Re: [new patch] Re: [RFC] Fix for gdb crash in "info thread" after exec().

[Pedro Alves <pedro@codesourcery.com>]

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A Wednesday 28 May 2008 18:09:40, Paul Pluzhnikov wrote:
> On Wed, May 28, 2008 at 8:26 AM, Pedro Alves <pedro@codesourcery.com> wrote:
> > What do you think?
>
> Looks good to me, except the "second" parameter in the test is no
> longer necessary, and there is an off-by-three bug in the allocation
> of new_image:
>

Outch!  How careless am I ?   :-)

New patch attached.  Can anyone approve (or reject) this?

-- 
Pedro Alves

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gdb/
2008-05-28  Pedro Alves  <pedro@codesourcery.com>

	* linux-thread-db.c (thread_db_wait): Don't trim event ptid.

testsuite/
2008-05-28  Paul Pluzhnikov  <ppluzhnikov@google.com>
            Pedro Alves  <pedro@codesourcery.com>

	* gdb.threads/execl.c, gdb.threads/execl1.c,
	gdb.threads/execl.exp: New tests.

---
 gdb/linux-thread-db.c               |    2 
 gdb/testsuite/gdb.threads/execl.c   |   38 ++++++++++++++++++
 gdb/testsuite/gdb.threads/execl.exp |   75 ++++++++++++++++++++++++++++++++++++
 gdb/testsuite/gdb.threads/execl1.c  |    9 ++++
 4 files changed, 123 insertions(+), 1 deletion(-)

Index: gdb/linux-thread-db.c
===================================================================
--- gdb/linux-thread-db.c.orig	2008-05-28 18:49:15.000000000 +0100
+++ gdb/linux-thread-db.c	2008-05-28 18:49:37.000000000 +0100
@@ -838,7 +838,7 @@ thread_db_wait (ptid_t ptid, struct targ
       unpush_target (&thread_db_ops);
       using_thread_db = 0;
 
-      return pid_to_ptid (GET_PID (ptid));
+      return ptid;
     }
 
   /* If we do not know about the main thread yet, this would be a good time to
Index: gdb/testsuite/gdb.threads/execl.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb/testsuite/gdb.threads/execl.c	2008-05-28 18:54:06.000000000 +0100
@@ -0,0 +1,38 @@
+/* Test handling thread control across an execl.  */
+
+/* The original image loads a thread library and has several threads,
+   while the new image does not load a thread library.  */
+
+#include <unistd.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+void *
+thread_function (void *arg)
+{
+  while (1)
+    sleep (100);
+  return NULL;
+}
+
+int
+main (int argc, char* argv[])
+{
+  pthread_t thread1;
+  pthread_t thread2;
+  char *new_image;
+
+  pthread_create (&thread1, NULL, thread_function, NULL);
+  pthread_create (&thread2, NULL, thread_function, NULL);
+
+  new_image = malloc (strlen (argv[0]) + 2);
+  strcpy (new_image, argv[0]);
+  strcat (new_image, "1");
+
+  if (execl (new_image, new_image, NULL) == -1) /* set breakpoint here */
+    return 1;
+
+  return 0;
+}
Index: gdb/testsuite/gdb.threads/execl.exp
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb/testsuite/gdb.threads/execl.exp	2008-05-28 18:53:39.000000000 +0100
@@ -0,0 +1,75 @@
+# Copyright (C) 2008 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/>.
+
+# Test handling of threads across an execl.
+
+
+# Original image, loads a thread library.
+set testfile "execl"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+    return -1
+}
+
+# New image, that does not load a thread library.
+set testfile1 "execl1"
+set srcfile1 ${testfile1}.c
+set binfile1 ${objdir}/${subdir}/${testfile1}
+
+if {[gdb_compile "${srcdir}/${subdir}/${srcfile1}" "${binfile1}" executable {debug}] != "" } {
+    return -1
+}
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load ${binfile}
+
+runto_main
+
+gdb_test "b [gdb_get_line_number "breakpoint here"]" \
+         ".*Breakpoint .*execl.*" "set breakpoint at execl"
+
+gdb_test "continue" ".*breakpoint here.*" "continue to exec"
+
+gdb_test "info threads" ".*3 Thread.*2 Thread.*1 Thread.*" "info threads before exec"
+
+# When continuing from this point we'll hit the breakpoint in main()
+# again, this time in the exec'd process.
+gdb_test "continue" ".*Breakpoint 1, main.*" \
+    "continue across exec"
+
+gdb_test "info threads" ".*" "info threads after exec"
+
+set test "info threads after exec"
+gdb_test_multiple "info threads" "$test" {
+    -re "2 Thread .*$gdb_prompt $" {
+	# Old threads left behind.
+	fail "$test"
+    }
+    -re "4 Thread .*$gdb_prompt $" {
+	# New threads registered.
+	fail "$test"
+    }
+    -re "$gdb_prompt $" {
+	# Target doesn't register the main thread, pass for now.
+	pass "$test"
+    }
+}
+
+gdb_test "continue" ".*Program exited normally\\." \
+    "continue to end"
Index: gdb/testsuite/gdb.threads/execl1.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gdb/testsuite/gdb.threads/execl1.c	2008-05-28 18:58:00.000000000 +0100
@@ -0,0 +1,9 @@
+/* Test handling thread control across an execl.  */
+
+/* New exec image that doesn't load any thread library.  */
+
+int
+main (int argc, char* argv[])
+{
+  return 0;
+}