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-rw-r--r--ChangeLog8
-rw-r--r--signal/Makefile4
-rw-r--r--signal/tst-sigwait-eintr.c85
-rw-r--r--sysdeps/unix/sysv/linux/sigwait.c11
4 files changed, 104 insertions, 4 deletions
diff --git a/ChangeLog b/ChangeLog
index 04fac09f2d..18b2aa9561 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2017-11-23  Florian Weimer  <fweimer@redhat.com>
 
+	[BZ #22478]
+	* sysdeps/unix/sysv/linux/sigwait.c (__sigwait): Retry on EINTR.
+	Return error code, not -1.
+	* signal/tst-sigwait-eintr.c: New file.
+	* signal/Makefile (tests): Add tst-sigwait-eintr.
+
+2017-11-23  Florian Weimer  <fweimer@redhat.com>
+
 	Linux: Add memfd_create system call wrapper
 	* sysdeps/unix/sysv/linux/Makefile [misc] (tests): Add
 	tst-memfd_create.
diff --git a/signal/Makefile b/signal/Makefile
index a6a1289437..c2dc719d70 100644
--- a/signal/Makefile
+++ b/signal/Makefile
@@ -45,8 +45,8 @@ routines	:= signal raise killpg \
 		   allocrtsig sigtimedwait sigwaitinfo sigqueue \
 		   sighold sigrelse sigignore sigset
 
-tests		:= tst-signal tst-sigset tst-sigsimple tst-raise tst-sigset2
-
+tests		:= tst-signal tst-sigset tst-sigsimple tst-raise tst-sigset2 \
+  tst-sigwait-eintr \
 
 include ../Rules
 
diff --git a/signal/tst-sigwait-eintr.c b/signal/tst-sigwait-eintr.c
new file mode 100644
index 0000000000..7149eb93c3
--- /dev/null
+++ b/signal/tst-sigwait-eintr.c
@@ -0,0 +1,85 @@
+/* Check that sigwait does not fail with EINTR (bug 22478).
+   Copyright (C) 2017 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 <stdio.h>
+#include <support/check.h>
+#include <support/xunistd.h>
+#include <time.h>
+#include <unistd.h>
+
+/* Handler for SIGUSR1.  */
+static void
+sigusr1_handler (int signo)
+{
+  TEST_VERIFY (signo == SIGUSR1);
+}
+
+/* Spawn a subprocess to send two signals: First SIGUSR1, then
+   SIGUSR2.  Return the PID of the process.  */
+static pid_t
+signal_sender (void)
+{
+  pid_t pid = xfork ();
+  if (pid == 0)
+    {
+      static const struct timespec delay = { 1, };
+      if (nanosleep (&delay, NULL) != 0)
+        FAIL_EXIT1 ("nanosleep: %m");
+      if (kill (getppid (), SIGUSR1) != 0)
+        FAIL_EXIT1 ("kill (SIGUSR1): %m");
+      if (nanosleep (&delay, NULL) != 0)
+        FAIL_EXIT1 ("nanosleep: %m");
+      if (kill (getppid (), SIGUSR2) != 0)
+        FAIL_EXIT1 ("kill (SIGUSR2): %m");
+      _exit (0);
+    }
+  return pid;
+}
+
+static int
+do_test (void)
+{
+  if (signal (SIGUSR1, sigusr1_handler) == SIG_ERR)
+    FAIL_EXIT1 ("signal (SIGUSR1): %m\n");
+
+  sigset_t sigs;
+  sigemptyset (&sigs);
+  sigaddset (&sigs, SIGUSR2);
+  if (sigprocmask (SIG_BLOCK, &sigs, NULL) != 0)
+    FAIL_EXIT1 ("sigprocmask (SIGBLOCK, SIGUSR2): %m");
+  pid_t pid = signal_sender ();
+  int signo = 0;
+  int ret = sigwait (&sigs, &signo);
+  if (ret != 0)
+    {
+      support_record_failure ();
+      errno = ret;
+      printf ("error: sigwait failed: %m (%d)\n", ret);
+    }
+  TEST_VERIFY (signo == SIGUSR2);
+
+  int status;
+  xwaitpid (pid, &status, 0);
+  TEST_VERIFY (status == 0);
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/sigwait.c b/sysdeps/unix/sysv/linux/sigwait.c
index e6fb32a610..443c3ad8e1 100644
--- a/sysdeps/unix/sysv/linux/sigwait.c
+++ b/sysdeps/unix/sysv/linux/sigwait.c
@@ -17,13 +17,20 @@
 
 #include <signal.h>
 #include <sysdep-cancel.h>
+#include <errno.h>
 
 int
 __sigwait (const sigset_t *set, int *sig)
 {
   siginfo_t si;
-  if (__sigtimedwait (set, &si, 0) < 0)
-    return -1;
+  int ret;
+  do
+    ret = __sigtimedwait (set, &si, 0);
+  /* Applications do not expect sigwait to return with EINTR, and the
+     error code is not specified by POSIX.  */
+  while (ret < 0 && errno == EINTR);
+  if (ret < 0)
+    return errno;
   *sig = si.si_signo;
   return 0;
 }