| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_STACKPROTECTOR_H |
| #define _LINUX_STACKPROTECTOR_H 1 |
| |
| #include <linux/compiler.h> |
| #include <linux/sched.h> |
| #include <linux/random.h> |
| |
| /* |
| * On 64-bit architectures, protect against non-terminated C string overflows |
| * by zeroing out the first byte of the canary; this leaves 56 bits of entropy. |
| */ |
| #ifdef CONFIG_64BIT |
| # ifdef __LITTLE_ENDIAN |
| # define CANARY_MASK 0xffffffffffffff00UL |
| # else /* big endian, 64 bits: */ |
| # define CANARY_MASK 0x00ffffffffffffffUL |
| # endif |
| #else /* 32 bits: */ |
| # define CANARY_MASK 0xffffffffUL |
| #endif |
| |
| static inline unsigned long get_random_canary(void) |
| { |
| return get_random_long() & CANARY_MASK; |
| } |
| |
| #if defined(CONFIG_STACKPROTECTOR) || defined(CONFIG_ARM64_PTR_AUTH) |
| # include <asm/stackprotector.h> |
| #else |
| static inline void boot_init_stack_canary(void) |
| { |
| } |
| #endif |
| |
| #endif |
