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author | Laura Abbott <lauraa@codeaurora.org> | 2014-06-25 23:55:03 +0100 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2014-07-09 12:23:48 +0100 |
commit | c0c264ae5112d1cdb7d37d4e208b7a7e766a7418 (patch) | |
tree | 6e9de5e48ed2b0b91e4a371d53eda59ff578a5f9 /arch/arm64/include/asm/stackprotector.h | |
parent | 4e6f7084096c08e37f909d7b075a91b72580405f (diff) | |
download | op-kernel-dev-c0c264ae5112d1cdb7d37d4e208b7a7e766a7418.zip op-kernel-dev-c0c264ae5112d1cdb7d37d4e208b7a7e766a7418.tar.gz |
arm64: Add CONFIG_CC_STACKPROTECTOR
arm64 currently lacks support for -fstack-protector. Add
similar functionality to arm to detect stack corruption.
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/stackprotector.h')
-rw-r--r-- | arch/arm64/include/asm/stackprotector.h | 38 |
1 files changed, 38 insertions, 0 deletions
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 */ |