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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-27 11:19:07 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-27 11:19:07 -0800 |
| commit | c6f1b355d451680a45d63ce66cea67057c938a87 (patch) | |
| tree | 413ed05d88e6a59d33a8b2034cfffdae1862e7b8 /arch/arm/include | |
| parent | c06e9ef6918b1a6d183f1fef78ebc66f054a7b5a (diff) | |
| parent | 189af4657186da08a2e79fb8e906cfd82b2ccddc (diff) | |
Merge tag 'gcc-plugins-v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull gcc-plugins update from Kees Cook:
"Both arm and arm64 are gaining per-task stack canaries (to match x86),
but arm is being done with a gcc plugin, hence it going through the
gcc-plugins tree.
New gcc-plugin:
- Enable per-task stack protector for ARM (Ard Biesheuvel)"
* tag 'gcc-plugins-v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
ARM: smp: add support for per-task stack canaries
Diffstat (limited to 'arch/arm/include')
| -rw-r--r-- | arch/arm/include/asm/stackprotector.h | 12 | ||||
| -rw-r--r-- | arch/arm/include/asm/thread_info.h | 3 |
2 files changed, 13 insertions, 2 deletions
diff --git a/arch/arm/include/asm/stackprotector.h b/arch/arm/include/asm/stackprotector.h index ef5f7b69443e..72a20c3a0a90 100644 --- a/arch/arm/include/asm/stackprotector.h +++ b/arch/arm/include/asm/stackprotector.h @@ -6,8 +6,10 @@ * the stack frame and verifying that it hasn't been overwritten when * returning from the function. The pattern is called stack canary * and gcc expects it to be defined by a global variable called - * "__stack_chk_guard" on ARM. This unfortunately means that on SMP - * we cannot have a different canary value per task. + * "__stack_chk_guard" on ARM. This prevents SMP systems from using a + * different value for each task unless we enable a GCC plugin that + * replaces these symbol references with references to each task's own + * value. */ #ifndef _ASM_STACKPROTECTOR_H @@ -16,6 +18,8 @@ #include <linux/random.h> #include <linux/version.h> +#include <asm/thread_info.h> + extern unsigned long __stack_chk_guard; /* @@ -33,7 +37,11 @@ static __always_inline void boot_init_stack_canary(void) canary ^= LINUX_VERSION_CODE; current->stack_canary = canary; +#ifndef CONFIG_STACKPROTECTOR_PER_TASK __stack_chk_guard = current->stack_canary; +#else + current_thread_info()->stack_canary = current->stack_canary; +#endif } #endif /* _ASM_STACKPROTECTOR_H */ diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h index 8f55dc520a3e..286eb61c632b 100644 --- a/arch/arm/include/asm/thread_info.h +++ b/arch/arm/include/asm/thread_info.h @@ -53,6 +53,9 @@ struct thread_info { struct task_struct *task; /* main task structure */ __u32 cpu; /* cpu */ __u32 cpu_domain; /* cpu domain */ +#ifdef CONFIG_STACKPROTECTOR_PER_TASK + unsigned long stack_canary; +#endif struct cpu_context_save cpu_context; /* cpu context */ __u32 syscall; /* syscall number */ __u8 used_cp[16]; /* thread used copro */ |