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[RFA/RFC] Fix watchpoint troubles on windows native.
- From: "Pierre Muller" <muller at ics dot u-strasbg dot fr>
- To: <gdb-patches at sourceware dot org>
- Date: Fri, 26 Jun 2009 01:07:20 +0200
- Subject: [RFA/RFC] Fix watchpoint troubles on windows native.
This patch includes a new test
which sets two watchpoints, and removes the first one
after some hits.
With the current GDB windows native from cvs HEAD,
I get failures due to the fact that
dr[0] and dr[1] both have the same address in the debuggee,
and despite the fact that only debug register 0
is active according to dr[7], dr[6] nevertheless
reports dr[1] as being hit instead of dr[0]
(bit one of dr[6] is set, instead of bit 0).
GDB finally reports a SIGTRAp instead of a watchpoint hit.
Adding cygwin_reset_dr function fixes this
bug.
The testsuite part of the patch is essentially there
to allow for a simple testing of the efficiency of the solution
to the problem exposed.
About the test itself, I was wondering if
it is OK to require being able to get two hardware watchpoints.
This test would probably fail on targets supporting only
one hardware watchpoint.
I would like an approval from Christopher Faylor
for the windows-nat.c patch
and comments about the test.
Pierre Muller
Pascal language support maintainer for GDB
gdb ChangeLog:
2009-06-26 Pierre Muller <muller@ics.u-strasbg.fr>
* windows-nat.c (cygwin_reset_dr): New forward declaration.
(init_windows_ops): Set i386_dr_low.reset_addr field to
cygwin_reset_dr.
(cygwin_reset_dr): New function
gdb/testsuite ChangeLog entry:
2009-06-26 Pierre Muller <muller@ics.u-strasbg.fr>
New test for two watchpoints, with disabling of
the first inserted.
* testsuite/gdb.base/watchpoints.c: New file.
* testsuite/gdb.base/watchpoints.exp: New file.
Index: windows-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-nat.c,v
retrieving revision 1.195
diff -u -p -r1.195 windows-nat.c
--- windows-nat.c 17 Jun 2009 18:44:23 -0000 1.195
+++ windows-nat.c 25 Jun 2009 22:44:17 -0000
@@ -142,6 +142,7 @@ static int windows_thread_alive (struct
static void windows_kill_inferior (struct target_ops *);
static void cygwin_set_dr (int i, CORE_ADDR addr);
+static void cygwin_reset_dr (int i);
static void cygwin_set_dr7 (unsigned long val);
static unsigned long cygwin_get_dr6 (void);
@@ -2179,7 +2180,7 @@ init_windows_ops (void)
i386_dr_low.set_control = cygwin_set_dr7;
i386_dr_low.set_addr = cygwin_set_dr;
- i386_dr_low.reset_addr = NULL;
+ i386_dr_low.reset_addr = cygwin_reset_dr;
i386_dr_low.get_status = cygwin_get_dr6;
/* i386_dr_low.debug_register_length field is set by
@@ -2298,6 +2299,13 @@ cygwin_set_dr (int i, CORE_ADDR addr)
debug_registers_used = 1;
}
+/* Reset dr[i], to stay in sync with i386-nat dr_mirror. */
+static void
+cygwin_reset_dr (int i)
+{
+ cygwin_set_dr (i, 0);
+}
+
/* Pass the value VAL to the inferior in the DR7 debug control
register. Here we just store the address in D_REGS, the watchpoint
will be actually set up in windows_wait. */
Index: testsuite/gdb.base/watchpoints.c
===================================================================
RCS file: testsuite/gdb.base/watchpoints.c
diff -N testsuite/gdb.base/watchpoints.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.base/watchpoints.c 25 Jun 2009 22:44:17 -0000
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <unistd.h>
+/*
+ * This source is mainly to test
+ * what happens when a watchpoint is removed
+ * while another watchpoint, inserted later is
+ * left active.
+ */
+
+int count = -1;
+int ival1 = -1;
+int ival2 = -1;
+int ival3 = -1;
+int ival4 = -1;
+
+int
+main ()
+{
+#ifdef usestubs
+ set_debug_traps();
+ breakpoint();
+#endif
+
+ for (count = 0; count < 4; count++) {
+ ival1 = count; ival2 = count;
+ ival3 = count; ival4 = count;
+ }
+
+ ival1 = count; ival2 = count; /* Outside loop */
+ ival3 = count; ival4 = count;
+
+ return 0;
+}
Index: testsuite/gdb.base/watchpoints.exp
===================================================================
RCS file: testsuite/gdb.base/watchpoints.exp
diff -N testsuite/gdb.base/watchpoints.exp
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.base/watchpoints.exp 25 Jun 2009 22:44:17 -0000
@@ -0,0 +1,101 @@
+# Copyright 2009
+# 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/>.
+
+# This file was written by Pierre Muller. (muller@ics.u-strasbg.fr)
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile "watchpoints"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+set wp_set 1
+
+if [get_compiler_info ${binfile}] {
+ return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable
{debug}] != "" } {
+ untested watchpoint.exp
+ return -1
+}
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load $binfile
+
+ runto_main
+ gdb_test "watch ival1" "" ""
+ gdb_test "watch ival3" "" ""
+
+ set timeout 600
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value =
-1.*New value = 0.*ival1 = count; ival2 = count;.*" "watchpoint hit, first
time"
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value =
-1.*New value = 0.*ival3 = count; ival4 = count;.*" "watchpoint hit, first
time"
+
+ # Check that the ival3 hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 1 time.*" "Watchpoint hit count
is 1"
+
+ # Continue until the next change for ival1, from 0 to 1.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value = 0.*New
value = 1.*ival1 = count; ival2 = count;.*" "watchpoint ival1 hit, second
time"
+
+ # Check that the hit count for ival1 is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival1\r\n\[ \t]+breakpoint already hit 2 times.*" "Watchpoint ival1 hit
count is 2"
+
+ # Continue until the next change for ival3, from 0 to 1.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 0.*New
value = 1.*ival3 = count; ival4 = count;.*" "watchpoint hit, second time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 2 times.*" "Watchpoint hit count
is 2"
+
+ # Continue until the next change, from 1 to 2.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value = 1.*New
value = 2.*ival1 = count; ival2 = count;.*" "watchpoint ival1 hit, third
time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival1\r\n\[ \t]+breakpoint already hit 3 times.*" "Watchpoint ival1 hit
count is 3"
+ # Disable ival1 watchpoint
+ gdb_test "disable 2" "" ""
+
+ # Continue until the next change, from 1 to 2.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 1.*New
value = 2.*ival3 = count; ival4 = count;.*" "watchpoint hit, third time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 3 times.*" "Watchpoint hit count
is 3"
+
+ # Continue until the next change, from 2 to 3.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 2.*New
value = 3.*ival3 = count; ival4 = count;.*" "watchpoint hit, fourth time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 4 times.*" "Watchpoint hit count
is 4"
+
+ # Continue until the next change, from 3 to 4.
+ # Note that this one is outside the loop.
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 3.*New
value = 4.*ival3 = count; ival4 = count;.*" "watchpoint hit, fifth time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 5 times.*" "Watchpoint hit count
is 5"
+
+
gdb ChangeLog:
2009-06-26 Pierre Muller <muller@ics.u-strasbg.fr>
* windows-nat.c (cygwin_reset_dr): New forward declaration.
(init_windows_ops): Set i386_dr_low.reset_addr field to
cygwin_reset_dr.
(cygwin_reset_dr): New function
gdb/testsuite ChangeLog entry:
2009-06-26 Pierre Muller <muller@ics.u-strasbg.fr>
New test for two watchpoints, with disabling of
the first inserted.
* testsuite/gdb.base/watchpoints.c: New file.
* testsuite/gdb.base/watchpoints.exp: New file.
Index: windows-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/windows-nat.c,v
retrieving revision 1.195
diff -u -p -r1.195 windows-nat.c
--- windows-nat.c 17 Jun 2009 18:44:23 -0000 1.195
+++ windows-nat.c 25 Jun 2009 22:44:17 -0000
@@ -142,6 +142,7 @@ static int windows_thread_alive (struct
static void windows_kill_inferior (struct target_ops *);
static void cygwin_set_dr (int i, CORE_ADDR addr);
+static void cygwin_reset_dr (int i);
static void cygwin_set_dr7 (unsigned long val);
static unsigned long cygwin_get_dr6 (void);
@@ -2179,7 +2180,7 @@ init_windows_ops (void)
i386_dr_low.set_control = cygwin_set_dr7;
i386_dr_low.set_addr = cygwin_set_dr;
- i386_dr_low.reset_addr = NULL;
+ i386_dr_low.reset_addr = cygwin_reset_dr;
i386_dr_low.get_status = cygwin_get_dr6;
/* i386_dr_low.debug_register_length field is set by
@@ -2298,6 +2299,13 @@ cygwin_set_dr (int i, CORE_ADDR addr)
debug_registers_used = 1;
}
+/* Reset dr[i], to stay in sync with i386-nat dr_mirror. */
+static void
+cygwin_reset_dr (int i)
+{
+ cygwin_set_dr (i, 0);
+}
+
/* Pass the value VAL to the inferior in the DR7 debug control
register. Here we just store the address in D_REGS, the watchpoint
will be actually set up in windows_wait. */
Index: testsuite/gdb.base/watchpoints.c
===================================================================
RCS file: testsuite/gdb.base/watchpoints.c
diff -N testsuite/gdb.base/watchpoints.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.base/watchpoints.c 25 Jun 2009 22:44:17 -0000
@@ -0,0 +1,33 @@
+#include <stdio.h>
+#include <unistd.h>
+/*
+ * This source is mainly to test
+ * what happens when a watchpoint is removed
+ * while another watchpoint, inserted later is
+ * left active.
+ */
+
+int count = -1;
+int ival1 = -1;
+int ival2 = -1;
+int ival3 = -1;
+int ival4 = -1;
+
+int
+main ()
+{
+#ifdef usestubs
+ set_debug_traps();
+ breakpoint();
+#endif
+
+ for (count = 0; count < 4; count++) {
+ ival1 = count; ival2 = count;
+ ival3 = count; ival4 = count;
+ }
+
+ ival1 = count; ival2 = count; /* Outside loop */
+ ival3 = count; ival4 = count;
+
+ return 0;
+}
Index: testsuite/gdb.base/watchpoints.exp
===================================================================
RCS file: testsuite/gdb.base/watchpoints.exp
diff -N testsuite/gdb.base/watchpoints.exp
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ testsuite/gdb.base/watchpoints.exp 25 Jun 2009 22:44:17 -0000
@@ -0,0 +1,101 @@
+# Copyright 2009
+# 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/>.
+
+# This file was written by Pierre Muller. (muller@ics.u-strasbg.fr)
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+set testfile "watchpoints"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+
+set wp_set 1
+
+if [get_compiler_info ${binfile}] {
+ return -1
+}
+
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable
{debug}] != "" } {
+ untested watchpoint.exp
+ return -1
+}
+
+# Start with a fresh gdb.
+
+gdb_exit
+gdb_start
+gdb_reinitialize_dir $srcdir/$subdir
+gdb_load $binfile
+
+ runto_main
+ gdb_test "watch ival1" "" ""
+ gdb_test "watch ival3" "" ""
+
+ set timeout 600
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value =
-1.*New value = 0.*ival1 = count; ival2 = count;.*" "watchpoint hit, first
time"
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value =
-1.*New value = 0.*ival3 = count; ival4 = count;.*" "watchpoint hit, first
time"
+
+ # Check that the ival3 hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 1 time.*" "Watchpoint hit count
is 1"
+
+ # Continue until the next change for ival1, from 0 to 1.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value = 0.*New
value = 1.*ival1 = count; ival2 = count;.*" "watchpoint ival1 hit, second
time"
+
+ # Check that the hit count for ival1 is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival1\r\n\[ \t]+breakpoint already hit 2 times.*" "Watchpoint ival1 hit
count is 2"
+
+ # Continue until the next change for ival3, from 0 to 1.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 0.*New
value = 1.*ival3 = count; ival4 = count;.*" "watchpoint hit, second time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 2 times.*" "Watchpoint hit count
is 2"
+
+ # Continue until the next change, from 1 to 2.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival1.*Old value = 1.*New
value = 2.*ival1 = count; ival2 = count;.*" "watchpoint ival1 hit, third
time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival1\r\n\[ \t]+breakpoint already hit 3 times.*" "Watchpoint ival1 hit
count is 3"
+ # Disable ival1 watchpoint
+ gdb_test "disable 2" "" ""
+
+ # Continue until the next change, from 1 to 2.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 1.*New
value = 2.*ival3 = count; ival4 = count;.*" "watchpoint hit, third time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 3 times.*" "Watchpoint hit count
is 3"
+
+ # Continue until the next change, from 2 to 3.
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 2.*New
value = 3.*ival3 = count; ival4 = count;.*" "watchpoint hit, fourth time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 4 times.*" "Watchpoint hit count
is 4"
+
+ # Continue until the next change, from 3 to 4.
+ # Note that this one is outside the loop.
+
+ gdb_test "cont" "Continuing.*\[Ww\]atchpoint.*ival3.*Old value = 3.*New
value = 4.*ival3 = count; ival4 = count;.*" "watchpoint hit, fifth time"
+
+ # Check that the hit count is reported correctly
+ gdb_test "info break" ".*watchpoint\[ \t\]+keep\[ \t\]+y\[
\t\]+ival3\r\n\[ \t]+breakpoint already hit 5 times.*" "Watchpoint hit count
is 5"
+
+