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1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */2/*3 * Stack protector support for NOLIBC4 * Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net>5 */6 7#ifndef _NOLIBC_STACKPROTECTOR_H8#define _NOLIBC_STACKPROTECTOR_H9 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 avoid18 * triggering stack protector errors themselves19 */20 21__attribute__((weak,used,noreturn,section(".text.nolibc_stack_chk")))22void __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")))32void __stack_chk_fail_local(void)33{34 __stack_chk_fail();35}36 37__attribute__((weak,used,section(".data.nolibc_stack_chk")))38uintptr_t __stack_chk_guard;39 40static __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) */48static void __stack_chk_init(void) {}49#endif /* defined(_NOLIBC_STACKPROTECTOR) */50 51#endif /* _NOLIBC_STACKPROTECTOR_H */52