mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-29 05:51:10 +00:00
d2dc5467c6
This patch filters out the internal NPTL signals (SIGCANCEL/SIGTIMER and
SIGSETXID) from signal functions. GLIBC on Linux requires both signals to
proper implement pthread cancellation, posix timers, and set*id posix
thread synchronization.
And not filtering out the internal signal is troublesome:
- A conformant program on a architecture that does not filter out the
signals might inadvertently disable pthread asynchronous cancellation,
set*id synchronization or posix timers.
- It might also to security issues if SIGSETXID is masked and set*id
functions are called (some threads might have effective user or group
id different from the rest).
The changes are basically:
- Change __is_internal_signal to bool and used on all signal function
that has a signal number as input. Also for signal function which accepts
signals sets (sigset_t) it assumes that canonical function were used to
add/remove signals which lead to some input simplification.
- Fix tst-sigset.c to avoid check for SIGCANCEL/SIGTIMER and SIGSETXID.
It is rewritten to check each signal indidually and to check realtime
signals using canonical macros.
- Add generic __clear_internal_signals and __is_internal_signal
version since both symbols are used on generic implementations.
- Remove superflous sysdeps/nptl/sigfillset.c.
- Remove superflous SIGTIMER handling on Linux __is_internal_signal
since it is the same of SIGCANCEL.
- Remove dangling define and obvious comment on nptl/sigaction.c.
Checked on x86_64-linux-gnu.
[BZ #22391]
* nptl/sigaction.c (__sigaction): Use __is_internal_signal to
check for internal nptl signals.
* nptl/sigaction.c (__sigaction): Likewise.
* signal/sigaddset.c (sigaddset): Likewise.
* signal/sigdelset.c (sigdelset): Likewise.
* sysdeps/posix/signal.c (__bsd_signal): Likewise.
* sysdeps/posix/sigset.c (sigset): Call and check sigaddset return
value.
* signal/sigfillset.c (sigfillset): User __clear_internal_signals
to filter out internal nptl signals.
* signal/tst-sigset.c (do_test): Check ech signal indidually and
also check realtime signals using standard macros.
* sysdeps/generic/internal-signals.h (__clear_internal_signals,
__is_internal_signal, __libc_signal_block_all,
__libc_signal_block_app, __libc_signal_restore_set): New functions.
* sysdeps/nptl/sigfillset.c: Remove file.
* sysdeps/unix/sysv/linux/internal-signals.h (__is_internal_signal):
Change return to bool.
(__clear_internal_signals): Remove SIGTIMER clean since it is
equal to SIGCANEL on Linux.
* sysdeps/unix/sysv/linux/sigtimedwait.c (__sigtimedwait): Assume
signal set was constructed using standard functions.
Reported-by: Yury Norov <ynorov@caviumnetworks.com>
53 lines
1.7 KiB
C
53 lines
1.7 KiB
C
/* BSD-like signal function.
|
|
Copyright (C) 1991-2018 Free Software Foundation, Inc.
|
|
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
|
|
License along with the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <sigsetops.h>
|
|
#include <internal-signals.h>
|
|
|
|
sigset_t _sigintr attribute_hidden; /* Set by siginterrupt. */
|
|
|
|
/* Set the handler for the signal SIG to HANDLER,
|
|
returning the old handler, or SIG_ERR on error. */
|
|
__sighandler_t
|
|
__bsd_signal (int sig, __sighandler_t handler)
|
|
{
|
|
struct sigaction act, oact;
|
|
|
|
/* Check signal extents to protect __sigismember. */
|
|
if (handler == SIG_ERR || sig < 1 || sig >= NSIG
|
|
|| __is_internal_signal (sig))
|
|
{
|
|
__set_errno (EINVAL);
|
|
return SIG_ERR;
|
|
}
|
|
|
|
act.sa_handler = handler;
|
|
__sigemptyset (&act.sa_mask);
|
|
__sigaddset (&act.sa_mask, sig);
|
|
act.sa_flags = __sigismember (&_sigintr, sig) ? 0 : SA_RESTART;
|
|
if (__sigaction (sig, &act, &oact) < 0)
|
|
return SIG_ERR;
|
|
|
|
return oact.sa_handler;
|
|
}
|
|
weak_alias (__bsd_signal, bsd_signal)
|
|
weak_alias (__bsd_signal, signal)
|
|
weak_alias (__bsd_signal, ssignal)
|