif
+		} arch;
+	} rseq_cs;
+
+	/*
+	 * Restartable sequences flags field.
+	 *
+	 * This field should only be updated by the thread which
+	 * registered this data structure. Read by the kernel.
+	 * Mainly used for single-stepping through rseq critical sections
+	 * with debuggers.
+	 *
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_PREEMPT
+	 *     Inhibit instruction sequence block restart on preemption
+	 *     for this thread.
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_SIGNAL
+	 *     Inhibit instruction sequence block restart on signal
+	 *     delivery for this thread.
+	 * - RSEQ_ABI_CS_FLAG_NO_RESTART_ON_MIGRATE
+	 *     Inhibit instruction sequence block restart on migration for
+	 *     this thread.
+	 */
+	__u32 flags;
+} __attribute__((aligned(4 * sizeof(__u64))));
+
+#endif /* _RSEQ_ABI_H */
diff --git a/tools/testing/selftests/rseq/rseq.c b/tools/testing/selftests/rseq/rseq.c
index fb440df..bfe1b26 100644
--- a/tools/testing/selftests/rseq/rseq.c
+++ b/tools/testing/selftests/rseq/rseq.c
@@ -30,8 +30,8 @@
 #include "../kselftest.h"
 #include "rseq.h"
 
-__thread volatile struct rseq __rseq_abi = {
-	.cpu_id = RSEQ_CPU_ID_UNINITIALIZED,
+__thread volatile struct rseq_abi __rseq_abi = {
+	.cpu_id = RSEQ_ABI_CPU_ID_UNINITIALIZED,
 };
 
 /*
@@ -66,7 +66,7 @@ static void signal_restore(sigset_t oldset)
 		abort();
 }
 
-static int sys_rseq(volatile struct rseq *rseq_abi, uint32_t rseq_len,
+static int sys_rseq(volatile struct rseq_abi *rseq_abi, uint32_t rseq_len,
 		    int flags, uint32_t sig)
 {
 	return syscall(__NR_rseq, rseq_abi, rseq_len, flags, sig);
@@ -86,13 +86,13 @@ int rseq_register_current_thread(void)
 	}
 	if (__rseq_refcount++)
 		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq), 0, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi), 0, RSEQ_SIG);
 	if (!rc) {
 		assert(rseq_current_cpu_raw() >= 0);
 		goto end;
 	}
 	if (errno != EBUSY)
-		__rseq_abi.cpu_id = RSEQ_CPU_ID_REGISTRATION_FAILED;
+		__rseq_abi.cpu_id = RSEQ_ABI_CPU_ID_REGISTRATION_FAILED;
 	ret = -1;
 	__rseq_refcount--;
 end:
@@ -114,8 +114,8 @@ int rseq_unregister_current_thread(void)
 	}
 	if (--__rseq_refcount)
 		goto end;
-	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq),
-		      RSEQ_FLAG_UNREGISTER, RSEQ_SIG);
+	rc = sys_rseq(&__rseq_abi, sizeof(struct rseq_abi),
+		      RSEQ_ABI_FLAG_UNREGISTER, RSEQ_SIG);
 	if (!rc)
 		goto end;
 	__rseq_refcount = 1;
diff --git a/tools/testing/selftests/rseq/rseq.h b/tools/testing/selftests/rseq/rseq.h
index 3f63eb3..cb6bbc5 100644
--- a/tools/testing/selftests/rseq/rseq.h
+++ b/tools/testing/selftests/rseq/rseq.h
@@ -16,7 +16,7 @@
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <linux/rseq.h>
+#include "rseq-abi.h"
 
 /*
  * Empty code injection macros, override when testing.
@@ -43,7 +43,7 @@
 #define RSEQ_INJECT_FAILED
 #endif
 
-extern __thread volatile struct rseq __rseq_abi;
+extern __thread volatile struct rseq_abi __rseq_abi;
 extern int __rseq_handled;
 
 #define rseq_likely(x)		__builtin_expect(!!(x), 1)
@@ -139,11 +139,7 @@ static inline uint32_t rseq_current_cpu(void)
 
 static inline void rseq_clear_rseq_cs(void)
 {
-#ifdef __LP64__
-	__rseq_abi.rseq_cs.ptr = 0;
-#else
-	__rseq_abi.rseq_cs.ptr.ptr32 = 0;
-#endif
+	__rseq_abi.rseq_cs.arch.ptr = 0;
 }
 
 /*

^ permalink raw reply related	[flat|nested] 40+ messages in thread

end of thread, other threads:[~2022-02-03 14:36 UTC | newest]

Thread overview: 40+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-01-24 17:12 [RFC PATCH 00/15] rseq uapi and selftest updates Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 01/15] selftests/rseq: introduce own copy of rseq uapi header Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 02/15] rseq: Remove broken uapi field layout on 32-bit little endian Mathieu Desnoyers
2022-01-25 12:21   ` Christian Brauner
2022-01-25 14:41     ` Mathieu Desnoyers
2022-01-25 19:00       ` Mathieu Desnoyers
2022-01-26  8:03         ` Christian Brauner
2022-01-26 11:00           ` Florian Weimer
2022-01-26 17:16         ` David Laight
2022-01-26 18:59           ` Mathieu Desnoyers
2022-01-27 15:27             ` [RFC PATCH v2] " Mathieu Desnoyers
2022-01-28  8:52               ` Christian Brauner
2022-02-03 14:33               ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 03/15] selftests/rseq: Remove useless assignment to cpu variable Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 04/15] selftests/rseq: Remove volatile from __rseq_abi Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 05/15] selftests/rseq: Introduce rseq_get_abi() helper Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 06/15] selftests/rseq: Introduce thread pointer getters Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 07/15] selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35 Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 08/15] selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 09/15] selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 10/15] selftests/rseq: Fix ppc32 offsets by using long rather than off_t Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 11/15] selftests/rseq: Fix warnings about #if checks of undefined tokens Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 12/15] selftests/rseq: Remove arm/mips asm goto compiler work-around Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 13/15] selftests/rseq: Fix: work-around asm goto compiler bugs Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 14/15] selftests/rseq: x86-64: use %fs segment selector for accessing rseq thread area Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-24 17:12 ` [RFC PATCH 15/15] selftests/rseq: x86-32: use %gs " Mathieu Desnoyers
2022-02-03 14:33   ` [tip: sched/core] " tip-bot2 for Mathieu Desnoyers
2022-01-27 15:46 ` [RFC PATCH 00/15] rseq uapi and selftest updates Peter Zijlstra

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