glibc/sysdeps/unix/sysv/linux/raise.c
Adhemerval Zanella 2ac88eecc5 Refactor Linux raise implementation (BZ#15368)
This patch changes both the nptl and libc Linux raise implementation
to avoid the issues described in BZ#15368.  The strategy used is
summarized in bug report first comment:

 1. Block all signals (including internal NPTL ones);
 2. Get pid and tid directly from syscall (not relying on cached
    values);
 3. Call tgkill;
 4. Restore old signal mask.

Tested on x86_64 and i686.

	[BZ #15368]
	* sysdeps/unix/sysv/linux/nptl-signals.h
	(__nptl_clear_internal_signals): New function.
	(__libc_signal_block_all): Likewise.
	(__libc_signal_block_app): Likewise.
	(__libc_signal_restore_set): Likewise.
	* sysdeps/unix/sysv/linux/pt-raise.c (raise): Use Linux raise.c
	implementation.
	* sysdeps/unix/sysv/linux/raise.c (raise): Reimplement to not use
	the cached pid/tid value in pthread structure.
2016-07-13 17:08:51 +01:00

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2.0 KiB
C

/* Copyright (C) 2002-2016 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <signal.h>
#include <sysdep.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <nptl-signals.h>
int
raise (int sig)
{
/* raise is an async-safe function so it could be called while the
fork/vfork function temporarily invalidated the PID field. To avoid
relying on cached value we block all user-defined signal handler
(which might call fork/vfork) and issue the getpid and gettid
syscalls directly. */
/* rt_sigprocmask may fail if:
1. sigsetsize != sizeof (sigset_t) (EINVAL)
2. a failure in copy from/to user space (EFAULT)
3. an invalid 'how' operation (EINVAL)
The first case is already handle in glibc syscall call by using the arch
defined _NSIG. Second case is handled by using a stack allocated mask.
The last one should be handled by the block/unblock functions. */
sigset_t set;
__libc_signal_block_app (&set);
INTERNAL_SYSCALL_DECL (err);
pid_t pid = INTERNAL_SYSCALL (getpid, err, 0);
pid_t tid = INTERNAL_SYSCALL (gettid, err, 0);
int ret = INLINE_SYSCALL (tgkill, 3, pid, tid, sig);
__libc_signal_restore_set (&set);
return ret;
}
libc_hidden_def (raise)
weak_alias (raise, gsignal)