gdb/

	* infrun.c (proceed): Revert previous change.
	(resume): Instead, handle the case of signal delivery while stepping
	off a breakpoint location here, and only if software single-stepping
	is used.  Handle nested signals.

	gdb/testsuite/
	* gdb.base/signest.exp: New file.
	* gdb.base/signest.c: Likewise.

2 files changed, 120 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.base/signest.c b/gdb/testsuite/gdb.base/signest.c
new file mode 100644
index 0000000..127c77f
--- /dev/null
+++ b/gdb/testsuite/gdb.base/signest.c
@@ -0,0 +1,53 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2011 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 <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+volatile char *p = NULL;
+
+extern long
+bowler (void)
+{
+  return *p;
+}
+
+extern void
+keeper (int sig)
+{
+  static int recurse = 0;
+  if (++recurse < 3)
+    bowler ();
+
+  _exit (0);
+}
+
+int
+main (void)
+{
+  struct sigaction act;
+  memset (&act, 0, sizeof act);
+  act.sa_handler = keeper;
+  act.sa_flags = SA_NODEFER;
+  sigaction (SIGSEGV, &act, NULL);
+  sigaction (SIGBUS, &act, NULL);
+
+  bowler ();
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.base/signest.exp b/gdb/testsuite/gdb.base/signest.exp
new file mode 100644
index 0000000..02f8134
--- /dev/null
+++ b/gdb/testsuite/gdb.base/signest.exp
@@ -0,0 +1,67 @@
+# This testcase is part of GDB, the GNU debugger.
+
+# Copyright 2011 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/>.
+
+set testfile "signest"
+set srcfile ${testfile}.c
+
+if [target_info exists gdb,nosignals] {
+    verbose "Skipping ${testfile}.exp because of nosignals."
+    return -1
+}
+
+if [prepare_for_testing ${testfile}.exp ${testfile} ${srcfile} {debug}] {
+    untested ${testfile}.exp
+    return -1
+}
+
+if ![runto_main] then {
+    untested ${testfile}.exp
+    return -1
+}
+
+# If we can examine what's at memory address 0, it is possible that we
+# could also execute it.  This could probably make us run away,
+# executing random code, which could have all sorts of ill effects,
+# especially on targets without an MMU.  Don't run the tests in that
+# case.
+
+gdb_test_multiple "x 0" "memory at address 0" {
+    -re "0x0:.*Cannot access memory at address 0x0.*$gdb_prompt $" { }
+    -re "0x0:.*Error accessing memory address 0x0.*$gdb_prompt $" { }
+    -re ".*$gdb_prompt $" {
+	untested "Memory at address 0 is possibly executable"
+	return -1
+    }
+}
+
+# Run until we hit the SIGSEGV (or SIGBUS on some platforms).
+gdb_test "continue" \
+	 ".*Program received signal (SIGBUS|SIGSEGV).*bowler.*" \
+         "continue to fault"
+
+# Insert conditional breakpoint at faulting instruction
+gdb_test "break if 0" ".*" "set conditional breakpoint"
+
+# Set SIGSEGV/SIGBUS to pass+nostop
+gdb_test "handle SIGSEGV nostop print pass" ".*" "pass SIGSEGV"
+gdb_test "handle SIGBUS nostop print pass" ".*" "pass SIGBUS"
+
+# Step off the faulting instruction into the handler, triggering nested faults
+gdb_test "continue" \
+         ".*Program received signal (SIGBUS|SIGSEGV).*Program received signal (SIGBUS|SIGSEGV).*exited normally.*" \
+	 "run through nested faults"
+