@@ -39,5 +39,42 @@ __nptl_is_internal_signal (int sig)
return (sig == SIGCANCEL) || (sig == SIGTIMER) || (sig == SIGSETXID);
}
+static inline void
+__nptl_clear_internal_signals (sigset_t *set)
+{
+ __sigdelset (set, SIGCANCEL);
+ __sigdelset (set, SIGTIMER);
+ __sigdelset (set, SIGSETXID);
+}
+
+#define SIGALL_SET \
+ ((__sigset_t) { .__val = {[0 ... _SIGSET_NWORDS-1 ] = -1 } })
+
+static inline int
+__libc_signal_block_all (const sigset_t *set)
+{
+ INTERNAL_SYSCALL_DECL (err);
+ return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &SIGALL_SET,
+ set, _NSIG / 8);
+}
+
+static inline int
+__libc_signal_block_app (const sigset_t *set)
+{
+ sigset_t allset = SIGALL_SET;
+ __nptl_clear_internal_signals (&allset);
+ INTERNAL_SYSCALL_DECL (err);
+ return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_BLOCK, &allset, set,
+ _NSIG / 8);
+}
+
+static inline int
+__libc_signal_restore_set (const sigset_t *set)
+{
+ INTERNAL_SYSCALL_DECL (err);
+ return INTERNAL_SYSCALL (rt_sigprocmask, err, 4, SIG_SETMASK, set, NULL,
+ _NSIG / 8);
+}
+
/* Used to communicate with signal handler. */
extern struct xid_command *__xidcmd attribute_hidden;
@@ -1,4 +1,5 @@
-/* Copyright (C) 2002-2016 Free Software Foundation, Inc.
+/* ISO C raise function for libpthread.
+ 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.
@@ -16,22 +17,4 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <errno.h>
-#include <signal.h>
-#include <sysdep.h>
-#include <tls.h>
-
-
-int
-raise (int sig)
-{
- /* raise is an async-safe function. It could be called while the
- fork function temporarily invalidated the PID field. Adjust for
- that. */
- pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
- if (__glibc_unlikely (pid < 0))
- pid = -pid;
-
- return INLINE_SYSCALL (tgkill, 3, pid, THREAD_GETMEM (THREAD_SELF, tid),
- sig);
-}
+#include <sysdeps/unix/sysv/linux/raise.c>
@@ -16,42 +16,27 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#include <errno.h>
-#include <limits.h>
#include <signal.h>
#include <sysdep.h>
-#include <nptl/pthreadP.h>
-
+#include <errno.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <nptl-signals.h>
int
raise (int sig)
{
- struct pthread *pd = THREAD_SELF;
- pid_t pid = THREAD_GETMEM (pd, pid);
- pid_t selftid = THREAD_GETMEM (pd, tid);
- if (selftid == 0)
- {
- /* This system call is not supposed to fail. */
-#ifdef INTERNAL_SYSCALL
- INTERNAL_SYSCALL_DECL (err);
- selftid = INTERNAL_SYSCALL (gettid, err, 0);
-#else
- selftid = INLINE_SYSCALL (gettid, 0);
-#endif
- THREAD_SETMEM (pd, tid, selftid);
-
- /* We do not set the PID field in the TID here since we might be
- called from a signal handler while the thread executes fork. */
- pid = selftid;
- }
- else
- /* raise is an async-safe function. It could be called while the
- fork/vfork function temporarily invalidated the PID field. Adjust for
- that. */
- if (__glibc_unlikely (pid <= 0))
- pid = (pid & INT_MAX) == 0 ? selftid : -pid;
-
- return INLINE_SYSCALL (tgkill, 3, pid, selftid, sig);
+ sigset_t set;
+ __libc_signal_block_app (&set);
+
+ pid_t pid = __getpid ();
+ pid_t tid = INLINE_SYSCALL (gettid, 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)
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. * 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. --- ChangeLog | 12 +++++++++ sysdeps/unix/sysv/linux/nptl-signals.h | 37 ++++++++++++++++++++++++++++ sysdeps/unix/sysv/linux/pt-raise.c | 23 +++-------------- sysdeps/unix/sysv/linux/raise.c | 45 ++++++++++++---------------------- 4 files changed, 67 insertions(+), 50 deletions(-)