| * 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) |
| /* 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 */ |