aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/pthread/raise.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/pthread/raise.c')
-rw-r--r--sysdeps/pthread/raise.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/sysdeps/pthread/raise.c b/sysdeps/pthread/raise.c
new file mode 100644
index 0000000000..583cd1535d
--- /dev/null
+++ b/sysdeps/pthread/raise.c
@@ -0,0 +1,76 @@
+/* ISO C raise function for libpthread.
+ Copyright (C) 2002-2018 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 <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <internal-signals.h>
+
+/* Raise the signal SIG. POSIX requires raise to be async-signal-safe,
+ but also requires it to be equivalent to pthread_kill (pthread_self (), sig),
+ and that construct is *not* async-signal safe. In particular, an
+ async signal handler that calls fork (which is also async-signal-safe)
+ could invalidate the handle returned by pthread_self, and/or cause
+ pthread_kill to be called twice. So we must block signals around
+ the operation. See bug 15368 for more detail.
+
+ Also, raise sets errno on failure, whereas pthread_kill returns the
+ error code. (It is not possible for pthread_self to fail.) */
+
+int
+__libc_raise (int sig)
+{
+ /* Disallow sending the signals we use for cancellation, timers,
+ setxid, etc. This check is also performed in pthread_kill, but
+ if we do it now we can avoid blocking and then unblocking signals
+ unnecessarily. */
+ if (__glibc_unlikely (__is_internal_signal (sig)))
+ {
+ __set_errno (EINVAL);
+ return -1;
+ }
+
+ /* We can safely assume that __libc_signal_block_app and
+ __libc_signal_restore_set will not fail, because
+ sigprocmask can only fail under three circumstances:
+
+ 1. sigsetsize != sizeof (sigset_t) (EINVAL)
+ 2. a failure in copy from/to user space (EFAULT)
+ 3. an invalid 'how' operation (EINVAL)
+
+ Getting any of these would indicate a bug in either the
+ definition of sigset_t or the implementations of the
+ wrappers. */
+ sigset_t omask;
+ __libc_signal_block_app (&omask);
+
+ int ret = __pthread_kill (__pthread_self (), sig);
+
+ __libc_signal_restore_set (&omask);
+
+ if (__glibc_unlikely (ret))
+ {
+ __set_errno (ret);
+ return -1;
+ }
+ return 0;
+}
+strong_alias (__libc_raise, raise)
+libc_hidden_def (raise)
+weak_alias (__libc_raise, gsignal)