Fix internal error caused by interaction between catch signal and fork

Author: Philippe Waroquiers

gdb/ChangeLog

@@ -1,3 +1,8 @@
+2013-05-21  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* breakpoints.c (detach_breakpoints): Do not
+	detach breakpoints locations with loc_type bp_loc_other.
+
 2013-05-21  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
 	Workaround Python 2.6.

gdb/breakpoint.c

@@ -3537,6 +3537,15 @@ detach_breakpoints (ptid_t ptid)
     if (bl->pspace != inf->pspace)
       continue;
 
+    /* This function must physically remove breakpoints locations
+       from the specified ptid, without modifying the breakpoint
+       package's state.  Locations of type bp_loc_other are only
+       maintained at GDB side.  So, there is no need to remove
+       these bp_loc_other locations.  Moreover, removing these
+       would modify the breakpoint package's state.  */
+    if (bl->loc_type == bp_loc_other)
+      continue;
+
     if (bl->inserted)
       val |= remove_breakpoint_1 (bl, mark_inserted);
   }

gdb/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2013-05-21  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
+
+	* gdb.base/catch-signal-fork.exp: New file.
+	* gdb.base/catch-signal-fork.c: New file.
+
 2013-05-21  Sterling Augustine  <saugustine@google.com>
 
 	* boards/remote-stdio-gdbserver.exp: New file.

gdb/testsuite/gdb.base/catch-signal-fork.c

@@ -0,0 +1,58 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2012-2013 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/>.  */
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+
+void
+do_nothing (void)
+{
+}
+
+void
+handle (int sig)
+{
+  do_nothing (); /* handle marker */
+}
+
+int
+main ()
+{
+  int i;
+  signal (SIGHUP, handle);
+
+  raise (SIGHUP);		/* first HUP */
+
+  signal (SIGCHLD, handle);
+  for (i = 0; i < 3; i++)	/* fork loop */
+    {
+      switch (fork())
+	{
+	case -1:
+	  perror ("fork");
+	  exit (1);
+	case 0:
+	  exit (0);
+	}
+      wait (NULL);
+    }
+
+  raise (SIGHUP);		/* second HUP */
+
+  raise (SIGHUP);		/* third HUP */
+}
+

gdb/testsuite/gdb.base/catch-signal-fork.exp

@@ -0,0 +1,43 @@
+# Copyright 2012-2013 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/>.
+
+if [target_info exists gdb,nosignals] {
+    verbose "Skipping catch-signal-fork.exp because of nosignals."
+    continue
+}
+
+standard_testfile
+
+if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
+    return -1
+}
+
+if {![runto_main]} {
+    return -1
+}
+
+# Test "catch signal SIGHUP"
+gdb_test "catch signal SIGHUP" "Catchpoint .*"
+gdb_breakpoint ${srcfile}:[gdb_get_line_number "first HUP"]
+gdb_breakpoint ${srcfile}:[gdb_get_line_number "fork loop"]
+
+gdb_continue_to_breakpoint "first HUP"
+gdb_test "continue" "Catchpoint .*"
+
+# Test interaction with fork.
+# This used to cause a gdb_assert in the code detaching the
+# breakpoints for the child.
+gdb_continue_to_breakpoint "fork loop"
+gdb_test "continue" "Catchpoint .* SIGHUP.*" "got SIGHUP after fork"