2012-07-20 Pedro Alves <palves@redhat.com>

	PR threads/11692
	PR gdb/12203

	gdb/
	* infrun.c (handle_inferior_event) <new thread>: Don't special
	case minus_one_ptid.
	<TARGET_WAITKIND_SPURIOUS>: Ditto.
	* linux-thread-db.c (thread_get_info_callback): Don't return early
	if the thread is zombie.
	(thread_from_lwp): Change return type to void.  Rewrite stale
	comment.
	(attach_thread): Don't return early if the thread is zombie,
	instead set its "dying" flag.
	(thread_db_wait): Don't return TARGET_WAITKIND_SPURIOUS anymore.
	(find_new_threads_callback): Don't return early if the thread is
	zombie.

	gdb/testsuite/
	* gdb.threads/create-fail.c: New file.
	* gdb.threads/create-fail.exp: New file.

2 files changed, 172 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.threads/create-fail.c b/gdb/testsuite/gdb.threads/create-fail.c
new file mode 100644
index 0000000..b926cf5
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/create-fail.c
@@ -0,0 +1,119 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#define _GNU_SOURCE
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sched.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <assert.h>
+
+/* Count the number of tasks/threads in the PID thread group.  */
+
+static int
+count_tasks (pid_t pid)
+{
+  char path[100];
+  int count;
+  DIR *d;
+
+  snprintf (path, sizeof (path), "/proc/%d/task/", (int) pid);
+  d = opendir (path);
+  if (d == NULL)
+    return -1;
+
+  for (count = 0; readdir (d) != NULL; count++)
+    ;
+  closedir (d);
+
+  /* Account for '.' and '..'.  */
+  assert (count > 2);
+  return count - 2;
+}
+
+pthread_attr_t attr[CPU_SETSIZE];
+pthread_t thr[CPU_SETSIZE];
+
+static void *
+mythread (void *_arg)
+{
+  return NULL;
+}
+
+int
+main ()
+{
+  int i;
+
+  for (i = 0; i < CPU_SETSIZE; i++)
+    {
+      cpu_set_t set;
+      int ret;
+
+      pthread_attr_init (&attr[i]);
+      CPU_ZERO_S (sizeof (set), &set);
+      CPU_SET_S (i, sizeof (set), &set);
+
+      ret = pthread_attr_setaffinity_np (&attr[i], sizeof (set), &set);
+      if (ret != 0)
+	{
+	  fprintf (stderr, "set_affinity: %d: %s\n", ret, strerror (ret));
+	  exit (3);
+	}
+      ret = pthread_create (&thr[i], &attr[i], mythread, NULL);
+      /* Should fail with EINVAL at some point.  */
+      if (ret != 0)
+	{
+	  unsigned long t;
+
+	  fprintf (stderr, "pthread_create: %d: %s\n", ret, strerror (ret));
+
+	  /* Wait for all threads to exit.  pthread_create spawns a
+	     clone thread even in the failing case, as it can only try
+	     to set the affinity after creating the thread.  That new
+	     thread is immediately canceled (because setting the
+	     affinity fails), by killing it with a SIGCANCEL signal,
+	     which may end up in pthread_cancel/unwind paths, which
+	     may trigger a libgcc_s.so load, making the thread hit the
+	     solib-event breakpoint.  Now, if we would let the program
+	     exit without waiting, sometimes it would happen that the
+	     inferior exits just while we're handling the solib-event,
+	     resulting in errors being thrown due to failing ptrace
+	     call fails (with ESCHR), breaking the test.  */
+	  t = 16;
+	  while (count_tasks (getpid ()) > 1)
+	    {
+	      usleep (t);
+
+	      if (t < 256)
+		t *= 2;
+	    }
+
+	  /* Normal exit, because this is what we are expecting.  */
+	  exit (0);
+	}
+    }
+
+  /* Should not normally be reached.  */
+  exit (1);
+}
diff --git a/gdb/testsuite/gdb.threads/create-fail.exp b/gdb/testsuite/gdb.threads/create-fail.exp
new file mode 100644
index 0000000..0cdacf6
--- /dev/null
+++ b/gdb/testsuite/gdb.threads/create-fail.exp
@@ -0,0 +1,53 @@
+# Copyright (C) 2012 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# On GNU/Linux, a creating a thread bound to an unexisting cpu spawns
+# the clone child thread for a bit, which is then immediately
+# cancelled.  The spawned child may trigger a dlopen (for libgcc_s)
+# while being cancelled, which results in a trap being reported to
+# GDB, for a thread that libthread_db considers to be TD_THR_ZOMBIE.
+# Make sure we handle that scenario properly.
+
+standard_testfile
+set executable ${testfile}
+
+if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+    return -1
+}
+
+set iterations 10
+for {set i 1} {$i <= $iterations} {incr i} {
+    with_test_prefix "iteration $i" {
+
+	clean_restart ${executable}
+
+	if ![runto_main] {
+	    return -1
+	}
+
+	set test "run till end"
+	gdb_test_multiple "continue" "$test" {
+	    -re "exited with code 01.*$gdb_prompt $" {
+		pass "$test"
+	    }
+	    -re "exited with code 02.*$gdb_prompt $" {
+		unsupported "$test (too many CPUs for test?)"
+	    }
+	    -re "exited normally.*$gdb_prompt $" {
+		pass "$test"
+	    }
+	}
+    }
+}