1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ 2/* 3 * Stack protector support for NOLIBC 4 * Copyright (C) 2023 Thomas Wei��schuh <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"))) 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,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