Warning: This file is not a C or C++ file. It does not have highlighting.
| 1 | /* SPDX-License-Identifier: LGPL-2.1 OR MIT */ |
|---|---|
| 2 | /* |
| 3 | * Stack protector support for NOLIBC |
| 4 | * Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net> |
| 5 | */ |
| 6 | |
| 7 | #ifndef _NOLIBC_STACKPROTECTOR_H |
| 8 | #define _NOLIBC_STACKPROTECTOR_H |
| 9 | |
| 10 | #include "compiler.h" |
| 11 | |
| 12 | #if defined(_NOLIBC_STACKPROTECTOR) |
| 13 | |
| 14 | #include "sys.h" |
| 15 | #include "stdlib.h" |
| 16 | |
| 17 | /* The functions in this header are using raw syscall macros to avoid |
| 18 | * triggering stack protector errors themselves |
| 19 | */ |
| 20 | |
| 21 | __attribute__((weak,noreturn,section(".text.nolibc_stack_chk"))) |
| 22 | void __stack_chk_fail(void) |
| 23 | { |
| 24 | pid_t pid; |
| 25 | my_syscall3(__NR_write, STDERR_FILENO, "!!Stack smashing detected!!\n", 28); |
| 26 | pid = my_syscall0(__NR_getpid); |
| 27 | my_syscall2(__NR_kill, pid, SIGABRT); |
| 28 | for (;;); |
| 29 | } |
| 30 | |
| 31 | __attribute__((weak,noreturn,section(".text.nolibc_stack_chk"))) |
| 32 | void __stack_chk_fail_local(void) |
| 33 | { |
| 34 | __stack_chk_fail(); |
| 35 | } |
| 36 | |
| 37 | __attribute__((weak,section(".data.nolibc_stack_chk"))) |
| 38 | uintptr_t __stack_chk_guard; |
| 39 | |
| 40 | static __no_stack_protector void __stack_chk_init(void) |
| 41 | { |
| 42 | my_syscall3(__NR_getrandom, &__stack_chk_guard, sizeof(__stack_chk_guard), 0); |
| 43 | /* a bit more randomness in case getrandom() fails, ensure the guard is never 0 */ |
| 44 | if (__stack_chk_guard != (uintptr_t) &__stack_chk_guard) |
| 45 | __stack_chk_guard ^= (uintptr_t) &__stack_chk_guard; |
| 46 | } |
| 47 | #else /* !defined(_NOLIBC_STACKPROTECTOR) */ |
| 48 | static void __stack_chk_init(void) {} |
| 49 | #endif /* defined(_NOLIBC_STACKPROTECTOR) */ |
| 50 | |
| 51 | #endif /* _NOLIBC_STACKPROTECTOR_H */ |
| 52 |
Warning: This file is not a C or C++ file. It does not have highlighting.