aboutsummaryrefslogtreecommitdiff
path: root/nptl
diff options
context:
space:
mode:
authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-10-31 23:10:37 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2018-04-03 13:30:49 -0300
commitd2dc5467c67bc8625a4fc8f285b6a5443bf43df4 (patch)
tree27ddabfd779bfcbcc92f095288be5778ec4370ca /nptl
parent511ed56f2e792bea5e7145e1d5d5c93b9f47c41f (diff)
downloadglibc-d2dc5467c67bc8625a4fc8f285b6a5443bf43df4.zip
glibc-d2dc5467c67bc8625a4fc8f285b6a5443bf43df4.tar.gz
glibc-d2dc5467c67bc8625a4fc8f285b6a5443bf43df4.tar.bz2
Filter out NPTL internal signals (BZ #22391)
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>
Diffstat (limited to 'nptl')
-rw-r--r--nptl/sigaction.c14
1 files changed, 2 insertions, 12 deletions
diff --git a/nptl/sigaction.c b/nptl/sigaction.c
index ddf6f5e..79b6fdc 100644
--- a/nptl/sigaction.c
+++ b/nptl/sigaction.c
@@ -16,22 +16,12 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-
-/* This is no complete implementation. The file is meant to be
- included in the real implementation to provide the wrapper around
- __libc_sigaction. */
-
-#include <nptl/pthreadP.h>
-
-/* We use the libc implementation but we tell it to not allow
- SIGCANCEL or SIGTIMER to be handled. */
-#define LIBC_SIGACTION 1
-
+#include <internal-signals.h>
int
__sigaction (int sig, const struct sigaction *act, struct sigaction *oact)
{
- if (__glibc_unlikely (sig == SIGCANCEL || sig == SIGSETXID))
+ if (sig <= 0 || sig >= NSIG || __is_internal_signal (sig))
{
__set_errno (EINVAL);
return -1;