| Message ID | 1403736903-25594-1-git-send-email-lauraa@codeaurora.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 25, 2014 at 11:55:03PM +0100, Laura Abbott wrote: > arm64 currently lacks support for -fstack-protector. Add > similar functionality to arm to detect stack corruption. > > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Laura Abbott <lauraa@codeaurora.org> Acked-by: Will Deacon <will.deacon@arm.com> Will
On Wed, Jun 25, 2014 at 11:55:03PM +0100, Laura Abbott wrote: > arm64 currently lacks support for -fstack-protector. Add > similar functionality to arm to detect stack corruption. > > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Acked-by: Kees Cook <keescook@chromium.org> > Signed-off-by: Laura Abbott <lauraa@codeaurora.org> > --- > arch/arm64/Kconfig | 1 + > arch/arm64/include/asm/stackprotector.h | 38 +++++++++++++++++++++++++++++++++ > arch/arm64/kernel/process.c | 6 ++++++ > 3 files changed, 45 insertions(+) > create mode 100644 arch/arm64/include/asm/stackprotector.h Applied for 3.17. Thanks.
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a474de34..f865436 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -32,6 +32,7 @@ config ARM64 select HAVE_ARCH_KGDB select HAVE_ARCH_TRACEHOOK select HAVE_C_RECORDMCOUNT + select HAVE_CC_STACKPROTECTOR select HAVE_DEBUG_BUGVERBOSE select HAVE_DEBUG_KMEMLEAK select HAVE_DMA_API_DEBUG diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h new file mode 100644 index 0000000..fe5e287 --- /dev/null +++ b/arch/arm64/include/asm/stackprotector.h @@ -0,0 +1,38 @@ +/* + * GCC stack protector support. + * + * Stack protector works by putting predefined pattern at the start of + * 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. + */ + +#ifndef __ASM_STACKPROTECTOR_H +#define __ASM_STACKPROTECTOR_H + +#include <linux/random.h> +#include <linux/version.h> + +extern unsigned long __stack_chk_guard; + +/* + * Initialize the stackprotector canary value. + * + * NOTE: this must only be called from functions that never return, + * and it must always be inlined. + */ +static __always_inline void boot_init_stack_canary(void) +{ + unsigned long canary; + + /* Try to get a semi random initial value. */ + get_random_bytes(&canary, sizeof(canary)); + canary ^= LINUX_VERSION_CODE; + + current->stack_canary = canary; + __stack_chk_guard = current->stack_canary; +} + +#endif /* _ASM_STACKPROTECTOR_H */ diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 43b7c34..1309d64 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -51,6 +51,12 @@ #include <asm/processor.h> #include <asm/stacktrace.h> +#ifdef CONFIG_CC_STACKPROTECTOR +#include <linux/stackprotector.h> +unsigned long __stack_chk_guard __read_mostly; +EXPORT_SYMBOL(__stack_chk_guard); +#endif + static void setup_restart(void) { /*