[PATCH v1 0/4] arm64/sme: ptrace support for TPIDR2_EL0

[PATCH v1 0/4] arm64/sme: ptrace support for TPIDR2_EL0

[Mark Brown]

When SME was initially merged we did not add support for TPIDR2_EL0 to
the ptrace interface, creating difficulties for debuggers in accessing
lazy save state for ZA. This series implements that support, extending
the existing NT_ARM_TLS regset to support the register when available,
and adds kselftest coverage for the existing and new NT_ARM_TLS
functionality.

Existing programs that query the size of the register set will be able
to observe the increased size of the register set. Programs that assume
the register set is single register will see no change. On systems that
do not support SME TPIDR2_EL0 will read as 0 and writes will be ignored,
support for SME should be queried via hwcaps as normal.

Mark Brown (4):
  kselftest/arm64: Add test coverage for NT_ARM_TLS
  arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0
  arm64/ptrace: Support access to TPIDR2_EL0
  kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface

 Documentation/arm64/sme.rst                  |   3 +
 arch/arm64/kernel/ptrace.c                   |  25 +-
 tools/testing/selftests/arm64/abi/.gitignore |   1 +
 tools/testing/selftests/arm64/abi/Makefile   |   2 +-
 tools/testing/selftests/arm64/abi/ptrace.c   | 241 +++++++++++++++++++
 5 files changed, 266 insertions(+), 6 deletions(-)
 create mode 100644 tools/testing/selftests/arm64/abi/ptrace.c


base-commit: a111daf0c53ae91e71fd2bfe7497862d14132e3e
-- 
2.30.2

[PATCH v1 0/4] arm64/sme: ptrace support for TPIDR2_EL0

[Mark Brown]

When SME was initially merged we did not add support for TPIDR2_EL0 to
the ptrace interface, creating difficulties for debuggers in accessing
lazy save state for ZA. This series implements that support, extending
the existing NT_ARM_TLS regset to support the register when available,
and adds kselftest coverage for the existing and new NT_ARM_TLS
functionality.

Existing programs that query the size of the register set will be able
to observe the increased size of the register set. Programs that assume
the register set is single register will see no change. On systems that
do not support SME TPIDR2_EL0 will read as 0 and writes will be ignored,
support for SME should be queried via hwcaps as normal.

Mark Brown (4):
  kselftest/arm64: Add test coverage for NT_ARM_TLS
  arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0
  arm64/ptrace: Support access to TPIDR2_EL0
  kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface

 Documentation/arm64/sme.rst                  |   3 +
 arch/arm64/kernel/ptrace.c                   |  25 +-
 tools/testing/selftests/arm64/abi/.gitignore |   1 +
 tools/testing/selftests/arm64/abi/Makefile   |   2 +-
 tools/testing/selftests/arm64/abi/ptrace.c   | 241 +++++++++++++++++++
 5 files changed, 266 insertions(+), 6 deletions(-)
 create mode 100644 tools/testing/selftests/arm64/abi/ptrace.c


base-commit: a111daf0c53ae91e71fd2bfe7497862d14132e3e
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v1 1/4] kselftest/arm64: Add test coverage for NT_ARM_TLS

[Mark Brown]

In preparation for extending support for NT_ARM_TLS to cover additional
TPIDRs add some tests for the existing interface. Do this in a generic
ptrace test program to provide a place to collect additional tests in
the future.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/abi/.gitignore |   1 +
 tools/testing/selftests/arm64/abi/Makefile   |   2 +-
 tools/testing/selftests/arm64/abi/ptrace.c   | 165 +++++++++++++++++++
 3 files changed, 167 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/arm64/abi/ptrace.c

diff --git a/tools/testing/selftests/arm64/abi/.gitignore b/tools/testing/selftests/arm64/abi/.gitignore
index b9e54417250d..12607c4580c6 100644
--- a/tools/testing/selftests/arm64/abi/.gitignore
+++ b/tools/testing/selftests/arm64/abi/.gitignore
@@ -1,2 +1,3 @@
+ptrace
 syscall-abi
 tpidr2
diff --git a/tools/testing/selftests/arm64/abi/Makefile b/tools/testing/selftests/arm64/abi/Makefile
index c8d7f2495eb2..445ac2dac4ee 100644
--- a/tools/testing/selftests/arm64/abi/Makefile
+++ b/tools/testing/selftests/arm64/abi/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 # Copyright (C) 2021 ARM Limited
 
-TEST_GEN_PROGS := syscall-abi tpidr2
+TEST_GEN_PROGS := ptrace syscall-abi tpidr2
 
 include ../../lib.mk
 
diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c
new file mode 100644
index 000000000000..4cc4d415b2e7
--- /dev/null
+++ b/tools/testing/selftests/arm64/abi/ptrace.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 ARM Limited.
+ */
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+#include "../../kselftest.h"
+
+#define EXPECTED_TESTS 3
+
+#define MAX_TPIDRS 1
+
+static bool have_sme(void)
+{
+	return getauxval(AT_HWCAP2) & HWCAP2_SME;
+}
+
+static void test_tpidr(pid_t child)
+{
+	uint64_t read_val[MAX_TPIDRS];
+	uint64_t write_val[MAX_TPIDRS];
+	struct iovec read_iov, write_iov;
+	int ret;
+
+	read_iov.iov_base = read_val;
+	write_iov.iov_base = write_val;
+
+	/* Should be able to read a single TPIDR... */
+	read_iov.iov_len = sizeof(uint64_t);
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	ksft_test_result(ret == 0, "read_tpidr_one\n");
+
+	/* ...write a new value.. */
+	write_iov.iov_len = sizeof(uint64_t);
+	write_val[0] = read_val[0]++;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+	ksft_test_result(ret == 0, "write_tpidr_one\n");
+
+	/* ...then read it back */
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	ksft_test_result(ret == 0 && write_val[0] == read_val[0],
+			 "verify_tpidr_one\n");
+}
+
+static int do_child(void)
+{
+	if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
+		ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
+
+	if (raise(SIGSTOP))
+		ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
+
+	return EXIT_SUCCESS;
+}
+
+static int do_parent(pid_t child)
+{
+	int ret = EXIT_FAILURE;
+	pid_t pid;
+	int status;
+	siginfo_t si;
+
+	/* Attach to the child */
+	while (1) {
+		int sig;
+
+		pid = wait(&status);
+		if (pid == -1) {
+			perror("wait");
+			goto error;
+		}
+
+		/*
+		 * This should never happen but it's hard to flag in
+		 * the framework.
+		 */
+		if (pid != child)
+			continue;
+
+		if (WIFEXITED(status) || WIFSIGNALED(status))
+			ksft_exit_fail_msg("Child died unexpectedly\n");
+
+		if (!WIFSTOPPED(status))
+			goto error;
+
+		sig = WSTOPSIG(status);
+
+		if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			if (errno == EINVAL) {
+				sig = 0; /* bust group-stop */
+				goto cont;
+			}
+
+			ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+
+		if (sig == SIGSTOP && si.si_code == SI_TKILL &&
+		    si.si_pid == pid)
+			break;
+
+	cont:
+		if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			ksft_test_result_fail("PTRACE_CONT: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+	}
+
+	ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
+
+	test_tpidr(child);
+
+	ret = EXIT_SUCCESS;
+
+error:
+	kill(child, SIGKILL);
+
+disappeared:
+	return ret;
+}
+
+int main(void)
+{
+	int ret = EXIT_SUCCESS;
+	pid_t child;
+
+	srandom(getpid());
+
+	ksft_print_header();
+
+	ksft_set_plan(EXPECTED_TESTS);
+
+	child = fork();
+	if (!child)
+		return do_child();
+
+	if (do_parent(child))
+		ret = EXIT_FAILURE;
+
+	ksft_print_cnts();
+
+	return ret;
+}
-- 
2.30.2

[PATCH v1 1/4] kselftest/arm64: Add test coverage for NT_ARM_TLS

[Mark Brown]

In preparation for extending support for NT_ARM_TLS to cover additional
TPIDRs add some tests for the existing interface. Do this in a generic
ptrace test program to provide a place to collect additional tests in
the future.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/abi/.gitignore |   1 +
 tools/testing/selftests/arm64/abi/Makefile   |   2 +-
 tools/testing/selftests/arm64/abi/ptrace.c   | 165 +++++++++++++++++++
 3 files changed, 167 insertions(+), 1 deletion(-)
 create mode 100644 tools/testing/selftests/arm64/abi/ptrace.c

diff --git a/tools/testing/selftests/arm64/abi/.gitignore b/tools/testing/selftests/arm64/abi/.gitignore
index b9e54417250d..12607c4580c6 100644
--- a/tools/testing/selftests/arm64/abi/.gitignore
+++ b/tools/testing/selftests/arm64/abi/.gitignore
@@ -1,2 +1,3 @@
+ptrace
 syscall-abi
 tpidr2
diff --git a/tools/testing/selftests/arm64/abi/Makefile b/tools/testing/selftests/arm64/abi/Makefile
index c8d7f2495eb2..445ac2dac4ee 100644
--- a/tools/testing/selftests/arm64/abi/Makefile
+++ b/tools/testing/selftests/arm64/abi/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 # Copyright (C) 2021 ARM Limited
 
-TEST_GEN_PROGS := syscall-abi tpidr2
+TEST_GEN_PROGS := ptrace syscall-abi tpidr2
 
 include ../../lib.mk
 
diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c
new file mode 100644
index 000000000000..4cc4d415b2e7
--- /dev/null
+++ b/tools/testing/selftests/arm64/abi/ptrace.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021 ARM Limited.
+ */
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/auxv.h>
+#include <sys/prctl.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <sys/wait.h>
+#include <asm/sigcontext.h>
+#include <asm/ptrace.h>
+
+#include "../../kselftest.h"
+
+#define EXPECTED_TESTS 3
+
+#define MAX_TPIDRS 1
+
+static bool have_sme(void)
+{
+	return getauxval(AT_HWCAP2) & HWCAP2_SME;
+}
+
+static void test_tpidr(pid_t child)
+{
+	uint64_t read_val[MAX_TPIDRS];
+	uint64_t write_val[MAX_TPIDRS];
+	struct iovec read_iov, write_iov;
+	int ret;
+
+	read_iov.iov_base = read_val;
+	write_iov.iov_base = write_val;
+
+	/* Should be able to read a single TPIDR... */
+	read_iov.iov_len = sizeof(uint64_t);
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	ksft_test_result(ret == 0, "read_tpidr_one\n");
+
+	/* ...write a new value.. */
+	write_iov.iov_len = sizeof(uint64_t);
+	write_val[0] = read_val[0]++;
+	ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+	ksft_test_result(ret == 0, "write_tpidr_one\n");
+
+	/* ...then read it back */
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	ksft_test_result(ret == 0 && write_val[0] == read_val[0],
+			 "verify_tpidr_one\n");
+}
+
+static int do_child(void)
+{
+	if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
+		ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));
+
+	if (raise(SIGSTOP))
+		ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));
+
+	return EXIT_SUCCESS;
+}
+
+static int do_parent(pid_t child)
+{
+	int ret = EXIT_FAILURE;
+	pid_t pid;
+	int status;
+	siginfo_t si;
+
+	/* Attach to the child */
+	while (1) {
+		int sig;
+
+		pid = wait(&status);
+		if (pid == -1) {
+			perror("wait");
+			goto error;
+		}
+
+		/*
+		 * This should never happen but it's hard to flag in
+		 * the framework.
+		 */
+		if (pid != child)
+			continue;
+
+		if (WIFEXITED(status) || WIFSIGNALED(status))
+			ksft_exit_fail_msg("Child died unexpectedly\n");
+
+		if (!WIFSTOPPED(status))
+			goto error;
+
+		sig = WSTOPSIG(status);
+
+		if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			if (errno == EINVAL) {
+				sig = 0; /* bust group-stop */
+				goto cont;
+			}
+
+			ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+
+		if (sig == SIGSTOP && si.si_code == SI_TKILL &&
+		    si.si_pid == pid)
+			break;
+
+	cont:
+		if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
+			if (errno == ESRCH)
+				goto disappeared;
+
+			ksft_test_result_fail("PTRACE_CONT: %s\n",
+					      strerror(errno));
+			goto error;
+		}
+	}
+
+	ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
+
+	test_tpidr(child);
+
+	ret = EXIT_SUCCESS;
+
+error:
+	kill(child, SIGKILL);
+
+disappeared:
+	return ret;
+}
+
+int main(void)
+{
+	int ret = EXIT_SUCCESS;
+	pid_t child;
+
+	srandom(getpid());
+
+	ksft_print_header();
+
+	ksft_set_plan(EXPECTED_TESTS);
+
+	child = fork();
+	if (!child)
+		return do_child();
+
+	if (do_parent(child))
+		ret = EXIT_FAILURE;
+
+	ksft_print_cnts();
+
+	return ret;
+}
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v1 2/4] arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0

[Mark Brown]

In order to allow debuggers to discover lazily saved SME state we need
to provide access to TPIDR2_EL0, we will extend the existing NT_ARM_TLS
used for TPIDR to also include TPIDR2_EL0 as the second register in the
regset.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 Documentation/arm64/sme.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst
index 937147f58cc5..16d2db4c2e2e 100644
--- a/Documentation/arm64/sme.rst
+++ b/Documentation/arm64/sme.rst
@@ -331,6 +331,9 @@ The regset data starts with struct user_za_header, containing:
   been read if a PTRACE_GETREGSET of NT_ARM_ZA were executed for each thread
   when the coredump was generated.
 
+* The NT_ARM_TLS note will be extended to two registers, the second register
+  will contain TPIDR2_EL0 on systems that support SME and will be read as
+  zero with writes ignored otherwise.
 
 9.  System runtime configuration
 --------------------------------
-- 
2.30.2

[PATCH v1 2/4] arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0

[Mark Brown]

In order to allow debuggers to discover lazily saved SME state we need
to provide access to TPIDR2_EL0, we will extend the existing NT_ARM_TLS
used for TPIDR to also include TPIDR2_EL0 as the second register in the
regset.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 Documentation/arm64/sme.rst | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst
index 937147f58cc5..16d2db4c2e2e 100644
--- a/Documentation/arm64/sme.rst
+++ b/Documentation/arm64/sme.rst
@@ -331,6 +331,9 @@ The regset data starts with struct user_za_header, containing:
   been read if a PTRACE_GETREGSET of NT_ARM_ZA were executed for each thread
   when the coredump was generated.
 
+* The NT_ARM_TLS note will be extended to two registers, the second register
+  will contain TPIDR2_EL0 on systems that support SME and will be read as
+  zero with writes ignored otherwise.
 
 9.  System runtime configuration
 --------------------------------
-- 
2.30.2


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v1 3/4] arm64/ptrace: Support access to TPIDR2_EL0

[Mark Brown]

SME introduces an additional EL0 register, TPIDR2_EL0, intended for use
by userspace as part of the SME. Provide ptrace access to it through the
existing NT_ARM_TLS regset used for TPIDR_EL0 by expanding it to two
registers with TPIDR2_EL0 being the second one.

Existing programs that query the size of the register set will be able
to observe the increased size of the register set. Programs that assume
the register set is single register will see no change. On systems that
do not support SME TPIDR2_EL0 will read as 0 and writes will be ignored,
support for SME should be queried via hwcaps as normal.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/kernel/ptrace.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 21da83187a60..82feabba3911 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -666,10 +666,18 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 		   struct membuf to)
 {
+	int ret;
+
 	if (target == current)
 		tls_preserve_current_state();
 
-	return membuf_store(&to, target->thread.uw.tp_value);
+	ret = membuf_store(&to, target->thread.uw.tp_value);
+	if (system_supports_tpidr2())
+		ret = membuf_store(&to, target->thread.tpidr2_el0);
+	else
+		ret = membuf_zero(&to, sizeof(u64));
+
+	return ret;
 }
 
 static int tls_set(struct task_struct *target, const struct user_regset *regset,
@@ -677,13 +685,20 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	unsigned long tls = target->thread.uw.tp_value;
+	unsigned long tls[2];
 
-	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
+	tls[0] = target->thread.uw.tp_value;
+	if (system_supports_sme())
+		tls[1] = target->thread.tpidr2_el0;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, tls, 0, count);
 	if (ret)
 		return ret;
 
-	target->thread.uw.tp_value = tls;
+	target->thread.uw.tp_value = tls[0];
+	if (system_supports_sme())
+		target->thread.tpidr2_el0 = tls[1];
+
 	return ret;
 }
 
@@ -1392,7 +1407,7 @@ static const struct user_regset aarch64_regsets[] = {
 	},
 	[REGSET_TLS] = {
 		.core_note_type = NT_ARM_TLS,
-		.n = 1,
+		.n = 2,
 		.size = sizeof(void *),
 		.align = sizeof(void *),
 		.regset_get = tls_get,
-- 
2.30.2

[PATCH v1 3/4] arm64/ptrace: Support access to TPIDR2_EL0

[Mark Brown]

SME introduces an additional EL0 register, TPIDR2_EL0, intended for use
by userspace as part of the SME. Provide ptrace access to it through the
existing NT_ARM_TLS regset used for TPIDR_EL0 by expanding it to two
registers with TPIDR2_EL0 being the second one.

Existing programs that query the size of the register set will be able
to observe the increased size of the register set. Programs that assume
the register set is single register will see no change. On systems that
do not support SME TPIDR2_EL0 will read as 0 and writes will be ignored,
support for SME should be queried via hwcaps as normal.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 arch/arm64/kernel/ptrace.c | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 21da83187a60..82feabba3911 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -666,10 +666,18 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 static int tls_get(struct task_struct *target, const struct user_regset *regset,
 		   struct membuf to)
 {
+	int ret;
+
 	if (target == current)
 		tls_preserve_current_state();
 
-	return membuf_store(&to, target->thread.uw.tp_value);
+	ret = membuf_store(&to, target->thread.uw.tp_value);
+	if (system_supports_tpidr2())
+		ret = membuf_store(&to, target->thread.tpidr2_el0);
+	else
+		ret = membuf_zero(&to, sizeof(u64));
+
+	return ret;
 }
 
 static int tls_set(struct task_struct *target, const struct user_regset *regset,
@@ -677,13 +685,20 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	unsigned long tls = target->thread.uw.tp_value;
+	unsigned long tls[2];
 
-	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
+	tls[0] = target->thread.uw.tp_value;
+	if (system_supports_sme())
+		tls[1] = target->thread.tpidr2_el0;
+
+	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, tls, 0, count);
 	if (ret)
 		return ret;
 
-	target->thread.uw.tp_value = tls;
+	target->thread.uw.tp_value = tls[0];
+	if (system_supports_sme())
+		target->thread.tpidr2_el0 = tls[1];
+
 	return ret;
 }
 
@@ -1392,7 +1407,7 @@ static const struct user_regset aarch64_regsets[] = {
 	},
 	[REGSET_TLS] = {
 		.core_note_type = NT_ARM_TLS,
-		.n = 1,
+		.n = 2,
 		.size = sizeof(void *),
 		.align = sizeof(void *),
 		.regset_get = tls_get,
-- 
2.30.2


_______________________________________________
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linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v1 4/4] kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface

[Mark Brown]

Extend the ptrace test support for NT_ARM_TLS to cover TPIDR2_EL0 - on
systems that support SME the NT_ARM_TLS regset can be up to 2 elements
long with the second element containing TPIDR2_EL0. On systems
supporting SME we verify that this value can be read and written while
on systems that do not support SME we verify correct truncation of reads
and writes.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/abi/ptrace.c | 82 +++++++++++++++++++++-
 1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c
index 4cc4d415b2e7..0a3d28a3972b 100644
--- a/tools/testing/selftests/arm64/abi/ptrace.c
+++ b/tools/testing/selftests/arm64/abi/ptrace.c
@@ -20,9 +20,9 @@
 
 #include "../../kselftest.h"
 
-#define EXPECTED_TESTS 3
+#define EXPECTED_TESTS 7
 
-#define MAX_TPIDRS 1
+#define MAX_TPIDRS 2
 
 static bool have_sme(void)
 {
@@ -34,7 +34,8 @@ static void test_tpidr(pid_t child)
 	uint64_t read_val[MAX_TPIDRS];
 	uint64_t write_val[MAX_TPIDRS];
 	struct iovec read_iov, write_iov;
-	int ret;
+	bool test_tpidr2 = false;
+	int ret, i;
 
 	read_iov.iov_base = read_val;
 	write_iov.iov_base = write_val;
@@ -54,6 +55,81 @@ static void test_tpidr(pid_t child)
 	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
 	ksft_test_result(ret == 0 && write_val[0] == read_val[0],
 			 "verify_tpidr_one\n");
+
+	/* If we have TPIDR2 we should be able to read it */
+	read_iov.iov_len = sizeof(read_val);
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	if (ret == 0) {
+		/* If we have SME there should be two TPIDRs */
+		if (read_iov.iov_len >= sizeof(read_val))
+			test_tpidr2 = true;
+
+		if (have_sme() && test_tpidr2) {
+			ksft_test_result(test_tpidr2, "count_tpidrs\n");
+		} else {
+			ksft_test_result(read_iov.iov_len % sizeof(uint64_t) == 0,
+					 "count_tpidrs\n");
+		}
+	} else {
+		ksft_test_result_fail("count_tpidrs\n");
+	}
+
+	if (test_tpidr2) {
+		/* Try to write new values to all known TPIDRs... */
+		write_iov.iov_len = sizeof(write_val);
+		for (i = 0; i < MAX_TPIDRS; i++)
+			write_val[i] = read_val[i] + 1;
+		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+
+		ksft_test_result(ret == 0 &&
+				 write_iov.iov_len == sizeof(write_val),
+				 "tpidr2_write\n");
+
+		/* ...then read them back */
+		read_iov.iov_len = sizeof(read_val);
+		ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+
+		if (have_sme()) {
+			/* Should read back the written value */
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 memcmp(read_val, write_val,
+						sizeof(read_val)) == 0,
+					 "tpidr2_read\n");
+		} else {
+			/* TPIDR2 should read as zero */
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 read_val[0] == write_val[0] &&
+					 read_val[1] == 0,
+					 "tpidr2_read\n");
+		}
+
+		/* Writing only TPIDR... */
+		write_iov.iov_len = sizeof(uint64_t);
+		memcpy(write_val, read_val, sizeof(read_val));
+		write_val[0] += 1;
+		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+
+		if (ret == 0) {
+			/* ...should leave TPIDR2 untouched */
+			read_iov.iov_len = sizeof(read_val);
+			ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS,
+				     &read_iov);
+
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 memcmp(read_val, write_val,
+						sizeof(read_val)) == 0,
+					 "write_tpidr_only\n");
+		} else {
+			ksft_test_result_fail("write_tpidr_only\n");
+		}
+	} else {
+		ksft_test_result_skip("tpidr2_write\n");
+		ksft_test_result_skip("tpidr2_read\n");
+		ksft_test_result_skip("write_tpidr_only\n");
+	}
 }
 
 static int do_child(void)
-- 
2.30.2

[PATCH v1 4/4] kselftest/arm64: Add coverage of TPIDR2_EL0 ptrace interface

[Mark Brown]

Extend the ptrace test support for NT_ARM_TLS to cover TPIDR2_EL0 - on
systems that support SME the NT_ARM_TLS regset can be up to 2 elements
long with the second element containing TPIDR2_EL0. On systems
supporting SME we verify that this value can be read and written while
on systems that do not support SME we verify correct truncation of reads
and writes.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/abi/ptrace.c | 82 +++++++++++++++++++++-
 1 file changed, 79 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/arm64/abi/ptrace.c b/tools/testing/selftests/arm64/abi/ptrace.c
index 4cc4d415b2e7..0a3d28a3972b 100644
--- a/tools/testing/selftests/arm64/abi/ptrace.c
+++ b/tools/testing/selftests/arm64/abi/ptrace.c
@@ -20,9 +20,9 @@
 
 #include "../../kselftest.h"
 
-#define EXPECTED_TESTS 3
+#define EXPECTED_TESTS 7
 
-#define MAX_TPIDRS 1
+#define MAX_TPIDRS 2
 
 static bool have_sme(void)
 {
@@ -34,7 +34,8 @@ static void test_tpidr(pid_t child)
 	uint64_t read_val[MAX_TPIDRS];
 	uint64_t write_val[MAX_TPIDRS];
 	struct iovec read_iov, write_iov;
-	int ret;
+	bool test_tpidr2 = false;
+	int ret, i;
 
 	read_iov.iov_base = read_val;
 	write_iov.iov_base = write_val;
@@ -54,6 +55,81 @@ static void test_tpidr(pid_t child)
 	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
 	ksft_test_result(ret == 0 && write_val[0] == read_val[0],
 			 "verify_tpidr_one\n");
+
+	/* If we have TPIDR2 we should be able to read it */
+	read_iov.iov_len = sizeof(read_val);
+	ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+	if (ret == 0) {
+		/* If we have SME there should be two TPIDRs */
+		if (read_iov.iov_len >= sizeof(read_val))
+			test_tpidr2 = true;
+
+		if (have_sme() && test_tpidr2) {
+			ksft_test_result(test_tpidr2, "count_tpidrs\n");
+		} else {
+			ksft_test_result(read_iov.iov_len % sizeof(uint64_t) == 0,
+					 "count_tpidrs\n");
+		}
+	} else {
+		ksft_test_result_fail("count_tpidrs\n");
+	}
+
+	if (test_tpidr2) {
+		/* Try to write new values to all known TPIDRs... */
+		write_iov.iov_len = sizeof(write_val);
+		for (i = 0; i < MAX_TPIDRS; i++)
+			write_val[i] = read_val[i] + 1;
+		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+
+		ksft_test_result(ret == 0 &&
+				 write_iov.iov_len == sizeof(write_val),
+				 "tpidr2_write\n");
+
+		/* ...then read them back */
+		read_iov.iov_len = sizeof(read_val);
+		ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
+
+		if (have_sme()) {
+			/* Should read back the written value */
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 memcmp(read_val, write_val,
+						sizeof(read_val)) == 0,
+					 "tpidr2_read\n");
+		} else {
+			/* TPIDR2 should read as zero */
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 read_val[0] == write_val[0] &&
+					 read_val[1] == 0,
+					 "tpidr2_read\n");
+		}
+
+		/* Writing only TPIDR... */
+		write_iov.iov_len = sizeof(uint64_t);
+		memcpy(write_val, read_val, sizeof(read_val));
+		write_val[0] += 1;
+		ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
+
+		if (ret == 0) {
+			/* ...should leave TPIDR2 untouched */
+			read_iov.iov_len = sizeof(read_val);
+			ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS,
+				     &read_iov);
+
+			ksft_test_result(ret == 0 &&
+					 read_iov.iov_len >= sizeof(read_val) &&
+					 memcmp(read_val, write_val,
+						sizeof(read_val)) == 0,
+					 "write_tpidr_only\n");
+		} else {
+			ksft_test_result_fail("write_tpidr_only\n");
+		}
+	} else {
+		ksft_test_result_skip("tpidr2_write\n");
+		ksft_test_result_skip("tpidr2_read\n");
+		ksft_test_result_skip("write_tpidr_only\n");
+	}
 }
 
 static int do_child(void)
-- 
2.30.2


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