2024-01-01 18:12:26 +00:00
|
|
|
/* Copyright (C) 1991-2024 Free Software Foundation, Inc.
|
2005-12-14 08:43:25 +00:00
|
|
|
This file is part of the GNU C Library.
|
|
|
|
|
|
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
|
|
|
modify it under the terms of the GNU Lesser General Public
|
|
|
|
|
License as published by the Free Software Foundation; either
|
|
|
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
|
|
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
|
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
|
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
|
|
|
Lesser General Public License for more details.
|
|
|
|
|
|
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
2012-02-09 23:18:22 +00:00
|
|
|
License along with the GNU C Library; if not, see
|
Prefer https to http for gnu.org and fsf.org URLs
Also, change sources.redhat.com to sourceware.org.
This patch was automatically generated by running the following shell
script, which uses GNU sed, and which avoids modifying files imported
from upstream:
sed -ri '
s,(http|ftp)(://(.*\.)?(gnu|fsf|sourceware)\.org($|[^.]|\.[^a-z])),https\2,g
s,(http|ftp)(://(.*\.)?)sources\.redhat\.com($|[^.]|\.[^a-z]),https\2sourceware.org\4,g
' \
$(find $(git ls-files) -prune -type f \
! -name '*.po' \
! -name 'ChangeLog*' \
! -path COPYING ! -path COPYING.LIB \
! -path manual/fdl-1.3.texi ! -path manual/lgpl-2.1.texi \
! -path manual/texinfo.tex ! -path scripts/config.guess \
! -path scripts/config.sub ! -path scripts/install-sh \
! -path scripts/mkinstalldirs ! -path scripts/move-if-change \
! -path INSTALL ! -path locale/programs/charmap-kw.h \
! -path po/libc.pot ! -path sysdeps/gnu/errlist.c \
! '(' -name configure \
-execdir test -f configure.ac -o -f configure.in ';' ')' \
! '(' -name preconfigure \
-execdir test -f preconfigure.ac ';' ')' \
-print)
and then by running 'make dist-prepare' to regenerate files built
from the altered files, and then executing the following to cleanup:
chmod a+x sysdeps/unix/sysv/linux/riscv/configure
# Omit irrelevant whitespace and comment-only changes,
# perhaps from a slightly-different Autoconf version.
git checkout -f \
sysdeps/csky/configure \
sysdeps/hppa/configure \
sysdeps/riscv/configure \
sysdeps/unix/sysv/linux/csky/configure
# Omit changes that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/powerpc/powerpc64/ppc-mcount.S: trailing lines
git checkout -f \
sysdeps/powerpc/powerpc64/ppc-mcount.S \
sysdeps/unix/sysv/linux/s390/s390-64/syscall.S
# Omit change that caused a pre-commit check to fail like this:
# remote: *** error: sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S: last line does not end in newline
git checkout -f sysdeps/sparc/sparc64/multiarch/memcpy-ultra3.S
2019-09-07 05:40:42 +00:00
|
|
|
<https://www.gnu.org/licenses/>. */
|
2005-12-14 08:43:25 +00:00
|
|
|
|
|
|
|
|
#include <signal.h>
|
2022-04-21 12:41:59 +00:00
|
|
|
#include <internal-signals.h>
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
#include <libc-lock.h>
|
|
|
|
|
#include <pthreadP.h>
|
|
|
|
|
#include <unistd.h>
|
2005-12-14 08:43:25 +00:00
|
|
|
|
|
|
|
|
/* Try to get a machine dependent instruction which will make the
|
|
|
|
|
program crash. This is used in case everything else fails. */
|
|
|
|
|
#include <abort-instr.h>
|
|
|
|
|
#ifndef ABORT_INSTRUCTION
|
|
|
|
|
/* No such instruction is available. */
|
|
|
|
|
# define ABORT_INSTRUCTION
|
|
|
|
|
#endif
|
|
|
|
|
|
2009-06-15 23:17:09 +00:00
|
|
|
/* Exported variable to locate abort message in core files etc. */
|
2021-07-09 18:09:14 +00:00
|
|
|
struct abort_msg_s *__abort_msg;
|
2009-06-15 23:17:09 +00:00
|
|
|
libc_hidden_def (__abort_msg)
|
|
|
|
|
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
/* The lock is used to prevent multiple thread to change the SIGABRT
|
|
|
|
|
to SIG_IGN while abort tries to change to SIG_DFL, and to avoid
|
|
|
|
|
a new process to see a wrong disposition if there is a SIGABRT
|
|
|
|
|
handler installed. */
|
|
|
|
|
__libc_rwlock_define_initialized (static, lock);
|
2005-12-14 08:43:25 +00:00
|
|
|
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
void
|
|
|
|
|
__abort_fork_reset_child (void)
|
|
|
|
|
{
|
|
|
|
|
__libc_rwlock_init (lock);
|
|
|
|
|
}
|
2005-12-14 08:43:25 +00:00
|
|
|
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
void
|
|
|
|
|
__abort_lock_rdlock (internal_sigset_t *set)
|
|
|
|
|
{
|
|
|
|
|
internal_signal_block_all (set);
|
|
|
|
|
__libc_rwlock_rdlock (lock);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void
|
|
|
|
|
__abort_lock_wrlock (internal_sigset_t *set)
|
|
|
|
|
{
|
|
|
|
|
internal_signal_block_all (set);
|
|
|
|
|
__libc_rwlock_wrlock (lock);
|
|
|
|
|
}
|
2005-12-14 08:43:25 +00:00
|
|
|
|
|
|
|
|
void
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
__abort_lock_unlock (const internal_sigset_t *set)
|
|
|
|
|
{
|
|
|
|
|
__libc_rwlock_unlock (lock);
|
|
|
|
|
internal_signal_restore_set (set);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Cause an abnormal program termination with core-dump. */
|
|
|
|
|
_Noreturn void
|
2005-12-14 08:43:25 +00:00
|
|
|
abort (void)
|
|
|
|
|
{
|
stdlib: Make abort/_Exit AS-safe (BZ 26275)
The recursive lock used on abort does not synchronize with a new process
creation (either by fork-like interfaces or posix_spawn ones), nor it
is reinitialized after fork().
Also, the SIGABRT unblock before raise() shows another race condition,
where a fork or posix_spawn() call by another thread, just after the
recursive lock release and before the SIGABRT signal, might create
programs with a non-expected signal mask. With the default option
(without POSIX_SPAWN_SETSIGDEF), the process can see SIG_DFL for
SIGABRT, where it should be SIG_IGN.
To fix the AS-safe, raise() does not change the process signal mask,
and an AS-safe lock is used if a SIGABRT is installed or the process
is blocked or ignored. With the signal mask change removal,
there is no need to use a recursive loc. The lock is also taken on
both _Fork() and posix_spawn(), to avoid the spawn process to see the
abort handler as SIG_DFL.
A read-write lock is used to avoid serialize _Fork and posix_spawn
execution. Both sigaction (SIGABRT) and abort() requires to lock
as writer (since both change the disposition).
The fallback is also simplified: there is no need to use a loop of
ABORT_INSTRUCTION after _exit() (if the syscall does not terminate the
process, the system is broken).
The proposed fix changes how setjmp works on a SIGABRT handler, where
glibc does not save the signal mask. So usage like the below will now
always abort.
static volatile int chk_fail_ok;
static jmp_buf chk_fail_buf;
static void
handler (int sig)
{
if (chk_fail_ok)
{
chk_fail_ok = 0;
longjmp (chk_fail_buf, 1);
}
else
_exit (127);
}
[...]
signal (SIGABRT, handler);
[....]
chk_fail_ok = 1;
if (! setjmp (chk_fail_buf))
{
// Something that can calls abort, like a failed fortify function.
chk_fail_ok = 0;
printf ("FAIL\n");
}
Such cases will need to use sigsetjmp instead.
The _dl_start_profile calls sigaction through _profil, and to avoid
pulling abort() on loader the call is replaced with __libc_sigaction.
Checked on x86_64-linux-gnu and aarch64-linux-gnu.
Reviewed-by: DJ Delorie <dj@redhat.com>
2024-10-03 18:41:10 +00:00
|
|
|
raise (SIGABRT);
|
|
|
|
|
|
|
|
|
|
/* There is a SIGABRT handle installed and it returned, or SIGABRT was
|
|
|
|
|
blocked or ignored. In this case use a AS-safe lock to prevent sigaction
|
|
|
|
|
to change the signal disposition again, set the handle to default
|
|
|
|
|
disposition, and re-raise the signal. Even if POSIX state this step is
|
|
|
|
|
optional, this a QoI by forcing the process termination through the
|
|
|
|
|
signal handler. */
|
|
|
|
|
__abort_lock_wrlock (NULL);
|
|
|
|
|
|
|
|
|
|
struct sigaction act = {.sa_handler = SIG_DFL, .sa_flags = 0 };
|
|
|
|
|
__sigfillset (&act.sa_mask);
|
|
|
|
|
__libc_sigaction (SIGABRT, &act, NULL);
|
|
|
|
|
__pthread_raise_internal (SIGABRT);
|
|
|
|
|
internal_signal_unblock_signal (SIGABRT);
|
|
|
|
|
|
|
|
|
|
/* This code should be unreachable, try the arch-specific code and the
|
|
|
|
|
syscall fallback. */
|
|
|
|
|
ABORT_INSTRUCTION;
|
|
|
|
|
|
|
|
|
|
_exit (127);
|
2005-12-14 08:43:25 +00:00
|
|
|
}
|
|
|
|
|
libc_hidden_def (abort)
|
