/* SPDX-License-Identifier: LGPL-2.1 OR MIT */ /* * Stack protector support for NOLIBC * Copyright (C) 2023 Thomas Weißschuh <linux@weissschuh.net> */ #ifndef _NOLIBC_STACKPROTECTOR_H #define _NOLIBC_STACKPROTECTOR_H #include "compiler.h" #if defined(_NOLIBC_STACKPROTECTOR) #include "sys.h" #include "stdlib.h" /* The functions in this header are using raw syscall macros to avoid * triggering stack protector errors themselves */ __attribute__((weak,noreturn,section(".text.nolibc_stack_chk"))) void __stack_chk_fail(void) { pid_t pid; my_syscall3(__NR_write, STDERR_FILENO, "!!Stack smashing detected!!\n", 28); pid = my_syscall0(__NR_getpid); my_syscall2(__NR_kill, pid, SIGABRT); for (;;); } __attribute__((weak,noreturn,section(".text.nolibc_stack_chk"))) void __stack_chk_fail_local(void) { __stack_chk_fail(); } __attribute__((weak,section(".data.nolibc_stack_chk"))) uintptr_t __stack_chk_guard; __attribute__((weak,section(".text.nolibc_stack_chk"))) __no_stack_protector void __stack_chk_init(void) { my_syscall3(__NR_getrandom, &__stack_chk_guard, sizeof(__stack_chk_guard), 0); /* a bit more randomness in case getrandom() fails, ensure the guard is never 0 */ if (__stack_chk_guard != (uintptr_t) &__stack_chk_guard) __stack_chk_guard ^= (uintptr_t) &__stack_chk_guard; } #endif /* defined(_NOLIBC_STACKPROTECTOR) */ #endif /* _NOLIBC_STACKPROTECTOR_H */