e76b70dec9
Not all compilers, notably GCC < 10, have support for __attribute__((no_stack_protector)). Fall back to a mechanism that also works there. Tested with GCC 9.5.0 from kernel.org crosstools. Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
51 lines
1.4 KiB
C
51 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;
|
|
|
|
__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 */
|