[PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

Ingo,


On top of all the patches which remove in-kernel calls to syscall functions
merged in commit 642e7fd23353, it now becomes easy for achitectures to
re-define the syscall calling convention. For x86, this may be used to
merely decode those entries from struct pt_regs which are needed for a
specific syscall.

This approach avoids leaking random user-provided register content down
the call chain. Therefore, the seventh patch of this series extends the
register clearing in the entry path to a few more registers.

To exemplify: sys_recv() is a classic 4-parameter syscall. For this syscall,
the DEFINE_SYSCALL macro creates the following stub:

	asmlinkage long sys_recv(struct pt_regs *regs)
	{
		return SyS_recv(regs->di, regs->si, regs->dx, regs->r10);
	}

The assembly of that function then becomes, in slightly reordered fashion:

	<sys_recv>:
		callq	<__fentry__>

		/* decode regs->di, ->si, ->dx and ->r10 */
		mov	0x70(%rdi),%rdi
		mov	0x68(%rdi),%rsi
		mov	0x60(%rdi),%rdx
		mov	0x38(%rdi),%rcx

		[ SyS_recv() is inlined here by the compiler, as it is tiny ]
		/* clear %r9 and %r8, the 5th and 6th args */
		xor	%r9d,%r9d
		xor	%r8d,%r8d

		/* do the actual work */
		callq	__sys_recvfrom

		/* cleanup and return */
		cltq
		retq

For IA32_EMULATION and X32, additional care needs to be taken as they use
different registers to pass parameters to syscalls; vsyscalls need to be
modified to use this new calling convention as well.

This actual conversion of x86 syscalls is heavily based on a proof-of-concept
by Linus[*]. This patchset here differs, for example, as it provides a generic
config symbol ARCH_HAS_SYSCALL_WRAPPER, introduces <asm/syscall_wrapper.h>,
splits up the patch into several parts, and adds the actual register clearing.

	[*] Accessible at
	    https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git WIP-syscall
	    It contains an additional patch
		x86: avoid per-cpu system call trampoline
	    which is not included in my series as it addresses a different
	    issue, but may be of interest to the x86 maintainers as well.

Compared to v4.16-rc5 baseline and on a random kernel config, these patches
(in combination with the large do-not-call-syscalls-in-the-kernel series)
lead to a minisculue increase in text (+0.005%) and data (+0.11%) size on a
pure 64bit system,

	    text	   data	   bss	     dec	    hex	filename
	18853337	9535476	938380	29327193	1bf7f59	vmlinux-orig
	18854227	9546100	938380	29338707	1bfac53	vmlinux,

with IA32_EMULATION and X32 enabled, the situation is just a little bit worse
for text size (+0.009%) and data (+0.38%) size.

	    text	   data	   bss	     dec	    hex	filename
	18902496	9603676	938444	29444616	1c14a08	vmlinux-orig
	18904136	9640604	938444	29483184	1c1e0b0 vmlinux.

The 64bit part of this series has worked flawlessly on my local system for a
few weeks. IA32_EMULATION and x32 has passed some basic testing as well, but
has not yet been tested as extensively as x86-64. Pure i386 kernels are left
as-is, as they use a different asmlinkage anyway.


Changes since the series sent out to linux-kernel on March 30th:

all patches:
- rebase on top of commit 642e7fd23353

several patches:
- further extend and fix commentary; spelling fixes (e.g., nospec, 64-bit,
  32-bit)

patch 3:
- do not clobber regs->dx on sys_getcpu() vsyscall

patch 5:
- rename __sys32_ia32_*() stubs to __sys_ia32_*()
- do not generate __sys_ia32_*() syscall table entries automatically, but
  have them explicitely in arch/x86/entry/syscalls/syscall_32.tbl
- this means that there is no need to redefine SYSCALL_DEFINE0
- rename compat_sys_*() to __compat_sys_ia32_*(), as the calling convention
  is different to "generic" compat_sys_*() [but see below]

patch 8: (your call...)
- introduce new patch 8: rename sys_*() to __sys_x86_*() -- while this
  avoids symbol space overlap per your request, it doesn't improve the
  code readibility by much. Moreover, if other architectures switch to
  this syscall calling convention, there is no real "default" calling
  convention any more. Therefore, I'd suggest *NOT* to apply this patch.

Thanks,
	Dominik

Dominik Brodowski (7):
  syscalls: introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER
  syscalls/x86: use struct pt_regs based syscall calling for 64-bit
    syscalls
  syscalls: prepare ARCH_HAS_SYSCALL_WRAPPER for compat syscalls
  syscalls/x86: use struct pt_regs based syscall calling for
    IA32_EMULATION and x32
  syscalls/x86: unconditionally enable struct pt_regs based syscalls on
    x86_64
  x86/entry/64: extend register clearing on syscall entry to lower
    registers
  syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*()

Linus Torvalds (1):
  x86: don't pointlessly reload the system call number

 arch/x86/Kconfig                       |   1 +
 arch/x86/entry/calling.h               |   2 +
 arch/x86/entry/common.c                |  20 +-
 arch/x86/entry/entry_64.S              |   3 +-
 arch/x86/entry/entry_64_compat.S       |   6 +
 arch/x86/entry/syscall_32.c            |  15 +-
 arch/x86/entry/syscall_64.c            |   6 +-
 arch/x86/entry/syscalls/syscall_32.tbl | 724 +++++++++++++++++----------------
 arch/x86/entry/syscalls/syscall_64.tbl | 712 ++++++++++++++++----------------
 arch/x86/entry/vsyscall/vsyscall_64.c  |  18 +-
 arch/x86/include/asm/syscall.h         |   4 +
 arch/x86/include/asm/syscall_wrapper.h | 197 +++++++++
 arch/x86/include/asm/syscalls.h        |  17 +-
 include/linux/compat.h                 |  22 +
 include/linux/syscalls.h               |  25 +-
 init/Kconfig                           |  10 +
 kernel/sys_ni.c                        |  10 +
 kernel/time/posix-stubs.c              |  10 +
 18 files changed, 1054 insertions(+), 748 deletions(-)
 create mode 100644 arch/x86/include/asm/syscall_wrapper.h

-- 
2.16.3

[PATCH 1/8] x86: don't pointlessly reload the system call number

[Dominik Brodowski]

From: Linus Torvalds <torvalds@linux-foundation.org>

We have it in a register in the low-level asm, just pass it in as an
argument rather than have do_syscall_64() load it back in from the
ptregs pointer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/entry/common.c   | 12 ++++++------
 arch/x86/entry/entry_64.S |  3 ++-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 74f6eee15179..a8b066dbbf48 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -266,14 +266,13 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs)
 }
 
 #ifdef CONFIG_X86_64
-__visible void do_syscall_64(struct pt_regs *regs)
+__visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 {
-	struct thread_info *ti = current_thread_info();
-	unsigned long nr = regs->orig_ax;
+	struct thread_info *ti;
 
 	enter_from_user_mode();
 	local_irq_enable();
-
+	ti = current_thread_info();
 	if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY)
 		nr = syscall_trace_enter(regs);
 
@@ -282,8 +281,9 @@ __visible void do_syscall_64(struct pt_regs *regs)
 	 * table.  The only functional difference is the x32 bit in
 	 * regs->orig_ax, which changes the behavior of some syscalls.
 	 */
-	if (likely((nr & __SYSCALL_MASK) < NR_syscalls)) {
-		nr = array_index_nospec(nr & __SYSCALL_MASK, NR_syscalls);
+	nr &= __SYSCALL_MASK;
+	if (likely(nr < NR_syscalls)) {
+		nr = array_index_nospec(nr, NR_syscalls);
 		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 936e19642eab..6cfe38665f3c 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -233,7 +233,8 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 	TRACE_IRQS_OFF
 
 	/* IRQs are off. */
-	movq	%rsp, %rdi
+	movq	%rax, %rdi
+	movq	%rsp, %rsi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
 	TRACE_IRQS_IRETQ		/* we're about to change IF */
-- 
2.16.3

[tip:x86/asm] x86/syscalls: Don't pointlessly reload the system call number

[tip-bot for Linus Torvalds]

Commit-ID:  dfe64506c01e57159a4c550fe537c13a317ff01b
Gitweb:     https://git.kernel.org/tip/dfe64506c01e57159a4c550fe537c13a317ff01b
Author:     Linus Torvalds <torvalds@linux-foundation.org>
AuthorDate: Thu, 5 Apr 2018 11:53:00 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:24 +0200

x86/syscalls: Don't pointlessly reload the system call number

We have it in a register in the low-level asm, just pass it in as an
argument rather than have do_syscall_64() load it back in from the
ptregs pointer.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-2-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/entry/common.c   | 12 ++++++------
 arch/x86/entry/entry_64.S |  3 ++-
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 74f6eee15179..a8b066dbbf48 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -266,14 +266,13 @@ __visible inline void syscall_return_slowpath(struct pt_regs *regs)
 }
 
 #ifdef CONFIG_X86_64
-__visible void do_syscall_64(struct pt_regs *regs)
+__visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 {
-	struct thread_info *ti = current_thread_info();
-	unsigned long nr = regs->orig_ax;
+	struct thread_info *ti;
 
 	enter_from_user_mode();
 	local_irq_enable();
-
+	ti = current_thread_info();
 	if (READ_ONCE(ti->flags) & _TIF_WORK_SYSCALL_ENTRY)
 		nr = syscall_trace_enter(regs);
 
@@ -282,8 +281,9 @@ __visible void do_syscall_64(struct pt_regs *regs)
 	 * table.  The only functional difference is the x32 bit in
 	 * regs->orig_ax, which changes the behavior of some syscalls.
 	 */
-	if (likely((nr & __SYSCALL_MASK) < NR_syscalls)) {
-		nr = array_index_nospec(nr & __SYSCALL_MASK, NR_syscalls);
+	nr &= __SYSCALL_MASK;
+	if (likely(nr < NR_syscalls)) {
+		nr = array_index_nospec(nr, NR_syscalls);
 		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 936e19642eab..6cfe38665f3c 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -233,7 +233,8 @@ GLOBAL(entry_SYSCALL_64_after_hwframe)
 	TRACE_IRQS_OFF
 
 	/* IRQs are off. */
-	movq	%rsp, %rdi
+	movq	%rax, %rdi
+	movq	%rsp, %rsi
 	call	do_syscall_64		/* returns with IRQs disabled */
 
 	TRACE_IRQS_IRETQ		/* we're about to change IF */

[PATCH 2/8] syscalls: introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER

[Dominik Brodowski]

It may be useful for an architecture to override the definitions of the
SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
in particular to use a different calling convention for syscalls.

This patch provides a mechanism to do so: It introduces
CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h>
is included in <linux/syscalls.h> and may be used to define the macros
mentioned above. Moreover, as the syscall calling convention may be
different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the syscall function
prototypes in <linux/syscalls.h> are #ifndef'd out in that case.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 include/linux/syscalls.h | 23 +++++++++++++++++++++++
 init/Kconfig             |  7 +++++++
 2 files changed, 30 insertions(+)

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b961184f597a..503ab245d4ce 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -81,6 +81,17 @@ union bpf_attr;
 #include <linux/key.h>
 #include <trace/syscall.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros, in particular to use a
+ * different calling convention for syscalls. To allow for that, the prototypes
+ * for the sys_*() functions below will *not* be included if
+ * CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
+ */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 /*
  * __MAP - apply a macro to syscall arguments
  * __MAP(n, m, t1, a1, t2, a2, ..., tn, an) will expand to
@@ -189,11 +200,13 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 }
 #endif
 
+#ifndef SYSCALL_DEFINE0
 #define SYSCALL_DEFINE0(sname)					\
 	SYSCALL_METADATA(_##sname, 0);				\
 	asmlinkage long sys_##sname(void);			\
 	ALLOW_ERROR_INJECTION(sys_##sname, ERRNO);		\
 	asmlinkage long sys_##sname(void)
+#endif /* SYSCALL_DEFINE0 */
 
 #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
@@ -209,6 +222,8 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 	__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
 
 #define __PROTECT(...) asmlinkage_protect(__VA_ARGS__)
+
+#ifndef __SYSCALL_DEFINEx
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
 		__attribute__((alias(__stringify(SyS##name))));		\
@@ -223,6 +238,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 		return ret;						\
 	}								\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* __SYSCALL_DEFINEx */
 
 /*
  * Called before coming back to user-mode. Returning to user-mode with an
@@ -252,7 +268,12 @@ static inline void addr_limit_user_check(void)
  * Please note that these prototypes here are only provided for information
  * purposes, for static analysis, and for linking from the syscall table.
  * These functions should not be called elsewhere from kernel code.
+ *
+ * As the syscall calling convention may be different from the default
+ * for architectures overriding the syscall calling convention, do not
+ * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
  */
+#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 asmlinkage long sys_io_setup(unsigned nr_reqs, aio_context_t __user *ctx);
 asmlinkage long sys_io_destroy(aio_context_t ctx);
 asmlinkage long sys_io_submit(aio_context_t, long,
@@ -1076,6 +1097,8 @@ asmlinkage long sys_old_mmap(struct mmap_arg_struct __user *arg);
  */
 asmlinkage long sys_ni_syscall(void);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly.
diff --git a/init/Kconfig b/init/Kconfig
index 2852692d7c9c..068eb6c3bbf7 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1923,3 +1923,10 @@ source "kernel/Kconfig.locks"
 
 config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 	bool
+
+# It may be useful for an architecture to override the definitions of the
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
+# in particular to use a different calling convention for syscalls.
+config ARCH_HAS_SYSCALL_WRAPPER
+	def_bool n
+	depends on !COMPAT
-- 
2.16.3

[tip:x86/asm] syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y

[tip-bot for Dominik Brodowski]

Commit-ID:  1bd21c6c21e848996339508d3ffb106d505256a8
Gitweb:     https://git.kernel.org/tip/1bd21c6c21e848996339508d3ffb106d505256a8
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:01 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:25 +0200

syscalls/core: Introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y

It may be useful for an architecture to override the definitions of the
SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
in particular to use a different calling convention for syscalls.

This patch provides a mechanism to do so: It introduces
CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled, <asm/sycall_wrapper.h>
is included in <linux/syscalls.h> and may be used to define the macros
mentioned above. Moreover, as the syscall calling convention may be
different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set, the syscall function
prototypes in <linux/syscalls.h> are #ifndef'd out in that case.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-3-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/syscalls.h | 23 +++++++++++++++++++++++
 init/Kconfig             |  7 +++++++
 2 files changed, 30 insertions(+)

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index b961184f597a..503ab245d4ce 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -81,6 +81,17 @@ union bpf_attr;
 #include <linux/key.h>
 #include <trace/syscall.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * SYSCALL_DEFINE0() and __SYSCALL_DEFINEx() macros, in particular to use a
+ * different calling convention for syscalls. To allow for that, the prototypes
+ * for the sys_*() functions below will *not* be included if
+ * CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
+ */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 /*
  * __MAP - apply a macro to syscall arguments
  * __MAP(n, m, t1, a1, t2, a2, ..., tn, an) will expand to
@@ -189,11 +200,13 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 }
 #endif
 
+#ifndef SYSCALL_DEFINE0
 #define SYSCALL_DEFINE0(sname)					\
 	SYSCALL_METADATA(_##sname, 0);				\
 	asmlinkage long sys_##sname(void);			\
 	ALLOW_ERROR_INJECTION(sys_##sname, ERRNO);		\
 	asmlinkage long sys_##sname(void)
+#endif /* SYSCALL_DEFINE0 */
 
 #define SYSCALL_DEFINE1(name, ...) SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
 #define SYSCALL_DEFINE2(name, ...) SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
@@ -209,6 +222,8 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 	__SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
 
 #define __PROTECT(...) asmlinkage_protect(__VA_ARGS__)
+
+#ifndef __SYSCALL_DEFINEx
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))	\
 		__attribute__((alias(__stringify(SyS##name))));		\
@@ -223,6 +238,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event)
 		return ret;						\
 	}								\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* __SYSCALL_DEFINEx */
 
 /*
  * Called before coming back to user-mode. Returning to user-mode with an
@@ -252,7 +268,12 @@ static inline void addr_limit_user_check(void)
  * Please note that these prototypes here are only provided for information
  * purposes, for static analysis, and for linking from the syscall table.
  * These functions should not be called elsewhere from kernel code.
+ *
+ * As the syscall calling convention may be different from the default
+ * for architectures overriding the syscall calling convention, do not
+ * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
  */
+#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 asmlinkage long sys_io_setup(unsigned nr_reqs, aio_context_t __user *ctx);
 asmlinkage long sys_io_destroy(aio_context_t ctx);
 asmlinkage long sys_io_submit(aio_context_t, long,
@@ -1076,6 +1097,8 @@ asmlinkage long sys_old_mmap(struct mmap_arg_struct __user *arg);
  */
 asmlinkage long sys_ni_syscall(void);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * Kernel code should not call syscalls (i.e., sys_xyzyyz()) directly.
diff --git a/init/Kconfig b/init/Kconfig
index 2852692d7c9c..068eb6c3bbf7 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1923,3 +1923,10 @@ source "kernel/Kconfig.locks"
 
 config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 	bool
+
+# It may be useful for an architecture to override the definitions of the
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
+# in particular to use a different calling convention for syscalls.
+config ARCH_HAS_SYSCALL_WRAPPER
+	def_bool n
+	depends on !COMPAT

[PATCH 3/8] syscalls/x86: use struct pt_regs based syscall calling for 64-bit syscalls

[Dominik Brodowski]

Let's make use of ARCH_HAS_SYSCALL_WRAPPER on pure 64-bit x86-64 systems:

Each syscall defines a stub which takes struct pt_regs as its only
argument. It decodes just those parameters it needs, e.g:

	asmlinkage long sys_xyzzy(const struct pt_regs *regs)
	{
		return SyS_xyzzy(regs->di, regs->si, regs->dx);
	}

This approach avoids leaking random user-provided register content down
the call chain.

For example, for sys_recv() which is a 4-parameter syscall, the assembly
now is (in slightly reordered fashion):

	<sys_recv>:
		callq	<__fentry__>

		/* decode regs->di, ->si, ->dx and ->r10 */
		mov	0x70(%rdi),%rdi
		mov	0x68(%rdi),%rsi
		mov	0x60(%rdi),%rdx
		mov	0x38(%rdi),%rcx

		[ SyS_recv() is automatically inlined by the compiler,
		  as it is not [yet] used anywhere else ]
		/* clear %r9 and %r8, the 5th and 6th args */
		xor	%r9d,%r9d
		xor	%r8d,%r8d

		/* do the actual work */
		callq	__sys_recvfrom

		/* cleanup and return */
		cltq
		retq

The only valid place in an x86-64 kernel which rightfully calls
a syscall function on its own -- vsyscall -- needs to be modified
to pass struct pt_regs onwards as well.

To keep the syscall table generation working independent of
SYSCALL_PTREGS being enabled, the stubs are named the same as the
"original" syscall stubs, i.e. sys_*().

This patch is based on an original proof-of-concept

	From: Linus Torvalds <torvalds@linux-foundation.org>
	Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

and was split up and heavily modified by me, in particular to base it on
ARCH_HAS_SYSCALL_WRAPPER, to limit it to 64-bit-only for the time being,
and to update the vsyscall to the new calling convention.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/Kconfig                       |  5 +++
 arch/x86/entry/common.c                |  4 ++
 arch/x86/entry/syscall_64.c            |  9 ++++-
 arch/x86/entry/vsyscall/vsyscall_64.c  | 22 +++++++++++
 arch/x86/include/asm/syscall.h         |  4 ++
 arch/x86/include/asm/syscall_wrapper.h | 70 ++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/syscalls.h        |  7 ++++
 include/linux/syscalls.h               |  2 +-
 8 files changed, 120 insertions(+), 3 deletions(-)
 create mode 100644 arch/x86/include/asm/syscall_wrapper.h

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 27fede438959..67348efc2540 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2954,3 +2954,8 @@ source "crypto/Kconfig"
 source "arch/x86/kvm/Kconfig"
 
 source "lib/Kconfig"
+
+config SYSCALL_PTREGS
+	def_bool y
+	depends on X86_64 && !COMPAT
+	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index a8b066dbbf48..e1b91bffa988 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -284,9 +284,13 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 	nr &= __SYSCALL_MASK;
 	if (likely(nr < NR_syscalls)) {
 		nr = array_index_nospec(nr, NR_syscalls);
+#ifdef CONFIG_SYSCALL_PTREGS
+		regs->ax = sys_call_table[nr](regs);
+#else
 		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
+#endif
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index c176d2fab1da..6197850adf91 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,19 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
+#ifdef CONFIG_SYSCALL_PTREGS
+/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
+extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+#else /* CONFIG_SYSCALL_PTREGS */
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
 #define __SYSCALL_64(nr, sym, qual) [nr] = sym,
 
-extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*
 	 * Smells like a compiler bug -- it doesn't work
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 317be365bce3..05eebbf9b989 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,6 +127,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	int vsyscall_nr, syscall_nr, tmp;
 	int prev_sig_on_uaccess_err;
 	long ret;
+#ifdef CONFIG_SYSCALL_PTREGS
+	unsigned long orig_dx;
+#endif
 
 	/*
 	 * No point in checking CS -- the only way to get here is a user mode
@@ -227,19 +230,38 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di and regs->si on its own */
+		ret = sys_gettimeofday(regs);
+#else
 		ret = sys_gettimeofday(
 			(struct timeval __user *)regs->di,
 			(struct timezone __user *)regs->si);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 1:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di on its own */
+		ret = sys_time(regs);
+#else
 		ret = sys_time((time_t __user *)regs->di);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 2:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* while we could clobber regs->dx, we didn't in the past... */
+		orig_dx = regs->dx;
+		regs->dx = 0;
+		/* this decodes regs->di, regs->si and regs->dx on its own */
+		ret = sys_getcpu(regs);
+		regs->dx = orig_dx;
+#else
 		ret = sys_getcpu((unsigned __user *)regs->di,
 				 (unsigned __user *)regs->si,
 				 NULL);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 	}
 
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 03eedc21246d..17c62373a6f9 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -20,9 +20,13 @@
 #include <asm/thread_info.h>	/* for TS_COMPAT */
 #include <asm/unistd.h>
 
+#ifdef CONFIG_SYSCALL_PTREGS
+typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);
+#else
 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
 					  unsigned long, unsigned long,
 					  unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
 extern const sys_call_ptr_t sys_call_table[];
 
 #if defined(CONFIG_X86_32)
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
new file mode 100644
index 000000000000..702bdee377af
--- /dev/null
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * syscall_wrapper.h - x86 specific wrappers to syscall definitions
+ */
+
+#ifndef _ASM_X86_SYSCALL_WRAPPER_H
+#define _ASM_X86_SYSCALL_WRAPPER_H
+
+/*
+ * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes
+ * struct pt_regs *regs as the only argument of the syscall stub named
+ * sys_*(). It decodes just the registers it needs and passes them on to
+ * the SyS_*() wrapper and then to the SYSC_*() function doing the actual job.
+ * These wrappers and functions are inlined, meaning that the assembly looks
+ * as follows (slightly re-ordered):
+ *
+ * <sys_recv>:			<-- syscall with 4 parameters
+ *	callq	<__fentry__>
+ *
+ *	mov	0x70(%rdi),%rdi	<-- decode regs->di
+ *	mov	0x68(%rdi),%rsi	<-- decode regs->si
+ *	mov	0x60(%rdi),%rdx	<-- decode regs->dx
+ *	mov	0x38(%rdi),%rcx	<-- decode regs->r10
+ *
+ *	xor	%r9d,%r9d	<-- clear %r9
+ *	xor	%r8d,%r8d	<-- clear %r8
+ *
+ *	callq	__sys_recvfrom	<-- do the actual work in __sys_recvfrom()
+ *				    which takes 6 arguments
+ *
+ *	cltq			<-- extend return value to 64-bit
+ *	retq			<-- return
+ *
+ * This approach avoids leaking random user-provided register content down
+ * the call chain.
+ *
+ * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
+ * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
+ * hurt, there is no need to override it.
+ */
+#define __SYSCALL_DEFINEx(x, name, ...)					\
+	asmlinkage long sys##name(const struct pt_regs *regs);		\
+	ALLOW_ERROR_INJECTION(sys##name, ERRNO);			\
+	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\
+	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long sys##name(const struct pt_regs *regs)		\
+	{								\
+		return SyS##name(__MAP(x,__SC_ARGS			\
+			,,regs->di,,regs->si,,regs->dx			\
+			,,regs->r10,,regs->r8,,regs->r9));		\
+	}								\
+	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{								\
+		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
+		__MAP(x,__SC_TEST,__VA_ARGS__);				\
+		__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__));	\
+		return ret;						\
+	}								\
+	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * For VSYSCALLS, we need to declare these three syscalls with the new
+ * pt_regs-based calling convention for in-kernel use.
+ */
+struct pt_regs;
+asmlinkage long sys_getcpu(const struct pt_regs *regs);		/* di,si,dx */
+asmlinkage long sys_gettimeofday(const struct pt_regs *regs);	/* di,si */
+asmlinkage long sys_time(const struct pt_regs *regs);		/* di */
+
+#endif /* _ASM_X86_SYSCALL_WRAPPER_H */
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index ae6e05fdc24b..e4ad93c05f02 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -18,6 +18,12 @@
 /* Common in X86_32 and X86_64 */
 /* kernel/ioport.c */
 long ksys_ioperm(unsigned long from, unsigned long num, int turn_on);
+
+#ifndef CONFIG_SYSCALL_PTREGS
+/*
+ * If CONFIG_SYSCALL_PTREGS is enabled, a different syscall calling convention
+ * is used. Do not include these -- invalid -- prototypes then
+ */
 asmlinkage long sys_ioperm(unsigned long, unsigned long, int);
 asmlinkage long sys_iopl(unsigned int);
 
@@ -53,4 +59,5 @@ asmlinkage long sys_mmap(unsigned long, unsigned long, unsigned long,
 			 unsigned long, unsigned long, unsigned long);
 
 #endif /* CONFIG_X86_32 */
+#endif /* CONFIG_SYSCALL_PTREGS */
 #endif /* _ASM_X86_SYSCALLS_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 503ab245d4ce..d7168b3a4b4c 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -102,7 +102,7 @@ union bpf_attr;
  * for SYSCALL_DEFINE<n>/COMPAT_SYSCALL_DEFINE<n>
  */
 #define __MAP0(m,...)
-#define __MAP1(m,t,a) m(t,a)
+#define __MAP1(m,t,a,...) m(t,a)
 #define __MAP2(m,t,a,...) m(t,a), __MAP1(m,__VA_ARGS__)
 #define __MAP3(m,t,a,...) m(t,a), __MAP2(m,__VA_ARGS__)
 #define __MAP4(m,t,a,...) m(t,a), __MAP3(m,__VA_ARGS__)
-- 
2.16.3

[tip:x86/asm] syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls

[tip-bot for Dominik Brodowski]

Commit-ID:  fa697140f9a20119a9ec8fd7460cc4314fbdaff3
Gitweb:     https://git.kernel.org/tip/fa697140f9a20119a9ec8fd7460cc4314fbdaff3
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:02 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:26 +0200

syscalls/x86: Use 'struct pt_regs' based syscall calling convention for 64-bit syscalls

Let's make use of ARCH_HAS_SYSCALL_WRAPPER=y on pure 64-bit x86-64 systems:

Each syscall defines a stub which takes struct pt_regs as its only
argument. It decodes just those parameters it needs, e.g:

	asmlinkage long sys_xyzzy(const struct pt_regs *regs)
	{
		return SyS_xyzzy(regs->di, regs->si, regs->dx);
	}

This approach avoids leaking random user-provided register content down
the call chain.

For example, for sys_recv() which is a 4-parameter syscall, the assembly
now is (in slightly reordered fashion):

	<sys_recv>:
		callq	<__fentry__>

		/* decode regs->di, ->si, ->dx and ->r10 */
		mov	0x70(%rdi),%rdi
		mov	0x68(%rdi),%rsi
		mov	0x60(%rdi),%rdx
		mov	0x38(%rdi),%rcx

		[ SyS_recv() is automatically inlined by the compiler,
		  as it is not [yet] used anywhere else ]
		/* clear %r9 and %r8, the 5th and 6th args */
		xor	%r9d,%r9d
		xor	%r8d,%r8d

		/* do the actual work */
		callq	__sys_recvfrom

		/* cleanup and return */
		cltq
		retq

The only valid place in an x86-64 kernel which rightfully calls
a syscall function on its own -- vsyscall -- needs to be modified
to pass struct pt_regs onwards as well.

To keep the syscall table generation working independent of
SYSCALL_PTREGS being enabled, the stubs are named the same as the
"original" syscall stubs, i.e. sys_*().

This patch is based on an original proof-of-concept

 | From: Linus Torvalds <torvalds@linux-foundation.org>
 | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

and was split up and heavily modified by me, in particular to base it on
ARCH_HAS_SYSCALL_WRAPPER, to limit it to 64-bit-only for the time being,
and to update the vsyscall to the new calling convention.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-4-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/Kconfig                       |  5 +++
 arch/x86/entry/common.c                |  4 ++
 arch/x86/entry/syscall_64.c            |  9 ++++-
 arch/x86/entry/vsyscall/vsyscall_64.c  | 22 +++++++++++
 arch/x86/include/asm/syscall.h         |  4 ++
 arch/x86/include/asm/syscall_wrapper.h | 70 ++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/syscalls.h        |  7 ++++
 include/linux/syscalls.h               |  2 +-
 8 files changed, 120 insertions(+), 3 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 27fede438959..67348efc2540 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2954,3 +2954,8 @@ source "crypto/Kconfig"
 source "arch/x86/kvm/Kconfig"
 
 source "lib/Kconfig"
+
+config SYSCALL_PTREGS
+	def_bool y
+	depends on X86_64 && !COMPAT
+	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index a8b066dbbf48..e1b91bffa988 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -284,9 +284,13 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 	nr &= __SYSCALL_MASK;
 	if (likely(nr < NR_syscalls)) {
 		nr = array_index_nospec(nr, NR_syscalls);
+#ifdef CONFIG_SYSCALL_PTREGS
+		regs->ax = sys_call_table[nr](regs);
+#else
 		regs->ax = sys_call_table[nr](
 			regs->di, regs->si, regs->dx,
 			regs->r10, regs->r8, regs->r9);
+#endif
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index c176d2fab1da..6197850adf91 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,19 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
+#ifdef CONFIG_SYSCALL_PTREGS
+/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
+extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+#else /* CONFIG_SYSCALL_PTREGS */
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
 #define __SYSCALL_64(nr, sym, qual) [nr] = sym,
 
-extern long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-
 asmlinkage const sys_call_ptr_t sys_call_table[__NR_syscall_max+1] = {
 	/*
 	 * Smells like a compiler bug -- it doesn't work
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 317be365bce3..05eebbf9b989 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,6 +127,9 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	int vsyscall_nr, syscall_nr, tmp;
 	int prev_sig_on_uaccess_err;
 	long ret;
+#ifdef CONFIG_SYSCALL_PTREGS
+	unsigned long orig_dx;
+#endif
 
 	/*
 	 * No point in checking CS -- the only way to get here is a user mode
@@ -227,19 +230,38 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di and regs->si on its own */
+		ret = sys_gettimeofday(regs);
+#else
 		ret = sys_gettimeofday(
 			(struct timeval __user *)regs->di,
 			(struct timezone __user *)regs->si);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 1:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* this decodes regs->di on its own */
+		ret = sys_time(regs);
+#else
 		ret = sys_time((time_t __user *)regs->di);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 2:
+#ifdef CONFIG_SYSCALL_PTREGS
+		/* while we could clobber regs->dx, we didn't in the past... */
+		orig_dx = regs->dx;
+		regs->dx = 0;
+		/* this decodes regs->di, regs->si and regs->dx on its own */
+		ret = sys_getcpu(regs);
+		regs->dx = orig_dx;
+#else
 		ret = sys_getcpu((unsigned __user *)regs->di,
 				 (unsigned __user *)regs->si,
 				 NULL);
+#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 	}
 
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 03eedc21246d..17c62373a6f9 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -20,9 +20,13 @@
 #include <asm/thread_info.h>	/* for TS_COMPAT */
 #include <asm/unistd.h>
 
+#ifdef CONFIG_SYSCALL_PTREGS
+typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);
+#else
 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
 					  unsigned long, unsigned long,
 					  unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
 extern const sys_call_ptr_t sys_call_table[];
 
 #if defined(CONFIG_X86_32)
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
new file mode 100644
index 000000000000..702bdee377af
--- /dev/null
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * syscall_wrapper.h - x86 specific wrappers to syscall definitions
+ */
+
+#ifndef _ASM_X86_SYSCALL_WRAPPER_H
+#define _ASM_X86_SYSCALL_WRAPPER_H
+
+/*
+ * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes
+ * struct pt_regs *regs as the only argument of the syscall stub named
+ * sys_*(). It decodes just the registers it needs and passes them on to
+ * the SyS_*() wrapper and then to the SYSC_*() function doing the actual job.
+ * These wrappers and functions are inlined, meaning that the assembly looks
+ * as follows (slightly re-ordered):
+ *
+ * <sys_recv>:			<-- syscall with 4 parameters
+ *	callq	<__fentry__>
+ *
+ *	mov	0x70(%rdi),%rdi	<-- decode regs->di
+ *	mov	0x68(%rdi),%rsi	<-- decode regs->si
+ *	mov	0x60(%rdi),%rdx	<-- decode regs->dx
+ *	mov	0x38(%rdi),%rcx	<-- decode regs->r10
+ *
+ *	xor	%r9d,%r9d	<-- clear %r9
+ *	xor	%r8d,%r8d	<-- clear %r8
+ *
+ *	callq	__sys_recvfrom	<-- do the actual work in __sys_recvfrom()
+ *				    which takes 6 arguments
+ *
+ *	cltq			<-- extend return value to 64-bit
+ *	retq			<-- return
+ *
+ * This approach avoids leaking random user-provided register content down
+ * the call chain.
+ *
+ * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
+ * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
+ * hurt, there is no need to override it.
+ */
+#define __SYSCALL_DEFINEx(x, name, ...)					\
+	asmlinkage long sys##name(const struct pt_regs *regs);		\
+	ALLOW_ERROR_INJECTION(sys##name, ERRNO);			\
+	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\
+	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
+	asmlinkage long sys##name(const struct pt_regs *regs)		\
+	{								\
+		return SyS##name(__MAP(x,__SC_ARGS			\
+			,,regs->di,,regs->si,,regs->dx			\
+			,,regs->r10,,regs->r8,,regs->r9));		\
+	}								\
+	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{								\
+		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
+		__MAP(x,__SC_TEST,__VA_ARGS__);				\
+		__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__));	\
+		return ret;						\
+	}								\
+	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * For VSYSCALLS, we need to declare these three syscalls with the new
+ * pt_regs-based calling convention for in-kernel use.
+ */
+struct pt_regs;
+asmlinkage long sys_getcpu(const struct pt_regs *regs);		/* di,si,dx */
+asmlinkage long sys_gettimeofday(const struct pt_regs *regs);	/* di,si */
+asmlinkage long sys_time(const struct pt_regs *regs);		/* di */
+
+#endif /* _ASM_X86_SYSCALL_WRAPPER_H */
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index ae6e05fdc24b..e4ad93c05f02 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -18,6 +18,12 @@
 /* Common in X86_32 and X86_64 */
 /* kernel/ioport.c */
 long ksys_ioperm(unsigned long from, unsigned long num, int turn_on);
+
+#ifndef CONFIG_SYSCALL_PTREGS
+/*
+ * If CONFIG_SYSCALL_PTREGS is enabled, a different syscall calling convention
+ * is used. Do not include these -- invalid -- prototypes then
+ */
 asmlinkage long sys_ioperm(unsigned long, unsigned long, int);
 asmlinkage long sys_iopl(unsigned int);
 
@@ -53,4 +59,5 @@ asmlinkage long sys_mmap(unsigned long, unsigned long, unsigned long,
 			 unsigned long, unsigned long, unsigned long);
 
 #endif /* CONFIG_X86_32 */
+#endif /* CONFIG_SYSCALL_PTREGS */
 #endif /* _ASM_X86_SYSCALLS_H */
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 503ab245d4ce..d7168b3a4b4c 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -102,7 +102,7 @@ union bpf_attr;
  * for SYSCALL_DEFINE<n>/COMPAT_SYSCALL_DEFINE<n>
  */
 #define __MAP0(m,...)
-#define __MAP1(m,t,a) m(t,a)
+#define __MAP1(m,t,a,...) m(t,a)
 #define __MAP2(m,t,a,...) m(t,a), __MAP1(m,__VA_ARGS__)
 #define __MAP3(m,t,a,...) m(t,a), __MAP2(m,__VA_ARGS__)
 #define __MAP4(m,t,a,...) m(t,a), __MAP3(m,__VA_ARGS__)

[PATCH 4/8] syscalls: prepare ARCH_HAS_SYSCALL_WRAPPER for compat syscalls

[Dominik Brodowski]

It may be useful for an architecture to override the definitions of the
COMPAT_SYSCALL_DEFINE0() and __COMPAT_SYSCALL_DEFINEx() macros in
<linux/compat.h>, in particular to use a different calling convention
for syscalls. This patch provides a mechanism to do so, based on the
previously introduced CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled,
<asm/sycall_wrapper.h> is included in <linux/compat.h> and may be used
to define the macros mentioned above. Moreover, as the syscall calling
convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set,
the compat syscall function prototypes in <linux/compat.h> are #ifndef'd
out in that case.

As some of the syscalls and/or compat syscalls may not be present,
the COND_SYSCALL() and COND_SYSCALL_COMPAT() macros in kernel/sys_ni.c
as well as the SYS_NI() and COMPAT_SYS_NI() macros in
kernel/time/posix-stubs.c can be re-defined in <asm/syscall_wrapper.h> iff
CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 include/linux/compat.h    | 22 ++++++++++++++++++++++
 init/Kconfig              |  9 ++++++---
 kernel/sys_ni.c           | 10 ++++++++++
 kernel/time/posix-stubs.c | 10 ++++++++++
 4 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9847c5a013c3..2d85ec5cfda2 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -24,6 +24,17 @@
 #include <asm/siginfo.h>
 #include <asm/signal.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * COMPAT_SYSCALL_DEFINE0 and COMPAT_SYSCALL_DEFINEx() macros, in particular
+ * to use a different calling convention for syscalls. To allow for that,
+ + the prototypes for the compat_sys_*() functions below will *not* be included
+ * if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
+ */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 #ifndef COMPAT_USE_64BIT_TIME
 #define COMPAT_USE_64BIT_TIME 0
 #endif
@@ -32,10 +43,12 @@
 #define __SC_DELOUSE(t,v) ((__force t)(unsigned long)(v))
 #endif
 
+#ifndef COMPAT_SYSCALL_DEFINE0
 #define COMPAT_SYSCALL_DEFINE0(name) \
 	asmlinkage long compat_sys_##name(void); \
 	ALLOW_ERROR_INJECTION(compat_sys_##name, ERRNO); \
 	asmlinkage long compat_sys_##name(void)
+#endif /* COMPAT_SYSCALL_DEFINE0 */
 
 #define COMPAT_SYSCALL_DEFINE1(name, ...) \
         COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
@@ -50,6 +63,7 @@
 #define COMPAT_SYSCALL_DEFINE6(name, ...) \
 	COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
 
+#ifndef COMPAT_SYSCALL_DEFINEx
 #define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
 	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
 	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\
@@ -62,6 +76,7 @@
 		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
 	}								\
 	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* COMPAT_SYSCALL_DEFINEx */
 
 #ifndef compat_user_stack_pointer
 #define compat_user_stack_pointer() current_user_stack_pointer()
@@ -517,7 +532,12 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long);
  * Please note that these prototypes here are only provided for information
  * purposes, for static analysis, and for linking from the syscall table.
  * These functions should not be called elsewhere from kernel code.
+ *
+ * As the syscall calling convention may be different from the default
+ * for architectures overriding the syscall calling convention, do not
+ * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
  */
+#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 asmlinkage long compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p);
 asmlinkage long compat_sys_io_submit(compat_aio_context_t ctx_id, int nr,
 				     u32 __user *iocb);
@@ -955,6 +975,8 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr);
 /* obsolete: net/socket.c */
 asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * For most but not all architectures, "am I in a compat syscall?" and
diff --git a/init/Kconfig b/init/Kconfig
index 068eb6c3bbf7..2dbc88051bde 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1925,8 +1925,11 @@ config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 	bool
 
 # It may be useful for an architecture to override the definitions of the
-# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
-# in particular to use a different calling convention for syscalls.
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
+# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
+# different calling convention for syscalls. They can also override the
+# macros for not-implemented syscalls in kernel/sys_ni.c and
+# kernel/time/posix-stubs.c. All these overrides need to be available in
+# <asm/syscall_wrapper.h>.
 config ARCH_HAS_SYSCALL_WRAPPER
 	def_bool n
-	depends on !COMPAT
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 6cafc008f6db..9791364925dc 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -5,6 +5,11 @@
 
 #include <asm/unistd.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/* Architectures may override COND_SYSCALL and COND_SYSCALL_COMPAT */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 /*  we can't #include <linux/syscalls.h> here,
     but tell gcc to not warn with -Wmissing-prototypes  */
 asmlinkage long sys_ni_syscall(void);
@@ -17,8 +22,13 @@ asmlinkage long sys_ni_syscall(void)
 	return -ENOSYS;
 }
 
+#ifndef COND_SYSCALL
 #define COND_SYSCALL(name) cond_syscall(sys_##name)
+#endif /* COND_SYSCALL */
+
+#ifndef COND_SYSCALL_COMPAT
 #define COND_SYSCALL_COMPAT(name) cond_syscall(compat_sys_##name)
+#endif /* COND_SYSCALL_COMPAT */
 
 /*
  * This list is kept in the same order as include/uapi/asm-generic/unistd.h.
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index b258bee13b02..69a937c3cd81 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -19,6 +19,11 @@
 #include <linux/posix-timers.h>
 #include <linux/compat.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/* Architectures may override SYS_NI and COMPAT_SYS_NI */
+#include <asm/syscall_wrapper.h>
+#endif
+
 asmlinkage long sys_ni_posix_timers(void)
 {
 	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
@@ -27,8 +32,13 @@ asmlinkage long sys_ni_posix_timers(void)
 	return -ENOSYS;
 }
 
+#ifndef SYS_NI
 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
+#endif
+
+#ifndef COMPAT_SYS_NI
 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
+#endif
 
 SYS_NI(timer_create);
 SYS_NI(timer_gettime);
-- 
2.16.3

[tip:x86/asm] syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls

[tip-bot for Dominik Brodowski]

Commit-ID:  7303e30ec1d8fb5ca1f07c92d069241c32b2ee1b
Gitweb:     https://git.kernel.org/tip/7303e30ec1d8fb5ca1f07c92d069241c32b2ee1b
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:03 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:38 +0200

syscalls/core: Prepare CONFIG_ARCH_HAS_SYSCALL_WRAPPER=y for compat syscalls

It may be useful for an architecture to override the definitions of the
COMPAT_SYSCALL_DEFINE0() and __COMPAT_SYSCALL_DEFINEx() macros in
<linux/compat.h>, in particular to use a different calling convention
for syscalls. This patch provides a mechanism to do so, based on the
previously introduced CONFIG_ARCH_HAS_SYSCALL_WRAPPER. If it is enabled,
<asm/sycall_wrapper.h> is included in <linux/compat.h> and may be used
to define the macros mentioned above. Moreover, as the syscall calling
convention may be different if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is set,
the compat syscall function prototypes in <linux/compat.h> are #ifndef'd
out in that case.

As some of the syscalls and/or compat syscalls may not be present,
the COND_SYSCALL() and COND_SYSCALL_COMPAT() macros in kernel/sys_ni.c
as well as the SYS_NI() and COMPAT_SYS_NI() macros in
kernel/time/posix-stubs.c can be re-defined in <asm/syscall_wrapper.h> iff
CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-5-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/linux/compat.h    | 22 ++++++++++++++++++++++
 init/Kconfig              |  9 ++++++---
 kernel/sys_ni.c           | 10 ++++++++++
 kernel/time/posix-stubs.c | 10 ++++++++++
 4 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 9847c5a013c3..2d85ec5cfda2 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -24,6 +24,17 @@
 #include <asm/siginfo.h>
 #include <asm/signal.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/*
+ * It may be useful for an architecture to override the definitions of the
+ * COMPAT_SYSCALL_DEFINE0 and COMPAT_SYSCALL_DEFINEx() macros, in particular
+ * to use a different calling convention for syscalls. To allow for that,
+ + the prototypes for the compat_sys_*() functions below will *not* be included
+ * if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
+ */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 #ifndef COMPAT_USE_64BIT_TIME
 #define COMPAT_USE_64BIT_TIME 0
 #endif
@@ -32,10 +43,12 @@
 #define __SC_DELOUSE(t,v) ((__force t)(unsigned long)(v))
 #endif
 
+#ifndef COMPAT_SYSCALL_DEFINE0
 #define COMPAT_SYSCALL_DEFINE0(name) \
 	asmlinkage long compat_sys_##name(void); \
 	ALLOW_ERROR_INJECTION(compat_sys_##name, ERRNO); \
 	asmlinkage long compat_sys_##name(void)
+#endif /* COMPAT_SYSCALL_DEFINE0 */
 
 #define COMPAT_SYSCALL_DEFINE1(name, ...) \
         COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
@@ -50,6 +63,7 @@
 #define COMPAT_SYSCALL_DEFINE6(name, ...) \
 	COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
 
+#ifndef COMPAT_SYSCALL_DEFINEx
 #define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
 	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
 	asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\
@@ -62,6 +76,7 @@
 		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
 	}								\
 	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+#endif /* COMPAT_SYSCALL_DEFINEx */
 
 #ifndef compat_user_stack_pointer
 #define compat_user_stack_pointer() current_user_stack_pointer()
@@ -517,7 +532,12 @@ int __compat_save_altstack(compat_stack_t __user *, unsigned long);
  * Please note that these prototypes here are only provided for information
  * purposes, for static analysis, and for linking from the syscall table.
  * These functions should not be called elsewhere from kernel code.
+ *
+ * As the syscall calling convention may be different from the default
+ * for architectures overriding the syscall calling convention, do not
+ * include the prototypes if CONFIG_ARCH_HAS_SYSCALL_WRAPPER is enabled.
  */
+#ifndef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
 asmlinkage long compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p);
 asmlinkage long compat_sys_io_submit(compat_aio_context_t ctx_id, int nr,
 				     u32 __user *iocb);
@@ -955,6 +975,8 @@ asmlinkage long compat_sys_stime(compat_time_t __user *tptr);
 /* obsolete: net/socket.c */
 asmlinkage long compat_sys_socketcall(int call, u32 __user *args);
 
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 
 /*
  * For most but not all architectures, "am I in a compat syscall?" and
diff --git a/init/Kconfig b/init/Kconfig
index 068eb6c3bbf7..2dbc88051bde 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1925,8 +1925,11 @@ config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
 	bool
 
 # It may be useful for an architecture to override the definitions of the
-# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>,
-# in particular to use a different calling convention for syscalls.
+# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
+# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
+# different calling convention for syscalls. They can also override the
+# macros for not-implemented syscalls in kernel/sys_ni.c and
+# kernel/time/posix-stubs.c. All these overrides need to be available in
+# <asm/syscall_wrapper.h>.
 config ARCH_HAS_SYSCALL_WRAPPER
 	def_bool n
-	depends on !COMPAT
diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c
index 6cafc008f6db..9791364925dc 100644
--- a/kernel/sys_ni.c
+++ b/kernel/sys_ni.c
@@ -5,6 +5,11 @@
 
 #include <asm/unistd.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/* Architectures may override COND_SYSCALL and COND_SYSCALL_COMPAT */
+#include <asm/syscall_wrapper.h>
+#endif /* CONFIG_ARCH_HAS_SYSCALL_WRAPPER */
+
 /*  we can't #include <linux/syscalls.h> here,
     but tell gcc to not warn with -Wmissing-prototypes  */
 asmlinkage long sys_ni_syscall(void);
@@ -17,8 +22,13 @@ asmlinkage long sys_ni_syscall(void)
 	return -ENOSYS;
 }
 
+#ifndef COND_SYSCALL
 #define COND_SYSCALL(name) cond_syscall(sys_##name)
+#endif /* COND_SYSCALL */
+
+#ifndef COND_SYSCALL_COMPAT
 #define COND_SYSCALL_COMPAT(name) cond_syscall(compat_sys_##name)
+#endif /* COND_SYSCALL_COMPAT */
 
 /*
  * This list is kept in the same order as include/uapi/asm-generic/unistd.h.
diff --git a/kernel/time/posix-stubs.c b/kernel/time/posix-stubs.c
index b258bee13b02..69a937c3cd81 100644
--- a/kernel/time/posix-stubs.c
+++ b/kernel/time/posix-stubs.c
@@ -19,6 +19,11 @@
 #include <linux/posix-timers.h>
 #include <linux/compat.h>
 
+#ifdef CONFIG_ARCH_HAS_SYSCALL_WRAPPER
+/* Architectures may override SYS_NI and COMPAT_SYS_NI */
+#include <asm/syscall_wrapper.h>
+#endif
+
 asmlinkage long sys_ni_posix_timers(void)
 {
 	pr_err_once("process %d (%s) attempted a POSIX timer syscall "
@@ -27,8 +32,13 @@ asmlinkage long sys_ni_posix_timers(void)
 	return -ENOSYS;
 }
 
+#ifndef SYS_NI
 #define SYS_NI(name)  SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers)
+#endif
+
+#ifndef COMPAT_SYS_NI
 #define COMPAT_SYS_NI(name)  SYSCALL_ALIAS(compat_sys_##name, sys_ni_posix_timers)
+#endif
 
 SYS_NI(timer_create);
 SYS_NI(timer_gettime);

[PATCH 5/8] syscalls/x86: use struct pt_regs based syscall calling for IA32_EMULATION and x32

[Dominik Brodowski]

Extend ARCH_HAS_SYSCALL_WRAPPER for i386 emulation and for x32 on 64-bit
x86.

For x32, all we need to do is to create an additional stub for each
compat syscall which decodes the parameters in x86-64 ordering, e.g.:

	asmlinkage long __compat_sys_x32_xyzzy(struct pt_regs *regs)
	{
		return c_SyS_xyzzy(regs->di, regs->si, regs->dx);
	}

For i386 emulation, we need to teach compat_sys_*() to take struct
pt_regs as its only argument, e.g.:

	asmlinkage long __compat_sys_ia32_xyzzy(struct pt_regs *regs)
	{
		return c_SyS_xyzzy(regs->bx, regs->cx, regs->dx);
	}

In addition, we need to create additional stubs for common syscalls
(that is, for syscalls which have the same parameters on 32-bit and
64-bit), e.g.:

	asmlinkage long __sys_ia32_xyzzy(struct pt_regs *regs)
	{
		return c_sys_xyzzy(regs->bx, regs->cx, regs->dx);
	}

This approach avoids leaking random user-provided register content down
the call chain.

This patch is based on an original proof-of-concept

        From: Linus Torvalds <torvalds@linux-foundation.org>
        Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

and was split up and heavily modified by me, in particular to base it on
ARCH_HAS_SYSCALL_WRAPPER.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: x86@kernel.org
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/Kconfig                       |   2 +-
 arch/x86/entry/common.c                |   4 +
 arch/x86/entry/syscall_32.c            |  15 +-
 arch/x86/entry/syscalls/syscall_32.tbl | 677 +++++++++++++++++----------------
 arch/x86/entry/syscalls/syscall_64.tbl |  74 ++--
 arch/x86/include/asm/syscall_wrapper.h | 117 +++++-
 6 files changed, 509 insertions(+), 380 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 67348efc2540..7bbd6a174722 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2957,5 +2957,5 @@ source "lib/Kconfig"
 
 config SYSCALL_PTREGS
 	def_bool y
-	depends on X86_64 && !COMPAT
+	depends on X86_64
 	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index e1b91bffa988..425f798b39e3 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -325,6 +325,9 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 
 	if (likely(nr < IA32_NR_syscalls)) {
 		nr = array_index_nospec(nr, IA32_NR_syscalls);
+#ifdef CONFIG_SYSCALL_PTREGS
+		regs->ax = ia32_sys_call_table[nr](regs);
+#else
 		/*
 		 * It's possible that a 32-bit syscall implementation
 		 * takes a 64-bit parameter but nonetheless assumes that
@@ -335,6 +338,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 			(unsigned int)regs->bx, (unsigned int)regs->cx,
 			(unsigned int)regs->dx, (unsigned int)regs->si,
 			(unsigned int)regs->di, (unsigned int)regs->bp);
+#endif /* CONFIG_SYSCALL_PTREGS */
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 95c294963612..47060dd8efb1 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -7,14 +7,23 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#ifdef CONFIG_SYSCALL_PTREGS
+/* On X86_64, we use struct pt_regs * to pass parameters to syscalls */
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+
+/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
+extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+
+#else /* CONFIG_SYSCALL_PTREGS */
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
+
 #include <asm/syscalls_32.h>
 #undef __SYSCALL_I386
 
 #define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
 
-extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-
 __visible const sys_call_ptr_t ia32_sys_call_table[__NR_syscall_compat_max+1] = {
 	/*
 	 * Smells like a compiler bug -- it doesn't work
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index c58f75b088c5..7f09a3da0b3d 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -4,390 +4,395 @@
 # The format is:
 # <number> <abi> <name> <entry point> <compat entry point>
 #
+# The __sys_ia32 and __compat_sys_ia32 stubs are created on-the-fly for
+# sys_*() system calls and compat_sys_*() compat system calls if
+# IA32_EMULATION is defined, and expect struct pt_regs *regs as their only
+# parameter.
+#
 # The abi is always "i386" for this file.
 #
 0	i386	restart_syscall		sys_restart_syscall
-1	i386	exit			sys_exit
+1	i386	exit			sys_exit			__sys_ia32_exit
 2	i386	fork			sys_fork
-3	i386	read			sys_read
-4	i386	write			sys_write
-5	i386	open			sys_open			compat_sys_open
-6	i386	close			sys_close
-7	i386	waitpid			sys_waitpid
-8	i386	creat			sys_creat
-9	i386	link			sys_link
-10	i386	unlink			sys_unlink
-11	i386	execve			sys_execve			compat_sys_execve
-12	i386	chdir			sys_chdir
-13	i386	time			sys_time			compat_sys_time
-14	i386	mknod			sys_mknod
-15	i386	chmod			sys_chmod
-16	i386	lchown			sys_lchown16
+3	i386	read			sys_read			__sys_ia32_read
+4	i386	write			sys_write			__sys_ia32_write
+5	i386	open			sys_open			__compat_sys_ia32_open
+6	i386	close			sys_close			__sys_ia32_close
+7	i386	waitpid			sys_waitpid			__sys_ia32_waitpid
+8	i386	creat			sys_creat			__sys_ia32_creat
+9	i386	link			sys_link			__sys_ia32_link
+10	i386	unlink			sys_unlink			__sys_ia32_unlink
+11	i386	execve			sys_execve			__compat_sys_ia32_execve
+12	i386	chdir			sys_chdir			__sys_ia32_chdir
+13	i386	time			sys_time			__compat_sys_ia32_time
+14	i386	mknod			sys_mknod			__sys_ia32_mknod
+15	i386	chmod			sys_chmod			__sys_ia32_chmod
+16	i386	lchown			sys_lchown16			__sys_ia32_lchown16
 17	i386	break
-18	i386	oldstat			sys_stat
-19	i386	lseek			sys_lseek			compat_sys_lseek
+18	i386	oldstat			sys_stat			__sys_ia32_stat
+19	i386	lseek			sys_lseek			__compat_sys_ia32_lseek
 20	i386	getpid			sys_getpid
-21	i386	mount			sys_mount			compat_sys_mount
-22	i386	umount			sys_oldumount
-23	i386	setuid			sys_setuid16
+21	i386	mount			sys_mount			__compat_sys_ia32_mount
+22	i386	umount			sys_oldumount			__sys_ia32_oldumount
+23	i386	setuid			sys_setuid16			__sys_ia32_setuid16
 24	i386	getuid			sys_getuid16
-25	i386	stime			sys_stime			compat_sys_stime
-26	i386	ptrace			sys_ptrace			compat_sys_ptrace
-27	i386	alarm			sys_alarm
-28	i386	oldfstat		sys_fstat
+25	i386	stime			sys_stime			__compat_sys_ia32_stime
+26	i386	ptrace			sys_ptrace			__compat_sys_ia32_ptrace
+27	i386	alarm			sys_alarm			__sys_ia32_alarm
+28	i386	oldfstat		sys_fstat			__sys_ia32_fstat
 29	i386	pause			sys_pause
-30	i386	utime			sys_utime			compat_sys_utime
+30	i386	utime			sys_utime			__compat_sys_ia32_utime
 31	i386	stty
 32	i386	gtty
-33	i386	access			sys_access
-34	i386	nice			sys_nice
+33	i386	access			sys_access			__sys_ia32_access
+34	i386	nice			sys_nice			__sys_ia32_nice
 35	i386	ftime
 36	i386	sync			sys_sync
-37	i386	kill			sys_kill
-38	i386	rename			sys_rename
-39	i386	mkdir			sys_mkdir
-40	i386	rmdir			sys_rmdir
-41	i386	dup			sys_dup
-42	i386	pipe			sys_pipe
-43	i386	times			sys_times			compat_sys_times
+37	i386	kill			sys_kill			__sys_ia32_kill
+38	i386	rename			sys_rename			__sys_ia32_rename
+39	i386	mkdir			sys_mkdir			__sys_ia32_mkdir
+40	i386	rmdir			sys_rmdir			__sys_ia32_rmdir
+41	i386	dup			sys_dup				__sys_ia32_dup
+42	i386	pipe			sys_pipe			__sys_ia32_pipe
+43	i386	times			sys_times			__compat_sys_ia32_times
 44	i386	prof
-45	i386	brk			sys_brk
-46	i386	setgid			sys_setgid16
+45	i386	brk			sys_brk				__sys_ia32_brk
+46	i386	setgid			sys_setgid16			__sys_ia32_setgid16
 47	i386	getgid			sys_getgid16
-48	i386	signal			sys_signal
+48	i386	signal			sys_signal			__sys_ia32_signal
 49	i386	geteuid			sys_geteuid16
 50	i386	getegid			sys_getegid16
-51	i386	acct			sys_acct
-52	i386	umount2			sys_umount
+51	i386	acct			sys_acct			__sys_ia32_acct
+52	i386	umount2			sys_umount			__sys_ia32_umount
 53	i386	lock
-54	i386	ioctl			sys_ioctl			compat_sys_ioctl
-55	i386	fcntl			sys_fcntl			compat_sys_fcntl64
+54	i386	ioctl			sys_ioctl			__compat_sys_ia32_ioctl
+55	i386	fcntl			sys_fcntl			__compat_sys_ia32_fcntl64
 56	i386	mpx
-57	i386	setpgid			sys_setpgid
+57	i386	setpgid			sys_setpgid			__sys_ia32_setpgid
 58	i386	ulimit
-59	i386	oldolduname		sys_olduname
-60	i386	umask			sys_umask
-61	i386	chroot			sys_chroot
-62	i386	ustat			sys_ustat			compat_sys_ustat
-63	i386	dup2			sys_dup2
+59	i386	oldolduname		sys_olduname			__sys_ia32_olduname
+60	i386	umask			sys_umask			__sys_ia32_umask
+61	i386	chroot			sys_chroot			__sys_ia32_chroot
+62	i386	ustat			sys_ustat			__compat_sys_ia32_ustat
+63	i386	dup2			sys_dup2			__sys_ia32_dup2
 64	i386	getppid			sys_getppid
 65	i386	getpgrp			sys_getpgrp
 66	i386	setsid			sys_setsid
-67	i386	sigaction		sys_sigaction			compat_sys_sigaction
+67	i386	sigaction		sys_sigaction			__compat_sys_ia32_sigaction
 68	i386	sgetmask		sys_sgetmask
-69	i386	ssetmask		sys_ssetmask
-70	i386	setreuid		sys_setreuid16
-71	i386	setregid		sys_setregid16
-72	i386	sigsuspend		sys_sigsuspend
-73	i386	sigpending		sys_sigpending			compat_sys_sigpending
-74	i386	sethostname		sys_sethostname
-75	i386	setrlimit		sys_setrlimit			compat_sys_setrlimit
-76	i386	getrlimit		sys_old_getrlimit		compat_sys_old_getrlimit
-77	i386	getrusage		sys_getrusage			compat_sys_getrusage
-78	i386	gettimeofday		sys_gettimeofday		compat_sys_gettimeofday
-79	i386	settimeofday		sys_settimeofday		compat_sys_settimeofday
-80	i386	getgroups		sys_getgroups16
-81	i386	setgroups		sys_setgroups16
-82	i386	select			sys_old_select			compat_sys_old_select
-83	i386	symlink			sys_symlink
-84	i386	oldlstat		sys_lstat
-85	i386	readlink		sys_readlink
-86	i386	uselib			sys_uselib
-87	i386	swapon			sys_swapon
-88	i386	reboot			sys_reboot
-89	i386	readdir			sys_old_readdir			compat_sys_old_readdir
-90	i386	mmap			sys_old_mmap			compat_sys_x86_mmap
-91	i386	munmap			sys_munmap
-92	i386	truncate		sys_truncate			compat_sys_truncate
-93	i386	ftruncate		sys_ftruncate			compat_sys_ftruncate
-94	i386	fchmod			sys_fchmod
-95	i386	fchown			sys_fchown16
-96	i386	getpriority		sys_getpriority
-97	i386	setpriority		sys_setpriority
+69	i386	ssetmask		sys_ssetmask			__sys_ia32_ssetmask
+70	i386	setreuid		sys_setreuid16			__sys_ia32_setreuid16
+71	i386	setregid		sys_setregid16			__sys_ia32_setregid16
+72	i386	sigsuspend		sys_sigsuspend			__sys_ia32_sigsuspend
+73	i386	sigpending		sys_sigpending			__compat_sys_ia32_sigpending
+74	i386	sethostname		sys_sethostname			__sys_ia32_sethostname
+75	i386	setrlimit		sys_setrlimit			__compat_sys_ia32_setrlimit
+76	i386	getrlimit		sys_old_getrlimit		__compat_sys_ia32_old_getrlimit
+77	i386	getrusage		sys_getrusage			__compat_sys_ia32_getrusage
+78	i386	gettimeofday		sys_gettimeofday		__compat_sys_ia32_gettimeofday
+79	i386	settimeofday		sys_settimeofday		__compat_sys_ia32_settimeofday
+80	i386	getgroups		sys_getgroups16			__sys_ia32_getgroups16
+81	i386	setgroups		sys_setgroups16			__sys_ia32_setgroups16
+82	i386	select			sys_old_select			__compat_sys_ia32_old_select
+83	i386	symlink			sys_symlink			__sys_ia32_symlink
+84	i386	oldlstat		sys_lstat			__sys_ia32_lstat
+85	i386	readlink		sys_readlink			__sys_ia32_readlink
+86	i386	uselib			sys_uselib			__sys_ia32_uselib
+87	i386	swapon			sys_swapon			__sys_ia32_swapon
+88	i386	reboot			sys_reboot			__sys_ia32_reboot
+89	i386	readdir			sys_old_readdir			__compat_sys_ia32_old_readdir
+90	i386	mmap			sys_old_mmap			__compat_sys_ia32_x86_mmap
+91	i386	munmap			sys_munmap			__sys_ia32_munmap
+92	i386	truncate		sys_truncate			__compat_sys_ia32_truncate
+93	i386	ftruncate		sys_ftruncate			__compat_sys_ia32_ftruncate
+94	i386	fchmod			sys_fchmod			__sys_ia32_fchmod
+95	i386	fchown			sys_fchown16			__sys_ia32_fchown16
+96	i386	getpriority		sys_getpriority			__sys_ia32_getpriority
+97	i386	setpriority		sys_setpriority			__sys_ia32_setpriority
 98	i386	profil
-99	i386	statfs			sys_statfs			compat_sys_statfs
-100	i386	fstatfs			sys_fstatfs			compat_sys_fstatfs
-101	i386	ioperm			sys_ioperm
-102	i386	socketcall		sys_socketcall			compat_sys_socketcall
-103	i386	syslog			sys_syslog
-104	i386	setitimer		sys_setitimer			compat_sys_setitimer
-105	i386	getitimer		sys_getitimer			compat_sys_getitimer
-106	i386	stat			sys_newstat			compat_sys_newstat
-107	i386	lstat			sys_newlstat			compat_sys_newlstat
-108	i386	fstat			sys_newfstat			compat_sys_newfstat
-109	i386	olduname		sys_uname
-110	i386	iopl			sys_iopl
+99	i386	statfs			sys_statfs			__compat_sys_ia32_statfs
+100	i386	fstatfs			sys_fstatfs			__compat_sys_ia32_fstatfs
+101	i386	ioperm			sys_ioperm			__sys_ia32_ioperm
+102	i386	socketcall		sys_socketcall			__compat_sys_ia32_socketcall
+103	i386	syslog			sys_syslog			__sys_ia32_syslog
+104	i386	setitimer		sys_setitimer			__compat_sys_ia32_setitimer
+105	i386	getitimer		sys_getitimer			__compat_sys_ia32_getitimer
+106	i386	stat			sys_newstat			__compat_sys_ia32_newstat
+107	i386	lstat			sys_newlstat			__compat_sys_ia32_newlstat
+108	i386	fstat			sys_newfstat			__compat_sys_ia32_newfstat
+109	i386	olduname		sys_uname			__sys_ia32_uname
+110	i386	iopl			sys_iopl			__sys_ia32_iopl
 111	i386	vhangup			sys_vhangup
 112	i386	idle
 113	i386	vm86old			sys_vm86old			sys_ni_syscall
-114	i386	wait4			sys_wait4			compat_sys_wait4
-115	i386	swapoff			sys_swapoff
-116	i386	sysinfo			sys_sysinfo			compat_sys_sysinfo
-117	i386	ipc			sys_ipc				compat_sys_ipc
-118	i386	fsync			sys_fsync
+114	i386	wait4			sys_wait4			__compat_sys_ia32_wait4
+115	i386	swapoff			sys_swapoff			__sys_ia32_swapoff
+116	i386	sysinfo			sys_sysinfo			__compat_sys_ia32_sysinfo
+117	i386	ipc			sys_ipc				__compat_sys_ia32_ipc
+118	i386	fsync			sys_fsync			__sys_ia32_fsync
 119	i386	sigreturn		sys_sigreturn			sys32_sigreturn
-120	i386	clone			sys_clone			compat_sys_x86_clone
-121	i386	setdomainname		sys_setdomainname
-122	i386	uname			sys_newuname
-123	i386	modify_ldt		sys_modify_ldt
-124	i386	adjtimex		sys_adjtimex			compat_sys_adjtimex
-125	i386	mprotect		sys_mprotect
-126	i386	sigprocmask		sys_sigprocmask			compat_sys_sigprocmask
+120	i386	clone			sys_clone			__compat_sys_ia32_x86_clone
+121	i386	setdomainname		sys_setdomainname		__sys_ia32_setdomainname
+122	i386	uname			sys_newuname			__sys_ia32_newuname
+123	i386	modify_ldt		sys_modify_ldt			__sys_ia32_modify_ldt
+124	i386	adjtimex		sys_adjtimex			__compat_sys_ia32_adjtimex
+125	i386	mprotect		sys_mprotect			__sys_ia32_mprotect
+126	i386	sigprocmask		sys_sigprocmask			__compat_sys_ia32_sigprocmask
 127	i386	create_module
-128	i386	init_module		sys_init_module
-129	i386	delete_module		sys_delete_module
+128	i386	init_module		sys_init_module			__sys_ia32_init_module
+129	i386	delete_module		sys_delete_module		__sys_ia32_delete_module
 130	i386	get_kernel_syms
-131	i386	quotactl		sys_quotactl			compat_sys_quotactl32
-132	i386	getpgid			sys_getpgid
-133	i386	fchdir			sys_fchdir
-134	i386	bdflush			sys_bdflush
-135	i386	sysfs			sys_sysfs
-136	i386	personality		sys_personality
+131	i386	quotactl		sys_quotactl			__compat_sys_ia32_quotactl32
+132	i386	getpgid			sys_getpgid			__sys_ia32_getpgid
+133	i386	fchdir			sys_fchdir			__sys_ia32_fchdir
+134	i386	bdflush			sys_bdflush			__sys_ia32_bdflush
+135	i386	sysfs			sys_sysfs			__sys_ia32_sysfs
+136	i386	personality		sys_personality			__sys_ia32_personality
 137	i386	afs_syscall
-138	i386	setfsuid		sys_setfsuid16
-139	i386	setfsgid		sys_setfsgid16
-140	i386	_llseek			sys_llseek
-141	i386	getdents		sys_getdents			compat_sys_getdents
-142	i386	_newselect		sys_select			compat_sys_select
-143	i386	flock			sys_flock
-144	i386	msync			sys_msync
-145	i386	readv			sys_readv			compat_sys_readv
-146	i386	writev			sys_writev			compat_sys_writev
-147	i386	getsid			sys_getsid
-148	i386	fdatasync		sys_fdatasync
-149	i386	_sysctl			sys_sysctl			compat_sys_sysctl
-150	i386	mlock			sys_mlock
-151	i386	munlock			sys_munlock
-152	i386	mlockall		sys_mlockall
+138	i386	setfsuid		sys_setfsuid16			__sys_ia32_setfsuid16
+139	i386	setfsgid		sys_setfsgid16			__sys_ia32_setfsgid16
+140	i386	_llseek			sys_llseek			__sys_ia32_llseek
+141	i386	getdents		sys_getdents			__compat_sys_ia32_getdents
+142	i386	_newselect		sys_select			__compat_sys_ia32_select
+143	i386	flock			sys_flock			__sys_ia32_flock
+144	i386	msync			sys_msync			__sys_ia32_msync
+145	i386	readv			sys_readv			__compat_sys_ia32_readv
+146	i386	writev			sys_writev			__compat_sys_ia32_writev
+147	i386	getsid			sys_getsid			__sys_ia32_getsid
+148	i386	fdatasync		sys_fdatasync			__sys_ia32_fdatasync
+149	i386	_sysctl			sys_sysctl			__compat_sys_ia32_sysctl
+150	i386	mlock			sys_mlock			__sys_ia32_mlock
+151	i386	munlock			sys_munlock			__sys_ia32_munlock
+152	i386	mlockall		sys_mlockall			__sys_ia32_mlockall
 153	i386	munlockall		sys_munlockall
-154	i386	sched_setparam		sys_sched_setparam
-155	i386	sched_getparam		sys_sched_getparam
-156	i386	sched_setscheduler	sys_sched_setscheduler
-157	i386	sched_getscheduler	sys_sched_getscheduler
+154	i386	sched_setparam		sys_sched_setparam		__sys_ia32_sched_setparam
+155	i386	sched_getparam		sys_sched_getparam		__sys_ia32_sched_getparam
+156	i386	sched_setscheduler	sys_sched_setscheduler		__sys_ia32_sched_setscheduler
+157	i386	sched_getscheduler	sys_sched_getscheduler		__sys_ia32_sched_getscheduler
 158	i386	sched_yield		sys_sched_yield
-159	i386	sched_get_priority_max	sys_sched_get_priority_max
-160	i386	sched_get_priority_min	sys_sched_get_priority_min
-161	i386	sched_rr_get_interval	sys_sched_rr_get_interval	compat_sys_sched_rr_get_interval
-162	i386	nanosleep		sys_nanosleep			compat_sys_nanosleep
-163	i386	mremap			sys_mremap
-164	i386	setresuid		sys_setresuid16
-165	i386	getresuid		sys_getresuid16
+159	i386	sched_get_priority_max	sys_sched_get_priority_max	__sys_ia32_sched_get_priority_max
+160	i386	sched_get_priority_min	sys_sched_get_priority_min	__sys_ia32_sched_get_priority_min
+161	i386	sched_rr_get_interval	sys_sched_rr_get_interval	__compat_sys_ia32_sched_rr_get_interval
+162	i386	nanosleep		sys_nanosleep			__compat_sys_ia32_nanosleep
+163	i386	mremap			sys_mremap			__sys_ia32_mremap
+164	i386	setresuid		sys_setresuid16			__sys_ia32_setresuid16
+165	i386	getresuid		sys_getresuid16			__sys_ia32_getresuid16
 166	i386	vm86			sys_vm86			sys_ni_syscall
 167	i386	query_module
-168	i386	poll			sys_poll
+168	i386	poll			sys_poll			__sys_ia32_poll
 169	i386	nfsservctl
-170	i386	setresgid		sys_setresgid16
-171	i386	getresgid		sys_getresgid16
-172	i386	prctl			sys_prctl
+170	i386	setresgid		sys_setresgid16			__sys_ia32_setresgid16
+171	i386	getresgid		sys_getresgid16			__sys_ia32_getresgid16
+172	i386	prctl			sys_prctl			__sys_ia32_prctl
 173	i386	rt_sigreturn		sys_rt_sigreturn		sys32_rt_sigreturn
-174	i386	rt_sigaction		sys_rt_sigaction		compat_sys_rt_sigaction
-175	i386	rt_sigprocmask		sys_rt_sigprocmask
-176	i386	rt_sigpending		sys_rt_sigpending		compat_sys_rt_sigpending
-177	i386	rt_sigtimedwait		sys_rt_sigtimedwait		compat_sys_rt_sigtimedwait
-178	i386	rt_sigqueueinfo		sys_rt_sigqueueinfo		compat_sys_rt_sigqueueinfo
-179	i386	rt_sigsuspend		sys_rt_sigsuspend
-180	i386	pread64			sys_pread64			compat_sys_x86_pread
-181	i386	pwrite64		sys_pwrite64			compat_sys_x86_pwrite
-182	i386	chown			sys_chown16
-183	i386	getcwd			sys_getcwd
-184	i386	capget			sys_capget
-185	i386	capset			sys_capset
-186	i386	sigaltstack		sys_sigaltstack			compat_sys_sigaltstack
-187	i386	sendfile		sys_sendfile			compat_sys_sendfile
+174	i386	rt_sigaction		sys_rt_sigaction		__compat_sys_ia32_rt_sigaction
+175	i386	rt_sigprocmask		sys_rt_sigprocmask		__sys_ia32_rt_sigprocmask
+176	i386	rt_sigpending		sys_rt_sigpending		__compat_sys_ia32_rt_sigpending
+177	i386	rt_sigtimedwait		sys_rt_sigtimedwait		__compat_sys_ia32_rt_sigtimedwait
+178	i386	rt_sigqueueinfo		sys_rt_sigqueueinfo		__compat_sys_ia32_rt_sigqueueinfo
+179	i386	rt_sigsuspend		sys_rt_sigsuspend		__sys_ia32_rt_sigsuspend
+180	i386	pread64			sys_pread64			__compat_sys_ia32_x86_pread
+181	i386	pwrite64		sys_pwrite64			__compat_sys_ia32_x86_pwrite
+182	i386	chown			sys_chown16			__sys_ia32_chown16
+183	i386	getcwd			sys_getcwd			__sys_ia32_getcwd
+184	i386	capget			sys_capget			__sys_ia32_capget
+185	i386	capset			sys_capset			__sys_ia32_capset
+186	i386	sigaltstack		sys_sigaltstack			__compat_sys_ia32_sigaltstack
+187	i386	sendfile		sys_sendfile			__compat_sys_ia32_sendfile
 188	i386	getpmsg
 189	i386	putpmsg
 190	i386	vfork			sys_vfork
-191	i386	ugetrlimit		sys_getrlimit			compat_sys_getrlimit
-192	i386	mmap2			sys_mmap_pgoff
-193	i386	truncate64		sys_truncate64			compat_sys_x86_truncate64
-194	i386	ftruncate64		sys_ftruncate64			compat_sys_x86_ftruncate64
-195	i386	stat64			sys_stat64			compat_sys_x86_stat64
-196	i386	lstat64			sys_lstat64			compat_sys_x86_lstat64
-197	i386	fstat64			sys_fstat64			compat_sys_x86_fstat64
-198	i386	lchown32		sys_lchown
+191	i386	ugetrlimit		sys_getrlimit			__compat_sys_ia32_getrlimit
+192	i386	mmap2			sys_mmap_pgoff			__sys_ia32_mmap_pgoff
+193	i386	truncate64		sys_truncate64			__compat_sys_ia32_x86_truncate64
+194	i386	ftruncate64		sys_ftruncate64			__compat_sys_ia32_x86_ftruncate64
+195	i386	stat64			sys_stat64			__compat_sys_ia32_x86_stat64
+196	i386	lstat64			sys_lstat64			__compat_sys_ia32_x86_lstat64
+197	i386	fstat64			sys_fstat64			__compat_sys_ia32_x86_fstat64
+198	i386	lchown32		sys_lchown			__sys_ia32_lchown
 199	i386	getuid32		sys_getuid
 200	i386	getgid32		sys_getgid
 201	i386	geteuid32		sys_geteuid
 202	i386	getegid32		sys_getegid
-203	i386	setreuid32		sys_setreuid
-204	i386	setregid32		sys_setregid
-205	i386	getgroups32		sys_getgroups
-206	i386	setgroups32		sys_setgroups
-207	i386	fchown32		sys_fchown
-208	i386	setresuid32		sys_setresuid
-209	i386	getresuid32		sys_getresuid
-210	i386	setresgid32		sys_setresgid
-211	i386	getresgid32		sys_getresgid
-212	i386	chown32			sys_chown
-213	i386	setuid32		sys_setuid
-214	i386	setgid32		sys_setgid
-215	i386	setfsuid32		sys_setfsuid
-216	i386	setfsgid32		sys_setfsgid
-217	i386	pivot_root		sys_pivot_root
-218	i386	mincore			sys_mincore
-219	i386	madvise			sys_madvise
-220	i386	getdents64		sys_getdents64
-221	i386	fcntl64			sys_fcntl64			compat_sys_fcntl64
+203	i386	setreuid32		sys_setreuid			__sys_ia32_setreuid
+204	i386	setregid32		sys_setregid			__sys_ia32_setregid
+205	i386	getgroups32		sys_getgroups			__sys_ia32_getgroups
+206	i386	setgroups32		sys_setgroups			__sys_ia32_setgroups
+207	i386	fchown32		sys_fchown			__sys_ia32_fchown
+208	i386	setresuid32		sys_setresuid			__sys_ia32_setresuid
+209	i386	getresuid32		sys_getresuid			__sys_ia32_getresuid
+210	i386	setresgid32		sys_setresgid			__sys_ia32_setresgid
+211	i386	getresgid32		sys_getresgid			__sys_ia32_getresgid
+212	i386	chown32			sys_chown			__sys_ia32_chown
+213	i386	setuid32		sys_setuid			__sys_ia32_setuid
+214	i386	setgid32		sys_setgid			__sys_ia32_setgid
+215	i386	setfsuid32		sys_setfsuid			__sys_ia32_setfsuid
+216	i386	setfsgid32		sys_setfsgid			__sys_ia32_setfsgid
+217	i386	pivot_root		sys_pivot_root			__sys_ia32_pivot_root
+218	i386	mincore			sys_mincore			__sys_ia32_mincore
+219	i386	madvise			sys_madvise			__sys_ia32_madvise
+220	i386	getdents64		sys_getdents64			__sys_ia32_getdents64
+221	i386	fcntl64			sys_fcntl64			__compat_sys_ia32_fcntl64
 # 222 is unused
 # 223 is unused
 224	i386	gettid			sys_gettid
-225	i386	readahead		sys_readahead			compat_sys_x86_readahead
-226	i386	setxattr		sys_setxattr
-227	i386	lsetxattr		sys_lsetxattr
-228	i386	fsetxattr		sys_fsetxattr
-229	i386	getxattr		sys_getxattr
-230	i386	lgetxattr		sys_lgetxattr
-231	i386	fgetxattr		sys_fgetxattr
-232	i386	listxattr		sys_listxattr
-233	i386	llistxattr		sys_llistxattr
-234	i386	flistxattr		sys_flistxattr
-235	i386	removexattr		sys_removexattr
-236	i386	lremovexattr		sys_lremovexattr
-237	i386	fremovexattr		sys_fremovexattr
-238	i386	tkill			sys_tkill
-239	i386	sendfile64		sys_sendfile64
-240	i386	futex			sys_futex			compat_sys_futex
-241	i386	sched_setaffinity	sys_sched_setaffinity		compat_sys_sched_setaffinity
-242	i386	sched_getaffinity	sys_sched_getaffinity		compat_sys_sched_getaffinity
-243	i386	set_thread_area		sys_set_thread_area
-244	i386	get_thread_area		sys_get_thread_area
-245	i386	io_setup		sys_io_setup			compat_sys_io_setup
-246	i386	io_destroy		sys_io_destroy
-247	i386	io_getevents		sys_io_getevents		compat_sys_io_getevents
-248	i386	io_submit		sys_io_submit			compat_sys_io_submit
-249	i386	io_cancel		sys_io_cancel
-250	i386	fadvise64		sys_fadvise64			compat_sys_x86_fadvise64
+225	i386	readahead		sys_readahead			__compat_sys_ia32_x86_readahead
+226	i386	setxattr		sys_setxattr			__sys_ia32_setxattr
+227	i386	lsetxattr		sys_lsetxattr			__sys_ia32_lsetxattr
+228	i386	fsetxattr		sys_fsetxattr			__sys_ia32_fsetxattr
+229	i386	getxattr		sys_getxattr			__sys_ia32_getxattr
+230	i386	lgetxattr		sys_lgetxattr			__sys_ia32_lgetxattr
+231	i386	fgetxattr		sys_fgetxattr			__sys_ia32_fgetxattr
+232	i386	listxattr		sys_listxattr			__sys_ia32_listxattr
+233	i386	llistxattr		sys_llistxattr			__sys_ia32_llistxattr
+234	i386	flistxattr		sys_flistxattr			__sys_ia32_flistxattr
+235	i386	removexattr		sys_removexattr			__sys_ia32_removexattr
+236	i386	lremovexattr		sys_lremovexattr		__sys_ia32_lremovexattr
+237	i386	fremovexattr		sys_fremovexattr		__sys_ia32_fremovexattr
+238	i386	tkill			sys_tkill			__sys_ia32_tkill
+239	i386	sendfile64		sys_sendfile64			__sys_ia32_sendfile64
+240	i386	futex			sys_futex			__compat_sys_ia32_futex
+241	i386	sched_setaffinity	sys_sched_setaffinity		__compat_sys_ia32_sched_setaffinity
+242	i386	sched_getaffinity	sys_sched_getaffinity		__compat_sys_ia32_sched_getaffinity
+243	i386	set_thread_area		sys_set_thread_area		__sys_ia32_set_thread_area
+244	i386	get_thread_area		sys_get_thread_area		__sys_ia32_get_thread_area
+245	i386	io_setup		sys_io_setup			__compat_sys_ia32_io_setup
+246	i386	io_destroy		sys_io_destroy			__sys_ia32_io_destroy
+247	i386	io_getevents		sys_io_getevents		__compat_sys_ia32_io_getevents
+248	i386	io_submit		sys_io_submit			__compat_sys_ia32_io_submit
+249	i386	io_cancel		sys_io_cancel			__sys_ia32_io_cancel
+250	i386	fadvise64		sys_fadvise64			__compat_sys_ia32_x86_fadvise64
 # 251 is available for reuse (was briefly sys_set_zone_reclaim)
-252	i386	exit_group		sys_exit_group
-253	i386	lookup_dcookie		sys_lookup_dcookie		compat_sys_lookup_dcookie
-254	i386	epoll_create		sys_epoll_create
-255	i386	epoll_ctl		sys_epoll_ctl
-256	i386	epoll_wait		sys_epoll_wait
-257	i386	remap_file_pages	sys_remap_file_pages
-258	i386	set_tid_address		sys_set_tid_address
-259	i386	timer_create		sys_timer_create		compat_sys_timer_create
-260	i386	timer_settime		sys_timer_settime		compat_sys_timer_settime
-261	i386	timer_gettime		sys_timer_gettime		compat_sys_timer_gettime
-262	i386	timer_getoverrun	sys_timer_getoverrun
-263	i386	timer_delete		sys_timer_delete
-264	i386	clock_settime		sys_clock_settime		compat_sys_clock_settime
-265	i386	clock_gettime		sys_clock_gettime		compat_sys_clock_gettime
-266	i386	clock_getres		sys_clock_getres		compat_sys_clock_getres
-267	i386	clock_nanosleep		sys_clock_nanosleep		compat_sys_clock_nanosleep
-268	i386	statfs64		sys_statfs64			compat_sys_statfs64
-269	i386	fstatfs64		sys_fstatfs64			compat_sys_fstatfs64
-270	i386	tgkill			sys_tgkill
-271	i386	utimes			sys_utimes			compat_sys_utimes
-272	i386	fadvise64_64		sys_fadvise64_64		compat_sys_x86_fadvise64_64
+252	i386	exit_group		sys_exit_group			__sys_ia32_exit_group
+253	i386	lookup_dcookie		sys_lookup_dcookie		__compat_sys_ia32_lookup_dcookie
+254	i386	epoll_create		sys_epoll_create		__sys_ia32_epoll_create
+255	i386	epoll_ctl		sys_epoll_ctl			__sys_ia32_epoll_ctl
+256	i386	epoll_wait		sys_epoll_wait			__sys_ia32_epoll_wait
+257	i386	remap_file_pages	sys_remap_file_pages		__sys_ia32_remap_file_pages
+258	i386	set_tid_address		sys_set_tid_address		__sys_ia32_set_tid_address
+259	i386	timer_create		sys_timer_create		__compat_sys_ia32_timer_create
+260	i386	timer_settime		sys_timer_settime		__compat_sys_ia32_timer_settime
+261	i386	timer_gettime		sys_timer_gettime		__compat_sys_ia32_timer_gettime
+262	i386	timer_getoverrun	sys_timer_getoverrun		__sys_ia32_timer_getoverrun
+263	i386	timer_delete		sys_timer_delete		__sys_ia32_timer_delete
+264	i386	clock_settime		sys_clock_settime		__compat_sys_ia32_clock_settime
+265	i386	clock_gettime		sys_clock_gettime		__compat_sys_ia32_clock_gettime
+266	i386	clock_getres		sys_clock_getres		__compat_sys_ia32_clock_getres
+267	i386	clock_nanosleep		sys_clock_nanosleep		__compat_sys_ia32_clock_nanosleep
+268	i386	statfs64		sys_statfs64			__compat_sys_ia32_statfs64
+269	i386	fstatfs64		sys_fstatfs64			__compat_sys_ia32_fstatfs64
+270	i386	tgkill			sys_tgkill			__sys_ia32_tgkill
+271	i386	utimes			sys_utimes			__compat_sys_ia32_utimes
+272	i386	fadvise64_64		sys_fadvise64_64		__compat_sys_ia32_x86_fadvise64_64
 273	i386	vserver
-274	i386	mbind			sys_mbind
-275	i386	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
-276	i386	set_mempolicy		sys_set_mempolicy
-277	i386	mq_open			sys_mq_open			compat_sys_mq_open
-278	i386	mq_unlink		sys_mq_unlink
-279	i386	mq_timedsend		sys_mq_timedsend		compat_sys_mq_timedsend
-280	i386	mq_timedreceive		sys_mq_timedreceive		compat_sys_mq_timedreceive
-281	i386	mq_notify		sys_mq_notify			compat_sys_mq_notify
-282	i386	mq_getsetattr		sys_mq_getsetattr		compat_sys_mq_getsetattr
-283	i386	kexec_load		sys_kexec_load			compat_sys_kexec_load
-284	i386	waitid			sys_waitid			compat_sys_waitid
+274	i386	mbind			sys_mbind			__sys_ia32_mbind
+275	i386	get_mempolicy		sys_get_mempolicy		__compat_sys_ia32_get_mempolicy
+276	i386	set_mempolicy		sys_set_mempolicy		__sys_ia32_set_mempolicy
+277	i386	mq_open			sys_mq_open			__compat_sys_ia32_mq_open
+278	i386	mq_unlink		sys_mq_unlink			__sys_ia32_mq_unlink
+279	i386	mq_timedsend		sys_mq_timedsend		__compat_sys_ia32_mq_timedsend
+280	i386	mq_timedreceive		sys_mq_timedreceive		__compat_sys_ia32_mq_timedreceive
+281	i386	mq_notify		sys_mq_notify			__compat_sys_ia32_mq_notify
+282	i386	mq_getsetattr		sys_mq_getsetattr		__compat_sys_ia32_mq_getsetattr
+283	i386	kexec_load		sys_kexec_load			__compat_sys_ia32_kexec_load
+284	i386	waitid			sys_waitid			__compat_sys_ia32_waitid
 # 285 sys_setaltroot
-286	i386	add_key			sys_add_key
-287	i386	request_key		sys_request_key
-288	i386	keyctl			sys_keyctl			compat_sys_keyctl
-289	i386	ioprio_set		sys_ioprio_set
-290	i386	ioprio_get		sys_ioprio_get
+286	i386	add_key			sys_add_key			__sys_ia32_add_key
+287	i386	request_key		sys_request_key			__sys_ia32_request_key
+288	i386	keyctl			sys_keyctl			__compat_sys_ia32_keyctl
+289	i386	ioprio_set		sys_ioprio_set			__sys_ia32_ioprio_set
+290	i386	ioprio_get		sys_ioprio_get			__sys_ia32_ioprio_get
 291	i386	inotify_init		sys_inotify_init
-292	i386	inotify_add_watch	sys_inotify_add_watch
-293	i386	inotify_rm_watch	sys_inotify_rm_watch
-294	i386	migrate_pages		sys_migrate_pages
-295	i386	openat			sys_openat			compat_sys_openat
-296	i386	mkdirat			sys_mkdirat
-297	i386	mknodat			sys_mknodat
-298	i386	fchownat		sys_fchownat
-299	i386	futimesat		sys_futimesat			compat_sys_futimesat
-300	i386	fstatat64		sys_fstatat64			compat_sys_x86_fstatat
-301	i386	unlinkat		sys_unlinkat
-302	i386	renameat		sys_renameat
-303	i386	linkat			sys_linkat
-304	i386	symlinkat		sys_symlinkat
-305	i386	readlinkat		sys_readlinkat
-306	i386	fchmodat		sys_fchmodat
-307	i386	faccessat		sys_faccessat
-308	i386	pselect6		sys_pselect6			compat_sys_pselect6
-309	i386	ppoll			sys_ppoll			compat_sys_ppoll
-310	i386	unshare			sys_unshare
-311	i386	set_robust_list		sys_set_robust_list		compat_sys_set_robust_list
-312	i386	get_robust_list		sys_get_robust_list		compat_sys_get_robust_list
-313	i386	splice			sys_splice
-314	i386	sync_file_range		sys_sync_file_range		compat_sys_x86_sync_file_range
-315	i386	tee			sys_tee
-316	i386	vmsplice		sys_vmsplice			compat_sys_vmsplice
-317	i386	move_pages		sys_move_pages			compat_sys_move_pages
-318	i386	getcpu			sys_getcpu
-319	i386	epoll_pwait		sys_epoll_pwait
-320	i386	utimensat		sys_utimensat			compat_sys_utimensat
-321	i386	signalfd		sys_signalfd			compat_sys_signalfd
-322	i386	timerfd_create		sys_timerfd_create
-323	i386	eventfd			sys_eventfd
-324	i386	fallocate		sys_fallocate			compat_sys_x86_fallocate
-325	i386	timerfd_settime		sys_timerfd_settime		compat_sys_timerfd_settime
-326	i386	timerfd_gettime		sys_timerfd_gettime		compat_sys_timerfd_gettime
-327	i386	signalfd4		sys_signalfd4			compat_sys_signalfd4
-328	i386	eventfd2		sys_eventfd2
-329	i386	epoll_create1		sys_epoll_create1
-330	i386	dup3			sys_dup3
-331	i386	pipe2			sys_pipe2
-332	i386	inotify_init1		sys_inotify_init1
-333	i386	preadv			sys_preadv			compat_sys_preadv
-334	i386	pwritev			sys_pwritev			compat_sys_pwritev
-335	i386	rt_tgsigqueueinfo	sys_rt_tgsigqueueinfo		compat_sys_rt_tgsigqueueinfo
-336	i386	perf_event_open		sys_perf_event_open
-337	i386	recvmmsg		sys_recvmmsg			compat_sys_recvmmsg
-338	i386	fanotify_init		sys_fanotify_init
-339	i386	fanotify_mark		sys_fanotify_mark		compat_sys_fanotify_mark
-340	i386	prlimit64		sys_prlimit64
-341	i386	name_to_handle_at	sys_name_to_handle_at
-342	i386	open_by_handle_at	sys_open_by_handle_at		compat_sys_open_by_handle_at
-343	i386	clock_adjtime		sys_clock_adjtime		compat_sys_clock_adjtime
-344	i386	syncfs			sys_syncfs
-345	i386	sendmmsg		sys_sendmmsg			compat_sys_sendmmsg
-346	i386	setns			sys_setns
-347	i386	process_vm_readv	sys_process_vm_readv		compat_sys_process_vm_readv
-348	i386	process_vm_writev	sys_process_vm_writev		compat_sys_process_vm_writev
-349	i386	kcmp			sys_kcmp
-350	i386	finit_module		sys_finit_module
-351	i386	sched_setattr		sys_sched_setattr
-352	i386	sched_getattr		sys_sched_getattr
-353	i386	renameat2		sys_renameat2
-354	i386	seccomp			sys_seccomp
-355	i386	getrandom		sys_getrandom
-356	i386	memfd_create		sys_memfd_create
-357	i386	bpf			sys_bpf
-358	i386	execveat		sys_execveat			compat_sys_execveat
-359	i386	socket			sys_socket
-360	i386	socketpair		sys_socketpair
-361	i386	bind			sys_bind
-362	i386	connect			sys_connect
-363	i386	listen			sys_listen
-364	i386	accept4			sys_accept4
-365	i386	getsockopt		sys_getsockopt			compat_sys_getsockopt
-366	i386	setsockopt		sys_setsockopt			compat_sys_setsockopt
-367	i386	getsockname		sys_getsockname
-368	i386	getpeername		sys_getpeername
-369	i386	sendto			sys_sendto
-370	i386	sendmsg			sys_sendmsg			compat_sys_sendmsg
-371	i386	recvfrom		sys_recvfrom			compat_sys_recvfrom
-372	i386	recvmsg			sys_recvmsg			compat_sys_recvmsg
-373	i386	shutdown		sys_shutdown
-374	i386	userfaultfd		sys_userfaultfd
-375	i386	membarrier		sys_membarrier
-376	i386	mlock2			sys_mlock2
-377	i386	copy_file_range		sys_copy_file_range
-378	i386	preadv2			sys_preadv2			compat_sys_preadv2
-379	i386	pwritev2		sys_pwritev2			compat_sys_pwritev2
-380	i386	pkey_mprotect		sys_pkey_mprotect
-381	i386	pkey_alloc		sys_pkey_alloc
-382	i386	pkey_free		sys_pkey_free
-383	i386	statx			sys_statx
-384	i386	arch_prctl		sys_arch_prctl			compat_sys_arch_prctl
+292	i386	inotify_add_watch	sys_inotify_add_watch		__sys_ia32_inotify_add_watch
+293	i386	inotify_rm_watch	sys_inotify_rm_watch		__sys_ia32_inotify_rm_watch
+294	i386	migrate_pages		sys_migrate_pages		__sys_ia32_migrate_pages
+295	i386	openat			sys_openat			__compat_sys_ia32_openat
+296	i386	mkdirat			sys_mkdirat			__sys_ia32_mkdirat
+297	i386	mknodat			sys_mknodat			__sys_ia32_mknodat
+298	i386	fchownat		sys_fchownat			__sys_ia32_fchownat
+299	i386	futimesat		sys_futimesat			__compat_sys_ia32_futimesat
+300	i386	fstatat64		sys_fstatat64			__compat_sys_ia32_x86_fstatat
+301	i386	unlinkat		sys_unlinkat			__sys_ia32_unlinkat
+302	i386	renameat		sys_renameat			__sys_ia32_renameat
+303	i386	linkat			sys_linkat			__sys_ia32_linkat
+304	i386	symlinkat		sys_symlinkat			__sys_ia32_symlinkat
+305	i386	readlinkat		sys_readlinkat			__sys_ia32_readlinkat
+306	i386	fchmodat		sys_fchmodat			__sys_ia32_fchmodat
+307	i386	faccessat		sys_faccessat			__sys_ia32_faccessat
+308	i386	pselect6		sys_pselect6			__compat_sys_ia32_pselect6
+309	i386	ppoll			sys_ppoll			__compat_sys_ia32_ppoll
+310	i386	unshare			sys_unshare			__sys_ia32_unshare
+311	i386	set_robust_list		sys_set_robust_list		__compat_sys_ia32_set_robust_list
+312	i386	get_robust_list		sys_get_robust_list		__compat_sys_ia32_get_robust_list
+313	i386	splice			sys_splice			__sys_ia32_splice
+314	i386	sync_file_range		sys_sync_file_range		__compat_sys_ia32_x86_sync_file_range
+315	i386	tee			sys_tee				__sys_ia32_tee
+316	i386	vmsplice		sys_vmsplice			__compat_sys_ia32_vmsplice
+317	i386	move_pages		sys_move_pages			__compat_sys_ia32_move_pages
+318	i386	getcpu			sys_getcpu			__sys_ia32_getcpu
+319	i386	epoll_pwait		sys_epoll_pwait			__sys_ia32_epoll_pwait
+320	i386	utimensat		sys_utimensat			__compat_sys_ia32_utimensat
+321	i386	signalfd		sys_signalfd			__compat_sys_ia32_signalfd
+322	i386	timerfd_create		sys_timerfd_create		__sys_ia32_timerfd_create
+323	i386	eventfd			sys_eventfd			__sys_ia32_eventfd
+324	i386	fallocate		sys_fallocate			__compat_sys_ia32_x86_fallocate
+325	i386	timerfd_settime		sys_timerfd_settime		__compat_sys_ia32_timerfd_settime
+326	i386	timerfd_gettime		sys_timerfd_gettime		__compat_sys_ia32_timerfd_gettime
+327	i386	signalfd4		sys_signalfd4			__compat_sys_ia32_signalfd4
+328	i386	eventfd2		sys_eventfd2			__sys_ia32_eventfd2
+329	i386	epoll_create1		sys_epoll_create1		__sys_ia32_epoll_create1
+330	i386	dup3			sys_dup3			__sys_ia32_dup3
+331	i386	pipe2			sys_pipe2			__sys_ia32_pipe2
+332	i386	inotify_init1		sys_inotify_init1		__sys_ia32_inotify_init1
+333	i386	preadv			sys_preadv			__compat_sys_ia32_preadv
+334	i386	pwritev			sys_pwritev			__compat_sys_ia32_pwritev
+335	i386	rt_tgsigqueueinfo	sys_rt_tgsigqueueinfo		__compat_sys_ia32_rt_tgsigqueueinfo
+336	i386	perf_event_open		sys_perf_event_open		__sys_ia32_perf_event_open
+337	i386	recvmmsg		sys_recvmmsg			__compat_sys_ia32_recvmmsg
+338	i386	fanotify_init		sys_fanotify_init		__sys_ia32_fanotify_init
+339	i386	fanotify_mark		sys_fanotify_mark		__compat_sys_ia32_fanotify_mark
+340	i386	prlimit64		sys_prlimit64			__sys_ia32_prlimit64
+341	i386	name_to_handle_at	sys_name_to_handle_at		__sys_ia32_name_to_handle_at
+342	i386	open_by_handle_at	sys_open_by_handle_at		__compat_sys_ia32_open_by_handle_at
+343	i386	clock_adjtime		sys_clock_adjtime		__compat_sys_ia32_clock_adjtime
+344	i386	syncfs			sys_syncfs			__sys_ia32_syncfs
+345	i386	sendmmsg		sys_sendmmsg			__compat_sys_ia32_sendmmsg
+346	i386	setns			sys_setns			__sys_ia32_setns
+347	i386	process_vm_readv	sys_process_vm_readv		__compat_sys_ia32_process_vm_readv
+348	i386	process_vm_writev	sys_process_vm_writev		__compat_sys_ia32_process_vm_writev
+349	i386	kcmp			sys_kcmp			__sys_ia32_kcmp
+350	i386	finit_module		sys_finit_module		__sys_ia32_finit_module
+351	i386	sched_setattr		sys_sched_setattr		__sys_ia32_sched_setattr
+352	i386	sched_getattr		sys_sched_getattr		__sys_ia32_sched_getattr
+353	i386	renameat2		sys_renameat2			__sys_ia32_renameat2
+354	i386	seccomp			sys_seccomp			__sys_ia32_seccomp
+355	i386	getrandom		sys_getrandom			__sys_ia32_getrandom
+356	i386	memfd_create		sys_memfd_create		__sys_ia32_memfd_create
+357	i386	bpf			sys_bpf				__sys_ia32_bpf
+358	i386	execveat		sys_execveat			__compat_sys_ia32_execveat
+359	i386	socket			sys_socket			__sys_ia32_socket
+360	i386	socketpair		sys_socketpair			__sys_ia32_socketpair
+361	i386	bind			sys_bind			__sys_ia32_bind
+362	i386	connect			sys_connect			__sys_ia32_connect
+363	i386	listen			sys_listen			__sys_ia32_listen
+364	i386	accept4			sys_accept4			__sys_ia32_accept4
+365	i386	getsockopt		sys_getsockopt			__compat_sys_ia32_getsockopt
+366	i386	setsockopt		sys_setsockopt			__compat_sys_ia32_setsockopt
+367	i386	getsockname		sys_getsockname			__sys_ia32_getsockname
+368	i386	getpeername		sys_getpeername			__sys_ia32_getpeername
+369	i386	sendto			sys_sendto			__sys_ia32_sendto
+370	i386	sendmsg			sys_sendmsg			__compat_sys_ia32_sendmsg
+371	i386	recvfrom		sys_recvfrom			__compat_sys_ia32_recvfrom
+372	i386	recvmsg			sys_recvmsg			__compat_sys_ia32_recvmsg
+373	i386	shutdown		sys_shutdown			__sys_ia32_shutdown
+374	i386	userfaultfd		sys_userfaultfd			__sys_ia32_userfaultfd
+375	i386	membarrier		sys_membarrier			__sys_ia32_membarrier
+376	i386	mlock2			sys_mlock2			__sys_ia32_mlock2
+377	i386	copy_file_range		sys_copy_file_range		__sys_ia32_copy_file_range
+378	i386	preadv2			sys_preadv2			__compat_sys_ia32_preadv2
+379	i386	pwritev2		sys_pwritev2			__compat_sys_ia32_pwritev2
+380	i386	pkey_mprotect		sys_pkey_mprotect		__sys_ia32_pkey_mprotect
+381	i386	pkey_alloc		sys_pkey_alloc			__sys_ia32_pkey_alloc
+382	i386	pkey_free		sys_pkey_free			__sys_ia32_pkey_free
+383	i386	statx			sys_statx			__sys_ia32_statx
+384	i386	arch_prctl		sys_arch_prctl			__compat_sys_ia32_arch_prctl
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 5aef183e2f85..a83c0f7f462f 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -342,41 +342,43 @@
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
-# for native 64-bit operation.
+# for native 64-bit operation. The __compat_sys_x32 stubs are created
+# on-the-fly for compat_sys_*() compatibility system calls if X86_X32
+# is defined.
 #
-512	x32	rt_sigaction		compat_sys_rt_sigaction
+512	x32	rt_sigaction		__compat_sys_x32_rt_sigaction
 513	x32	rt_sigreturn		sys32_x32_rt_sigreturn
-514	x32	ioctl			compat_sys_ioctl
-515	x32	readv			compat_sys_readv
-516	x32	writev			compat_sys_writev
-517	x32	recvfrom		compat_sys_recvfrom
-518	x32	sendmsg			compat_sys_sendmsg
-519	x32	recvmsg			compat_sys_recvmsg
-520	x32	execve			compat_sys_execve/ptregs
-521	x32	ptrace			compat_sys_ptrace
-522	x32	rt_sigpending		compat_sys_rt_sigpending
-523	x32	rt_sigtimedwait		compat_sys_rt_sigtimedwait
-524	x32	rt_sigqueueinfo		compat_sys_rt_sigqueueinfo
-525	x32	sigaltstack		compat_sys_sigaltstack
-526	x32	timer_create		compat_sys_timer_create
-527	x32	mq_notify		compat_sys_mq_notify
-528	x32	kexec_load		compat_sys_kexec_load
-529	x32	waitid			compat_sys_waitid
-530	x32	set_robust_list		compat_sys_set_robust_list
-531	x32	get_robust_list		compat_sys_get_robust_list
-532	x32	vmsplice		compat_sys_vmsplice
-533	x32	move_pages		compat_sys_move_pages
-534	x32	preadv			compat_sys_preadv64
-535	x32	pwritev			compat_sys_pwritev64
-536	x32	rt_tgsigqueueinfo	compat_sys_rt_tgsigqueueinfo
-537	x32	recvmmsg		compat_sys_recvmmsg
-538	x32	sendmmsg		compat_sys_sendmmsg
-539	x32	process_vm_readv	compat_sys_process_vm_readv
-540	x32	process_vm_writev	compat_sys_process_vm_writev
-541	x32	setsockopt		compat_sys_setsockopt
-542	x32	getsockopt		compat_sys_getsockopt
-543	x32	io_setup		compat_sys_io_setup
-544	x32	io_submit		compat_sys_io_submit
-545	x32	execveat		compat_sys_execveat/ptregs
-546	x32	preadv2			compat_sys_preadv64v2
-547	x32	pwritev2		compat_sys_pwritev64v2
+514	x32	ioctl			__compat_sys_x32_ioctl
+515	x32	readv			__compat_sys_x32_readv
+516	x32	writev			__compat_sys_x32_writev
+517	x32	recvfrom		__compat_sys_x32_recvfrom
+518	x32	sendmsg			__compat_sys_x32_sendmsg
+519	x32	recvmsg			__compat_sys_x32_recvmsg
+520	x32	execve			__compat_sys_x32_execve/ptregs
+521	x32	ptrace			__compat_sys_x32_ptrace
+522	x32	rt_sigpending		__compat_sys_x32_rt_sigpending
+523	x32	rt_sigtimedwait		__compat_sys_x32_rt_sigtimedwait
+524	x32	rt_sigqueueinfo		__compat_sys_x32_rt_sigqueueinfo
+525	x32	sigaltstack		__compat_sys_x32_sigaltstack
+526	x32	timer_create		__compat_sys_x32_timer_create
+527	x32	mq_notify		__compat_sys_x32_mq_notify
+528	x32	kexec_load		__compat_sys_x32_kexec_load
+529	x32	waitid			__compat_sys_x32_waitid
+530	x32	set_robust_list		__compat_sys_x32_set_robust_list
+531	x32	get_robust_list		__compat_sys_x32_get_robust_list
+532	x32	vmsplice		__compat_sys_x32_vmsplice
+533	x32	move_pages		__compat_sys_x32_move_pages
+534	x32	preadv			__compat_sys_x32_preadv64
+535	x32	pwritev			__compat_sys_x32_pwritev64
+536	x32	rt_tgsigqueueinfo	__compat_sys_x32_rt_tgsigqueueinfo
+537	x32	recvmmsg		__compat_sys_x32_recvmmsg
+538	x32	sendmmsg		__compat_sys_x32_sendmmsg
+539	x32	process_vm_readv	__compat_sys_x32_process_vm_readv
+540	x32	process_vm_writev	__compat_sys_x32_process_vm_writev
+541	x32	setsockopt		__compat_sys_x32_setsockopt
+542	x32	getsockopt		__compat_sys_x32_getsockopt
+543	x32	io_setup		__compat_sys_x32_io_setup
+544	x32	io_submit		__compat_sys_x32_io_submit
+545	x32	execveat		__compat_sys_x32_execveat/ptregs
+546	x32	preadv2			__compat_sys_x32_preadv64v2
+547	x32	pwritev2		__compat_sys_x32_pwritev64v2
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index 702bdee377af..49d7e4970110 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -6,6 +6,111 @@
 #ifndef _ASM_X86_SYSCALL_WRAPPER_H
 #define _ASM_X86_SYSCALL_WRAPPER_H
 
+/* Mapping of registers to parameters for syscalls on x86-64 and x32 */
+#define SC_X86_64_REGS_TO_ARGS(x, ...)					\
+	__MAP(x,__SC_ARGS						\
+		,,regs->di,,regs->si,,regs->dx				\
+		,,regs->r10,,regs->r8,,regs->r9)			\
+
+/* Mapping of registers to parameters for syscalls on i386 */
+#define SC_IA32_REGS_TO_ARGS(x, ...)					\
+	__MAP(x,__SC_ARGS						\
+	      ,,(unsigned int)regs->bx,,(unsigned int)regs->cx		\
+	      ,,(unsigned int)regs->dx,,(unsigned int)regs->si		\
+	      ,,(unsigned int)regs->di,,(unsigned int)regs->bp)
+
+#ifdef CONFIG_IA32_EMULATION
+/*
+ * For IA32 emulation, we need to handle "compat" syscalls *and* create
+ * additional wrappers (aptly named __sys_ia32_sys_xyzzy) which decode the
+ * ia32 regs in the proper order for shared or "common" syscalls. As some
+ * syscalls may not be implemented, we need to expand COND_SYSCALL in
+ * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this
+ * case as well.
+ */
+#define COMPAT_SC_IA32_STUBx(x, name, ...)				\
+	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__compat_sys_ia32##name, ERRNO);		\
+	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs)\
+	{								\
+		return c_SyS##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
+	}								\
+
+#define SC_IA32_WRAPPERx(x, name, ...)					\
+	asmlinkage long __sys_ia32##name(const struct pt_regs *regs);	\
+	ALLOW_ERROR_INJECTION(__sys_ia32##name, ERRNO);			\
+	asmlinkage long __sys_ia32##name(const struct pt_regs *regs)	\
+	{								\
+		return SyS##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));	\
+	}
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(sys_##name);					\
+	cond_syscall(__sys_ia32_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers);			\
+	SYSCALL_ALIAS(__sys_ia32_##name, sys_ni_posix_timers)
+
+#else /* CONFIG_IA32_EMULATION */
+#define COMPAT_SC_IA32_STUBx(x, name, ...)
+#define SC_IA32_WRAPPERx(x, fullname, name, ...)
+#endif /* CONFIG_IA32_EMULATION */
+
+
+#ifdef CONFIG_X86_X32
+/*
+ * For the x32 ABI, we need to create a stub for compat_sys_*() which is aware
+ * of the x86-64-style parameter ordering of x32 syscalls. The syscalls common
+ * with x86_64 obviously do not need such care.
+ */
+#define COMPAT_SC_X32_STUBx(x, name, ...)				\
+	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__compat_sys_x32##name, ERRNO);		\
+	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs)\
+	{								\
+		return c_SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
+	}								\
+
+#else /* CONFIG_X86_X32 */
+#define COMPAT_SC_X32_STUBx(x, name, ...)
+#endif /* CONFIG_X86_X32 */
+
+
+#ifdef CONFIG_COMPAT
+/*
+ * Compat means IA32_EMULATION and/or X86_X32. As they use a different
+ * mapping of registers to parameters, we need to generate stubs for each
+ * of them. There is no need to implement COMPAT_SYSCALL_DEFINE0, as it is
+ * unused on x86.
+ */
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
+	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	COMPAT_SC_IA32_STUBx(x, name, __VA_ARGS__)			\
+	COMPAT_SC_X32_STUBx(x, name, __VA_ARGS__)			\
+	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{								\
+		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
+	}								\
+	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * As some compat syscalls may not be implemented, we need to expand
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
+ * kernel/time/posix-stubs.c to cover this case as well.
+ */
+#define COND_SYSCALL_COMPAT(name) 					\
+	cond_syscall(__compat_sys_ia32_##name);				\
+	cond_syscall(__compat_sys_x32_##name)
+
+#define COMPAT_SYS_NI(name)						\
+	SYSCALL_ALIAS(__compat_sys_ia32_##name, sys_ni_posix_timers);	\
+	SYSCALL_ALIAS(__compat_sys_x32_##name, sys_ni_posix_timers)
+
+#endif /* CONFIG_COMPAT */
+
+
 /*
  * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes
  * struct pt_regs *regs as the only argument of the syscall stub named
@@ -34,9 +139,14 @@
  * This approach avoids leaking random user-provided register content down
  * the call chain.
  *
+ * If IA32_EMULATION is enabled, this macro generates an additional wrapper
+ * named __sys_ia32_*() which decodes the struct pt_regs *regs according
+ * to the i386 calling convention (bx, cx, dx, si, di, bp).
+ *
  * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
  * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
- * hurt, there is no need to override it.
+ * hurt, there is no need to override it, or to define it differently for
+ * IA32_EMULATION.
  */
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(const struct pt_regs *regs);		\
@@ -45,10 +155,9 @@
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
 	asmlinkage long sys##name(const struct pt_regs *regs)		\
 	{								\
-		return SyS##name(__MAP(x,__SC_ARGS			\
-			,,regs->di,,regs->si,,regs->dx			\
-			,,regs->r10,,regs->r8,,regs->r9));		\
+		return SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
 	}								\
+	SC_IA32_WRAPPERx(x, name, __VA_ARGS__)				\
 	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
 	{								\
 		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\
-- 
2.16.3

[tip:x86/asm] syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32

[tip-bot for Dominik Brodowski]

Commit-ID:  ebeb8c82ffaf94435806ff0b686fffd41dd410b5
Gitweb:     https://git.kernel.org/tip/ebeb8c82ffaf94435806ff0b686fffd41dd410b5
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:04 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:38 +0200

syscalls/x86: Use 'struct pt_regs' based syscall calling for IA32_EMULATION and x32

Extend ARCH_HAS_SYSCALL_WRAPPER for i386 emulation and for x32 on 64-bit
x86.

For x32, all we need to do is to create an additional stub for each
compat syscall which decodes the parameters in x86-64 ordering, e.g.:

	asmlinkage long __compat_sys_x32_xyzzy(struct pt_regs *regs)
	{
		return c_SyS_xyzzy(regs->di, regs->si, regs->dx);
	}

For i386 emulation, we need to teach compat_sys_*() to take struct
pt_regs as its only argument, e.g.:

	asmlinkage long __compat_sys_ia32_xyzzy(struct pt_regs *regs)
	{
		return c_SyS_xyzzy(regs->bx, regs->cx, regs->dx);
	}

In addition, we need to create additional stubs for common syscalls
(that is, for syscalls which have the same parameters on 32-bit and
64-bit), e.g.:

	asmlinkage long __sys_ia32_xyzzy(struct pt_regs *regs)
	{
		return c_sys_xyzzy(regs->bx, regs->cx, regs->dx);
	}

This approach avoids leaking random user-provided register content down
the call chain.

This patch is based on an original proof-of-concept

 | From: Linus Torvalds <torvalds@linux-foundation.org>
 | Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

and was split up and heavily modified by me, in particular to base it on
ARCH_HAS_SYSCALL_WRAPPER.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-6-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/Kconfig                       |   2 +-
 arch/x86/entry/common.c                |   4 +
 arch/x86/entry/syscall_32.c            |  15 +-
 arch/x86/entry/syscalls/syscall_32.tbl | 677 +++++++++++++++++----------------
 arch/x86/entry/syscalls/syscall_64.tbl |  74 ++--
 arch/x86/include/asm/syscall_wrapper.h | 117 +++++-
 6 files changed, 509 insertions(+), 380 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 67348efc2540..7bbd6a174722 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2957,5 +2957,5 @@ source "lib/Kconfig"
 
 config SYSCALL_PTREGS
 	def_bool y
-	depends on X86_64 && !COMPAT
+	depends on X86_64
 	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index e1b91bffa988..425f798b39e3 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -325,6 +325,9 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 
 	if (likely(nr < IA32_NR_syscalls)) {
 		nr = array_index_nospec(nr, IA32_NR_syscalls);
+#ifdef CONFIG_SYSCALL_PTREGS
+		regs->ax = ia32_sys_call_table[nr](regs);
+#else
 		/*
 		 * It's possible that a 32-bit syscall implementation
 		 * takes a 64-bit parameter but nonetheless assumes that
@@ -335,6 +338,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 			(unsigned int)regs->bx, (unsigned int)regs->cx,
 			(unsigned int)regs->dx, (unsigned int)regs->si,
 			(unsigned int)regs->di, (unsigned int)regs->bp);
+#endif /* CONFIG_SYSCALL_PTREGS */
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 95c294963612..47060dd8efb1 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -7,14 +7,23 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long) ;
+#ifdef CONFIG_SYSCALL_PTREGS
+/* On X86_64, we use struct pt_regs * to pass parameters to syscalls */
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
+
+/* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
+extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
+
+#else /* CONFIG_SYSCALL_PTREGS */
+#define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
+#endif /* CONFIG_SYSCALL_PTREGS */
+
 #include <asm/syscalls_32.h>
 #undef __SYSCALL_I386
 
 #define __SYSCALL_I386(nr, sym, qual) [nr] = sym,
 
-extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-
 __visible const sys_call_ptr_t ia32_sys_call_table[__NR_syscall_compat_max+1] = {
 	/*
 	 * Smells like a compiler bug -- it doesn't work
diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index c58f75b088c5..7f09a3da0b3d 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -4,390 +4,395 @@
 # The format is:
 # <number> <abi> <name> <entry point> <compat entry point>
 #
+# The __sys_ia32 and __compat_sys_ia32 stubs are created on-the-fly for
+# sys_*() system calls and compat_sys_*() compat system calls if
+# IA32_EMULATION is defined, and expect struct pt_regs *regs as their only
+# parameter.
+#
 # The abi is always "i386" for this file.
 #
 0	i386	restart_syscall		sys_restart_syscall
-1	i386	exit			sys_exit
+1	i386	exit			sys_exit			__sys_ia32_exit
 2	i386	fork			sys_fork
-3	i386	read			sys_read
-4	i386	write			sys_write
-5	i386	open			sys_open			compat_sys_open
-6	i386	close			sys_close
-7	i386	waitpid			sys_waitpid
-8	i386	creat			sys_creat
-9	i386	link			sys_link
-10	i386	unlink			sys_unlink
-11	i386	execve			sys_execve			compat_sys_execve
-12	i386	chdir			sys_chdir
-13	i386	time			sys_time			compat_sys_time
-14	i386	mknod			sys_mknod
-15	i386	chmod			sys_chmod
-16	i386	lchown			sys_lchown16
+3	i386	read			sys_read			__sys_ia32_read
+4	i386	write			sys_write			__sys_ia32_write
+5	i386	open			sys_open			__compat_sys_ia32_open
+6	i386	close			sys_close			__sys_ia32_close
+7	i386	waitpid			sys_waitpid			__sys_ia32_waitpid
+8	i386	creat			sys_creat			__sys_ia32_creat
+9	i386	link			sys_link			__sys_ia32_link
+10	i386	unlink			sys_unlink			__sys_ia32_unlink
+11	i386	execve			sys_execve			__compat_sys_ia32_execve
+12	i386	chdir			sys_chdir			__sys_ia32_chdir
+13	i386	time			sys_time			__compat_sys_ia32_time
+14	i386	mknod			sys_mknod			__sys_ia32_mknod
+15	i386	chmod			sys_chmod			__sys_ia32_chmod
+16	i386	lchown			sys_lchown16			__sys_ia32_lchown16
 17	i386	break
-18	i386	oldstat			sys_stat
-19	i386	lseek			sys_lseek			compat_sys_lseek
+18	i386	oldstat			sys_stat			__sys_ia32_stat
+19	i386	lseek			sys_lseek			__compat_sys_ia32_lseek
 20	i386	getpid			sys_getpid
-21	i386	mount			sys_mount			compat_sys_mount
-22	i386	umount			sys_oldumount
-23	i386	setuid			sys_setuid16
+21	i386	mount			sys_mount			__compat_sys_ia32_mount
+22	i386	umount			sys_oldumount			__sys_ia32_oldumount
+23	i386	setuid			sys_setuid16			__sys_ia32_setuid16
 24	i386	getuid			sys_getuid16
-25	i386	stime			sys_stime			compat_sys_stime
-26	i386	ptrace			sys_ptrace			compat_sys_ptrace
-27	i386	alarm			sys_alarm
-28	i386	oldfstat		sys_fstat
+25	i386	stime			sys_stime			__compat_sys_ia32_stime
+26	i386	ptrace			sys_ptrace			__compat_sys_ia32_ptrace
+27	i386	alarm			sys_alarm			__sys_ia32_alarm
+28	i386	oldfstat		sys_fstat			__sys_ia32_fstat
 29	i386	pause			sys_pause
-30	i386	utime			sys_utime			compat_sys_utime
+30	i386	utime			sys_utime			__compat_sys_ia32_utime
 31	i386	stty
 32	i386	gtty
-33	i386	access			sys_access
-34	i386	nice			sys_nice
+33	i386	access			sys_access			__sys_ia32_access
+34	i386	nice			sys_nice			__sys_ia32_nice
 35	i386	ftime
 36	i386	sync			sys_sync
-37	i386	kill			sys_kill
-38	i386	rename			sys_rename
-39	i386	mkdir			sys_mkdir
-40	i386	rmdir			sys_rmdir
-41	i386	dup			sys_dup
-42	i386	pipe			sys_pipe
-43	i386	times			sys_times			compat_sys_times
+37	i386	kill			sys_kill			__sys_ia32_kill
+38	i386	rename			sys_rename			__sys_ia32_rename
+39	i386	mkdir			sys_mkdir			__sys_ia32_mkdir
+40	i386	rmdir			sys_rmdir			__sys_ia32_rmdir
+41	i386	dup			sys_dup				__sys_ia32_dup
+42	i386	pipe			sys_pipe			__sys_ia32_pipe
+43	i386	times			sys_times			__compat_sys_ia32_times
 44	i386	prof
-45	i386	brk			sys_brk
-46	i386	setgid			sys_setgid16
+45	i386	brk			sys_brk				__sys_ia32_brk
+46	i386	setgid			sys_setgid16			__sys_ia32_setgid16
 47	i386	getgid			sys_getgid16
-48	i386	signal			sys_signal
+48	i386	signal			sys_signal			__sys_ia32_signal
 49	i386	geteuid			sys_geteuid16
 50	i386	getegid			sys_getegid16
-51	i386	acct			sys_acct
-52	i386	umount2			sys_umount
+51	i386	acct			sys_acct			__sys_ia32_acct
+52	i386	umount2			sys_umount			__sys_ia32_umount
 53	i386	lock
-54	i386	ioctl			sys_ioctl			compat_sys_ioctl
-55	i386	fcntl			sys_fcntl			compat_sys_fcntl64
+54	i386	ioctl			sys_ioctl			__compat_sys_ia32_ioctl
+55	i386	fcntl			sys_fcntl			__compat_sys_ia32_fcntl64
 56	i386	mpx
-57	i386	setpgid			sys_setpgid
+57	i386	setpgid			sys_setpgid			__sys_ia32_setpgid
 58	i386	ulimit
-59	i386	oldolduname		sys_olduname
-60	i386	umask			sys_umask
-61	i386	chroot			sys_chroot
-62	i386	ustat			sys_ustat			compat_sys_ustat
-63	i386	dup2			sys_dup2
+59	i386	oldolduname		sys_olduname			__sys_ia32_olduname
+60	i386	umask			sys_umask			__sys_ia32_umask
+61	i386	chroot			sys_chroot			__sys_ia32_chroot
+62	i386	ustat			sys_ustat			__compat_sys_ia32_ustat
+63	i386	dup2			sys_dup2			__sys_ia32_dup2
 64	i386	getppid			sys_getppid
 65	i386	getpgrp			sys_getpgrp
 66	i386	setsid			sys_setsid
-67	i386	sigaction		sys_sigaction			compat_sys_sigaction
+67	i386	sigaction		sys_sigaction			__compat_sys_ia32_sigaction
 68	i386	sgetmask		sys_sgetmask
-69	i386	ssetmask		sys_ssetmask
-70	i386	setreuid		sys_setreuid16
-71	i386	setregid		sys_setregid16
-72	i386	sigsuspend		sys_sigsuspend
-73	i386	sigpending		sys_sigpending			compat_sys_sigpending
-74	i386	sethostname		sys_sethostname
-75	i386	setrlimit		sys_setrlimit			compat_sys_setrlimit
-76	i386	getrlimit		sys_old_getrlimit		compat_sys_old_getrlimit
-77	i386	getrusage		sys_getrusage			compat_sys_getrusage
-78	i386	gettimeofday		sys_gettimeofday		compat_sys_gettimeofday
-79	i386	settimeofday		sys_settimeofday		compat_sys_settimeofday
-80	i386	getgroups		sys_getgroups16
-81	i386	setgroups		sys_setgroups16
-82	i386	select			sys_old_select			compat_sys_old_select
-83	i386	symlink			sys_symlink
-84	i386	oldlstat		sys_lstat
-85	i386	readlink		sys_readlink
-86	i386	uselib			sys_uselib
-87	i386	swapon			sys_swapon
-88	i386	reboot			sys_reboot
-89	i386	readdir			sys_old_readdir			compat_sys_old_readdir
-90	i386	mmap			sys_old_mmap			compat_sys_x86_mmap
-91	i386	munmap			sys_munmap
-92	i386	truncate		sys_truncate			compat_sys_truncate
-93	i386	ftruncate		sys_ftruncate			compat_sys_ftruncate
-94	i386	fchmod			sys_fchmod
-95	i386	fchown			sys_fchown16
-96	i386	getpriority		sys_getpriority
-97	i386	setpriority		sys_setpriority
+69	i386	ssetmask		sys_ssetmask			__sys_ia32_ssetmask
+70	i386	setreuid		sys_setreuid16			__sys_ia32_setreuid16
+71	i386	setregid		sys_setregid16			__sys_ia32_setregid16
+72	i386	sigsuspend		sys_sigsuspend			__sys_ia32_sigsuspend
+73	i386	sigpending		sys_sigpending			__compat_sys_ia32_sigpending
+74	i386	sethostname		sys_sethostname			__sys_ia32_sethostname
+75	i386	setrlimit		sys_setrlimit			__compat_sys_ia32_setrlimit
+76	i386	getrlimit		sys_old_getrlimit		__compat_sys_ia32_old_getrlimit
+77	i386	getrusage		sys_getrusage			__compat_sys_ia32_getrusage
+78	i386	gettimeofday		sys_gettimeofday		__compat_sys_ia32_gettimeofday
+79	i386	settimeofday		sys_settimeofday		__compat_sys_ia32_settimeofday
+80	i386	getgroups		sys_getgroups16			__sys_ia32_getgroups16
+81	i386	setgroups		sys_setgroups16			__sys_ia32_setgroups16
+82	i386	select			sys_old_select			__compat_sys_ia32_old_select
+83	i386	symlink			sys_symlink			__sys_ia32_symlink
+84	i386	oldlstat		sys_lstat			__sys_ia32_lstat
+85	i386	readlink		sys_readlink			__sys_ia32_readlink
+86	i386	uselib			sys_uselib			__sys_ia32_uselib
+87	i386	swapon			sys_swapon			__sys_ia32_swapon
+88	i386	reboot			sys_reboot			__sys_ia32_reboot
+89	i386	readdir			sys_old_readdir			__compat_sys_ia32_old_readdir
+90	i386	mmap			sys_old_mmap			__compat_sys_ia32_x86_mmap
+91	i386	munmap			sys_munmap			__sys_ia32_munmap
+92	i386	truncate		sys_truncate			__compat_sys_ia32_truncate
+93	i386	ftruncate		sys_ftruncate			__compat_sys_ia32_ftruncate
+94	i386	fchmod			sys_fchmod			__sys_ia32_fchmod
+95	i386	fchown			sys_fchown16			__sys_ia32_fchown16
+96	i386	getpriority		sys_getpriority			__sys_ia32_getpriority
+97	i386	setpriority		sys_setpriority			__sys_ia32_setpriority
 98	i386	profil
-99	i386	statfs			sys_statfs			compat_sys_statfs
-100	i386	fstatfs			sys_fstatfs			compat_sys_fstatfs
-101	i386	ioperm			sys_ioperm
-102	i386	socketcall		sys_socketcall			compat_sys_socketcall
-103	i386	syslog			sys_syslog
-104	i386	setitimer		sys_setitimer			compat_sys_setitimer
-105	i386	getitimer		sys_getitimer			compat_sys_getitimer
-106	i386	stat			sys_newstat			compat_sys_newstat
-107	i386	lstat			sys_newlstat			compat_sys_newlstat
-108	i386	fstat			sys_newfstat			compat_sys_newfstat
-109	i386	olduname		sys_uname
-110	i386	iopl			sys_iopl
+99	i386	statfs			sys_statfs			__compat_sys_ia32_statfs
+100	i386	fstatfs			sys_fstatfs			__compat_sys_ia32_fstatfs
+101	i386	ioperm			sys_ioperm			__sys_ia32_ioperm
+102	i386	socketcall		sys_socketcall			__compat_sys_ia32_socketcall
+103	i386	syslog			sys_syslog			__sys_ia32_syslog
+104	i386	setitimer		sys_setitimer			__compat_sys_ia32_setitimer
+105	i386	getitimer		sys_getitimer			__compat_sys_ia32_getitimer
+106	i386	stat			sys_newstat			__compat_sys_ia32_newstat
+107	i386	lstat			sys_newlstat			__compat_sys_ia32_newlstat
+108	i386	fstat			sys_newfstat			__compat_sys_ia32_newfstat
+109	i386	olduname		sys_uname			__sys_ia32_uname
+110	i386	iopl			sys_iopl			__sys_ia32_iopl
 111	i386	vhangup			sys_vhangup
 112	i386	idle
 113	i386	vm86old			sys_vm86old			sys_ni_syscall
-114	i386	wait4			sys_wait4			compat_sys_wait4
-115	i386	swapoff			sys_swapoff
-116	i386	sysinfo			sys_sysinfo			compat_sys_sysinfo
-117	i386	ipc			sys_ipc				compat_sys_ipc
-118	i386	fsync			sys_fsync
+114	i386	wait4			sys_wait4			__compat_sys_ia32_wait4
+115	i386	swapoff			sys_swapoff			__sys_ia32_swapoff
+116	i386	sysinfo			sys_sysinfo			__compat_sys_ia32_sysinfo
+117	i386	ipc			sys_ipc				__compat_sys_ia32_ipc
+118	i386	fsync			sys_fsync			__sys_ia32_fsync
 119	i386	sigreturn		sys_sigreturn			sys32_sigreturn
-120	i386	clone			sys_clone			compat_sys_x86_clone
-121	i386	setdomainname		sys_setdomainname
-122	i386	uname			sys_newuname
-123	i386	modify_ldt		sys_modify_ldt
-124	i386	adjtimex		sys_adjtimex			compat_sys_adjtimex
-125	i386	mprotect		sys_mprotect
-126	i386	sigprocmask		sys_sigprocmask			compat_sys_sigprocmask
+120	i386	clone			sys_clone			__compat_sys_ia32_x86_clone
+121	i386	setdomainname		sys_setdomainname		__sys_ia32_setdomainname
+122	i386	uname			sys_newuname			__sys_ia32_newuname
+123	i386	modify_ldt		sys_modify_ldt			__sys_ia32_modify_ldt
+124	i386	adjtimex		sys_adjtimex			__compat_sys_ia32_adjtimex
+125	i386	mprotect		sys_mprotect			__sys_ia32_mprotect
+126	i386	sigprocmask		sys_sigprocmask			__compat_sys_ia32_sigprocmask
 127	i386	create_module
-128	i386	init_module		sys_init_module
-129	i386	delete_module		sys_delete_module
+128	i386	init_module		sys_init_module			__sys_ia32_init_module
+129	i386	delete_module		sys_delete_module		__sys_ia32_delete_module
 130	i386	get_kernel_syms
-131	i386	quotactl		sys_quotactl			compat_sys_quotactl32
-132	i386	getpgid			sys_getpgid
-133	i386	fchdir			sys_fchdir
-134	i386	bdflush			sys_bdflush
-135	i386	sysfs			sys_sysfs
-136	i386	personality		sys_personality
+131	i386	quotactl		sys_quotactl			__compat_sys_ia32_quotactl32
+132	i386	getpgid			sys_getpgid			__sys_ia32_getpgid
+133	i386	fchdir			sys_fchdir			__sys_ia32_fchdir
+134	i386	bdflush			sys_bdflush			__sys_ia32_bdflush
+135	i386	sysfs			sys_sysfs			__sys_ia32_sysfs
+136	i386	personality		sys_personality			__sys_ia32_personality
 137	i386	afs_syscall
-138	i386	setfsuid		sys_setfsuid16
-139	i386	setfsgid		sys_setfsgid16
-140	i386	_llseek			sys_llseek
-141	i386	getdents		sys_getdents			compat_sys_getdents
-142	i386	_newselect		sys_select			compat_sys_select
-143	i386	flock			sys_flock
-144	i386	msync			sys_msync
-145	i386	readv			sys_readv			compat_sys_readv
-146	i386	writev			sys_writev			compat_sys_writev
-147	i386	getsid			sys_getsid
-148	i386	fdatasync		sys_fdatasync
-149	i386	_sysctl			sys_sysctl			compat_sys_sysctl
-150	i386	mlock			sys_mlock
-151	i386	munlock			sys_munlock
-152	i386	mlockall		sys_mlockall
+138	i386	setfsuid		sys_setfsuid16			__sys_ia32_setfsuid16
+139	i386	setfsgid		sys_setfsgid16			__sys_ia32_setfsgid16
+140	i386	_llseek			sys_llseek			__sys_ia32_llseek
+141	i386	getdents		sys_getdents			__compat_sys_ia32_getdents
+142	i386	_newselect		sys_select			__compat_sys_ia32_select
+143	i386	flock			sys_flock			__sys_ia32_flock
+144	i386	msync			sys_msync			__sys_ia32_msync
+145	i386	readv			sys_readv			__compat_sys_ia32_readv
+146	i386	writev			sys_writev			__compat_sys_ia32_writev
+147	i386	getsid			sys_getsid			__sys_ia32_getsid
+148	i386	fdatasync		sys_fdatasync			__sys_ia32_fdatasync
+149	i386	_sysctl			sys_sysctl			__compat_sys_ia32_sysctl
+150	i386	mlock			sys_mlock			__sys_ia32_mlock
+151	i386	munlock			sys_munlock			__sys_ia32_munlock
+152	i386	mlockall		sys_mlockall			__sys_ia32_mlockall
 153	i386	munlockall		sys_munlockall
-154	i386	sched_setparam		sys_sched_setparam
-155	i386	sched_getparam		sys_sched_getparam
-156	i386	sched_setscheduler	sys_sched_setscheduler
-157	i386	sched_getscheduler	sys_sched_getscheduler
+154	i386	sched_setparam		sys_sched_setparam		__sys_ia32_sched_setparam
+155	i386	sched_getparam		sys_sched_getparam		__sys_ia32_sched_getparam
+156	i386	sched_setscheduler	sys_sched_setscheduler		__sys_ia32_sched_setscheduler
+157	i386	sched_getscheduler	sys_sched_getscheduler		__sys_ia32_sched_getscheduler
 158	i386	sched_yield		sys_sched_yield
-159	i386	sched_get_priority_max	sys_sched_get_priority_max
-160	i386	sched_get_priority_min	sys_sched_get_priority_min
-161	i386	sched_rr_get_interval	sys_sched_rr_get_interval	compat_sys_sched_rr_get_interval
-162	i386	nanosleep		sys_nanosleep			compat_sys_nanosleep
-163	i386	mremap			sys_mremap
-164	i386	setresuid		sys_setresuid16
-165	i386	getresuid		sys_getresuid16
+159	i386	sched_get_priority_max	sys_sched_get_priority_max	__sys_ia32_sched_get_priority_max
+160	i386	sched_get_priority_min	sys_sched_get_priority_min	__sys_ia32_sched_get_priority_min
+161	i386	sched_rr_get_interval	sys_sched_rr_get_interval	__compat_sys_ia32_sched_rr_get_interval
+162	i386	nanosleep		sys_nanosleep			__compat_sys_ia32_nanosleep
+163	i386	mremap			sys_mremap			__sys_ia32_mremap
+164	i386	setresuid		sys_setresuid16			__sys_ia32_setresuid16
+165	i386	getresuid		sys_getresuid16			__sys_ia32_getresuid16
 166	i386	vm86			sys_vm86			sys_ni_syscall
 167	i386	query_module
-168	i386	poll			sys_poll
+168	i386	poll			sys_poll			__sys_ia32_poll
 169	i386	nfsservctl
-170	i386	setresgid		sys_setresgid16
-171	i386	getresgid		sys_getresgid16
-172	i386	prctl			sys_prctl
+170	i386	setresgid		sys_setresgid16			__sys_ia32_setresgid16
+171	i386	getresgid		sys_getresgid16			__sys_ia32_getresgid16
+172	i386	prctl			sys_prctl			__sys_ia32_prctl
 173	i386	rt_sigreturn		sys_rt_sigreturn		sys32_rt_sigreturn
-174	i386	rt_sigaction		sys_rt_sigaction		compat_sys_rt_sigaction
-175	i386	rt_sigprocmask		sys_rt_sigprocmask
-176	i386	rt_sigpending		sys_rt_sigpending		compat_sys_rt_sigpending
-177	i386	rt_sigtimedwait		sys_rt_sigtimedwait		compat_sys_rt_sigtimedwait
-178	i386	rt_sigqueueinfo		sys_rt_sigqueueinfo		compat_sys_rt_sigqueueinfo
-179	i386	rt_sigsuspend		sys_rt_sigsuspend
-180	i386	pread64			sys_pread64			compat_sys_x86_pread
-181	i386	pwrite64		sys_pwrite64			compat_sys_x86_pwrite
-182	i386	chown			sys_chown16
-183	i386	getcwd			sys_getcwd
-184	i386	capget			sys_capget
-185	i386	capset			sys_capset
-186	i386	sigaltstack		sys_sigaltstack			compat_sys_sigaltstack
-187	i386	sendfile		sys_sendfile			compat_sys_sendfile
+174	i386	rt_sigaction		sys_rt_sigaction		__compat_sys_ia32_rt_sigaction
+175	i386	rt_sigprocmask		sys_rt_sigprocmask		__sys_ia32_rt_sigprocmask
+176	i386	rt_sigpending		sys_rt_sigpending		__compat_sys_ia32_rt_sigpending
+177	i386	rt_sigtimedwait		sys_rt_sigtimedwait		__compat_sys_ia32_rt_sigtimedwait
+178	i386	rt_sigqueueinfo		sys_rt_sigqueueinfo		__compat_sys_ia32_rt_sigqueueinfo
+179	i386	rt_sigsuspend		sys_rt_sigsuspend		__sys_ia32_rt_sigsuspend
+180	i386	pread64			sys_pread64			__compat_sys_ia32_x86_pread
+181	i386	pwrite64		sys_pwrite64			__compat_sys_ia32_x86_pwrite
+182	i386	chown			sys_chown16			__sys_ia32_chown16
+183	i386	getcwd			sys_getcwd			__sys_ia32_getcwd
+184	i386	capget			sys_capget			__sys_ia32_capget
+185	i386	capset			sys_capset			__sys_ia32_capset
+186	i386	sigaltstack		sys_sigaltstack			__compat_sys_ia32_sigaltstack
+187	i386	sendfile		sys_sendfile			__compat_sys_ia32_sendfile
 188	i386	getpmsg
 189	i386	putpmsg
 190	i386	vfork			sys_vfork
-191	i386	ugetrlimit		sys_getrlimit			compat_sys_getrlimit
-192	i386	mmap2			sys_mmap_pgoff
-193	i386	truncate64		sys_truncate64			compat_sys_x86_truncate64
-194	i386	ftruncate64		sys_ftruncate64			compat_sys_x86_ftruncate64
-195	i386	stat64			sys_stat64			compat_sys_x86_stat64
-196	i386	lstat64			sys_lstat64			compat_sys_x86_lstat64
-197	i386	fstat64			sys_fstat64			compat_sys_x86_fstat64
-198	i386	lchown32		sys_lchown
+191	i386	ugetrlimit		sys_getrlimit			__compat_sys_ia32_getrlimit
+192	i386	mmap2			sys_mmap_pgoff			__sys_ia32_mmap_pgoff
+193	i386	truncate64		sys_truncate64			__compat_sys_ia32_x86_truncate64
+194	i386	ftruncate64		sys_ftruncate64			__compat_sys_ia32_x86_ftruncate64
+195	i386	stat64			sys_stat64			__compat_sys_ia32_x86_stat64
+196	i386	lstat64			sys_lstat64			__compat_sys_ia32_x86_lstat64
+197	i386	fstat64			sys_fstat64			__compat_sys_ia32_x86_fstat64
+198	i386	lchown32		sys_lchown			__sys_ia32_lchown
 199	i386	getuid32		sys_getuid
 200	i386	getgid32		sys_getgid
 201	i386	geteuid32		sys_geteuid
 202	i386	getegid32		sys_getegid
-203	i386	setreuid32		sys_setreuid
-204	i386	setregid32		sys_setregid
-205	i386	getgroups32		sys_getgroups
-206	i386	setgroups32		sys_setgroups
-207	i386	fchown32		sys_fchown
-208	i386	setresuid32		sys_setresuid
-209	i386	getresuid32		sys_getresuid
-210	i386	setresgid32		sys_setresgid
-211	i386	getresgid32		sys_getresgid
-212	i386	chown32			sys_chown
-213	i386	setuid32		sys_setuid
-214	i386	setgid32		sys_setgid
-215	i386	setfsuid32		sys_setfsuid
-216	i386	setfsgid32		sys_setfsgid
-217	i386	pivot_root		sys_pivot_root
-218	i386	mincore			sys_mincore
-219	i386	madvise			sys_madvise
-220	i386	getdents64		sys_getdents64
-221	i386	fcntl64			sys_fcntl64			compat_sys_fcntl64
+203	i386	setreuid32		sys_setreuid			__sys_ia32_setreuid
+204	i386	setregid32		sys_setregid			__sys_ia32_setregid
+205	i386	getgroups32		sys_getgroups			__sys_ia32_getgroups
+206	i386	setgroups32		sys_setgroups			__sys_ia32_setgroups
+207	i386	fchown32		sys_fchown			__sys_ia32_fchown
+208	i386	setresuid32		sys_setresuid			__sys_ia32_setresuid
+209	i386	getresuid32		sys_getresuid			__sys_ia32_getresuid
+210	i386	setresgid32		sys_setresgid			__sys_ia32_setresgid
+211	i386	getresgid32		sys_getresgid			__sys_ia32_getresgid
+212	i386	chown32			sys_chown			__sys_ia32_chown
+213	i386	setuid32		sys_setuid			__sys_ia32_setuid
+214	i386	setgid32		sys_setgid			__sys_ia32_setgid
+215	i386	setfsuid32		sys_setfsuid			__sys_ia32_setfsuid
+216	i386	setfsgid32		sys_setfsgid			__sys_ia32_setfsgid
+217	i386	pivot_root		sys_pivot_root			__sys_ia32_pivot_root
+218	i386	mincore			sys_mincore			__sys_ia32_mincore
+219	i386	madvise			sys_madvise			__sys_ia32_madvise
+220	i386	getdents64		sys_getdents64			__sys_ia32_getdents64
+221	i386	fcntl64			sys_fcntl64			__compat_sys_ia32_fcntl64
 # 222 is unused
 # 223 is unused
 224	i386	gettid			sys_gettid
-225	i386	readahead		sys_readahead			compat_sys_x86_readahead
-226	i386	setxattr		sys_setxattr
-227	i386	lsetxattr		sys_lsetxattr
-228	i386	fsetxattr		sys_fsetxattr
-229	i386	getxattr		sys_getxattr
-230	i386	lgetxattr		sys_lgetxattr
-231	i386	fgetxattr		sys_fgetxattr
-232	i386	listxattr		sys_listxattr
-233	i386	llistxattr		sys_llistxattr
-234	i386	flistxattr		sys_flistxattr
-235	i386	removexattr		sys_removexattr
-236	i386	lremovexattr		sys_lremovexattr
-237	i386	fremovexattr		sys_fremovexattr
-238	i386	tkill			sys_tkill
-239	i386	sendfile64		sys_sendfile64
-240	i386	futex			sys_futex			compat_sys_futex
-241	i386	sched_setaffinity	sys_sched_setaffinity		compat_sys_sched_setaffinity
-242	i386	sched_getaffinity	sys_sched_getaffinity		compat_sys_sched_getaffinity
-243	i386	set_thread_area		sys_set_thread_area
-244	i386	get_thread_area		sys_get_thread_area
-245	i386	io_setup		sys_io_setup			compat_sys_io_setup
-246	i386	io_destroy		sys_io_destroy
-247	i386	io_getevents		sys_io_getevents		compat_sys_io_getevents
-248	i386	io_submit		sys_io_submit			compat_sys_io_submit
-249	i386	io_cancel		sys_io_cancel
-250	i386	fadvise64		sys_fadvise64			compat_sys_x86_fadvise64
+225	i386	readahead		sys_readahead			__compat_sys_ia32_x86_readahead
+226	i386	setxattr		sys_setxattr			__sys_ia32_setxattr
+227	i386	lsetxattr		sys_lsetxattr			__sys_ia32_lsetxattr
+228	i386	fsetxattr		sys_fsetxattr			__sys_ia32_fsetxattr
+229	i386	getxattr		sys_getxattr			__sys_ia32_getxattr
+230	i386	lgetxattr		sys_lgetxattr			__sys_ia32_lgetxattr
+231	i386	fgetxattr		sys_fgetxattr			__sys_ia32_fgetxattr
+232	i386	listxattr		sys_listxattr			__sys_ia32_listxattr
+233	i386	llistxattr		sys_llistxattr			__sys_ia32_llistxattr
+234	i386	flistxattr		sys_flistxattr			__sys_ia32_flistxattr
+235	i386	removexattr		sys_removexattr			__sys_ia32_removexattr
+236	i386	lremovexattr		sys_lremovexattr		__sys_ia32_lremovexattr
+237	i386	fremovexattr		sys_fremovexattr		__sys_ia32_fremovexattr
+238	i386	tkill			sys_tkill			__sys_ia32_tkill
+239	i386	sendfile64		sys_sendfile64			__sys_ia32_sendfile64
+240	i386	futex			sys_futex			__compat_sys_ia32_futex
+241	i386	sched_setaffinity	sys_sched_setaffinity		__compat_sys_ia32_sched_setaffinity
+242	i386	sched_getaffinity	sys_sched_getaffinity		__compat_sys_ia32_sched_getaffinity
+243	i386	set_thread_area		sys_set_thread_area		__sys_ia32_set_thread_area
+244	i386	get_thread_area		sys_get_thread_area		__sys_ia32_get_thread_area
+245	i386	io_setup		sys_io_setup			__compat_sys_ia32_io_setup
+246	i386	io_destroy		sys_io_destroy			__sys_ia32_io_destroy
+247	i386	io_getevents		sys_io_getevents		__compat_sys_ia32_io_getevents
+248	i386	io_submit		sys_io_submit			__compat_sys_ia32_io_submit
+249	i386	io_cancel		sys_io_cancel			__sys_ia32_io_cancel
+250	i386	fadvise64		sys_fadvise64			__compat_sys_ia32_x86_fadvise64
 # 251 is available for reuse (was briefly sys_set_zone_reclaim)
-252	i386	exit_group		sys_exit_group
-253	i386	lookup_dcookie		sys_lookup_dcookie		compat_sys_lookup_dcookie
-254	i386	epoll_create		sys_epoll_create
-255	i386	epoll_ctl		sys_epoll_ctl
-256	i386	epoll_wait		sys_epoll_wait
-257	i386	remap_file_pages	sys_remap_file_pages
-258	i386	set_tid_address		sys_set_tid_address
-259	i386	timer_create		sys_timer_create		compat_sys_timer_create
-260	i386	timer_settime		sys_timer_settime		compat_sys_timer_settime
-261	i386	timer_gettime		sys_timer_gettime		compat_sys_timer_gettime
-262	i386	timer_getoverrun	sys_timer_getoverrun
-263	i386	timer_delete		sys_timer_delete
-264	i386	clock_settime		sys_clock_settime		compat_sys_clock_settime
-265	i386	clock_gettime		sys_clock_gettime		compat_sys_clock_gettime
-266	i386	clock_getres		sys_clock_getres		compat_sys_clock_getres
-267	i386	clock_nanosleep		sys_clock_nanosleep		compat_sys_clock_nanosleep
-268	i386	statfs64		sys_statfs64			compat_sys_statfs64
-269	i386	fstatfs64		sys_fstatfs64			compat_sys_fstatfs64
-270	i386	tgkill			sys_tgkill
-271	i386	utimes			sys_utimes			compat_sys_utimes
-272	i386	fadvise64_64		sys_fadvise64_64		compat_sys_x86_fadvise64_64
+252	i386	exit_group		sys_exit_group			__sys_ia32_exit_group
+253	i386	lookup_dcookie		sys_lookup_dcookie		__compat_sys_ia32_lookup_dcookie
+254	i386	epoll_create		sys_epoll_create		__sys_ia32_epoll_create
+255	i386	epoll_ctl		sys_epoll_ctl			__sys_ia32_epoll_ctl
+256	i386	epoll_wait		sys_epoll_wait			__sys_ia32_epoll_wait
+257	i386	remap_file_pages	sys_remap_file_pages		__sys_ia32_remap_file_pages
+258	i386	set_tid_address		sys_set_tid_address		__sys_ia32_set_tid_address
+259	i386	timer_create		sys_timer_create		__compat_sys_ia32_timer_create
+260	i386	timer_settime		sys_timer_settime		__compat_sys_ia32_timer_settime
+261	i386	timer_gettime		sys_timer_gettime		__compat_sys_ia32_timer_gettime
+262	i386	timer_getoverrun	sys_timer_getoverrun		__sys_ia32_timer_getoverrun
+263	i386	timer_delete		sys_timer_delete		__sys_ia32_timer_delete
+264	i386	clock_settime		sys_clock_settime		__compat_sys_ia32_clock_settime
+265	i386	clock_gettime		sys_clock_gettime		__compat_sys_ia32_clock_gettime
+266	i386	clock_getres		sys_clock_getres		__compat_sys_ia32_clock_getres
+267	i386	clock_nanosleep		sys_clock_nanosleep		__compat_sys_ia32_clock_nanosleep
+268	i386	statfs64		sys_statfs64			__compat_sys_ia32_statfs64
+269	i386	fstatfs64		sys_fstatfs64			__compat_sys_ia32_fstatfs64
+270	i386	tgkill			sys_tgkill			__sys_ia32_tgkill
+271	i386	utimes			sys_utimes			__compat_sys_ia32_utimes
+272	i386	fadvise64_64		sys_fadvise64_64		__compat_sys_ia32_x86_fadvise64_64
 273	i386	vserver
-274	i386	mbind			sys_mbind
-275	i386	get_mempolicy		sys_get_mempolicy		compat_sys_get_mempolicy
-276	i386	set_mempolicy		sys_set_mempolicy
-277	i386	mq_open			sys_mq_open			compat_sys_mq_open
-278	i386	mq_unlink		sys_mq_unlink
-279	i386	mq_timedsend		sys_mq_timedsend		compat_sys_mq_timedsend
-280	i386	mq_timedreceive		sys_mq_timedreceive		compat_sys_mq_timedreceive
-281	i386	mq_notify		sys_mq_notify			compat_sys_mq_notify
-282	i386	mq_getsetattr		sys_mq_getsetattr		compat_sys_mq_getsetattr
-283	i386	kexec_load		sys_kexec_load			compat_sys_kexec_load
-284	i386	waitid			sys_waitid			compat_sys_waitid
+274	i386	mbind			sys_mbind			__sys_ia32_mbind
+275	i386	get_mempolicy		sys_get_mempolicy		__compat_sys_ia32_get_mempolicy
+276	i386	set_mempolicy		sys_set_mempolicy		__sys_ia32_set_mempolicy
+277	i386	mq_open			sys_mq_open			__compat_sys_ia32_mq_open
+278	i386	mq_unlink		sys_mq_unlink			__sys_ia32_mq_unlink
+279	i386	mq_timedsend		sys_mq_timedsend		__compat_sys_ia32_mq_timedsend
+280	i386	mq_timedreceive		sys_mq_timedreceive		__compat_sys_ia32_mq_timedreceive
+281	i386	mq_notify		sys_mq_notify			__compat_sys_ia32_mq_notify
+282	i386	mq_getsetattr		sys_mq_getsetattr		__compat_sys_ia32_mq_getsetattr
+283	i386	kexec_load		sys_kexec_load			__compat_sys_ia32_kexec_load
+284	i386	waitid			sys_waitid			__compat_sys_ia32_waitid
 # 285 sys_setaltroot
-286	i386	add_key			sys_add_key
-287	i386	request_key		sys_request_key
-288	i386	keyctl			sys_keyctl			compat_sys_keyctl
-289	i386	ioprio_set		sys_ioprio_set
-290	i386	ioprio_get		sys_ioprio_get
+286	i386	add_key			sys_add_key			__sys_ia32_add_key
+287	i386	request_key		sys_request_key			__sys_ia32_request_key
+288	i386	keyctl			sys_keyctl			__compat_sys_ia32_keyctl
+289	i386	ioprio_set		sys_ioprio_set			__sys_ia32_ioprio_set
+290	i386	ioprio_get		sys_ioprio_get			__sys_ia32_ioprio_get
 291	i386	inotify_init		sys_inotify_init
-292	i386	inotify_add_watch	sys_inotify_add_watch
-293	i386	inotify_rm_watch	sys_inotify_rm_watch
-294	i386	migrate_pages		sys_migrate_pages
-295	i386	openat			sys_openat			compat_sys_openat
-296	i386	mkdirat			sys_mkdirat
-297	i386	mknodat			sys_mknodat
-298	i386	fchownat		sys_fchownat
-299	i386	futimesat		sys_futimesat			compat_sys_futimesat
-300	i386	fstatat64		sys_fstatat64			compat_sys_x86_fstatat
-301	i386	unlinkat		sys_unlinkat
-302	i386	renameat		sys_renameat
-303	i386	linkat			sys_linkat
-304	i386	symlinkat		sys_symlinkat
-305	i386	readlinkat		sys_readlinkat
-306	i386	fchmodat		sys_fchmodat
-307	i386	faccessat		sys_faccessat
-308	i386	pselect6		sys_pselect6			compat_sys_pselect6
-309	i386	ppoll			sys_ppoll			compat_sys_ppoll
-310	i386	unshare			sys_unshare
-311	i386	set_robust_list		sys_set_robust_list		compat_sys_set_robust_list
-312	i386	get_robust_list		sys_get_robust_list		compat_sys_get_robust_list
-313	i386	splice			sys_splice
-314	i386	sync_file_range		sys_sync_file_range		compat_sys_x86_sync_file_range
-315	i386	tee			sys_tee
-316	i386	vmsplice		sys_vmsplice			compat_sys_vmsplice
-317	i386	move_pages		sys_move_pages			compat_sys_move_pages
-318	i386	getcpu			sys_getcpu
-319	i386	epoll_pwait		sys_epoll_pwait
-320	i386	utimensat		sys_utimensat			compat_sys_utimensat
-321	i386	signalfd		sys_signalfd			compat_sys_signalfd
-322	i386	timerfd_create		sys_timerfd_create
-323	i386	eventfd			sys_eventfd
-324	i386	fallocate		sys_fallocate			compat_sys_x86_fallocate
-325	i386	timerfd_settime		sys_timerfd_settime		compat_sys_timerfd_settime
-326	i386	timerfd_gettime		sys_timerfd_gettime		compat_sys_timerfd_gettime
-327	i386	signalfd4		sys_signalfd4			compat_sys_signalfd4
-328	i386	eventfd2		sys_eventfd2
-329	i386	epoll_create1		sys_epoll_create1
-330	i386	dup3			sys_dup3
-331	i386	pipe2			sys_pipe2
-332	i386	inotify_init1		sys_inotify_init1
-333	i386	preadv			sys_preadv			compat_sys_preadv
-334	i386	pwritev			sys_pwritev			compat_sys_pwritev
-335	i386	rt_tgsigqueueinfo	sys_rt_tgsigqueueinfo		compat_sys_rt_tgsigqueueinfo
-336	i386	perf_event_open		sys_perf_event_open
-337	i386	recvmmsg		sys_recvmmsg			compat_sys_recvmmsg
-338	i386	fanotify_init		sys_fanotify_init
-339	i386	fanotify_mark		sys_fanotify_mark		compat_sys_fanotify_mark
-340	i386	prlimit64		sys_prlimit64
-341	i386	name_to_handle_at	sys_name_to_handle_at
-342	i386	open_by_handle_at	sys_open_by_handle_at		compat_sys_open_by_handle_at
-343	i386	clock_adjtime		sys_clock_adjtime		compat_sys_clock_adjtime
-344	i386	syncfs			sys_syncfs
-345	i386	sendmmsg		sys_sendmmsg			compat_sys_sendmmsg
-346	i386	setns			sys_setns
-347	i386	process_vm_readv	sys_process_vm_readv		compat_sys_process_vm_readv
-348	i386	process_vm_writev	sys_process_vm_writev		compat_sys_process_vm_writev
-349	i386	kcmp			sys_kcmp
-350	i386	finit_module		sys_finit_module
-351	i386	sched_setattr		sys_sched_setattr
-352	i386	sched_getattr		sys_sched_getattr
-353	i386	renameat2		sys_renameat2
-354	i386	seccomp			sys_seccomp
-355	i386	getrandom		sys_getrandom
-356	i386	memfd_create		sys_memfd_create
-357	i386	bpf			sys_bpf
-358	i386	execveat		sys_execveat			compat_sys_execveat
-359	i386	socket			sys_socket
-360	i386	socketpair		sys_socketpair
-361	i386	bind			sys_bind
-362	i386	connect			sys_connect
-363	i386	listen			sys_listen
-364	i386	accept4			sys_accept4
-365	i386	getsockopt		sys_getsockopt			compat_sys_getsockopt
-366	i386	setsockopt		sys_setsockopt			compat_sys_setsockopt
-367	i386	getsockname		sys_getsockname
-368	i386	getpeername		sys_getpeername
-369	i386	sendto			sys_sendto
-370	i386	sendmsg			sys_sendmsg			compat_sys_sendmsg
-371	i386	recvfrom		sys_recvfrom			compat_sys_recvfrom
-372	i386	recvmsg			sys_recvmsg			compat_sys_recvmsg
-373	i386	shutdown		sys_shutdown
-374	i386	userfaultfd		sys_userfaultfd
-375	i386	membarrier		sys_membarrier
-376	i386	mlock2			sys_mlock2
-377	i386	copy_file_range		sys_copy_file_range
-378	i386	preadv2			sys_preadv2			compat_sys_preadv2
-379	i386	pwritev2		sys_pwritev2			compat_sys_pwritev2
-380	i386	pkey_mprotect		sys_pkey_mprotect
-381	i386	pkey_alloc		sys_pkey_alloc
-382	i386	pkey_free		sys_pkey_free
-383	i386	statx			sys_statx
-384	i386	arch_prctl		sys_arch_prctl			compat_sys_arch_prctl
+292	i386	inotify_add_watch	sys_inotify_add_watch		__sys_ia32_inotify_add_watch
+293	i386	inotify_rm_watch	sys_inotify_rm_watch		__sys_ia32_inotify_rm_watch
+294	i386	migrate_pages		sys_migrate_pages		__sys_ia32_migrate_pages
+295	i386	openat			sys_openat			__compat_sys_ia32_openat
+296	i386	mkdirat			sys_mkdirat			__sys_ia32_mkdirat
+297	i386	mknodat			sys_mknodat			__sys_ia32_mknodat
+298	i386	fchownat		sys_fchownat			__sys_ia32_fchownat
+299	i386	futimesat		sys_futimesat			__compat_sys_ia32_futimesat
+300	i386	fstatat64		sys_fstatat64			__compat_sys_ia32_x86_fstatat
+301	i386	unlinkat		sys_unlinkat			__sys_ia32_unlinkat
+302	i386	renameat		sys_renameat			__sys_ia32_renameat
+303	i386	linkat			sys_linkat			__sys_ia32_linkat
+304	i386	symlinkat		sys_symlinkat			__sys_ia32_symlinkat
+305	i386	readlinkat		sys_readlinkat			__sys_ia32_readlinkat
+306	i386	fchmodat		sys_fchmodat			__sys_ia32_fchmodat
+307	i386	faccessat		sys_faccessat			__sys_ia32_faccessat
+308	i386	pselect6		sys_pselect6			__compat_sys_ia32_pselect6
+309	i386	ppoll			sys_ppoll			__compat_sys_ia32_ppoll
+310	i386	unshare			sys_unshare			__sys_ia32_unshare
+311	i386	set_robust_list		sys_set_robust_list		__compat_sys_ia32_set_robust_list
+312	i386	get_robust_list		sys_get_robust_list		__compat_sys_ia32_get_robust_list
+313	i386	splice			sys_splice			__sys_ia32_splice
+314	i386	sync_file_range		sys_sync_file_range		__compat_sys_ia32_x86_sync_file_range
+315	i386	tee			sys_tee				__sys_ia32_tee
+316	i386	vmsplice		sys_vmsplice			__compat_sys_ia32_vmsplice
+317	i386	move_pages		sys_move_pages			__compat_sys_ia32_move_pages
+318	i386	getcpu			sys_getcpu			__sys_ia32_getcpu
+319	i386	epoll_pwait		sys_epoll_pwait			__sys_ia32_epoll_pwait
+320	i386	utimensat		sys_utimensat			__compat_sys_ia32_utimensat
+321	i386	signalfd		sys_signalfd			__compat_sys_ia32_signalfd
+322	i386	timerfd_create		sys_timerfd_create		__sys_ia32_timerfd_create
+323	i386	eventfd			sys_eventfd			__sys_ia32_eventfd
+324	i386	fallocate		sys_fallocate			__compat_sys_ia32_x86_fallocate
+325	i386	timerfd_settime		sys_timerfd_settime		__compat_sys_ia32_timerfd_settime
+326	i386	timerfd_gettime		sys_timerfd_gettime		__compat_sys_ia32_timerfd_gettime
+327	i386	signalfd4		sys_signalfd4			__compat_sys_ia32_signalfd4
+328	i386	eventfd2		sys_eventfd2			__sys_ia32_eventfd2
+329	i386	epoll_create1		sys_epoll_create1		__sys_ia32_epoll_create1
+330	i386	dup3			sys_dup3			__sys_ia32_dup3
+331	i386	pipe2			sys_pipe2			__sys_ia32_pipe2
+332	i386	inotify_init1		sys_inotify_init1		__sys_ia32_inotify_init1
+333	i386	preadv			sys_preadv			__compat_sys_ia32_preadv
+334	i386	pwritev			sys_pwritev			__compat_sys_ia32_pwritev
+335	i386	rt_tgsigqueueinfo	sys_rt_tgsigqueueinfo		__compat_sys_ia32_rt_tgsigqueueinfo
+336	i386	perf_event_open		sys_perf_event_open		__sys_ia32_perf_event_open
+337	i386	recvmmsg		sys_recvmmsg			__compat_sys_ia32_recvmmsg
+338	i386	fanotify_init		sys_fanotify_init		__sys_ia32_fanotify_init
+339	i386	fanotify_mark		sys_fanotify_mark		__compat_sys_ia32_fanotify_mark
+340	i386	prlimit64		sys_prlimit64			__sys_ia32_prlimit64
+341	i386	name_to_handle_at	sys_name_to_handle_at		__sys_ia32_name_to_handle_at
+342	i386	open_by_handle_at	sys_open_by_handle_at		__compat_sys_ia32_open_by_handle_at
+343	i386	clock_adjtime		sys_clock_adjtime		__compat_sys_ia32_clock_adjtime
+344	i386	syncfs			sys_syncfs			__sys_ia32_syncfs
+345	i386	sendmmsg		sys_sendmmsg			__compat_sys_ia32_sendmmsg
+346	i386	setns			sys_setns			__sys_ia32_setns
+347	i386	process_vm_readv	sys_process_vm_readv		__compat_sys_ia32_process_vm_readv
+348	i386	process_vm_writev	sys_process_vm_writev		__compat_sys_ia32_process_vm_writev
+349	i386	kcmp			sys_kcmp			__sys_ia32_kcmp
+350	i386	finit_module		sys_finit_module		__sys_ia32_finit_module
+351	i386	sched_setattr		sys_sched_setattr		__sys_ia32_sched_setattr
+352	i386	sched_getattr		sys_sched_getattr		__sys_ia32_sched_getattr
+353	i386	renameat2		sys_renameat2			__sys_ia32_renameat2
+354	i386	seccomp			sys_seccomp			__sys_ia32_seccomp
+355	i386	getrandom		sys_getrandom			__sys_ia32_getrandom
+356	i386	memfd_create		sys_memfd_create		__sys_ia32_memfd_create
+357	i386	bpf			sys_bpf				__sys_ia32_bpf
+358	i386	execveat		sys_execveat			__compat_sys_ia32_execveat
+359	i386	socket			sys_socket			__sys_ia32_socket
+360	i386	socketpair		sys_socketpair			__sys_ia32_socketpair
+361	i386	bind			sys_bind			__sys_ia32_bind
+362	i386	connect			sys_connect			__sys_ia32_connect
+363	i386	listen			sys_listen			__sys_ia32_listen
+364	i386	accept4			sys_accept4			__sys_ia32_accept4
+365	i386	getsockopt		sys_getsockopt			__compat_sys_ia32_getsockopt
+366	i386	setsockopt		sys_setsockopt			__compat_sys_ia32_setsockopt
+367	i386	getsockname		sys_getsockname			__sys_ia32_getsockname
+368	i386	getpeername		sys_getpeername			__sys_ia32_getpeername
+369	i386	sendto			sys_sendto			__sys_ia32_sendto
+370	i386	sendmsg			sys_sendmsg			__compat_sys_ia32_sendmsg
+371	i386	recvfrom		sys_recvfrom			__compat_sys_ia32_recvfrom
+372	i386	recvmsg			sys_recvmsg			__compat_sys_ia32_recvmsg
+373	i386	shutdown		sys_shutdown			__sys_ia32_shutdown
+374	i386	userfaultfd		sys_userfaultfd			__sys_ia32_userfaultfd
+375	i386	membarrier		sys_membarrier			__sys_ia32_membarrier
+376	i386	mlock2			sys_mlock2			__sys_ia32_mlock2
+377	i386	copy_file_range		sys_copy_file_range		__sys_ia32_copy_file_range
+378	i386	preadv2			sys_preadv2			__compat_sys_ia32_preadv2
+379	i386	pwritev2		sys_pwritev2			__compat_sys_ia32_pwritev2
+380	i386	pkey_mprotect		sys_pkey_mprotect		__sys_ia32_pkey_mprotect
+381	i386	pkey_alloc		sys_pkey_alloc			__sys_ia32_pkey_alloc
+382	i386	pkey_free		sys_pkey_free			__sys_ia32_pkey_free
+383	i386	statx			sys_statx			__sys_ia32_statx
+384	i386	arch_prctl		sys_arch_prctl			__compat_sys_ia32_arch_prctl
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index 5aef183e2f85..a83c0f7f462f 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -342,41 +342,43 @@
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
-# for native 64-bit operation.
+# for native 64-bit operation. The __compat_sys_x32 stubs are created
+# on-the-fly for compat_sys_*() compatibility system calls if X86_X32
+# is defined.
 #
-512	x32	rt_sigaction		compat_sys_rt_sigaction
+512	x32	rt_sigaction		__compat_sys_x32_rt_sigaction
 513	x32	rt_sigreturn		sys32_x32_rt_sigreturn
-514	x32	ioctl			compat_sys_ioctl
-515	x32	readv			compat_sys_readv
-516	x32	writev			compat_sys_writev
-517	x32	recvfrom		compat_sys_recvfrom
-518	x32	sendmsg			compat_sys_sendmsg
-519	x32	recvmsg			compat_sys_recvmsg
-520	x32	execve			compat_sys_execve/ptregs
-521	x32	ptrace			compat_sys_ptrace
-522	x32	rt_sigpending		compat_sys_rt_sigpending
-523	x32	rt_sigtimedwait		compat_sys_rt_sigtimedwait
-524	x32	rt_sigqueueinfo		compat_sys_rt_sigqueueinfo
-525	x32	sigaltstack		compat_sys_sigaltstack
-526	x32	timer_create		compat_sys_timer_create
-527	x32	mq_notify		compat_sys_mq_notify
-528	x32	kexec_load		compat_sys_kexec_load
-529	x32	waitid			compat_sys_waitid
-530	x32	set_robust_list		compat_sys_set_robust_list
-531	x32	get_robust_list		compat_sys_get_robust_list
-532	x32	vmsplice		compat_sys_vmsplice
-533	x32	move_pages		compat_sys_move_pages
-534	x32	preadv			compat_sys_preadv64
-535	x32	pwritev			compat_sys_pwritev64
-536	x32	rt_tgsigqueueinfo	compat_sys_rt_tgsigqueueinfo
-537	x32	recvmmsg		compat_sys_recvmmsg
-538	x32	sendmmsg		compat_sys_sendmmsg
-539	x32	process_vm_readv	compat_sys_process_vm_readv
-540	x32	process_vm_writev	compat_sys_process_vm_writev
-541	x32	setsockopt		compat_sys_setsockopt
-542	x32	getsockopt		compat_sys_getsockopt
-543	x32	io_setup		compat_sys_io_setup
-544	x32	io_submit		compat_sys_io_submit
-545	x32	execveat		compat_sys_execveat/ptregs
-546	x32	preadv2			compat_sys_preadv64v2
-547	x32	pwritev2		compat_sys_pwritev64v2
+514	x32	ioctl			__compat_sys_x32_ioctl
+515	x32	readv			__compat_sys_x32_readv
+516	x32	writev			__compat_sys_x32_writev
+517	x32	recvfrom		__compat_sys_x32_recvfrom
+518	x32	sendmsg			__compat_sys_x32_sendmsg
+519	x32	recvmsg			__compat_sys_x32_recvmsg
+520	x32	execve			__compat_sys_x32_execve/ptregs
+521	x32	ptrace			__compat_sys_x32_ptrace
+522	x32	rt_sigpending		__compat_sys_x32_rt_sigpending
+523	x32	rt_sigtimedwait		__compat_sys_x32_rt_sigtimedwait
+524	x32	rt_sigqueueinfo		__compat_sys_x32_rt_sigqueueinfo
+525	x32	sigaltstack		__compat_sys_x32_sigaltstack
+526	x32	timer_create		__compat_sys_x32_timer_create
+527	x32	mq_notify		__compat_sys_x32_mq_notify
+528	x32	kexec_load		__compat_sys_x32_kexec_load
+529	x32	waitid			__compat_sys_x32_waitid
+530	x32	set_robust_list		__compat_sys_x32_set_robust_list
+531	x32	get_robust_list		__compat_sys_x32_get_robust_list
+532	x32	vmsplice		__compat_sys_x32_vmsplice
+533	x32	move_pages		__compat_sys_x32_move_pages
+534	x32	preadv			__compat_sys_x32_preadv64
+535	x32	pwritev			__compat_sys_x32_pwritev64
+536	x32	rt_tgsigqueueinfo	__compat_sys_x32_rt_tgsigqueueinfo
+537	x32	recvmmsg		__compat_sys_x32_recvmmsg
+538	x32	sendmmsg		__compat_sys_x32_sendmmsg
+539	x32	process_vm_readv	__compat_sys_x32_process_vm_readv
+540	x32	process_vm_writev	__compat_sys_x32_process_vm_writev
+541	x32	setsockopt		__compat_sys_x32_setsockopt
+542	x32	getsockopt		__compat_sys_x32_getsockopt
+543	x32	io_setup		__compat_sys_x32_io_setup
+544	x32	io_submit		__compat_sys_x32_io_submit
+545	x32	execveat		__compat_sys_x32_execveat/ptregs
+546	x32	preadv2			__compat_sys_x32_preadv64v2
+547	x32	pwritev2		__compat_sys_x32_pwritev64v2
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index 702bdee377af..49d7e4970110 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -6,6 +6,111 @@
 #ifndef _ASM_X86_SYSCALL_WRAPPER_H
 #define _ASM_X86_SYSCALL_WRAPPER_H
 
+/* Mapping of registers to parameters for syscalls on x86-64 and x32 */
+#define SC_X86_64_REGS_TO_ARGS(x, ...)					\
+	__MAP(x,__SC_ARGS						\
+		,,regs->di,,regs->si,,regs->dx				\
+		,,regs->r10,,regs->r8,,regs->r9)			\
+
+/* Mapping of registers to parameters for syscalls on i386 */
+#define SC_IA32_REGS_TO_ARGS(x, ...)					\
+	__MAP(x,__SC_ARGS						\
+	      ,,(unsigned int)regs->bx,,(unsigned int)regs->cx		\
+	      ,,(unsigned int)regs->dx,,(unsigned int)regs->si		\
+	      ,,(unsigned int)regs->di,,(unsigned int)regs->bp)
+
+#ifdef CONFIG_IA32_EMULATION
+/*
+ * For IA32 emulation, we need to handle "compat" syscalls *and* create
+ * additional wrappers (aptly named __sys_ia32_sys_xyzzy) which decode the
+ * ia32 regs in the proper order for shared or "common" syscalls. As some
+ * syscalls may not be implemented, we need to expand COND_SYSCALL in
+ * kernel/sys_ni.c and SYS_NI in kernel/time/posix-stubs.c to cover this
+ * case as well.
+ */
+#define COMPAT_SC_IA32_STUBx(x, name, ...)				\
+	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__compat_sys_ia32##name, ERRNO);		\
+	asmlinkage long __compat_sys_ia32##name(const struct pt_regs *regs)\
+	{								\
+		return c_SyS##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));\
+	}								\
+
+#define SC_IA32_WRAPPERx(x, name, ...)					\
+	asmlinkage long __sys_ia32##name(const struct pt_regs *regs);	\
+	ALLOW_ERROR_INJECTION(__sys_ia32##name, ERRNO);			\
+	asmlinkage long __sys_ia32##name(const struct pt_regs *regs)	\
+	{								\
+		return SyS##name(SC_IA32_REGS_TO_ARGS(x,__VA_ARGS__));	\
+	}
+
+#define COND_SYSCALL(name)						\
+	cond_syscall(sys_##name);					\
+	cond_syscall(__sys_ia32_##name)
+
+#define SYS_NI(name)							\
+	SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers);			\
+	SYSCALL_ALIAS(__sys_ia32_##name, sys_ni_posix_timers)
+
+#else /* CONFIG_IA32_EMULATION */
+#define COMPAT_SC_IA32_STUBx(x, name, ...)
+#define SC_IA32_WRAPPERx(x, fullname, name, ...)
+#endif /* CONFIG_IA32_EMULATION */
+
+
+#ifdef CONFIG_X86_X32
+/*
+ * For the x32 ABI, we need to create a stub for compat_sys_*() which is aware
+ * of the x86-64-style parameter ordering of x32 syscalls. The syscalls common
+ * with x86_64 obviously do not need such care.
+ */
+#define COMPAT_SC_X32_STUBx(x, name, ...)				\
+	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs);\
+	ALLOW_ERROR_INJECTION(__compat_sys_x32##name, ERRNO);		\
+	asmlinkage long __compat_sys_x32##name(const struct pt_regs *regs)\
+	{								\
+		return c_SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
+	}								\
+
+#else /* CONFIG_X86_X32 */
+#define COMPAT_SC_X32_STUBx(x, name, ...)
+#endif /* CONFIG_X86_X32 */
+
+
+#ifdef CONFIG_COMPAT
+/*
+ * Compat means IA32_EMULATION and/or X86_X32. As they use a different
+ * mapping of registers to parameters, we need to generate stubs for each
+ * of them. There is no need to implement COMPAT_SYSCALL_DEFINE0, as it is
+ * unused on x86.
+ */
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)				\
+	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));	\
+	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	COMPAT_SC_IA32_STUBx(x, name, __VA_ARGS__)			\
+	COMPAT_SC_X32_STUBx(x, name, __VA_ARGS__)			\
+	static long c_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
+	{								\
+		return C_SYSC##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));	\
+	}								\
+	static inline long C_SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
+/*
+ * As some compat syscalls may not be implemented, we need to expand
+ * COND_SYSCALL_COMPAT in kernel/sys_ni.c and COMPAT_SYS_NI in
+ * kernel/time/posix-stubs.c to cover this case as well.
+ */
+#define COND_SYSCALL_COMPAT(name) 					\
+	cond_syscall(__compat_sys_ia32_##name);				\
+	cond_syscall(__compat_sys_x32_##name)
+
+#define COMPAT_SYS_NI(name)						\
+	SYSCALL_ALIAS(__compat_sys_ia32_##name, sys_ni_posix_timers);	\
+	SYSCALL_ALIAS(__compat_sys_x32_##name, sys_ni_posix_timers)
+
+#endif /* CONFIG_COMPAT */
+
+
 /*
  * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes
  * struct pt_regs *regs as the only argument of the syscall stub named
@@ -34,9 +139,14 @@
  * This approach avoids leaking random user-provided register content down
  * the call chain.
  *
+ * If IA32_EMULATION is enabled, this macro generates an additional wrapper
+ * named __sys_ia32_*() which decodes the struct pt_regs *regs according
+ * to the i386 calling convention (bx, cx, dx, si, di, bp).
+ *
  * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
  * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
- * hurt, there is no need to override it.
+ * hurt, there is no need to override it, or to define it differently for
+ * IA32_EMULATION.
  */
 #define __SYSCALL_DEFINEx(x, name, ...)					\
 	asmlinkage long sys##name(const struct pt_regs *regs);		\
@@ -45,10 +155,9 @@
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
 	asmlinkage long sys##name(const struct pt_regs *regs)		\
 	{								\
-		return SyS##name(__MAP(x,__SC_ARGS			\
-			,,regs->di,,regs->si,,regs->dx			\
-			,,regs->r10,,regs->r8,,regs->r9));		\
+		return SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
 	}								\
+	SC_IA32_WRAPPERx(x, name, __VA_ARGS__)				\
 	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\
 	{								\
 		long ret = SYSC##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\

[PATCH 6/8] syscalls/x86: unconditionally enable struct pt_regs based syscalls on x86_64

[Dominik Brodowski]

Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting
ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify
several codepaths.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/Kconfig                      |  6 +-----
 arch/x86/entry/common.c               | 10 ++--------
 arch/x86/entry/syscall_32.c           |  6 +++---
 arch/x86/entry/syscall_64.c           |  5 -----
 arch/x86/entry/vsyscall/vsyscall_64.c | 18 ------------------
 arch/x86/include/asm/syscall.h        |  4 ++--
 arch/x86/include/asm/syscalls.h       | 20 ++++----------------
 7 files changed, 12 insertions(+), 57 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7bbd6a174722..bcdd3e0e2ef5 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,6 +29,7 @@ config X86_64
 	select HAVE_ARCH_SOFT_DIRTY
 	select MODULES_USE_ELF_RELA
 	select X86_DEV_DMA_OPS
+	select ARCH_HAS_SYSCALL_WRAPPER
 
 #
 # Arch settings
@@ -2954,8 +2955,3 @@ source "crypto/Kconfig"
 source "arch/x86/kvm/Kconfig"
 
 source "lib/Kconfig"
-
-config SYSCALL_PTREGS
-	def_bool y
-	depends on X86_64
-	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 425f798b39e3..fbf6a6c3fd2d 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -284,13 +284,7 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 	nr &= __SYSCALL_MASK;
 	if (likely(nr < NR_syscalls)) {
 		nr = array_index_nospec(nr, NR_syscalls);
-#ifdef CONFIG_SYSCALL_PTREGS
 		regs->ax = sys_call_table[nr](regs);
-#else
-		regs->ax = sys_call_table[nr](
-			regs->di, regs->si, regs->dx,
-			regs->r10, regs->r8, regs->r9);
-#endif
 	}
 
 	syscall_return_slowpath(regs);
@@ -325,7 +319,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 
 	if (likely(nr < IA32_NR_syscalls)) {
 		nr = array_index_nospec(nr, IA32_NR_syscalls);
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_IA32_EMULATION
 		regs->ax = ia32_sys_call_table[nr](regs);
 #else
 		/*
@@ -338,7 +332,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 			(unsigned int)regs->bx, (unsigned int)regs->cx,
 			(unsigned int)regs->dx, (unsigned int)regs->si,
 			(unsigned int)regs->di, (unsigned int)regs->bp);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_IA32_EMULATION */
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 47060dd8efb1..aa3336a7cb15 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -7,17 +7,17 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_IA32_EMULATION
 /* On X86_64, we use struct pt_regs * to pass parameters to syscalls */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
 
 /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
 extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
 
-#else /* CONFIG_SYSCALL_PTREGS */
+#else /* CONFIG_IA32_EMULATION */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_IA32_EMULATION */
 
 #include <asm/syscalls_32.h>
 #undef __SYSCALL_I386
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 6197850adf91..d5252bc1e380 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,9 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
 /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
 extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
-#else /* CONFIG_SYSCALL_PTREGS */
-extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 05eebbf9b989..20b3d4a88ee4 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,9 +127,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	int vsyscall_nr, syscall_nr, tmp;
 	int prev_sig_on_uaccess_err;
 	long ret;
-#ifdef CONFIG_SYSCALL_PTREGS
 	unsigned long orig_dx;
-#endif
 
 	/*
 	 * No point in checking CS -- the only way to get here is a user mode
@@ -230,38 +228,22 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* this decodes regs->di and regs->si on its own */
 		ret = sys_gettimeofday(regs);
-#else
-		ret = sys_gettimeofday(
-			(struct timeval __user *)regs->di,
-			(struct timezone __user *)regs->si);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 1:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* this decodes regs->di on its own */
 		ret = sys_time(regs);
-#else
-		ret = sys_time((time_t __user *)regs->di);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 2:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* while we could clobber regs->dx, we didn't in the past... */
 		orig_dx = regs->dx;
 		regs->dx = 0;
 		/* this decodes regs->di, regs->si and regs->dx on its own */
 		ret = sys_getcpu(regs);
 		regs->dx = orig_dx;
-#else
-		ret = sys_getcpu((unsigned __user *)regs->di,
-				 (unsigned __user *)regs->si,
-				 NULL);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 	}
 
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 17c62373a6f9..d653139857af 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -20,13 +20,13 @@
 #include <asm/thread_info.h>	/* for TS_COMPAT */
 #include <asm/unistd.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_X86_64
 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);
 #else
 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
 					  unsigned long, unsigned long,
 					  unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_X86_64 */
 extern const sys_call_ptr_t sys_call_table[];
 
 #if defined(CONFIG_X86_32)
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index e4ad93c05f02..d4d18d94695c 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -19,10 +19,10 @@
 /* kernel/ioport.c */
 long ksys_ioperm(unsigned long from, unsigned long num, int turn_on);
 
-#ifndef CONFIG_SYSCALL_PTREGS
-/*
- * If CONFIG_SYSCALL_PTREGS is enabled, a different syscall calling convention
- * is used. Do not include these -- invalid -- prototypes then
+#ifdef CONFIG_X86_32
+/* 
+ * These definitions are only valid on pure 32-bit systems; x86-64 uses a
+ * different syscall calling convention
  */
 asmlinkage long sys_ioperm(unsigned long, unsigned long, int);
 asmlinkage long sys_iopl(unsigned int);
@@ -38,7 +38,6 @@ asmlinkage long sys_set_thread_area(struct user_desc __user *);
 asmlinkage long sys_get_thread_area(struct user_desc __user *);
 
 /* X86_32 only */
-#ifdef CONFIG_X86_32
 
 /* kernel/signal.c */
 asmlinkage long sys_sigreturn(void);
@@ -48,16 +47,5 @@ struct vm86_struct;
 asmlinkage long sys_vm86old(struct vm86_struct __user *);
 asmlinkage long sys_vm86(unsigned long, unsigned long);
 
-#else /* CONFIG_X86_32 */
-
-/* X86_64 only */
-/* kernel/process_64.c */
-asmlinkage long sys_arch_prctl(int, unsigned long);
-
-/* kernel/sys_x86_64.c */
-asmlinkage long sys_mmap(unsigned long, unsigned long, unsigned long,
-			 unsigned long, unsigned long, unsigned long);
-
 #endif /* CONFIG_X86_32 */
-#endif /* CONFIG_SYSCALL_PTREGS */
 #endif /* _ASM_X86_SYSCALLS_H */
-- 
2.16.3

[tip:x86/asm] syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64

[tip-bot for Dominik Brodowski]

Commit-ID:  f8781c4a226319fe60e652118b90cf094ccfe747
Gitweb:     https://git.kernel.org/tip/f8781c4a226319fe60e652118b90cf094ccfe747
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:05 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:38 +0200

syscalls/x86: Unconditionally enable 'struct pt_regs' based syscalls on x86_64

Removing CONFIG_SYSCALL_PTREGS from arch/x86/Kconfig and simply selecting
ARCH_HAS_SYSCALL_WRAPPER unconditionally on x86-64 allows us to simplify
several codepaths.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-7-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/Kconfig                      |  6 +-----
 arch/x86/entry/common.c               | 10 ++--------
 arch/x86/entry/syscall_32.c           |  6 +++---
 arch/x86/entry/syscall_64.c           |  5 -----
 arch/x86/entry/vsyscall/vsyscall_64.c | 18 ------------------
 arch/x86/include/asm/syscall.h        |  4 ++--
 arch/x86/include/asm/syscalls.h       | 20 ++++----------------
 7 files changed, 12 insertions(+), 57 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 7bbd6a174722..bcdd3e0e2ef5 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,6 +29,7 @@ config X86_64
 	select HAVE_ARCH_SOFT_DIRTY
 	select MODULES_USE_ELF_RELA
 	select X86_DEV_DMA_OPS
+	select ARCH_HAS_SYSCALL_WRAPPER
 
 #
 # Arch settings
@@ -2954,8 +2955,3 @@ source "crypto/Kconfig"
 source "arch/x86/kvm/Kconfig"
 
 source "lib/Kconfig"
-
-config SYSCALL_PTREGS
-	def_bool y
-	depends on X86_64
-	select ARCH_HAS_SYSCALL_WRAPPER
diff --git a/arch/x86/entry/common.c b/arch/x86/entry/common.c
index 425f798b39e3..fbf6a6c3fd2d 100644
--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -284,13 +284,7 @@ __visible void do_syscall_64(unsigned long nr, struct pt_regs *regs)
 	nr &= __SYSCALL_MASK;
 	if (likely(nr < NR_syscalls)) {
 		nr = array_index_nospec(nr, NR_syscalls);
-#ifdef CONFIG_SYSCALL_PTREGS
 		regs->ax = sys_call_table[nr](regs);
-#else
-		regs->ax = sys_call_table[nr](
-			regs->di, regs->si, regs->dx,
-			regs->r10, regs->r8, regs->r9);
-#endif
 	}
 
 	syscall_return_slowpath(regs);
@@ -325,7 +319,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 
 	if (likely(nr < IA32_NR_syscalls)) {
 		nr = array_index_nospec(nr, IA32_NR_syscalls);
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_IA32_EMULATION
 		regs->ax = ia32_sys_call_table[nr](regs);
 #else
 		/*
@@ -338,7 +332,7 @@ static __always_inline void do_syscall_32_irqs_on(struct pt_regs *regs)
 			(unsigned int)regs->bx, (unsigned int)regs->cx,
 			(unsigned int)regs->dx, (unsigned int)regs->si,
 			(unsigned int)regs->di, (unsigned int)regs->bp);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_IA32_EMULATION */
 	}
 
 	syscall_return_slowpath(regs);
diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 47060dd8efb1..aa3336a7cb15 100644
--- a/arch/x86/entry/syscall_32.c
+++ b/arch/x86/entry/syscall_32.c
@@ -7,17 +7,17 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_IA32_EMULATION
 /* On X86_64, we use struct pt_regs * to pass parameters to syscalls */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
 
 /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
 extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
 
-#else /* CONFIG_SYSCALL_PTREGS */
+#else /* CONFIG_IA32_EMULATION */
 #define __SYSCALL_I386(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
 extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_IA32_EMULATION */
 
 #include <asm/syscalls_32.h>
 #undef __SYSCALL_I386
diff --git a/arch/x86/entry/syscall_64.c b/arch/x86/entry/syscall_64.c
index 6197850adf91..d5252bc1e380 100644
--- a/arch/x86/entry/syscall_64.c
+++ b/arch/x86/entry/syscall_64.c
@@ -7,14 +7,9 @@
 #include <asm/asm-offsets.h>
 #include <asm/syscall.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
 /* this is a lie, but it does not hurt as sys_ni_syscall just returns -EINVAL */
 extern asmlinkage long sys_ni_syscall(const struct pt_regs *);
 #define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(const struct pt_regs *);
-#else /* CONFIG_SYSCALL_PTREGS */
-extern asmlinkage long sys_ni_syscall(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#define __SYSCALL_64(nr, sym, qual) extern asmlinkage long sym(unsigned long, unsigned long, unsigned long, unsigned long, unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
 #include <asm/syscalls_64.h>
 #undef __SYSCALL_64
 
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 05eebbf9b989..20b3d4a88ee4 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -127,9 +127,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	int vsyscall_nr, syscall_nr, tmp;
 	int prev_sig_on_uaccess_err;
 	long ret;
-#ifdef CONFIG_SYSCALL_PTREGS
 	unsigned long orig_dx;
-#endif
 
 	/*
 	 * No point in checking CS -- the only way to get here is a user mode
@@ -230,38 +228,22 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	ret = -EFAULT;
 	switch (vsyscall_nr) {
 	case 0:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* this decodes regs->di and regs->si on its own */
 		ret = sys_gettimeofday(regs);
-#else
-		ret = sys_gettimeofday(
-			(struct timeval __user *)regs->di,
-			(struct timezone __user *)regs->si);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 1:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* this decodes regs->di on its own */
 		ret = sys_time(regs);
-#else
-		ret = sys_time((time_t __user *)regs->di);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 
 	case 2:
-#ifdef CONFIG_SYSCALL_PTREGS
 		/* while we could clobber regs->dx, we didn't in the past... */
 		orig_dx = regs->dx;
 		regs->dx = 0;
 		/* this decodes regs->di, regs->si and regs->dx on its own */
 		ret = sys_getcpu(regs);
 		regs->dx = orig_dx;
-#else
-		ret = sys_getcpu((unsigned __user *)regs->di,
-				 (unsigned __user *)regs->si,
-				 NULL);
-#endif /* CONFIG_SYSCALL_PTREGS */
 		break;
 	}
 
diff --git a/arch/x86/include/asm/syscall.h b/arch/x86/include/asm/syscall.h
index 17c62373a6f9..d653139857af 100644
--- a/arch/x86/include/asm/syscall.h
+++ b/arch/x86/include/asm/syscall.h
@@ -20,13 +20,13 @@
 #include <asm/thread_info.h>	/* for TS_COMPAT */
 #include <asm/unistd.h>
 
-#ifdef CONFIG_SYSCALL_PTREGS
+#ifdef CONFIG_X86_64
 typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);
 #else
 typedef asmlinkage long (*sys_call_ptr_t)(unsigned long, unsigned long,
 					  unsigned long, unsigned long,
 					  unsigned long, unsigned long);
-#endif /* CONFIG_SYSCALL_PTREGS */
+#endif /* CONFIG_X86_64 */
 extern const sys_call_ptr_t sys_call_table[];
 
 #if defined(CONFIG_X86_32)
diff --git a/arch/x86/include/asm/syscalls.h b/arch/x86/include/asm/syscalls.h
index e4ad93c05f02..d4d18d94695c 100644
--- a/arch/x86/include/asm/syscalls.h
+++ b/arch/x86/include/asm/syscalls.h
@@ -19,10 +19,10 @@
 /* kernel/ioport.c */
 long ksys_ioperm(unsigned long from, unsigned long num, int turn_on);
 
-#ifndef CONFIG_SYSCALL_PTREGS
-/*
- * If CONFIG_SYSCALL_PTREGS is enabled, a different syscall calling convention
- * is used. Do not include these -- invalid -- prototypes then
+#ifdef CONFIG_X86_32
+/* 
+ * These definitions are only valid on pure 32-bit systems; x86-64 uses a
+ * different syscall calling convention
  */
 asmlinkage long sys_ioperm(unsigned long, unsigned long, int);
 asmlinkage long sys_iopl(unsigned int);
@@ -38,7 +38,6 @@ asmlinkage long sys_set_thread_area(struct user_desc __user *);
 asmlinkage long sys_get_thread_area(struct user_desc __user *);
 
 /* X86_32 only */
-#ifdef CONFIG_X86_32
 
 /* kernel/signal.c */
 asmlinkage long sys_sigreturn(void);
@@ -48,16 +47,5 @@ struct vm86_struct;
 asmlinkage long sys_vm86old(struct vm86_struct __user *);
 asmlinkage long sys_vm86(unsigned long, unsigned long);
 
-#else /* CONFIG_X86_32 */
-
-/* X86_64 only */
-/* kernel/process_64.c */
-asmlinkage long sys_arch_prctl(int, unsigned long);
-
-/* kernel/sys_x86_64.c */
-asmlinkage long sys_mmap(unsigned long, unsigned long, unsigned long,
-			 unsigned long, unsigned long, unsigned long);
-
 #endif /* CONFIG_X86_32 */
-#endif /* CONFIG_SYSCALL_PTREGS */
 #endif /* _ASM_X86_SYSCALLS_H */

[PATCH 7/8] x86/entry/64: extend register clearing on syscall entry to lower registers

[Dominik Brodowski]

To reduce the chance that random user space content leaks down the call
chain in registers, also clear lower registers on syscall entry:

For 64-bit syscalls, extend the register clearing in PUSH_AND_CLEAR_REGS
to %dx and %cx. This should not hurt at all, also on the other callers
of that macro. We do not need to clear %rdi and %rsi for syscall entry,
as those registers are used to pass the parameters to do_syscall_64().

For the 32-bit compat syscalls, do_int80_syscall_32() and
do_fast_syscall_32() each only take one parameter. Therefore, extend the
register clearing to %dx, %cx, and %si in entry_SYSCALL_compat and
entry_INT80_compat.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/entry/calling.h         | 2 ++
 arch/x86/entry/entry_64_compat.S | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index be63330c5511..352e70cd33e8 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -114,7 +114,9 @@ For 32-bit we have the following conventions - kernel is built with
 	pushq   %rsi		/* pt_regs->si */
 	.endif
 	pushq	\rdx		/* pt_regs->dx */
+	xorl	%edx, %edx	/* nospec   dx */
 	pushq   %rcx		/* pt_regs->cx */
+	xorl	%ecx, %ecx	/* nospec   cx */
 	pushq   \rax		/* pt_regs->ax */
 	pushq   %r8		/* pt_regs->r8 */
 	xorl	%r8d, %r8d	/* nospec   r8 */
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 08425c42f8b7..9af927e59d49 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -220,8 +220,11 @@ GLOBAL(entry_SYSCALL_compat_after_hwframe)
 	pushq	%rax			/* pt_regs->orig_ax */
 	pushq	%rdi			/* pt_regs->di */
 	pushq	%rsi			/* pt_regs->si */
+	xorl	%esi, %esi		/* nospec   si */
 	pushq	%rdx			/* pt_regs->dx */
+	xorl	%edx, %edx		/* nospec   dx */
 	pushq	%rbp			/* pt_regs->cx (stashed in bp) */
+	xorl	%ecx, %ecx		/* nospec   cx */
 	pushq	$-ENOSYS		/* pt_regs->ax */
 	pushq   $0			/* pt_regs->r8  = 0 */
 	xorl	%r8d, %r8d		/* nospec   r8 */
@@ -365,8 +368,11 @@ ENTRY(entry_INT80_compat)
 
 	pushq	(%rdi)			/* pt_regs->di */
 	pushq	%rsi			/* pt_regs->si */
+	xorl	%esi, %esi		/* nospec   si */
 	pushq	%rdx			/* pt_regs->dx */
+	xorl	%edx, %edx		/* nospec   dx */
 	pushq	%rcx			/* pt_regs->cx */
+	xorl	%ecx, %ecx		/* nospec   cx */
 	pushq	$-ENOSYS		/* pt_regs->ax */
 	pushq   $0			/* pt_regs->r8  = 0 */
 	xorl	%r8d, %r8d		/* nospec   r8 */
-- 
2.16.3

[tip:x86/asm] syscalls/x86: Extend register clearing on syscall entry to lower registers

[tip-bot for Dominik Brodowski]

Commit-ID:  6dc936f175cc6d12a8eb14d29b87e9238e460383
Gitweb:     https://git.kernel.org/tip/6dc936f175cc6d12a8eb14d29b87e9238e460383
Author:     Dominik Brodowski <linux@dominikbrodowski.net>
AuthorDate: Thu, 5 Apr 2018 11:53:06 +0200
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 5 Apr 2018 16:59:39 +0200

syscalls/x86: Extend register clearing on syscall entry to lower registers

To reduce the chance that random user space content leaks down the call
chain in registers, also clear lower registers on syscall entry:

For 64-bit syscalls, extend the register clearing in PUSH_AND_CLEAR_REGS
to %dx and %cx. This should not hurt at all, also on the other callers
of that macro. We do not need to clear %rdi and %rsi for syscall entry,
as those registers are used to pass the parameters to do_syscall_64().

For the 32-bit compat syscalls, do_int80_syscall_32() and
do_fast_syscall_32() each only take one parameter. Therefore, extend the
register clearing to %dx, %cx, and %si in entry_SYSCALL_compat and
entry_INT80_compat.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180405095307.3730-8-linux@dominikbrodowski.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/entry/calling.h         | 2 ++
 arch/x86/entry/entry_64_compat.S | 6 ++++++
 2 files changed, 8 insertions(+)

diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index be63330c5511..352e70cd33e8 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -114,7 +114,9 @@ For 32-bit we have the following conventions - kernel is built with
 	pushq   %rsi		/* pt_regs->si */
 	.endif
 	pushq	\rdx		/* pt_regs->dx */
+	xorl	%edx, %edx	/* nospec   dx */
 	pushq   %rcx		/* pt_regs->cx */
+	xorl	%ecx, %ecx	/* nospec   cx */
 	pushq   \rax		/* pt_regs->ax */
 	pushq   %r8		/* pt_regs->r8 */
 	xorl	%r8d, %r8d	/* nospec   r8 */
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 08425c42f8b7..9af927e59d49 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -220,8 +220,11 @@ GLOBAL(entry_SYSCALL_compat_after_hwframe)
 	pushq	%rax			/* pt_regs->orig_ax */
 	pushq	%rdi			/* pt_regs->di */
 	pushq	%rsi			/* pt_regs->si */
+	xorl	%esi, %esi		/* nospec   si */
 	pushq	%rdx			/* pt_regs->dx */
+	xorl	%edx, %edx		/* nospec   dx */
 	pushq	%rbp			/* pt_regs->cx (stashed in bp) */
+	xorl	%ecx, %ecx		/* nospec   cx */
 	pushq	$-ENOSYS		/* pt_regs->ax */
 	pushq   $0			/* pt_regs->r8  = 0 */
 	xorl	%r8d, %r8d		/* nospec   r8 */
@@ -365,8 +368,11 @@ ENTRY(entry_INT80_compat)
 
 	pushq	(%rdi)			/* pt_regs->di */
 	pushq	%rsi			/* pt_regs->si */
+	xorl	%esi, %esi		/* nospec   si */
 	pushq	%rdx			/* pt_regs->dx */
+	xorl	%edx, %edx		/* nospec   dx */
 	pushq	%rcx			/* pt_regs->cx */
+	xorl	%ecx, %ecx		/* nospec   cx */
 	pushq	$-ENOSYS		/* pt_regs->ax */
 	pushq   $0			/* pt_regs->r8  = 0 */
 	xorl	%r8d, %r8d		/* nospec   r8 */

[PATCH 8/8] syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*()

[Dominik Brodowski]

While it may make sense to name different things differently, I am not so
sure that the additional code is worth it here...

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
---
 arch/x86/entry/syscalls/syscall_32.tbl |  49 +--
 arch/x86/entry/syscalls/syscall_64.tbl | 638 +++++++++++++++++----------------
 arch/x86/entry/vsyscall/vsyscall_64.c  |   6 +-
 arch/x86/include/asm/syscall_wrapper.h |  48 ++-
 4 files changed, 381 insertions(+), 360 deletions(-)

diff --git a/arch/x86/entry/syscalls/syscall_32.tbl b/arch/x86/entry/syscalls/syscall_32.tbl
index 7f09a3da0b3d..9b0973a20a65 100644
--- a/arch/x86/entry/syscalls/syscall_32.tbl
+++ b/arch/x86/entry/syscalls/syscall_32.tbl
@@ -7,13 +7,14 @@
 # The __sys_ia32 and __compat_sys_ia32 stubs are created on-the-fly for
 # sys_*() system calls and compat_sys_*() compat system calls if
 # IA32_EMULATION is defined, and expect struct pt_regs *regs as their only
-# parameter.
+# parameter. The __sys_x86_ stubs below, which are common to x86-64, refer
+# solely to 0-parameter syscalls.
 #
 # The abi is always "i386" for this file.
 #
-0	i386	restart_syscall		sys_restart_syscall
+0	i386	restart_syscall		sys_restart_syscall		__sys_x86_restart_syscall
 1	i386	exit			sys_exit			__sys_ia32_exit
-2	i386	fork			sys_fork
+2	i386	fork			sys_fork			__sys_x86_fork
 3	i386	read			sys_read			__sys_ia32_read
 4	i386	write			sys_write			__sys_ia32_write
 5	i386	open			sys_open			__compat_sys_ia32_open
@@ -31,23 +32,23 @@
 17	i386	break
 18	i386	oldstat			sys_stat			__sys_ia32_stat
 19	i386	lseek			sys_lseek			__compat_sys_ia32_lseek
-20	i386	getpid			sys_getpid
+20	i386	getpid			sys_getpid			__sys_x86_getpid
 21	i386	mount			sys_mount			__compat_sys_ia32_mount
 22	i386	umount			sys_oldumount			__sys_ia32_oldumount
 23	i386	setuid			sys_setuid16			__sys_ia32_setuid16
-24	i386	getuid			sys_getuid16
+24	i386	getuid			sys_getuid16			__sys_x86_getuid16
 25	i386	stime			sys_stime			__compat_sys_ia32_stime
 26	i386	ptrace			sys_ptrace			__compat_sys_ia32_ptrace
 27	i386	alarm			sys_alarm			__sys_ia32_alarm
 28	i386	oldfstat		sys_fstat			__sys_ia32_fstat
-29	i386	pause			sys_pause
+29	i386	pause			sys_pause			__sys_x86_pause
 30	i386	utime			sys_utime			__compat_sys_ia32_utime
 31	i386	stty
 32	i386	gtty
 33	i386	access			sys_access			__sys_ia32_access
 34	i386	nice			sys_nice			__sys_ia32_nice
 35	i386	ftime
-36	i386	sync			sys_sync
+36	i386	sync			sys_sync			__sys_x86_sync
 37	i386	kill			sys_kill			__sys_ia32_kill
 38	i386	rename			sys_rename			__sys_ia32_rename
 39	i386	mkdir			sys_mkdir			__sys_ia32_mkdir
@@ -58,10 +59,10 @@
 44	i386	prof
 45	i386	brk			sys_brk				__sys_ia32_brk
 46	i386	setgid			sys_setgid16			__sys_ia32_setgid16
-47	i386	getgid			sys_getgid16
+47	i386	getgid			sys_getgid16			__sys_x86_getgid16
 48	i386	signal			sys_signal			__sys_ia32_signal
-49	i386	geteuid			sys_geteuid16
-50	i386	getegid			sys_getegid16
+49	i386	geteuid			sys_geteuid16			__sys_x86_geteuid16
+50	i386	getegid			sys_getegid16			__sys_x86_getegid16
 51	i386	acct			sys_acct			__sys_ia32_acct
 52	i386	umount2			sys_umount			__sys_ia32_umount
 53	i386	lock
@@ -75,11 +76,11 @@
 61	i386	chroot			sys_chroot			__sys_ia32_chroot
 62	i386	ustat			sys_ustat			__compat_sys_ia32_ustat
 63	i386	dup2			sys_dup2			__sys_ia32_dup2
-64	i386	getppid			sys_getppid
-65	i386	getpgrp			sys_getpgrp
-66	i386	setsid			sys_setsid
+64	i386	getppid			sys_getppid			__sys_x86_getppid
+65	i386	getpgrp			sys_getpgrp			__sys_x86_getpgrp
+66	i386	setsid			sys_setsid			__sys_x86_setsid
 67	i386	sigaction		sys_sigaction			__compat_sys_ia32_sigaction
-68	i386	sgetmask		sys_sgetmask
+68	i386	sgetmask		sys_sgetmask			__sys_x86_sgetmask
 69	i386	ssetmask		sys_ssetmask			__sys_ia32_ssetmask
 70	i386	setreuid		sys_setreuid16			__sys_ia32_setreuid16
 71	i386	setregid		sys_setregid16			__sys_ia32_setregid16
@@ -122,7 +123,7 @@
 108	i386	fstat			sys_newfstat			__compat_sys_ia32_newfstat
 109	i386	olduname		sys_uname			__sys_ia32_uname
 110	i386	iopl			sys_iopl			__sys_ia32_iopl
-111	i386	vhangup			sys_vhangup
+111	i386	vhangup			sys_vhangup			__sys_x86_vhangup
 112	i386	idle
 113	i386	vm86old			sys_vm86old			sys_ni_syscall
 114	i386	wait4			sys_wait4			__compat_sys_ia32_wait4
@@ -164,12 +165,12 @@
 150	i386	mlock			sys_mlock			__sys_ia32_mlock
 151	i386	munlock			sys_munlock			__sys_ia32_munlock
 152	i386	mlockall		sys_mlockall			__sys_ia32_mlockall
-153	i386	munlockall		sys_munlockall
+153	i386	munlockall		sys_munlockall			__sys_x86_munlockall
 154	i386	sched_setparam		sys_sched_setparam		__sys_ia32_sched_setparam
 155	i386	sched_getparam		sys_sched_getparam		__sys_ia32_sched_getparam
 156	i386	sched_setscheduler	sys_sched_setscheduler		__sys_ia32_sched_setscheduler
 157	i386	sched_getscheduler	sys_sched_getscheduler		__sys_ia32_sched_getscheduler
-158	i386	sched_yield		sys_sched_yield
+158	i386	sched_yield		sys_sched_yield			__sys_x86_sched_yield
 159	i386	sched_get_priority_max	sys_sched_get_priority_max	__sys_ia32_sched_get_priority_max
 160	i386	sched_get_priority_min	sys_sched_get_priority_min	__sys_ia32_sched_get_priority_min
 161	i386	sched_rr_get_interval	sys_sched_rr_get_interval	__compat_sys_ia32_sched_rr_get_interval
@@ -201,7 +202,7 @@
 187	i386	sendfile		sys_sendfile			__compat_sys_ia32_sendfile
 188	i386	getpmsg
 189	i386	putpmsg
-190	i386	vfork			sys_vfork
+190	i386	vfork			sys_vfork			__sys_x86_vfork
 191	i386	ugetrlimit		sys_getrlimit			__compat_sys_ia32_getrlimit
 192	i386	mmap2			sys_mmap_pgoff			__sys_ia32_mmap_pgoff
 193	i386	truncate64		sys_truncate64			__compat_sys_ia32_x86_truncate64
@@ -210,10 +211,10 @@
 196	i386	lstat64			sys_lstat64			__compat_sys_ia32_x86_lstat64
 197	i386	fstat64			sys_fstat64			__compat_sys_ia32_x86_fstat64
 198	i386	lchown32		sys_lchown			__sys_ia32_lchown
-199	i386	getuid32		sys_getuid
-200	i386	getgid32		sys_getgid
-201	i386	geteuid32		sys_geteuid
-202	i386	getegid32		sys_getegid
+199	i386	getuid32		sys_getuid			__sys_x86_getuid
+200	i386	getgid32		sys_getgid			__sys_x86_getgid
+201	i386	geteuid32		sys_geteuid			__sys_x86_geteuid
+202	i386	getegid32		sys_getegid			__sys_x86_getegid
 203	i386	setreuid32		sys_setreuid			__sys_ia32_setreuid
 204	i386	setregid32		sys_setregid			__sys_ia32_setregid
 205	i386	getgroups32		sys_getgroups			__sys_ia32_getgroups
@@ -235,7 +236,7 @@
 221	i386	fcntl64			sys_fcntl64			__compat_sys_ia32_fcntl64
 # 222 is unused
 # 223 is unused
-224	i386	gettid			sys_gettid
+224	i386	gettid			sys_gettid			__sys_x86_gettid
 225	i386	readahead		sys_readahead			__compat_sys_ia32_x86_readahead
 226	i386	setxattr		sys_setxattr			__sys_ia32_setxattr
 227	i386	lsetxattr		sys_lsetxattr			__sys_ia32_lsetxattr
@@ -302,7 +303,7 @@
 288	i386	keyctl			sys_keyctl			__compat_sys_ia32_keyctl
 289	i386	ioprio_set		sys_ioprio_set			__sys_ia32_ioprio_set
 290	i386	ioprio_get		sys_ioprio_get			__sys_ia32_ioprio_get
-291	i386	inotify_init		sys_inotify_init
+291	i386	inotify_init		sys_inotify_init		__sys_x86_inotify_init
 292	i386	inotify_add_watch	sys_inotify_add_watch		__sys_ia32_inotify_add_watch
 293	i386	inotify_rm_watch	sys_inotify_rm_watch		__sys_ia32_inotify_rm_watch
 294	i386	migrate_pages		sys_migrate_pages		__sys_ia32_migrate_pages
diff --git a/arch/x86/entry/syscalls/syscall_64.tbl b/arch/x86/entry/syscalls/syscall_64.tbl
index a83c0f7f462f..58ff63bb55aa 100644
--- a/arch/x86/entry/syscalls/syscall_64.tbl
+++ b/arch/x86/entry/syscalls/syscall_64.tbl
@@ -4,341 +4,343 @@
 # The format is:
 # <number> <abi> <name> <entry point>
 #
+# The __sys_x86_x86_*() stubs are created on-the-fly for sys_x86_*() system calls
+#
 # The abi is "common", "64" or "x32" for this file.
 #
-0	common	read			sys_read
-1	common	write			sys_write
-2	common	open			sys_open
-3	common	close			sys_close
-4	common	stat			sys_newstat
-5	common	fstat			sys_newfstat
-6	common	lstat			sys_newlstat
-7	common	poll			sys_poll
-8	common	lseek			sys_lseek
-9	common	mmap			sys_mmap
-10	common	mprotect		sys_mprotect
-11	common	munmap			sys_munmap
-12	common	brk			sys_brk
-13	64	rt_sigaction		sys_rt_sigaction
-14	common	rt_sigprocmask		sys_rt_sigprocmask
-15	64	rt_sigreturn		sys_rt_sigreturn/ptregs
-16	64	ioctl			sys_ioctl
-17	common	pread64			sys_pread64
-18	common	pwrite64		sys_pwrite64
-19	64	readv			sys_readv
-20	64	writev			sys_writev
-21	common	access			sys_access
-22	common	pipe			sys_pipe
-23	common	select			sys_select
-24	common	sched_yield		sys_sched_yield
-25	common	mremap			sys_mremap
-26	common	msync			sys_msync
-27	common	mincore			sys_mincore
-28	common	madvise			sys_madvise
-29	common	shmget			sys_shmget
-30	common	shmat			sys_shmat
-31	common	shmctl			sys_shmctl
-32	common	dup			sys_dup
-33	common	dup2			sys_dup2
-34	common	pause			sys_pause
-35	common	nanosleep		sys_nanosleep
-36	common	getitimer		sys_getitimer
-37	common	alarm			sys_alarm
-38	common	setitimer		sys_setitimer
-39	common	getpid			sys_getpid
-40	common	sendfile		sys_sendfile64
-41	common	socket			sys_socket
-42	common	connect			sys_connect
-43	common	accept			sys_accept
-44	common	sendto			sys_sendto
-45	64	recvfrom		sys_recvfrom
-46	64	sendmsg			sys_sendmsg
-47	64	recvmsg			sys_recvmsg
-48	common	shutdown		sys_shutdown
-49	common	bind			sys_bind
-50	common	listen			sys_listen
-51	common	getsockname		sys_getsockname
-52	common	getpeername		sys_getpeername
-53	common	socketpair		sys_socketpair
-54	64	setsockopt		sys_setsockopt
-55	64	getsockopt		sys_getsockopt
-56	common	clone			sys_clone/ptregs
-57	common	fork			sys_fork/ptregs
-58	common	vfork			sys_vfork/ptregs
-59	64	execve			sys_execve/ptregs
-60	common	exit			sys_exit
-61	common	wait4			sys_wait4
-62	common	kill			sys_kill
-63	common	uname			sys_newuname
-64	common	semget			sys_semget
-65	common	semop			sys_semop
-66	common	semctl			sys_semctl
-67	common	shmdt			sys_shmdt
-68	common	msgget			sys_msgget
-69	common	msgsnd			sys_msgsnd
-70	common	msgrcv			sys_msgrcv
-71	common	msgctl			sys_msgctl
-72	common	fcntl			sys_fcntl
-73	common	flock			sys_flock
-74	common	fsync			sys_fsync
-75	common	fdatasync		sys_fdatasync
-76	common	truncate		sys_truncate
-77	common	ftruncate		sys_ftruncate
-78	common	getdents		sys_getdents
-79	common	getcwd			sys_getcwd
-80	common	chdir			sys_chdir
-81	common	fchdir			sys_fchdir
-82	common	rename			sys_rename
-83	common	mkdir			sys_mkdir
-84	common	rmdir			sys_rmdir
-85	common	creat			sys_creat
-86	common	link			sys_link
-87	common	unlink			sys_unlink
-88	common	symlink			sys_symlink
-89	common	readlink		sys_readlink
-90	common	chmod			sys_chmod
-91	common	fchmod			sys_fchmod
-92	common	chown			sys_chown
-93	common	fchown			sys_fchown
-94	common	lchown			sys_lchown
-95	common	umask			sys_umask
-96	common	gettimeofday		sys_gettimeofday
-97	common	getrlimit		sys_getrlimit
-98	common	getrusage		sys_getrusage
-99	common	sysinfo			sys_sysinfo
-100	common	times			sys_times
-101	64	ptrace			sys_ptrace
-102	common	getuid			sys_getuid
-103	common	syslog			sys_syslog
-104	common	getgid			sys_getgid
-105	common	setuid			sys_setuid
-106	common	setgid			sys_setgid
-107	common	geteuid			sys_geteuid
-108	common	getegid			sys_getegid
-109	common	setpgid			sys_setpgid
-110	common	getppid			sys_getppid
-111	common	getpgrp			sys_getpgrp
-112	common	setsid			sys_setsid
-113	common	setreuid		sys_setreuid
-114	common	setregid		sys_setregid
-115	common	getgroups		sys_getgroups
-116	common	setgroups		sys_setgroups
-117	common	setresuid		sys_setresuid
-118	common	getresuid		sys_getresuid
-119	common	setresgid		sys_setresgid
-120	common	getresgid		sys_getresgid
-121	common	getpgid			sys_getpgid
-122	common	setfsuid		sys_setfsuid
-123	common	setfsgid		sys_setfsgid
-124	common	getsid			sys_getsid
-125	common	capget			sys_capget
-126	common	capset			sys_capset
-127	64	rt_sigpending		sys_rt_sigpending
-128	64	rt_sigtimedwait		sys_rt_sigtimedwait
-129	64	rt_sigqueueinfo		sys_rt_sigqueueinfo
-130	common	rt_sigsuspend		sys_rt_sigsuspend
-131	64	sigaltstack		sys_sigaltstack
-132	common	utime			sys_utime
-133	common	mknod			sys_mknod
+0	common	read			__sys_x86_read
+1	common	write			__sys_x86_write
+2	common	open			__sys_x86_open
+3	common	close			__sys_x86_close
+4	common	stat			__sys_x86_newstat
+5	common	fstat			__sys_x86_newfstat
+6	common	lstat			__sys_x86_newlstat
+7	common	poll			__sys_x86_poll
+8	common	lseek			__sys_x86_lseek
+9	common	mmap			__sys_x86_mmap
+10	common	mprotect		__sys_x86_mprotect
+11	common	munmap			__sys_x86_munmap
+12	common	brk			__sys_x86_brk
+13	64	rt_sigaction		__sys_x86_rt_sigaction
+14	common	rt_sigprocmask		__sys_x86_rt_sigprocmask
+15	64	rt_sigreturn		__sys_x86_rt_sigreturn/ptregs
+16	64	ioctl			__sys_x86_ioctl
+17	common	pread64			__sys_x86_pread64
+18	common	pwrite64		__sys_x86_pwrite64
+19	64	readv			__sys_x86_readv
+20	64	writev			__sys_x86_writev
+21	common	access			__sys_x86_access
+22	common	pipe			__sys_x86_pipe
+23	common	select			__sys_x86_select
+24	common	sched_yield		__sys_x86_sched_yield
+25	common	mremap			__sys_x86_mremap
+26	common	msync			__sys_x86_msync
+27	common	mincore			__sys_x86_mincore
+28	common	madvise			__sys_x86_madvise
+29	common	shmget			__sys_x86_shmget
+30	common	shmat			__sys_x86_shmat
+31	common	shmctl			__sys_x86_shmctl
+32	common	dup			__sys_x86_dup
+33	common	dup2			__sys_x86_dup2
+34	common	pause			__sys_x86_pause
+35	common	nanosleep		__sys_x86_nanosleep
+36	common	getitimer		__sys_x86_getitimer
+37	common	alarm			__sys_x86_alarm
+38	common	setitimer		__sys_x86_setitimer
+39	common	getpid			__sys_x86_getpid
+40	common	sendfile		__sys_x86_sendfile64
+41	common	socket			__sys_x86_socket
+42	common	connect			__sys_x86_connect
+43	common	accept			__sys_x86_accept
+44	common	sendto			__sys_x86_sendto
+45	64	recvfrom		__sys_x86_recvfrom
+46	64	sendmsg			__sys_x86_sendmsg
+47	64	recvmsg			__sys_x86_recvmsg
+48	common	shutdown		__sys_x86_shutdown
+49	common	bind			__sys_x86_bind
+50	common	listen			__sys_x86_listen
+51	common	getsockname		__sys_x86_getsockname
+52	common	getpeername		__sys_x86_getpeername
+53	common	socketpair		__sys_x86_socketpair
+54	64	setsockopt		__sys_x86_setsockopt
+55	64	getsockopt		__sys_x86_getsockopt
+56	common	clone			__sys_x86_clone/ptregs
+57	common	fork			__sys_x86_fork/ptregs
+58	common	vfork			__sys_x86_vfork/ptregs
+59	64	execve			__sys_x86_execve/ptregs
+60	common	exit			__sys_x86_exit
+61	common	wait4			__sys_x86_wait4
+62	common	kill			__sys_x86_kill
+63	common	uname			__sys_x86_newuname
+64	common	semget			__sys_x86_semget
+65	common	semop			__sys_x86_semop
+66	common	semctl			__sys_x86_semctl
+67	common	shmdt			__sys_x86_shmdt
+68	common	msgget			__sys_x86_msgget
+69	common	msgsnd			__sys_x86_msgsnd
+70	common	msgrcv			__sys_x86_msgrcv
+71	common	msgctl			__sys_x86_msgctl
+72	common	fcntl			__sys_x86_fcntl
+73	common	flock			__sys_x86_flock
+74	common	fsync			__sys_x86_fsync
+75	common	fdatasync		__sys_x86_fdatasync
+76	common	truncate		__sys_x86_truncate
+77	common	ftruncate		__sys_x86_ftruncate
+78	common	getdents		__sys_x86_getdents
+79	common	getcwd			__sys_x86_getcwd
+80	common	chdir			__sys_x86_chdir
+81	common	fchdir			__sys_x86_fchdir
+82	common	rename			__sys_x86_rename
+83	common	mkdir			__sys_x86_mkdir
+84	common	rmdir			__sys_x86_rmdir
+85	common	creat			__sys_x86_creat
+86	common	link			__sys_x86_link
+87	common	unlink			__sys_x86_unlink
+88	common	symlink			__sys_x86_symlink
+89	common	readlink		__sys_x86_readlink
+90	common	chmod			__sys_x86_chmod
+91	common	fchmod			__sys_x86_fchmod
+92	common	chown			__sys_x86_chown
+93	common	fchown			__sys_x86_fchown
+94	common	lchown			__sys_x86_lchown
+95	common	umask			__sys_x86_umask
+96	common	gettimeofday		__sys_x86_gettimeofday
+97	common	getrlimit		__sys_x86_getrlimit
+98	common	getrusage		__sys_x86_getrusage
+99	common	sysinfo			__sys_x86_sysinfo
+100	common	times			__sys_x86_times
+101	64	ptrace			__sys_x86_ptrace
+102	common	getuid			__sys_x86_getuid
+103	common	syslog			__sys_x86_syslog
+104	common	getgid			__sys_x86_getgid
+105	common	setuid			__sys_x86_setuid
+106	common	setgid			__sys_x86_setgid
+107	common	geteuid			__sys_x86_geteuid
+108	common	getegid			__sys_x86_getegid
+109	common	setpgid			__sys_x86_setpgid
+110	common	getppid			__sys_x86_getppid
+111	common	getpgrp			__sys_x86_getpgrp
+112	common	setsid			__sys_x86_setsid
+113	common	setreuid		__sys_x86_setreuid
+114	common	setregid		__sys_x86_setregid
+115	common	getgroups		__sys_x86_getgroups
+116	common	setgroups		__sys_x86_setgroups
+117	common	setresuid		__sys_x86_setresuid
+118	common	getresuid		__sys_x86_getresuid
+119	common	setresgid		__sys_x86_setresgid
+120	common	getresgid		__sys_x86_getresgid
+121	common	getpgid			__sys_x86_getpgid
+122	common	setfsuid		__sys_x86_setfsuid
+123	common	setfsgid		__sys_x86_setfsgid
+124	common	getsid			__sys_x86_getsid
+125	common	capget			__sys_x86_capget
+126	common	capset			__sys_x86_capset
+127	64	rt_sigpending		__sys_x86_rt_sigpending
+128	64	rt_sigtimedwait		__sys_x86_rt_sigtimedwait
+129	64	rt_sigqueueinfo		__sys_x86_rt_sigqueueinfo
+130	common	rt_sigsuspend		__sys_x86_rt_sigsuspend
+131	64	sigaltstack		__sys_x86_sigaltstack
+132	common	utime			__sys_x86_utime
+133	common	mknod			__sys_x86_mknod
 134	64	uselib
-135	common	personality		sys_personality
-136	common	ustat			sys_ustat
-137	common	statfs			sys_statfs
-138	common	fstatfs			sys_fstatfs
-139	common	sysfs			sys_sysfs
-140	common	getpriority		sys_getpriority
-141	common	setpriority		sys_setpriority
-142	common	sched_setparam		sys_sched_setparam
-143	common	sched_getparam		sys_sched_getparam
-144	common	sched_setscheduler	sys_sched_setscheduler
-145	common	sched_getscheduler	sys_sched_getscheduler
-146	common	sched_get_priority_max	sys_sched_get_priority_max
-147	common	sched_get_priority_min	sys_sched_get_priority_min
-148	common	sched_rr_get_interval	sys_sched_rr_get_interval
-149	common	mlock			sys_mlock
-150	common	munlock			sys_munlock
-151	common	mlockall		sys_mlockall
-152	common	munlockall		sys_munlockall
-153	common	vhangup			sys_vhangup
-154	common	modify_ldt		sys_modify_ldt
-155	common	pivot_root		sys_pivot_root
-156	64	_sysctl			sys_sysctl
-157	common	prctl			sys_prctl
-158	common	arch_prctl		sys_arch_prctl
-159	common	adjtimex		sys_adjtimex
-160	common	setrlimit		sys_setrlimit
-161	common	chroot			sys_chroot
-162	common	sync			sys_sync
-163	common	acct			sys_acct
-164	common	settimeofday		sys_settimeofday
-165	common	mount			sys_mount
-166	common	umount2			sys_umount
-167	common	swapon			sys_swapon
-168	common	swapoff			sys_swapoff
-169	common	reboot			sys_reboot
-170	common	sethostname		sys_sethostname
-171	common	setdomainname		sys_setdomainname
-172	common	iopl			sys_iopl/ptregs
-173	common	ioperm			sys_ioperm
+135	common	personality		__sys_x86_personality
+136	common	ustat			__sys_x86_ustat
+137	common	statfs			__sys_x86_statfs
+138	common	fstatfs			__sys_x86_fstatfs
+139	common	sysfs			__sys_x86_sysfs
+140	common	getpriority		__sys_x86_getpriority
+141	common	setpriority		__sys_x86_setpriority
+142	common	sched_setparam		__sys_x86_sched_setparam
+143	common	sched_getparam		__sys_x86_sched_getparam
+144	common	sched_setscheduler	__sys_x86_sched_setscheduler
+145	common	sched_getscheduler	__sys_x86_sched_getscheduler
+146	common	sched_get_priority_max	__sys_x86_sched_get_priority_max
+147	common	sched_get_priority_min	__sys_x86_sched_get_priority_min
+148	common	sched_rr_get_interval	__sys_x86_sched_rr_get_interval
+149	common	mlock			__sys_x86_mlock
+150	common	munlock			__sys_x86_munlock
+151	common	mlockall		__sys_x86_mlockall
+152	common	munlockall		__sys_x86_munlockall
+153	common	vhangup			__sys_x86_vhangup
+154	common	modify_ldt		__sys_x86_modify_ldt
+155	common	pivot_root		__sys_x86_pivot_root
+156	64	_sysctl			__sys_x86_sysctl
+157	common	prctl			__sys_x86_prctl
+158	common	arch_prctl		__sys_x86_arch_prctl
+159	common	adjtimex		__sys_x86_adjtimex
+160	common	setrlimit		__sys_x86_setrlimit
+161	common	chroot			__sys_x86_chroot
+162	common	sync			__sys_x86_sync
+163	common	acct			__sys_x86_acct
+164	common	settimeofday		__sys_x86_settimeofday
+165	common	mount			__sys_x86_mount
+166	common	umount2			__sys_x86_umount
+167	common	swapon			__sys_x86_swapon
+168	common	swapoff			__sys_x86_swapoff
+169	common	reboot			__sys_x86_reboot
+170	common	sethostname		__sys_x86_sethostname
+171	common	setdomainname		__sys_x86_setdomainname
+172	common	iopl			__sys_x86_iopl/ptregs
+173	common	ioperm			__sys_x86_ioperm
 174	64	create_module
-175	common	init_module		sys_init_module
-176	common	delete_module		sys_delete_module
+175	common	init_module		__sys_x86_init_module
+176	common	delete_module		__sys_x86_delete_module
 177	64	get_kernel_syms
 178	64	query_module
-179	common	quotactl		sys_quotactl
+179	common	quotactl		__sys_x86_quotactl
 180	64	nfsservctl
 181	common	getpmsg
 182	common	putpmsg
 183	common	afs_syscall
 184	common	tuxcall
 185	common	security
-186	common	gettid			sys_gettid
-187	common	readahead		sys_readahead
-188	common	setxattr		sys_setxattr
-189	common	lsetxattr		sys_lsetxattr
-190	common	fsetxattr		sys_fsetxattr
-191	common	getxattr		sys_getxattr
-192	common	lgetxattr		sys_lgetxattr
-193	common	fgetxattr		sys_fgetxattr
-194	common	listxattr		sys_listxattr
-195	common	llistxattr		sys_llistxattr
-196	common	flistxattr		sys_flistxattr
-197	common	removexattr		sys_removexattr
-198	common	lremovexattr		sys_lremovexattr
-199	common	fremovexattr		sys_fremovexattr
-200	common	tkill			sys_tkill
-201	common	time			sys_time
-202	common	futex			sys_futex
-203	common	sched_setaffinity	sys_sched_setaffinity
-204	common	sched_getaffinity	sys_sched_getaffinity
+186	common	gettid			__sys_x86_gettid
+187	common	readahead		__sys_x86_readahead
+188	common	setxattr		__sys_x86_setxattr
+189	common	lsetxattr		__sys_x86_lsetxattr
+190	common	fsetxattr		__sys_x86_fsetxattr
+191	common	getxattr		__sys_x86_getxattr
+192	common	lgetxattr		__sys_x86_lgetxattr
+193	common	fgetxattr		__sys_x86_fgetxattr
+194	common	listxattr		__sys_x86_listxattr
+195	common	llistxattr		__sys_x86_llistxattr
+196	common	flistxattr		__sys_x86_flistxattr
+197	common	removexattr		__sys_x86_removexattr
+198	common	lremovexattr		__sys_x86_lremovexattr
+199	common	fremovexattr		__sys_x86_fremovexattr
+200	common	tkill			__sys_x86_tkill
+201	common	time			__sys_x86_time
+202	common	futex			__sys_x86_futex
+203	common	sched_setaffinity	__sys_x86_sched_setaffinity
+204	common	sched_getaffinity	__sys_x86_sched_getaffinity
 205	64	set_thread_area
-206	64	io_setup		sys_io_setup
-207	common	io_destroy		sys_io_destroy
-208	common	io_getevents		sys_io_getevents
-209	64	io_submit		sys_io_submit
-210	common	io_cancel		sys_io_cancel
+206	64	io_setup		__sys_x86_io_setup
+207	common	io_destroy		__sys_x86_io_destroy
+208	common	io_getevents		__sys_x86_io_getevents
+209	64	io_submit		__sys_x86_io_submit
+210	common	io_cancel		__sys_x86_io_cancel
 211	64	get_thread_area
-212	common	lookup_dcookie		sys_lookup_dcookie
-213	common	epoll_create		sys_epoll_create
+212	common	lookup_dcookie		__sys_x86_lookup_dcookie
+213	common	epoll_create		__sys_x86_epoll_create
 214	64	epoll_ctl_old
 215	64	epoll_wait_old
-216	common	remap_file_pages	sys_remap_file_pages
-217	common	getdents64		sys_getdents64
-218	common	set_tid_address		sys_set_tid_address
-219	common	restart_syscall		sys_restart_syscall
-220	common	semtimedop		sys_semtimedop
-221	common	fadvise64		sys_fadvise64
-222	64	timer_create		sys_timer_create
-223	common	timer_settime		sys_timer_settime
-224	common	timer_gettime		sys_timer_gettime
-225	common	timer_getoverrun	sys_timer_getoverrun
-226	common	timer_delete		sys_timer_delete
-227	common	clock_settime		sys_clock_settime
-228	common	clock_gettime		sys_clock_gettime
-229	common	clock_getres		sys_clock_getres
-230	common	clock_nanosleep		sys_clock_nanosleep
-231	common	exit_group		sys_exit_group
-232	common	epoll_wait		sys_epoll_wait
-233	common	epoll_ctl		sys_epoll_ctl
-234	common	tgkill			sys_tgkill
-235	common	utimes			sys_utimes
+216	common	remap_file_pages	__sys_x86_remap_file_pages
+217	common	getdents64		__sys_x86_getdents64
+218	common	set_tid_address		__sys_x86_set_tid_address
+219	common	restart_syscall		__sys_x86_restart_syscall
+220	common	semtimedop		__sys_x86_semtimedop
+221	common	fadvise64		__sys_x86_fadvise64
+222	64	timer_create		__sys_x86_timer_create
+223	common	timer_settime		__sys_x86_timer_settime
+224	common	timer_gettime		__sys_x86_timer_gettime
+225	common	timer_getoverrun	__sys_x86_timer_getoverrun
+226	common	timer_delete		__sys_x86_timer_delete
+227	common	clock_settime		__sys_x86_clock_settime
+228	common	clock_gettime		__sys_x86_clock_gettime
+229	common	clock_getres		__sys_x86_clock_getres
+230	common	clock_nanosleep		__sys_x86_clock_nanosleep
+231	common	exit_group		__sys_x86_exit_group
+232	common	epoll_wait		__sys_x86_epoll_wait
+233	common	epoll_ctl		__sys_x86_epoll_ctl
+234	common	tgkill			__sys_x86_tgkill
+235	common	utimes			__sys_x86_utimes
 236	64	vserver
-237	common	mbind			sys_mbind
-238	common	set_mempolicy		sys_set_mempolicy
-239	common	get_mempolicy		sys_get_mempolicy
-240	common	mq_open			sys_mq_open
-241	common	mq_unlink		sys_mq_unlink
-242	common	mq_timedsend		sys_mq_timedsend
-243	common	mq_timedreceive		sys_mq_timedreceive
-244	64	mq_notify		sys_mq_notify
-245	common	mq_getsetattr		sys_mq_getsetattr
-246	64	kexec_load		sys_kexec_load
-247	64	waitid			sys_waitid
-248	common	add_key			sys_add_key
-249	common	request_key		sys_request_key
-250	common	keyctl			sys_keyctl
-251	common	ioprio_set		sys_ioprio_set
-252	common	ioprio_get		sys_ioprio_get
-253	common	inotify_init		sys_inotify_init
-254	common	inotify_add_watch	sys_inotify_add_watch
-255	common	inotify_rm_watch	sys_inotify_rm_watch
-256	common	migrate_pages		sys_migrate_pages
-257	common	openat			sys_openat
-258	common	mkdirat			sys_mkdirat
-259	common	mknodat			sys_mknodat
-260	common	fchownat		sys_fchownat
-261	common	futimesat		sys_futimesat
-262	common	newfstatat		sys_newfstatat
-263	common	unlinkat		sys_unlinkat
-264	common	renameat		sys_renameat
-265	common	linkat			sys_linkat
-266	common	symlinkat		sys_symlinkat
-267	common	readlinkat		sys_readlinkat
-268	common	fchmodat		sys_fchmodat
-269	common	faccessat		sys_faccessat
-270	common	pselect6		sys_pselect6
-271	common	ppoll			sys_ppoll
-272	common	unshare			sys_unshare
-273	64	set_robust_list		sys_set_robust_list
-274	64	get_robust_list		sys_get_robust_list
-275	common	splice			sys_splice
-276	common	tee			sys_tee
-277	common	sync_file_range		sys_sync_file_range
-278	64	vmsplice		sys_vmsplice
-279	64	move_pages		sys_move_pages
-280	common	utimensat		sys_utimensat
-281	common	epoll_pwait		sys_epoll_pwait
-282	common	signalfd		sys_signalfd
-283	common	timerfd_create		sys_timerfd_create
-284	common	eventfd			sys_eventfd
-285	common	fallocate		sys_fallocate
-286	common	timerfd_settime		sys_timerfd_settime
-287	common	timerfd_gettime		sys_timerfd_gettime
-288	common	accept4			sys_accept4
-289	common	signalfd4		sys_signalfd4
-290	common	eventfd2		sys_eventfd2
-291	common	epoll_create1		sys_epoll_create1
-292	common	dup3			sys_dup3
-293	common	pipe2			sys_pipe2
-294	common	inotify_init1		sys_inotify_init1
-295	64	preadv			sys_preadv
-296	64	pwritev			sys_pwritev
-297	64	rt_tgsigqueueinfo	sys_rt_tgsigqueueinfo
-298	common	perf_event_open		sys_perf_event_open
-299	64	recvmmsg		sys_recvmmsg
-300	common	fanotify_init		sys_fanotify_init
-301	common	fanotify_mark		sys_fanotify_mark
-302	common	prlimit64		sys_prlimit64
-303	common	name_to_handle_at	sys_name_to_handle_at
-304	common	open_by_handle_at	sys_open_by_handle_at
-305	common	clock_adjtime		sys_clock_adjtime
-306	common	syncfs			sys_syncfs
-307	64	sendmmsg		sys_sendmmsg
-308	common	setns			sys_setns
-309	common	getcpu			sys_getcpu
-310	64	process_vm_readv	sys_process_vm_readv
-311	64	process_vm_writev	sys_process_vm_writev
-312	common	kcmp			sys_kcmp
-313	common	finit_module		sys_finit_module
-314	common	sched_setattr		sys_sched_setattr
-315	common	sched_getattr		sys_sched_getattr
-316	common	renameat2		sys_renameat2
-317	common	seccomp			sys_seccomp
-318	common	getrandom		sys_getrandom
-319	common	memfd_create		sys_memfd_create
-320	common	kexec_file_load		sys_kexec_file_load
-321	common	bpf			sys_bpf
-322	64	execveat		sys_execveat/ptregs
-323	common	userfaultfd		sys_userfaultfd
-324	common	membarrier		sys_membarrier
-325	common	mlock2			sys_mlock2
-326	common	copy_file_range		sys_copy_file_range
-327	64	preadv2			sys_preadv2
-328	64	pwritev2		sys_pwritev2
-329	common	pkey_mprotect		sys_pkey_mprotect
-330	common	pkey_alloc		sys_pkey_alloc
-331	common	pkey_free		sys_pkey_free
-332	common	statx			sys_statx
+237	common	mbind			__sys_x86_mbind
+238	common	set_mempolicy		__sys_x86_set_mempolicy
+239	common	get_mempolicy		__sys_x86_get_mempolicy
+240	common	mq_open			__sys_x86_mq_open
+241	common	mq_unlink		__sys_x86_mq_unlink
+242	common	mq_timedsend		__sys_x86_mq_timedsend
+243	common	mq_timedreceive		__sys_x86_mq_timedreceive
+244	64	mq_notify		__sys_x86_mq_notify
+245	common	mq_getsetattr		__sys_x86_mq_getsetattr
+246	64	kexec_load		__sys_x86_kexec_load
+247	64	waitid			__sys_x86_waitid
+248	common	add_key			__sys_x86_add_key
+249	common	request_key		__sys_x86_request_key
+250	common	keyctl			__sys_x86_keyctl
+251	common	ioprio_set		__sys_x86_ioprio_set
+252	common	ioprio_get		__sys_x86_ioprio_get
+253	common	inotify_init		__sys_x86_inotify_init
+254	common	inotify_add_watch	__sys_x86_inotify_add_watch
+255	common	inotify_rm_watch	__sys_x86_inotify_rm_watch
+256	common	migrate_pages		__sys_x86_migrate_pages
+257	common	openat			__sys_x86_openat
+258	common	mkdirat			__sys_x86_mkdirat
+259	common	mknodat			__sys_x86_mknodat
+260	common	fchownat		__sys_x86_fchownat
+261	common	futimesat		__sys_x86_futimesat
+262	common	newfstatat		__sys_x86_newfstatat
+263	common	unlinkat		__sys_x86_unlinkat
+264	common	renameat		__sys_x86_renameat
+265	common	linkat			__sys_x86_linkat
+266	common	symlinkat		__sys_x86_symlinkat
+267	common	readlinkat		__sys_x86_readlinkat
+268	common	fchmodat		__sys_x86_fchmodat
+269	common	faccessat		__sys_x86_faccessat
+270	common	pselect6		__sys_x86_pselect6
+271	common	ppoll			__sys_x86_ppoll
+272	common	unshare			__sys_x86_unshare
+273	64	set_robust_list		__sys_x86_set_robust_list
+274	64	get_robust_list		__sys_x86_get_robust_list
+275	common	splice			__sys_x86_splice
+276	common	tee			__sys_x86_tee
+277	common	sync_file_range		__sys_x86_sync_file_range
+278	64	vmsplice		__sys_x86_vmsplice
+279	64	move_pages		__sys_x86_move_pages
+280	common	utimensat		__sys_x86_utimensat
+281	common	epoll_pwait		__sys_x86_epoll_pwait
+282	common	signalfd		__sys_x86_signalfd
+283	common	timerfd_create		__sys_x86_timerfd_create
+284	common	eventfd			__sys_x86_eventfd
+285	common	fallocate		__sys_x86_fallocate
+286	common	timerfd_settime		__sys_x86_timerfd_settime
+287	common	timerfd_gettime		__sys_x86_timerfd_gettime
+288	common	accept4			__sys_x86_accept4
+289	common	signalfd4		__sys_x86_signalfd4
+290	common	eventfd2		__sys_x86_eventfd2
+291	common	epoll_create1		__sys_x86_epoll_create1
+292	common	dup3			__sys_x86_dup3
+293	common	pipe2			__sys_x86_pipe2
+294	common	inotify_init1		__sys_x86_inotify_init1
+295	64	preadv			__sys_x86_preadv
+296	64	pwritev			__sys_x86_pwritev
+297	64	rt_tgsigqueueinfo	__sys_x86_rt_tgsigqueueinfo
+298	common	perf_event_open		__sys_x86_perf_event_open
+299	64	recvmmsg		__sys_x86_recvmmsg
+300	common	fanotify_init		__sys_x86_fanotify_init
+301	common	fanotify_mark		__sys_x86_fanotify_mark
+302	common	prlimit64		__sys_x86_prlimit64
+303	common	name_to_handle_at	__sys_x86_name_to_handle_at
+304	common	open_by_handle_at	__sys_x86_open_by_handle_at
+305	common	clock_adjtime		__sys_x86_clock_adjtime
+306	common	syncfs			__sys_x86_syncfs
+307	64	sendmmsg		__sys_x86_sendmmsg
+308	common	setns			__sys_x86_setns
+309	common	getcpu			__sys_x86_getcpu
+310	64	process_vm_readv	__sys_x86_process_vm_readv
+311	64	process_vm_writev	__sys_x86_process_vm_writev
+312	common	kcmp			__sys_x86_kcmp
+313	common	finit_module		__sys_x86_finit_module
+314	common	sched_setattr		__sys_x86_sched_setattr
+315	common	sched_getattr		__sys_x86_sched_getattr
+316	common	renameat2		__sys_x86_renameat2
+317	common	seccomp			__sys_x86_seccomp
+318	common	getrandom		__sys_x86_getrandom
+319	common	memfd_create		__sys_x86_memfd_create
+320	common	kexec_file_load		__sys_x86_kexec_file_load
+321	common	bpf			__sys_x86_bpf
+322	64	execveat		__sys_x86_execveat/ptregs
+323	common	userfaultfd		__sys_x86_userfaultfd
+324	common	membarrier		__sys_x86_membarrier
+325	common	mlock2			__sys_x86_mlock2
+326	common	copy_file_range		__sys_x86_copy_file_range
+327	64	preadv2			__sys_x86_preadv2
+328	64	pwritev2		__sys_x86_pwritev2
+329	common	pkey_mprotect		__sys_x86_pkey_mprotect
+330	common	pkey_alloc		__sys_x86_pkey_alloc
+331	common	pkey_free		__sys_x86_pkey_free
+332	common	statx			__sys_x86_statx
 
 #
 # x32-specific system call numbers start at 512 to avoid cache impact
diff --git a/arch/x86/entry/vsyscall/vsyscall_64.c b/arch/x86/entry/vsyscall/vsyscall_64.c
index 20b3d4a88ee4..6da86e0a8a9c 100644
--- a/arch/x86/entry/vsyscall/vsyscall_64.c
+++ b/arch/x86/entry/vsyscall/vsyscall_64.c
@@ -229,12 +229,12 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 	switch (vsyscall_nr) {
 	case 0:
 		/* this decodes regs->di and regs->si on its own */
-		ret = sys_gettimeofday(regs);
+		ret = __sys_x86_gettimeofday(regs);
 		break;
 
 	case 1:
 		/* this decodes regs->di on its own */
-		ret = sys_time(regs);
+		ret = __sys_x86_time(regs);
 		break;
 
 	case 2:
@@ -242,7 +242,7 @@ bool emulate_vsyscall(struct pt_regs *regs, unsigned long address)
 		orig_dx = regs->dx;
 		regs->dx = 0;
 		/* this decodes regs->di, regs->si and regs->dx on its own */
-		ret = sys_getcpu(regs);
+		ret = __sys_x86_getcpu(regs);
 		regs->dx = orig_dx;
 		break;
 	}
diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
index 49d7e4970110..5159c10314e4 100644
--- a/arch/x86/include/asm/syscall_wrapper.h
+++ b/arch/x86/include/asm/syscall_wrapper.h
@@ -45,11 +45,11 @@
 	}
 
 #define COND_SYSCALL(name)						\
-	cond_syscall(sys_##name);					\
+	cond_syscall(__sys_x86_##name);					\
 	cond_syscall(__sys_ia32_##name)
 
 #define SYS_NI(name)							\
-	SYSCALL_ALIAS(sys_##name, sys_ni_posix_timers);			\
+	SYSCALL_ALIAS(__sys_x86_##name, sys_ni_posix_timers);		\
 	SYSCALL_ALIAS(__sys_ia32_##name, sys_ni_posix_timers)
 
 #else /* CONFIG_IA32_EMULATION */
@@ -114,12 +114,12 @@
 /*
  * Instead of the generic __SYSCALL_DEFINEx() definition, this macro takes
  * struct pt_regs *regs as the only argument of the syscall stub named
- * sys_*(). It decodes just the registers it needs and passes them on to
+ * __sys_x86_*(). It decodes just the registers it needs and passes them on to
  * the SyS_*() wrapper and then to the SYSC_*() function doing the actual job.
  * These wrappers and functions are inlined, meaning that the assembly looks
  * as follows (slightly re-ordered):
  *
- * <sys_recv>:			<-- syscall with 4 parameters
+ * <__sys_x86_recv>:		<-- syscall with 4 parameters
  *	callq	<__fentry__>
  *
  *	mov	0x70(%rdi),%rdi	<-- decode regs->di
@@ -142,18 +142,13 @@
  * If IA32_EMULATION is enabled, this macro generates an additional wrapper
  * named __sys_ia32_*() which decodes the struct pt_regs *regs according
  * to the i386 calling convention (bx, cx, dx, si, di, bp).
- *
- * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
- * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
- * hurt, there is no need to override it, or to define it differently for
- * IA32_EMULATION.
  */
 #define __SYSCALL_DEFINEx(x, name, ...)					\
-	asmlinkage long sys##name(const struct pt_regs *regs);		\
-	ALLOW_ERROR_INJECTION(sys##name, ERRNO);			\
+	asmlinkage long __sys_x86##name(const struct pt_regs *regs);	\
+	ALLOW_ERROR_INJECTION(__sys_x86##name, ERRNO);			\
 	static long SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\
-	asmlinkage long sys##name(const struct pt_regs *regs)		\
+	asmlinkage long __sys_x86##name(const struct pt_regs *regs)	\
 	{								\
 		return SyS##name(SC_X86_64_REGS_TO_ARGS(x,__VA_ARGS__));\
 	}								\
@@ -167,13 +162,36 @@
 	}								\
 	static inline long SYSC##name(__MAP(x,__SC_DECL,__VA_ARGS__))
 
+
+/*
+ * As the generic SYSCALL_DEFINE0() macro does not decode any parameters for
+ * obvious reasons, and passing struct pt_regs *regs to it in %rdi does not
+ * hurt, we only need to re-define it here to keep the naming congruent to
+ * SYSCALL_DEFINEx() -- which is essential for the COND_SYSCALL() and SYS_NI()
+ * macros to work correctly
+ */
+#define SYSCALL_DEFINE0(sname)					\
+	SYSCALL_METADATA(_##sname, 0);				\
+	asmlinkage long __sys_x86_##sname(void);		\
+	ALLOW_ERROR_INJECTION(__sys_x86_##sname, ERRNO);	\
+	asmlinkage long __sys_x86_##sname(void)
+
+#ifndef COND_SYSCALL
+#define COND_SYSCALL(name) cond_syscall(__sys_x86_##name)
+#endif
+
+#ifndef SYS_NI
+#define SYS_NI(name) SYSCALL_ALIAS(__sys_x86_##name, sys_ni_posix_timers);
+#endif
+
+
 /*
  * For VSYSCALLS, we need to declare these three syscalls with the new
  * pt_regs-based calling convention for in-kernel use.
  */
 struct pt_regs;
-asmlinkage long sys_getcpu(const struct pt_regs *regs);		/* di,si,dx */
-asmlinkage long sys_gettimeofday(const struct pt_regs *regs);	/* di,si */
-asmlinkage long sys_time(const struct pt_regs *regs);		/* di */
+asmlinkage long __sys_x86_getcpu(const struct pt_regs *regs);
+asmlinkage long __sys_x86_gettimeofday(const struct pt_regs *regs);
+asmlinkage long __sys_x86_time(const struct pt_regs *regs);
 
 #endif /* _ASM_X86_SYSCALL_WRAPPER_H */
-- 
2.16.3

Re: [PATCH 8/8] syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*()

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 2677 bytes --]

Hi Dominik,

I love your patch! Yet something to improve:

[auto build test ERROR on linus/master]
[also build test ERROR on next-20180405]
[cannot apply to tip/x86/core v4.16]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Dominik-Brodowski/use-struct-pt_regs-based-syscall-calling-for-x86-64/20180406-003520
config: um-x86_64_defconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um SUBARCH=x86_64

All errors (new ones prefixed by >>):

>> arch/x86/um/sys_call_table_64.o:(.rodata+0x0): undefined reference to `__sys_x86_read'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x8): undefined reference to `__sys_x86_write'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x10): undefined reference to `__sys_x86_open'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x18): undefined reference to `__sys_x86_close'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x20): undefined reference to `__sys_x86_newstat'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x28): undefined reference to `__sys_x86_newfstat'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x30): undefined reference to `__sys_x86_newlstat'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x38): undefined reference to `__sys_x86_poll'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x40): undefined reference to `__sys_x86_lseek'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x48): undefined reference to `__sys_x86_mmap'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x50): undefined reference to `__sys_x86_mprotect'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x58): undefined reference to `__sys_x86_munmap'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x60): undefined reference to `__sys_x86_brk'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x68): undefined reference to `__sys_x86_rt_sigaction'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x70): undefined reference to `__sys_x86_rt_sigprocmask'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x78): undefined reference to `__sys_x86_rt_sigreturn'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x80): undefined reference to `__sys_x86_ioctl'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x88): undefined reference to `__sys_x86_pread64'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x90): undefined reference to `__sys_x86_pwrite64'
>> arch/x86/um/sys_call_table_64.o:(.rodata+0x98): undefined reference to `__sys_x86_readv'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 7357 bytes --]

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Ingo Molnar]

* Dominik Brodowski <linux@dominikbrodowski.net> wrote:

> Dominik Brodowski (7):
>   syscalls: introduce CONFIG_ARCH_HAS_SYSCALL_WRAPPER
>   syscalls/x86: use struct pt_regs based syscall calling for 64-bit
>     syscalls
>   syscalls: prepare ARCH_HAS_SYSCALL_WRAPPER for compat syscalls
>   syscalls/x86: use struct pt_regs based syscall calling for
>     IA32_EMULATION and x32
>   syscalls/x86: unconditionally enable struct pt_regs based syscalls on
>     x86_64
>   x86/entry/64: extend register clearing on syscall entry to lower
>     registers
>   syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*()
> 
> Linus Torvalds (1):
>   x86: don't pointlessly reload the system call number
> 
>  arch/x86/Kconfig                       |   1 +
>  arch/x86/entry/calling.h               |   2 +
>  arch/x86/entry/common.c                |  20 +-
>  arch/x86/entry/entry_64.S              |   3 +-
>  arch/x86/entry/entry_64_compat.S       |   6 +
>  arch/x86/entry/syscall_32.c            |  15 +-
>  arch/x86/entry/syscall_64.c            |   6 +-
>  arch/x86/entry/syscalls/syscall_32.tbl | 724 +++++++++++++++++----------------
>  arch/x86/entry/syscalls/syscall_64.tbl | 712 ++++++++++++++++----------------
>  arch/x86/entry/vsyscall/vsyscall_64.c  |  18 +-
>  arch/x86/include/asm/syscall.h         |   4 +
>  arch/x86/include/asm/syscall_wrapper.h | 197 +++++++++
>  arch/x86/include/asm/syscalls.h        |  17 +-
>  include/linux/compat.h                 |  22 +
>  include/linux/syscalls.h               |  25 +-
>  init/Kconfig                           |  10 +
>  kernel/sys_ni.c                        |  10 +
>  kernel/time/posix-stubs.c              |  10 +
>  18 files changed, 1054 insertions(+), 748 deletions(-)
>  create mode 100644 arch/x86/include/asm/syscall_wrapper.h

Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:

 make[2]: *** No rule to make target 'archheaders'.  Stop.
 arch/um/Makefile:119: recipe for target 'archheaders' failed
 make[1]: *** [archheaders] Error 2
 make[1]: *** Waiting for unfinished jobs....

Thanks,

	Ingo

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> 
>  make[2]: *** No rule to make target 'archheaders'.  Stop.
>  arch/um/Makefile:119: recipe for target 'archheaders' failed
>  make[1]: *** [archheaders] Error 2
>  make[1]: *** Waiting for unfinished jobs....

Ah, that's caused by patch 8/8 which I did and do not like all that much
anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
__sys_x86_pread64, but expects the generic syscall stub sys_pread64
referenced there. Fixup patch below; could be folded with patch 8/8. Or
patch 8/8 could simply be dropped from the series altogether...

Thanks,
	Dominik

--------------------------------------------------------------------------
>From f5049ea4e1e5e7751e72a22cbc1b3a9389959a04 Mon Sep 17 00:00:00 2001
From: Dominik Brodowski <linux@dominikbrodowski.net>
Date: Thu, 5 Apr 2018 22:16:23 +0200
Subject: [PATCH] syscalls/x86: fix UML syscall table

To differentiate the different calling regime used on x86, the syscall
functions received __sys_x86_ as prefix (instead of sys_). This breaks
the build of UML on 64-bit x86, as it re-uses the same syscall table.

To fix this, replace the __sys_x86_ prefix with sys_ during the generation
of <asm/syscalls_64.h>.

Fixes: syscalls/x86: rename struct pt_regs-based sys_*() to __sys_x86_*()
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: x86@kernel.org
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

diff --git a/arch/x86/entry/syscalls/syscalltbl.sh b/arch/x86/entry/syscalls/syscalltbl.sh
index d71ef4bd3615..d6376b87ecb2 100644
--- a/arch/x86/entry/syscalls/syscalltbl.sh
+++ b/arch/x86/entry/syscalls/syscalltbl.sh
@@ -20,17 +20,47 @@ syscall_macro() {
     echo "__SYSCALL_${abi}($nr, $real_entry, $qualifier)"
 }
 
-emit() {
+emit64() {
     abi="$1"
     nr="$2"
     entry="$3"
     compat="$4"
 
-    if [ "$abi" = "64" -a -n "$compat" ]; then
+    if [ "$abi" = "I386" ]; then
+	echo "emit64() called for a 32-bit syscall" >&2
+	exit 1
+    fi
+
+    if [ -n "$compat" ]; then
 	echo "a compat entry for a 64-bit syscall makes no sense" >&2
 	exit 1
     fi
 
+    if [ -n "$entry" ]; then
+	# For CONFIG_UML, we need to strip the __sys_x86 prefix
+	if [ "${entry}" = "${entry#__compat_sys}" ]; then
+            umlentry="sys${entry#__sys_x86}"
+	fi
+
+	echo "#ifdef CONFIG_X86"
+	syscall_macro "$abi" "$nr" "$entry"
+	echo "#else /* CONFIG_UML */"
+	syscall_macro "$abi" "$nr" "$umlentry"
+	echo "#endif"
+    fi
+}
+
+emit32() {
+    abi="$1"
+    nr="$2"
+    entry="$3"
+    compat="$4"
+
+    if [ "$abi" = "64" ]; then
+	echo "emit32() called for a 64-bit syscall" >&2
+	exit 1
+    fi
+
     if [ -z "$compat" ]; then
 	if [ -n "$entry" ]; then
 	    syscall_macro "$abi" "$nr" "$entry"
@@ -53,14 +83,14 @@ grep '^[0-9]' "$in" | sort -n | (
 	    # COMMON is the same as 64, except that we don't expect X32
 	    # programs to use it.  Our expectation has nothing to do with
 	    # any generated code, so treat them the same.
-	    emit 64 "$nr" "$entry" "$compat"
+	    emit64 64 "$nr" "$entry" "$compat"
 	elif [ "$abi" = "X32" ]; then
 	    # X32 is equivalent to 64 on an X32-compatible kernel.
 	    echo "#ifdef CONFIG_X86_X32_ABI"
-	    emit 64 "$nr" "$entry" "$compat"
+	    emit64 64 "$nr" "$entry" "$compat"
 	    echo "#endif"
 	elif [ "$abi" = "I386" ]; then
-	    emit "$abi" "$nr" "$entry" "$compat"
+	    emit32 "$abi" "$nr" "$entry" "$compat"
 	else
 	    echo "Unknown abi $abi" >&2
 	    exit 1

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Ingo Molnar]

* Dominik Brodowski <linux@dominikbrodowski.net> wrote:

> On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> > 
> >  make[2]: *** No rule to make target 'archheaders'.  Stop.
> >  arch/um/Makefile:119: recipe for target 'archheaders' failed
> >  make[1]: *** [archheaders] Error 2
> >  make[1]: *** Waiting for unfinished jobs....
> 
> Ah, that's caused by patch 8/8 which I did and do not like all that much
> anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
> __sys_x86_pread64, but expects the generic syscall stub sys_pread64
> referenced there. Fixup patch below; could be folded with patch 8/8. Or
> patch 8/8 could simply be dropped from the series altogether...

I still like the 'truth in advertising' aspect. For example if I see this in the 
syscall table:

 10      common  mprotect                __sys_x86_mprotect

I can immediately find the _real_ syscall entry point:

ffffffff81180a10 <__sys_x86_mprotect>:
ffffffff81180a10:       48 8b 57 60             mov    0x60(%rdi),%rdx
ffffffff81180a14:       48 8b 77 68             mov    0x68(%rdi),%rsi
ffffffff81180a18:       b9 ff ff ff ff          mov    $0xffffffff,%ecx
ffffffff81180a1d:       48 8b 7f 70             mov    0x70(%rdi),%rdi
ffffffff81180a21:       e8 fa fc ff ff          callq  ffffffff81180720 <do_mprotect_pkey>
ffffffff81180a26:       48 98                   cltq   
ffffffff81180a28:       c3                      retq   
ffffffff81180a29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)

If, on the other hand, I see this entry:

 10     common  mprotect                sys_mprotect

Then, as a first step, no symbol anywhere matches with this:

 triton:~/tip> grep sys_mprotect System.map 
 triton:~/tip> 

"sys_mprotect" does not exist in any easily discoverable sense. You have to *know* 
to replace the sys_ prefix with __sys_x86_ to find it.

Now arguably we could use a __sys_ prefix instead of the grep-barrier __sys_x86 
prefix - but that too would be somewhat confusing I think.

I mean, the fact that we are passing in a ptregs pointer is a complexity of the 
x86 kernel that *exists*, why hide it and make it harder to discover what's 
happening, for something as important as system calls?

In terms of UML breakage, UML arguably is tightly coupled to its host 
architecture:

> Subject: [PATCH] syscalls/x86: fix UML syscall table

Even with your patch applied I still see build failures:

  $ make ARCH=um defconfig
  $ make ARCH=um linux
  ...
  arch/um/os-Linux/signal.c: In function ‘hard_handler’:
  arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to incomplete type 
  ‘struct ucontext’
    mcontext_t *mc = &uc->uc_mcontext;
                        ^~
  scripts/Makefile.build:324: recipe for target 'arch/um/os-Linux/signal.o' failed
  make[1]: *** [arch/um/os-Linux/signal.o] Error 1

Thanks,

	Ingo

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

On Fri, Apr 06, 2018 at 10:23:22AM +0200, Ingo Molnar wrote:
> 
> * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> 
> > On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> > > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> > > 
> > >  make[2]: *** No rule to make target 'archheaders'.  Stop.
> > >  arch/um/Makefile:119: recipe for target 'archheaders' failed
> > >  make[1]: *** [archheaders] Error 2
> > >  make[1]: *** Waiting for unfinished jobs....
> > 
> > Ah, that's caused by patch 8/8 which I did and do not like all that much
> > anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
> > __sys_x86_pread64, but expects the generic syscall stub sys_pread64
> > referenced there. Fixup patch below; could be folded with patch 8/8. Or
> > patch 8/8 could simply be dropped from the series altogether...
> 
> I still like the 'truth in advertising' aspect. For example if I see this in the 
> syscall table:
> 
>  10      common  mprotect                __sys_x86_mprotect
> 
> I can immediately find the _real_ syscall entry point:
> 
> ffffffff81180a10 <__sys_x86_mprotect>:
> ffffffff81180a10:       48 8b 57 60             mov    0x60(%rdi),%rdx
> ffffffff81180a14:       48 8b 77 68             mov    0x68(%rdi),%rsi
> ffffffff81180a18:       b9 ff ff ff ff          mov    $0xffffffff,%ecx
> ffffffff81180a1d:       48 8b 7f 70             mov    0x70(%rdi),%rdi
> ffffffff81180a21:       e8 fa fc ff ff          callq  ffffffff81180720 <do_mprotect_pkey>
> ffffffff81180a26:       48 98                   cltq   
> ffffffff81180a28:       c3                      retq   
> ffffffff81180a29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
> 
> If, on the other hand, I see this entry:
> 
>  10     common  mprotect                sys_mprotect
> 
> Then, as a first step, no symbol anywhere matches with this:
> 
>  triton:~/tip> grep sys_mprotect System.map 
>  triton:~/tip> 
> 
> "sys_mprotect" does not exist in any easily discoverable sense. You have to *know* 
> to replace the sys_ prefix with __sys_x86_ to find it.
> 
> Now arguably we could use a __sys_ prefix instead of the grep-barrier __sys_x86 
> prefix - but that too would be somewhat confusing I think.
> 
> I mean, the fact that we are passing in a ptregs pointer is a complexity of the 
> x86 kernel that *exists*, why hide it and make it harder to discover what's 
> happening, for something as important as system calls?
> 
> In terms of UML breakage, UML arguably is tightly coupled to its host 
> architecture:
> 
> > Subject: [PATCH] syscalls/x86: fix UML syscall table
> 
> Even with your patch applied I still see build failures:
> 
>   $ make ARCH=um defconfig
>   $ make ARCH=um linux
>   ...
>   arch/um/os-Linux/signal.c: In function ‘hard_handler’:
>   arch/um/os-Linux/signal.c:163:22: error: dereferencing pointer to incomplete type 
>   ‘struct ucontext’
>     mcontext_t *mc = &uc->uc_mcontext;
>                         ^~
>   scripts/Makefile.build:324: recipe for target 'arch/um/os-Linux/signal.o' failed
>   make[1]: *** [arch/um/os-Linux/signal.o] Error 1

That build failure is already present in mainline as of 38c23685b273
(when building on Arch / gcc-7.3.1; building on Debian oldstable / gcc-4.9
works fine). And -- just checked -- this build failure also exists for
plain v4.16.

Thanks,
	Dominik

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

On Fri, Apr 06, 2018 at 10:23:22AM +0200, Ingo Molnar wrote:
> 
> * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> 
> > On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> > > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> > > 
> > >  make[2]: *** No rule to make target 'archheaders'.  Stop.
> > >  arch/um/Makefile:119: recipe for target 'archheaders' failed
> > >  make[1]: *** [archheaders] Error 2
> > >  make[1]: *** Waiting for unfinished jobs....
> > 
> > Ah, that's caused by patch 8/8 which I did and do not like all that much
> > anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
> > __sys_x86_pread64, but expects the generic syscall stub sys_pread64
> > referenced there. Fixup patch below; could be folded with patch 8/8. Or
> > patch 8/8 could simply be dropped from the series altogether...
> 
> I still like the 'truth in advertising' aspect. For example if I see this in the 
> syscall table:
> 
>  10      common  mprotect                __sys_x86_mprotect
> 
> I can immediately find the _real_ syscall entry point:
> 
> ffffffff81180a10 <__sys_x86_mprotect>:
> ffffffff81180a10:       48 8b 57 60             mov    0x60(%rdi),%rdx
> ffffffff81180a14:       48 8b 77 68             mov    0x68(%rdi),%rsi
> ffffffff81180a18:       b9 ff ff ff ff          mov    $0xffffffff,%ecx
> ffffffff81180a1d:       48 8b 7f 70             mov    0x70(%rdi),%rdi
> ffffffff81180a21:       e8 fa fc ff ff          callq  ffffffff81180720 <do_mprotect_pkey>
> ffffffff81180a26:       48 98                   cltq   
> ffffffff81180a28:       c3                      retq   
> ffffffff81180a29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
> 
> If, on the other hand, I see this entry:
> 
>  10     common  mprotect                sys_mprotect
> 
> Then, as a first step, no symbol anywhere matches with this:
> 
>  triton:~/tip> grep sys_mprotect System.map 
>  triton:~/tip> 
> 
> "sys_mprotect" does not exist in any easily discoverable sense. You have to *know* 
> to replace the sys_ prefix with __sys_x86_ to find it.
> 
> Now arguably we could use a __sys_ prefix instead of the grep-barrier __sys_x86 
> prefix - but that too would be somewhat confusing I think.

Well, if looking at the ARCH="um" kernel, you won't find the
__sys_x86_mprotect there in its System.map -- so we either have to
disentangle um and plain x86, or live with some cause for confusion.

__sys_mprotect as prefix won't work by the way, as the double-underscore
__sys_ variant is already used in net/* for internal syscall helpers.

Thanks,
	Dominik

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Ingo Molnar]

* Dominik Brodowski <linux@dominikbrodowski.net> wrote:

> On Fri, Apr 06, 2018 at 10:23:22AM +0200, Ingo Molnar wrote:
> > 
> > * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> > 
> > > On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> > > > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> > > > 
> > > >  make[2]: *** No rule to make target 'archheaders'.  Stop.
> > > >  arch/um/Makefile:119: recipe for target 'archheaders' failed
> > > >  make[1]: *** [archheaders] Error 2
> > > >  make[1]: *** Waiting for unfinished jobs....
> > > 
> > > Ah, that's caused by patch 8/8 which I did and do not like all that much
> > > anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
> > > __sys_x86_pread64, but expects the generic syscall stub sys_pread64
> > > referenced there. Fixup patch below; could be folded with patch 8/8. Or
> > > patch 8/8 could simply be dropped from the series altogether...
> > 
> > I still like the 'truth in advertising' aspect. For example if I see this in the 
> > syscall table:
> > 
> >  10      common  mprotect                __sys_x86_mprotect
> > 
> > I can immediately find the _real_ syscall entry point:
> > 
> > ffffffff81180a10 <__sys_x86_mprotect>:
> > ffffffff81180a10:       48 8b 57 60             mov    0x60(%rdi),%rdx
> > ffffffff81180a14:       48 8b 77 68             mov    0x68(%rdi),%rsi
> > ffffffff81180a18:       b9 ff ff ff ff          mov    $0xffffffff,%ecx
> > ffffffff81180a1d:       48 8b 7f 70             mov    0x70(%rdi),%rdi
> > ffffffff81180a21:       e8 fa fc ff ff          callq  ffffffff81180720 <do_mprotect_pkey>
> > ffffffff81180a26:       48 98                   cltq   
> > ffffffff81180a28:       c3                      retq   
> > ffffffff81180a29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
> > 
> > If, on the other hand, I see this entry:
> > 
> >  10     common  mprotect                sys_mprotect
> > 
> > Then, as a first step, no symbol anywhere matches with this:
> > 
> >  triton:~/tip> grep sys_mprotect System.map 
> >  triton:~/tip> 
> > 
> > "sys_mprotect" does not exist in any easily discoverable sense. You have to *know* 
> > to replace the sys_ prefix with __sys_x86_ to find it.
> > 
> > Now arguably we could use a __sys_ prefix instead of the grep-barrier __sys_x86 
> > prefix - but that too would be somewhat confusing I think.
> 
> Well, if looking at the ARCH="um" kernel, you won't find the __sys_x86_mprotect 
> there in its System.map -- so we either have to disentangle um and plain x86, or 
> live with some cause for confusion.

I'm primarily concerned about everything making sense on x86 - UML is an entirely 
separate architecture with heavy tradeoffs and kludges.

> __sys_mprotect as prefix won't work by the way, as the double-underscore __sys_ 
> variant is already used in net/* for internal syscall helpers.

Ok - then triple underscore - but overall I think it's more confusing.

Btw., what was the problem with calling the x86 ptregs wrapper sys_mprotect?

The only reason I suggested the __sys_x86_ prefix was because you originally 
suggested that there's symbol name overlap, but I don't think that's the case 
within the same kernel build, as the regular non-ptregs prototype:

  asmlinkage long sys_mprotect(unsigned long start, size_t len, unsigned long prot);

... will only exist on !CONFIG_ARCH_HAS_SYSCALL_WRAPPER kernels.

So maybe that's the simplest and least confusing solution.

Thanks,

	Ingo

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

On Fri, Apr 06, 2018 at 11:20:46AM +0200, Ingo Molnar wrote:
> 
> * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> 
> > On Fri, Apr 06, 2018 at 10:23:22AM +0200, Ingo Molnar wrote:
> > > 
> > > * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> > > 
> > > > On Thu, Apr 05, 2018 at 05:19:33PM +0200, Ingo Molnar wrote:
> > > > > Ok, this series looks mostly good to me, but AFAICS this breaks the UML build:
> > > > > 
> > > > >  make[2]: *** No rule to make target 'archheaders'.  Stop.
> > > > >  arch/um/Makefile:119: recipe for target 'archheaders' failed
> > > > >  make[1]: *** [archheaders] Error 2
> > > > >  make[1]: *** Waiting for unfinished jobs....
> > > > 
> > > > Ah, that's caused by patch 8/8 which I did and do not like all that much
> > > > anyway: UML re-uses syscall_64.tbl which now has x86-specific entries like
> > > > __sys_x86_pread64, but expects the generic syscall stub sys_pread64
> > > > referenced there. Fixup patch below; could be folded with patch 8/8. Or
> > > > patch 8/8 could simply be dropped from the series altogether...
> > > 
> > > I still like the 'truth in advertising' aspect. For example if I see this in the 
> > > syscall table:
> > > 
> > >  10      common  mprotect                __sys_x86_mprotect
> > > 
> > > I can immediately find the _real_ syscall entry point:
> > > 
> > > ffffffff81180a10 <__sys_x86_mprotect>:
> > > ffffffff81180a10:       48 8b 57 60             mov    0x60(%rdi),%rdx
> > > ffffffff81180a14:       48 8b 77 68             mov    0x68(%rdi),%rsi
> > > ffffffff81180a18:       b9 ff ff ff ff          mov    $0xffffffff,%ecx
> > > ffffffff81180a1d:       48 8b 7f 70             mov    0x70(%rdi),%rdi
> > > ffffffff81180a21:       e8 fa fc ff ff          callq  ffffffff81180720 <do_mprotect_pkey>
> > > ffffffff81180a26:       48 98                   cltq   
> > > ffffffff81180a28:       c3                      retq   
> > > ffffffff81180a29:       0f 1f 80 00 00 00 00    nopl   0x0(%rax)
> > > 
> > > If, on the other hand, I see this entry:
> > > 
> > >  10     common  mprotect                sys_mprotect
> > > 
> > > Then, as a first step, no symbol anywhere matches with this:
> > > 
> > >  triton:~/tip> grep sys_mprotect System.map 
> > >  triton:~/tip> 
> > > 
> > > "sys_mprotect" does not exist in any easily discoverable sense. You have to *know* 
> > > to replace the sys_ prefix with __sys_x86_ to find it.
> > > 
> > > Now arguably we could use a __sys_ prefix instead of the grep-barrier __sys_x86 
> > > prefix - but that too would be somewhat confusing I think.
> > 
> > Well, if looking at the ARCH="um" kernel, you won't find the __sys_x86_mprotect 
> > there in its System.map -- so we either have to disentangle um and plain x86, or 
> > live with some cause for confusion.
> 
> I'm primarily concerned about everything making sense on x86 - UML is an entirely 
> separate architecture with heavy tradeoffs and kludges.

Agreed.

> > __sys_mprotect as prefix won't work by the way, as the double-underscore __sys_ 
> > variant is already used in net/* for internal syscall helpers.
> 
> Ok - then triple underscore - but overall I think it's more confusing.
> 
> Btw., what was the problem with calling the x86 ptregs wrapper sys_mprotect?
> 
> The only reason I suggested the __sys_x86_ prefix was because you originally 
> suggested that there's symbol name overlap, but I don't think that's the case 
> within the same kernel build, as the regular non-ptregs prototype:

Indeed, there's no symbol name overlap within the same kernel build, but
technically different stubs named the same. If that's fine, just drop patch
8/8 (including the UML fixup) and things should be fine, with the stub and
the entry in the syscall table both named sys_mprotect.

For IA32_EMULATION, we have __sys_ia32_mprotect as stub for the same
syscall, including this name as entry in syscall_32.tbl.

More problematic is the naming for the compat stubs for IA32_EMAULATION and
X32, where we have

	__compat_sys_ia32_waitid
	__compat_sys_x32_waitid

for example. We *could* rename one of those to compat_sys_waitid() and levae
the other as-is, but actually I prefer it now how it is.

Thanks,
	Dominik

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Ingo Molnar]

* Dominik Brodowski <linux@dominikbrodowski.net> wrote:

> > > __sys_mprotect as prefix won't work by the way, as the double-underscore __sys_ 
> > > variant is already used in net/* for internal syscall helpers.
> > 
> > Ok - then triple underscore - but overall I think it's more confusing.
> > 
> > Btw., what was the problem with calling the x86 ptregs wrapper sys_mprotect?
> > 
> > The only reason I suggested the __sys_x86_ prefix was because you originally 
> > suggested that there's symbol name overlap, but I don't think that's the case 
> > within the same kernel build, as the regular non-ptregs prototype:
> 
> Indeed, there's no symbol name overlap within the same kernel build, but
> technically different stubs named the same. If that's fine, just drop patch
> 8/8 (including the UML fixup) and things should be fine, with the stub and
> the entry in the syscall table both named sys_mprotect.

Ok, I've dropped patch #8.

> For IA32_EMULATION, we have __sys_ia32_mprotect as stub for the same
> syscall, including this name as entry in syscall_32.tbl.
> 
> More problematic is the naming for the compat stubs for IA32_EMAULATION and
> X32, where we have
> 
> 	__compat_sys_ia32_waitid
> 	__compat_sys_x32_waitid
> 
> for example. We *could* rename one of those to compat_sys_waitid() and levae
> the other as-is, but actually I prefer it now how it is.

yeah, this is more symmetric I think.

So right now we have these symbols:

 triton:~/tip> grep waitid System.map 

 ffffffff8105f1e0 t kernel_waitid               # common C function (64-bit kargs)
 ffffffff8105f2b0 t SYSC_waitid                 # 64-bit uaddr args C function       352 bytes
 ffffffff8105f410 T sys_waitid                  # 64-bit-ptregs -> C stub,            32 bytes
 ffffffff8105f430 T __sys_ia32_waitid           # 32-bit-ptregs -> C stub,            32 bytes
 ffffffff8105f450 t C_SYSC_waitid               # 32-bit uaddr args C function,      400 bytes
 ffffffff8105f5e0 T __compat_sys_ia32_waitid    # 32-bit-ptregs -> C stub,            32 bytes
 ffffffff8105f600 T __compat_sys_x32_waitid     # 64-bit-ptregs -> C stub,            32 bytes

BTW., what is the role of generating __sys_ia32_waitid()? It seems unused when a 
syscall has a compat variant otherwise - like here.

Naming wise the odd thumb out is sys_waitid :-/

I'd argue that we should at minimum name it __sys_waitid:

 ffffffff8105f1e0 t kernel_waitid               # common C function (64-bit kargs)
 ffffffff8105f2b0 t SYSC_waitid                 # 64-bit uaddr args C function
 ffffffff8105f410 T __sys_waitid                # 64-bit-ptregs -> C stub
 ffffffff8105f430 T __sys_ia32_waitid           # 32-bit-ptregs -> C stub
 ffffffff8105f450 t C_SYSC_waitid               # 32-bit uaddr args C function
 ffffffff8105f5e0 T __compat_sys_ia32_waitid    # 32-bit-ptregs -> C stub
 ffffffff8105f600 T __compat_sys_x32_waitid     # 64-bit-ptregs -> C stub

because that makes it all organized based on the same principle:

    {__compat|_}_sys{_ia32|_x32|}_waittid

But arguably there are a whole lot more naming weirdnesses we could fix:

 - I find it somewhat confusing that that 'C' in C_SYSC stands not for a C callign 
   convention, but for 'COMPAT' - i.e. COMPAT_SYSC would be better.

 - Another detail is that why is it called 'SYSC', if the other functions use the 
   'sys' prefix? Wouldn't 'SYS' be more consistent?

 - If we introduced a prefix for the regular 64-bit system call format as well,
   we could have: x64, x32 and ia32.

 - And finally, I think the argument format modifiers should be consistently
   prefixes - right now they are a mixture of pre- and post-fixes.

I.e. I'd generate the names like this:

    __{x64,x32,ia32}[_compat]_sys_waittid()

The fully consistent nomenclature would be someting like this:

 ffffffff8105f1e0 t            kernel_waitid    # common C function (64-bit kargs)
 ffffffff8105f2b0 t               SYS_waitid    # 64-bit uaddr args C function
 ffffffff8105f410 T         __x64_sys_waitid    # 64-bit-ptregs -> C stub
 ffffffff8105f430 T        __ia32_sys_waitid    # 32-bit-ptregs -> C stub
 ffffffff8105f450 t        COMPAT_SYS_waitid    # 32-bit uaddr args C function
 ffffffff8105f5e0 T __ia32_compat_sys_waitid    # 32-bit-ptregs -> C stub
 ffffffff8105f600 T  __x32_compat_sys_waitid    # 64-bit-ptregs -> C stub

Looks a lot tidier and a lot more logical, doesn't it?

Makes grepping easier as well, because (case-insensitive) patterns like 
'sys_waittid' would identify all the variants.

Personally I'd also do a s/ia32/i32 rename:

 ffffffff8105f1e0 t            kernel_waitid    # common C function (64-bit kargs)
 ffffffff8105f2b0 t               SYS_waitid    # 64-bit uaddr args C function
 ffffffff8105f410 T         __x64_sys_waitid    # 64-bit-ptregs -> C stub
 ffffffff8105f430 T         __i32_sys_waitid    # 32-bit-ptregs -> C stub
 ffffffff8105f450 t        COMPAT_SYS_waitid    # 32-bit uaddr args C function
 ffffffff8105f5e0 T  __i32_compat_sys_waitid    # 32-bit-ptregs -> C stub
 ffffffff8105f600 T  __x32_compat_sys_waitid    # 64-bit-ptregs -> C stub

... but maybe that's too much ;-)

Thanks,

	Ingo

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Dominik Brodowski]

On Fri, Apr 06, 2018 at 02:34:20PM +0200, Ingo Molnar wrote:
> 
> * Dominik Brodowski <linux@dominikbrodowski.net> wrote:
> 
> > > > __sys_mprotect as prefix won't work by the way, as the double-underscore __sys_ 
> > > > variant is already used in net/* for internal syscall helpers.
> > > 
> > > Ok - then triple underscore - but overall I think it's more confusing.
> > > 
> > > Btw., what was the problem with calling the x86 ptregs wrapper sys_mprotect?
> > > 
> > > The only reason I suggested the __sys_x86_ prefix was because you originally 
> > > suggested that there's symbol name overlap, but I don't think that's the case 
> > > within the same kernel build, as the regular non-ptregs prototype:
> > 
> > Indeed, there's no symbol name overlap within the same kernel build, but
> > technically different stubs named the same. If that's fine, just drop patch
> > 8/8 (including the UML fixup) and things should be fine, with the stub and
> > the entry in the syscall table both named sys_mprotect.
> 
> Ok, I've dropped patch #8.

Thanks!

> > For IA32_EMULATION, we have __sys_ia32_mprotect as stub for the same
> > syscall, including this name as entry in syscall_32.tbl.
> > 
> > More problematic is the naming for the compat stubs for IA32_EMAULATION and
> > X32, where we have
> > 
> > 	__compat_sys_ia32_waitid
> > 	__compat_sys_x32_waitid
> > 
> > for example. We *could* rename one of those to compat_sys_waitid() and levae
> > the other as-is, but actually I prefer it now how it is.
> 
> yeah, this is more symmetric I think.
> 
> So right now we have these symbols:
> 
>  triton:~/tip> grep waitid System.map 
> 
>  ffffffff8105f1e0 t kernel_waitid               # common C function (64-bit kargs)
>  ffffffff8105f2b0 t SYSC_waitid                 # 64-bit uaddr args C function       352 bytes
>  ffffffff8105f410 T sys_waitid                  # 64-bit-ptregs -> C stub,            32 bytes
>  ffffffff8105f430 T __sys_ia32_waitid           # 32-bit-ptregs -> C stub,            32 bytes
>  ffffffff8105f450 t C_SYSC_waitid               # 32-bit uaddr args C function,      400 bytes
>  ffffffff8105f5e0 T __compat_sys_ia32_waitid    # 32-bit-ptregs -> C stub,            32 bytes
>  ffffffff8105f600 T __compat_sys_x32_waitid     # 64-bit-ptregs -> C stub,            32 bytes
> 
> BTW., what is the role of generating __sys_ia32_waitid()? It seems unused when a 
> syscall has a compat variant otherwise - like here.

Indeed it is unused -- but when compiling

	SYSCALL_DEFINE5(waitid, ...)

we don't know yet that somewhere else in the kernel there is

	COMPAT_SYSCALL_DEFINE5(waitid, ...)

So if we want to compile the __sys_ia32_ stub only iff it is used, we'd 
need to have different macros for syscalls which have compat variants and
for those which do not. Or do you have an idea how we could trick the
compiler to do the right thing?

> Naming wise the odd thumb out is sys_waitid :-/
> 
> I'd argue that we should at minimum name it __sys_waitid:

Can't do, as that namespace is already taken.

>  ffffffff8105f1e0 t kernel_waitid               # common C function (64-bit kargs)
>  ffffffff8105f2b0 t SYSC_waitid                 # 64-bit uaddr args C function
>  ffffffff8105f410 T __sys_waitid                # 64-bit-ptregs -> C stub
>  ffffffff8105f430 T __sys_ia32_waitid           # 32-bit-ptregs -> C stub
>  ffffffff8105f450 t C_SYSC_waitid               # 32-bit uaddr args C function
>  ffffffff8105f5e0 T __compat_sys_ia32_waitid    # 32-bit-ptregs -> C stub
>  ffffffff8105f600 T __compat_sys_x32_waitid     # 64-bit-ptregs -> C stub
> 
> because that makes it all organized based on the same principle:
> 
>     {__compat|_}_sys{_ia32|_x32|}_waittid
> 
> But arguably there are a whole lot more naming weirdnesses we could fix:
> 
>  - I find it somewhat confusing that that 'C' in C_SYSC stands not for a C callign 
>    convention, but for 'COMPAT' - i.e. COMPAT_SYSC would be better.
> 
>  - Another detail is that why is it called 'SYSC', if the other functions use the 
>    'sys' prefix? Wouldn't 'SYS' be more consistent?

It sounds totally reasonable to re-name those, but we should do it not only
for the x86 case, but in include/linux/syscalls.h as well.

>  - If we introduced a prefix for the regular 64-bit system call format as well,
>    we could have: x64, x32 and ia32.
> 
>  - And finally, I think the argument format modifiers should be consistently
>    prefixes - right now they are a mixture of pre- and post-fixes.
> 
> I.e. I'd generate the names like this:
> 
>     __{x64,x32,ia32}[_compat]_sys_waittid()
> 
> The fully consistent nomenclature would be someting like this:
> 
>  ffffffff8105f1e0 t            kernel_waitid    # common C function (64-bit kargs)
>  ffffffff8105f2b0 t               SYS_waitid    # 64-bit uaddr args C function
>  ffffffff8105f410 T         __x64_sys_waitid    # 64-bit-ptregs -> C stub
>  ffffffff8105f430 T        __ia32_sys_waitid    # 32-bit-ptregs -> C stub
>  ffffffff8105f450 t        COMPAT_SYS_waitid    # 32-bit uaddr args C function
>  ffffffff8105f5e0 T __ia32_compat_sys_waitid    # 32-bit-ptregs -> C stub
>  ffffffff8105f600 T  __x32_compat_sys_waitid    # 64-bit-ptregs -> C stub
> 
> Looks a lot tidier and a lot more logical, doesn't it?

Indeed. Want me to prepare a new patch 8/8 on top which does the renaming
(for x86 and for the generic case), or will you do the re-naming while
merging my patches yourself?

> Personally I'd also do a s/ia32/i32 rename:

Uh, no, please. It makes things align more beautifully, yes, but the
32-bit sub-architecture commonly is referred to as either i386 or ia32...

Thanks,
	Dominik

Re: [PATCH 0/8] use struct pt_regs based syscall calling for x86-64

[Ingo Molnar]

* Dominik Brodowski <linux@dominikbrodowski.net> wrote:

> > I.e. I'd generate the names like this:
> > 
> >     __{x64,x32,ia32}[_compat]_sys_waittid()
> > 
> > The fully consistent nomenclature would be someting like this:
> > 
> >  ffffffff8105f1e0 t            kernel_waitid    # common C function (64-bit kargs)
> >  ffffffff8105f2b0 t               SYS_waitid    # 64-bit uaddr args C function
> >  ffffffff8105f410 T         __x64_sys_waitid    # 64-bit-ptregs -> C stub
> >  ffffffff8105f430 T        __ia32_sys_waitid    # 32-bit-ptregs -> C stub
> >  ffffffff8105f450 t        COMPAT_SYS_waitid    # 32-bit uaddr args C function
> >  ffffffff8105f5e0 T __ia32_compat_sys_waitid    # 32-bit-ptregs -> C stub
> >  ffffffff8105f600 T  __x32_compat_sys_waitid    # 64-bit-ptregs -> C stub
> > 
> > Looks a lot tidier and a lot more logical, doesn't it?
> 
> Indeed. Want me to prepare a new patch 8/8 on top which does the renaming
> (for x86 and for the generic case), or will you do the re-naming while
> merging my patches yourself?

Please do an 8/8 patch that does the rename - I'll push out the first 7 patches so 
they get more testing.

Note, I have not checked the above name space for namespace collisions - but 
unless we are unlucky it should be fine.

BTW., is there any deep reason why some of these names are capitalized?

I.e. could we use:

  ffffffff8105f1e0 t            kernel_waitid    # common C function (64-bit kargs)
  ffffffff8105f2b0 t               sys_waitid    # 64-bit uaddr args C function
  ffffffff8105f410 T         __x64_sys_waitid    # 64-bit-ptregs -> C stub
  ffffffff8105f430 T        __ia32_sys_waitid    # 32-bit-ptregs -> C stub
  ffffffff8105f450 t        compat_sys_waitid    # 32-bit uaddr args C function
  ffffffff8105f5e0 T __ia32_compat_sys_waitid    # 32-bit-ptregs -> C stub
  ffffffff8105f600 T  __x32_compat_sys_waitid    # 64-bit-ptregs -> C stub

?

Note how this reduces naming complexity and increases the self-consistency even more.

Thanks,

	Ingo