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| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
|---|---|
| 2 | /* |
| 3 | * GCC stack protector support. |
| 4 | * |
| 5 | * Stack protector works by putting predefined pattern at the start of |
| 6 | * the stack frame and verifying that it hasn't been overwritten when |
| 7 | * returning from the function. The pattern is called stack canary |
| 8 | * and gcc expects it to be defined by a global variable called |
| 9 | * "__stack_chk_guard" on ARM. This prevents SMP systems from using a |
| 10 | * different value for each task unless we enable a GCC plugin that |
| 11 | * replaces these symbol references with references to each task's own |
| 12 | * value. |
| 13 | */ |
| 14 | |
| 15 | #ifndef _ASM_STACKPROTECTOR_H |
| 16 | #define _ASM_STACKPROTECTOR_H 1 |
| 17 | |
| 18 | #include <asm/thread_info.h> |
| 19 | |
| 20 | extern unsigned long __stack_chk_guard; |
| 21 | |
| 22 | /* |
| 23 | * Initialize the stackprotector canary value. |
| 24 | * |
| 25 | * NOTE: this must only be called from functions that never return, |
| 26 | * and it must always be inlined. |
| 27 | */ |
| 28 | static __always_inline void boot_init_stack_canary(void) |
| 29 | { |
| 30 | unsigned long canary = get_random_canary(); |
| 31 | |
| 32 | current->stack_canary = canary; |
| 33 | #ifndef CONFIG_STACKPROTECTOR_PER_TASK |
| 34 | __stack_chk_guard = current->stack_canary; |
| 35 | #endif |
| 36 | } |
| 37 | |
| 38 | #endif /* _ASM_STACKPROTECTOR_H */ |
| 39 |
Warning: This file is not a C or C++ file. It does not have highlighting.