[patch 2/4]#3 Fix lost siginfo_t for inferior calls

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

testcase from: http://sourceware.org/ml/gdb-patches/2010-09/msg00105.html

Hi,

as siginfo_t is still stored separately from enum target_signal:

Inferior calls need to store and restore target_signal.  Therefeore they  must
do so also for siginfo_t, not just the enum target_signal.


Thanks,
Jan


gdb/
2010-09-20  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix lost siginfo_t for inferior calls
	* infrun.c
	(struct inferior_thread_state) <siginfo_gdbarch, siginfo_data>: New.
	(save_inferior_thread_state): New variables regcache, gdbarch and
	siginfo_data.  Initialize SIGINFO_DATA if gdbarch_get_siginfo_type_p.
	Move INF_STATE allocation later, pre-clear it.  Initialize REGISTERS
	using REGCACHE.
	(restore_inferior_thread_state): New variables regcache and gdbarch.
	Restore SIGINFO_DATA for matching GDBARCH.  Restore REGISTERS using
	REGCACHE.  Free also SIGINFO_DATA.

gdb/testsuite/
2010-09-20  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Fix lost siginfo_t for inferior calls
	* gdb.base/siginfo-infcall.exp: New file.
	* gdb.base/siginfo-infcall.c: New file.

--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -6037,18 +6037,57 @@ struct inferior_thread_state
   enum target_signal stop_signal;
   CORE_ADDR stop_pc;
   struct regcache *registers;
+
+  /* Format of SIGINFO or NULL if it is not present.  */
+  struct gdbarch *siginfo_gdbarch;
+
+  /* The inferior format depends on SIGINFO_GDBARCH and it has a length of
+     TYPE_LENGTH (gdbarch_get_siginfo_type ()).  For different gdbarch the
+     content would be invalid.  */
+  gdb_byte *siginfo_data;
 };
 
 struct inferior_thread_state *
 save_inferior_thread_state (void)
 {
-  struct inferior_thread_state *inf_state = XMALLOC (struct inferior_thread_state);
+  struct inferior_thread_state *inf_state;
   struct thread_info *tp = inferior_thread ();
+  struct regcache *regcache = get_current_regcache ();
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
+  gdb_byte *siginfo_data = NULL;
+
+  if (gdbarch_get_siginfo_type_p (gdbarch))
+    {
+      struct type *type = gdbarch_get_siginfo_type (gdbarch);
+      size_t len = TYPE_LENGTH (type);
+      struct cleanup *back_to;
+
+      siginfo_data = xmalloc (len);
+      back_to = make_cleanup (xfree, siginfo_data);
+
+      if (target_read (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
+		       siginfo_data, 0, len) == len)
+	discard_cleanups (back_to);
+      else
+	{
+	  /* Errors ignored.  */
+	  do_cleanups (back_to);
+	  siginfo_data = NULL;
+	}
+    }
+
+  inf_state = XZALLOC (struct inferior_thread_state);
+
+  if (siginfo_data)
+    {
+      inf_state->siginfo_gdbarch = gdbarch;
+      inf_state->siginfo_data = siginfo_data;
+    }
 
   inf_state->stop_signal = tp->stop_signal;
   inf_state->stop_pc = stop_pc;
 
-  inf_state->registers = regcache_dup (get_current_regcache ());
+  inf_state->registers = regcache_dup (regcache);
 
   return inf_state;
 }
@@ -6059,16 +6098,29 @@ void
 restore_inferior_thread_state (struct inferior_thread_state *inf_state)
 {
   struct thread_info *tp = inferior_thread ();
+  struct regcache *regcache = get_current_regcache ();
+  struct gdbarch *gdbarch = get_regcache_arch (regcache);
 
   tp->stop_signal = inf_state->stop_signal;
   stop_pc = inf_state->stop_pc;
 
+  if (inf_state->siginfo_gdbarch == gdbarch)
+    {
+      struct type *type = gdbarch_get_siginfo_type (gdbarch);
+      size_t len = TYPE_LENGTH (type);
+
+      /* Errors ignored.  */
+      target_write (&current_target, TARGET_OBJECT_SIGNAL_INFO, NULL,
+		    inf_state->siginfo_data, 0, len);
+    }
+
   /* The inferior can be gone if the user types "print exit(0)"
      (and perhaps other times).  */
   if (target_has_execution)
     /* NB: The register write goes through to the target.  */
-    regcache_cpy (get_current_regcache (), inf_state->registers);
+    regcache_cpy (regcache, inf_state->registers);
   regcache_xfree (inf_state->registers);
+  xfree (inf_state->siginfo_data);
   xfree (inf_state);
 }
 
--- /dev/null
+++ b/gdb/testsuite/gdb.base/siginfo-infcall.c
@@ -0,0 +1,79 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2010 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 <assert.h>
+#include <string.h>
+#include <unistd.h>
+
+#ifndef SA_SIGINFO
+# error "SA_SIGINFO is required for this test"
+#endif
+
+static int
+callme (void)
+{
+  return 42;
+}
+
+static int
+pass (void)
+{
+  return 1;
+}
+
+static int
+fail (void)
+{
+  return 1;
+}
+
+static void
+handler (int sig, siginfo_t *siginfo, void *context)
+{
+  assert (sig == SIGUSR1);
+  assert (siginfo->si_signo == SIGUSR1);
+  if (siginfo->si_pid == getpid ())
+    pass ();
+  else
+    fail ();
+}
+
+int
+main (void)
+{
+  struct sigaction sa;
+  int i;
+
+  callme ();
+
+  memset (&sa, 0, sizeof (sa));
+  sa.sa_sigaction = handler;
+  sa.sa_flags = SA_SIGINFO;
+
+  i = sigemptyset (&sa.sa_mask);
+  assert (i == 0);
+
+  i = sigaction (SIGUSR1, &sa, NULL);
+  assert (i == 0);
+
+  i = raise (SIGUSR1);
+  assert (i == 0);
+
+  sleep (600);
+  return 0;
+}
--- /dev/null
+++ b/gdb/testsuite/gdb.base/siginfo-infcall.exp
@@ -0,0 +1,47 @@
+# Copyright 2010 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 siginfo-infcall.exp because of nosignals."
+    continue
+}
+
+set testfile siginfo-infcall
+set srcfile ${testfile}.c
+set executable ${testfile}
+if { [prepare_for_testing ${testfile}.exp $executable] } {
+    return -1
+}
+
+if ![runto_main] {
+    return -1
+}
+
+gdb_breakpoint "pass"
+gdb_breakpoint "fail"
+
+gdb_test "continue" "Program received signal SIGUSR1, .*" "continue to SIGUSR1"
+
+gdb_test "p callme ()" " = 42"
+
+set test "continue to the handler"
+gdb_test_multiple "continue" $test {
+    -re "Breakpoint \[0-9\]+,\[^\r\n\]* pass .*\r\n$gdb_prompt $" {
+	pass $test
+    }
+    -re "Breakpoint \[0-9\]+,\[^\r\n\]* fail .*\r\n$gdb_prompt $" {
+	fail $test
+    }
+}