linux/tools/include/nolibc/stackprotector.h
Zhangjin Wu dcb677c3d3 tools/nolibc: stackprotector.h: make __stack_chk_init static
This allows to generate smaller text/data/dec size.

As the _start_c() function added by crt.h, __stack_chk_init() is called
from _start_c() instead of the assembly _start. So, it is able to mark
it with static now.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2023-08-23 05:17:07 +02:00

52 lines
1.4 KiB
C

/* 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 */