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Diffstat (limited to 'tools/include/nolibc/stackprotector.h')
-rw-r--r-- | tools/include/nolibc/stackprotector.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/tools/include/nolibc/stackprotector.h b/tools/include/nolibc/stackprotector.h new file mode 100644 index 0000000000..13f1d0e603 --- /dev/null +++ b/tools/include/nolibc/stackprotector.h @@ -0,0 +1,51 @@ +/* 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; + +static __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; +} +#else /* !defined(_NOLIBC_STACKPROTECTOR) */ +static void __stack_chk_init(void) {} +#endif /* defined(_NOLIBC_STACKPROTECTOR) */ + +#endif /* _NOLIBC_STACKPROTECTOR_H */ |