Fix exit() from signal handlers in LinuxThreads

[Daniel Jacobowitz <drow at false dot org>]

This is a patch I've had sitting around; the test case is fairly
self-explanatory.  When exit was called from a signal handler, the restart
from the manager processing the exit request instead restarted the thread
in pthread_cond_timedwait.  Tested and committed.

-- 
Daniel Jacobowitz
CodeSourcery

2006-05-01  Daniel Jacobowitz  <dan@codesourcery.com>

	* Makefile (tests): Add tst-sighandler1 and tst-sighandler2.
	* tst-sighandler1.c, tst-sighandler2.c: New files.
	* pthread.c (pthread_onexit_process): Reset p_signal_jmp.

diff -u Makefile Makefile
--- Makefile	1 May 2006 16:25:23 -0000
+++ Makefile	1 May 2006 17:00:50 -0000
@@ -111,7 +111,7 @@
 	ex17 ex18 tst-cancel tst-context bug-sleep \
 	tst-cancel1 tst-cancel2 tst-cancel3 tst-cancel4 tst-cancel5 \
 	tst-cancel6 tst-cancel7 tst-cancel8 tst-popen tst-popen2 tst-attr1 \
-	tst-stack1 tst-align tst-tsd1
+	tst-stack1 tst-align tst-tsd1 tst-sighandler1 tst-sighandler2
 test-srcs = tst-signal
 # These tests are linked with libc before libpthread
 tests-reverse += tst-cancel5
unchanged:
--- pthread.c	26 Apr 2006 15:04:12 -0000	1.137
+++ pthread.c	1 May 2006 16:25:23 -0000
@@ -1014,6 +1014,10 @@ static void pthread_onexit_process(int r
     struct pthread_request request;
     pthread_descr self = thread_self();
 
+    /* Make sure we come back here after suspend(), in case we entered
+       from a signal handler.  */
+    THREAD_SETMEM(self, p_signal_jmp, NULL);
+
     request.req_thread = self;
     request.req_kind = REQ_PROCESS_EXIT;
     request.req_args.exit.code = retcode;
diff -u tst-sighandler1.c tst-sighandler1.c
--- tst-sighandler1.c	1 May 2006 16:25:23 -0000
+++ tst-sighandler1.c	1 May 2006 17:00:50 -0000
@@ -0,0 +1,175 @@
+/* Copyright (C) 2006 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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <pthread.h>
+#include <errno.h>
+#include <stdio.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/time.h>
+#include <limits.h>
+
+pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+pthread_mutex_t mutex2 = PTHREAD_MUTEX_INITIALIZER;
+pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+
+static void *
+tf (void *arg)
+{
+  int fd = (long) arg;
+  int pid = getpid ();
+#ifdef TIMED
+  struct timespec ts;
+#endif
+
+  if (pthread_mutex_lock (&mutex) != 0)
+    {
+      puts ("Could not lock mutex in thread");
+      return (void *) 1L;
+    }
+
+  write (fd, &pid, sizeof (int));
+
+  if (pthread_mutex_unlock (&mutex2) != 0)
+    {
+      puts ("Could not unlock mutex2 in thread");
+      return (void *) 1L;
+    }
+
+#ifdef TIMED
+  ts.tv_sec = INT_MAX;
+  ts.tv_nsec = 0;
+  if (pthread_cond_timedwait (&cond, &mutex, &ts) != 0)
+    {
+      puts ("pthread_cond_wait failed in thread");
+      return (void *) 1L;
+    }
+#else
+  if (pthread_cond_wait (&cond, &mutex) != 0)
+    {
+      puts ("pthread_cond_wait failed in thread");
+      return (void *) 1L;
+    }
+#endif
+
+  if (pthread_mutex_unlock (&mutex) != 0)
+    {
+      puts ("Could not unlock mutex in thread");
+      return (void *) 1L;
+    }
+
+  return NULL;
+}
+
+static void
+sig_segv (int unused)
+{
+  exit (2);
+}
+
+int
+do_test (void)
+{
+  int fds[2];
+  pthread_t thr;
+
+  if (pipe (fds) < 0)
+    {
+      printf ("couldn't create pipe: %m\n");
+      return 1;
+    }
+
+  pid_t pid = fork ();
+  if (pid < 0)
+    {
+      printf ("fork failed: %m\n");
+      return 1;
+    }
+
+  if (!pid)
+    {
+      void *ret;
+
+      close (fds[0]);
+      signal (SIGSEGV, sig_segv);
+      pthread_mutex_lock (&mutex2);
+      pthread_create (&thr, NULL, tf, (void *) (long) (fds[1]));
+      /* Wait for the thread to go into cond_wait.  */
+      pthread_mutex_lock (&mutex2);
+      pthread_mutex_lock (&mutex);
+      write (fds[1], "", 1);
+      pthread_join (thr, &ret);
+      exit (0);
+    }
+
+  close (fds[1]);
+
+  int child_pid;
+  if (TEMP_FAILURE_RETRY (read (fds[0], &child_pid, sizeof (int)))
+      != sizeof (int))
+    {
+      puts ("could not read pid from child");
+      return 1;
+    }
+
+  char dummy;
+  if (TEMP_FAILURE_RETRY (read (fds[0], &dummy, 1)) != 1)
+    {
+      puts ("could not read sync byte from child");
+      return 1;
+    }
+
+  close (fds[0]);
+
+  /* The sync byte may come immediately after the mutex is released;
+     wait a little bit more to make sure the thread has suspended, to
+     test the right bug.  */
+  struct timespec ts;
+  ts.tv_sec = 0;
+  ts.tv_nsec = 200000000;
+  nanosleep (&ts, NULL);
+
+  kill (child_pid, SIGSEGV);
+
+  pid_t termpid;
+  int status;
+  termpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));
+  if (termpid == -1)
+    {
+      printf ("waitpid failed: %m\n");
+      return 1;
+    }
+  else if (termpid != pid)
+    {
+      printf ("waitpid returned %ld != %ld\n",
+	      (long int) termpid, (long int) pid);
+      return 1;
+    }
+  else if (!WIFEXITED (status) || WEXITSTATUS (status) != 2)
+    {
+      puts ("child hasn't exited with exit status 2");
+      return 1;
+    }
+
+  return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
only in patch2:
unchanged:
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ tst-sighandler2.c	1 May 2006 17:00:50 -0000
@@ -0,0 +1,2 @@
+#define TIMED
+#include "tst-sighandler1.c"