This is a note to let you know that I've just added the patch titled selftests/rseq: Introduce thread pointer getters to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: selftests-rseq-introduce-thread-pointer-getters.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 886ddfba933f5ce9d76c278165d834d114ba4ffc Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Date: Mon, 24 Jan 2022 12:12:44 -0500 Subject: selftests/rseq: Introduce thread pointer getters From: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> commit 886ddfba933f5ce9d76c278165d834d114ba4ffc upstream. This is done in preparation for the selftest uplift to become compatible with glibc-2.35. glibc-2.35 exposes the rseq per-thread data in the TCB, accessible at an offset from the thread pointer. The toolchains do not implement accessing the thread pointer on all architectures. Provide thread pointer getters for ppc and x86 which lack (or lacked until recently) toolchain support. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/20220124171253.22072-7-mathieu.desnoyers@xxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/rseq/rseq-generic-thread-pointer.h | 25 ++++++++ tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h | 30 +++++++++ tools/testing/selftests/rseq/rseq-thread-pointer.h | 19 ++++++ tools/testing/selftests/rseq/rseq-x86-thread-pointer.h | 40 +++++++++++++ 4 files changed, 114 insertions(+) create mode 100644 tools/testing/selftests/rseq/rseq-generic-thread-pointer.h create mode 100644 tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h create mode 100644 tools/testing/selftests/rseq/rseq-thread-pointer.h create mode 100644 tools/testing/selftests/rseq/rseq-x86-thread-pointer.h --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-generic-thread-pointer.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */ +/* + * rseq-generic-thread-pointer.h + * + * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> + */ + +#ifndef _RSEQ_GENERIC_THREAD_POINTER +#define _RSEQ_GENERIC_THREAD_POINTER + +#ifdef __cplusplus +extern "C" { +#endif + +/* Use gcc builtin thread pointer. */ +static inline void *rseq_thread_pointer(void) +{ + return __builtin_thread_pointer(); +} + +#ifdef __cplusplus +} +#endif + +#endif --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-ppc-thread-pointer.h @@ -0,0 +1,30 @@ +/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */ +/* + * rseq-ppc-thread-pointer.h + * + * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> + */ + +#ifndef _RSEQ_PPC_THREAD_POINTER +#define _RSEQ_PPC_THREAD_POINTER + +#ifdef __cplusplus +extern "C" { +#endif + +static inline void *rseq_thread_pointer(void) +{ +#ifdef __powerpc64__ + register void *__result asm ("r13"); +#else + register void *__result asm ("r2"); +#endif + asm ("" : "=r" (__result)); + return __result; +} + +#ifdef __cplusplus +} +#endif + +#endif --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-thread-pointer.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */ +/* + * rseq-thread-pointer.h + * + * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> + */ + +#ifndef _RSEQ_THREAD_POINTER +#define _RSEQ_THREAD_POINTER + +#if defined(__x86_64__) || defined(__i386__) +#include "rseq-x86-thread-pointer.h" +#elif defined(__PPC__) +#include "rseq-ppc-thread-pointer.h" +#else +#include "rseq-generic-thread-pointer.h" +#endif + +#endif --- /dev/null +++ b/tools/testing/selftests/rseq/rseq-x86-thread-pointer.h @@ -0,0 +1,40 @@ +/* SPDX-License-Identifier: LGPL-2.1-only OR MIT */ +/* + * rseq-x86-thread-pointer.h + * + * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> + */ + +#ifndef _RSEQ_X86_THREAD_POINTER +#define _RSEQ_X86_THREAD_POINTER + +#include <features.h> + +#ifdef __cplusplus +extern "C" { +#endif + +#if __GNUC_PREREQ (11, 1) +static inline void *rseq_thread_pointer(void) +{ + return __builtin_thread_pointer(); +} +#else +static inline void *rseq_thread_pointer(void) +{ + void *__result; + +# ifdef __x86_64__ + __asm__ ("mov %%fs:0, %0" : "=r" (__result)); +# else + __asm__ ("mov %%gs:0, %0" : "=r" (__result)); +# endif + return __result; +} +#endif /* !GCC 11 */ + +#ifdef __cplusplus +} +#endif + +#endif Patches currently in stable-queue which might be from mathieu.desnoyers@xxxxxxxxxxxx are queue-5.10/selftests-rseq-fix-work-around-asm-goto-compiler-bugs.patch queue-5.10/selftests-rseq-remove-arm-mips-asm-goto-compiler-work-around.patch queue-5.10/selftests-rseq-uplift-rseq-selftests-for-compatibility-with-glibc-2.35.patch queue-5.10/selftests-rseq-introduce-thread-pointer-getters.patch queue-5.10/selftests-rseq-introduce-own-copy-of-rseq-uapi-header.patch queue-5.10/selftests-rseq-introduce-rseq_get_abi-helper.patch queue-5.10/selftests-rseq-fix-ppc32-missing-instruction-selection-u-and-x-for-load-store.patch queue-5.10/selftests-rseq-change-type-of-rseq_offset-to-ptrdiff_t.patch queue-5.10/selftests-rseq-fix-ppc32-wrong-rseq_cs-32-bit-field-pointer-on-big-endian.patch queue-5.10/selftests-rseq-x86-32-use-gs-segment-selector-for-accessing-rseq-thread-area.patch queue-5.10/selftests-rseq-remove-volatile-from-__rseq_abi.patch queue-5.10/selftests-rseq-fix-warnings-about-if-checks-of-undefined-tokens.patch queue-5.10/selftests-rseq-fix-ppc32-offsets-by-using-long-rather-than-off_t.patch queue-5.10/selftests-rseq-remove-useless-assignment-to-cpu-variable.patch queue-5.10/selftests-rseq-x86-64-use-fs-segment-selector-for-accessing-rseq-thread-area.patch