https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=209521
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=219118
http://sources.redhat.com/ml/gdb-patches/2006-09/msg00092.html
Specific to Red Hat kernels, kernel.org kernels lockup on gdb "attach".
2007-03-20 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.base/attachstop.exp: Fix an incorrect adaptation on utrace
regression of `kernel-xen-2.6.18-1.2767.el5.i686'.
2006-12-11 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb-6.5/gdb/linux-nat.c (linux_nat_attach): Handle already stopped
processes, compiled either in a nonthreaded or a threaded mode.
2006-12-11 Jeff Johnston <jjohnstn@redhat.com>
Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.base/attachstop.exp, gdb.base/attachstop.c: New files,
test attaching to already stopped processes, compiled either in
a nonthreaded or a threaded mode.
diff -u -ruNp gdb-6.5-orig/gdb/linux-nat.c gdb-6.5/gdb/linux-nat.c
--- gdb-6.5-orig/gdb/linux-nat.c 2006-12-12 00:30:18.000000000 +0100
+++ gdb-6.5/gdb/linux-nat.c 2006-12-11 23:42:23.000000000 +0100
@@ -567,7 +567,9 @@ linux_handle_extended_wait (int pid, int
else if (ret != new_pid)
internal_error (__FILE__, __LINE__,
_("wait returned unexpected PID %d"), ret);
- else if (!WIFSTOPPED (status) || WSTOPSIG (status) != SIGSTOP)
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
+ else if (!WIFSTOPPED (status) ||
+ (WSTOPSIG (status) != SIGSTOP && WSTOPSIG (status) != 0))
internal_error (__FILE__, __LINE__,
_("wait returned unexpected status 0x%x"), status);
}
@@ -1007,8 +1009,9 @@ lin_lwp_attach_lwp (ptid_t ptid, int ver
lp->cloned = 1;
}
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
gdb_assert (pid == GET_LWP (ptid)
- && WIFSTOPPED (status) && WSTOPSIG (status));
+ && WIFSTOPPED (status));
target_post_attach (pid);
@@ -1062,13 +1065,14 @@ linux_nat_attach (char *args, int from_t
lp->cloned = 1;
}
- gdb_assert (pid == GET_PID (inferior_ptid)
- && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP);
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
+ gdb_assert (pid == GET_PID (inferior_ptid) && WIFSTOPPED (status)
+ && (WSTOPSIG (status) == SIGSTOP || WSTOPSIG (status) == 0));
lp->stopped = 1;
- /* Fake the SIGSTOP that core GDB expects. */
- lp->status = W_STOPCODE (SIGSTOP);
+ /* Provide the stop status that core GDB expects. */
+ lp->status = status;
lp->resumed = 1;
if (debug_linux_nat)
{
@@ -1509,7 +1513,8 @@ stop_wait_callback (struct lwp_info *lp,
return stop_wait_callback (lp, flush_mask);
}
- if (WSTOPSIG (status) != SIGSTOP)
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
+ if (WSTOPSIG (status) != SIGSTOP && WSTOPSIG (status) != 0)
{
if (WSTOPSIG (status) == SIGTRAP)
{
@@ -2093,8 +2098,10 @@ retry:
if (options & __WCLONE)
lp->cloned = 1;
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
gdb_assert (WIFSTOPPED (status)
- && WSTOPSIG (status) == SIGSTOP);
+ && (WSTOPSIG (status) == SIGSTOP
+ || WSTOPSIG (status) == 0));
lp->signalled = 1;
if (!in_thread_list (inferior_ptid))
@@ -2195,8 +2202,10 @@ retry:
/* Make sure we don't report a SIGSTOP that we sent
ourselves in an attempt to stop an LWP, unless we
intentionally want to see the SIGSTOP. */
+ /* In some cases we get 0 for the `SIGSTOP' signal. */
if (lp->signalled && !intentional_stop
- && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP)
+ && WIFSTOPPED (status) && (WSTOPSIG (status) == SIGSTOP
+ || WSTOPSIG (status) == 0))
{
if (debug_linux_nat)
fprintf_unfiltered (gdb_stdlog,
diff -u -ruNp gdb-6.5-orig/gdb/testsuite/gdb.base/attachstop.c gdb-6.5/gdb/testsuite/gdb.base/attachstop.c
--- gdb-6.5-orig/gdb/testsuite/gdb.base/attachstop.c 1970-01-01 01:00:00.000000000 +0100
+++ gdb-6.5/gdb/testsuite/gdb.base/attachstop.c 2006-12-11 23:58:22.000000000 +0100
@@ -0,0 +1,51 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2005 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 2 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, write to the Free Software
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
+
+/* This program is intended to be started outside of gdb, then
+ manually stopped via a signal. */
+
+#include <stddef.h>
+#include <unistd.h>
+#ifdef USE_THREADS
+#include <pthread.h>
+#endif
+
+static void *func (void *arg)
+{
+ sleep (10000); /* Ridiculous time, but we will eventually kill it. */
+ sleep (10000); /* Second sleep. */
+ return NULL;
+}
+
+int main ()
+{
+
+#ifndef USE_THREADS
+
+ func (NULL);
+
+#else
+
+ pthread_t th;
+ pthread_create (&th, NULL, func, NULL);
+ pthread_join (th, NULL);
+
+#endif
+
+ return 0;
+}
diff -u -ruNp gdb-6.5-orig/gdb/testsuite/gdb.base/attachstop.exp gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp
--- gdb-6.5-orig/gdb/testsuite/gdb.base/attachstop.exp 1970-01-01 01:00:00.000000000 +0100
+++ gdb-6.5/gdb/testsuite/gdb.base/attachstop.exp 2006-12-12 00:26:39.000000000 +0100
@@ -0,0 +1,228 @@
+# Copyright 2005-2006
+
+# 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 2 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, write to the Free Software
+# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+# This test was created by modifying attach.exp.
+# This file was created by Jeff Johnston <jjohnstn@redhat.com>.
+# This file was updated by Jan Kratochvil <jan.kratochvil@redhat.com>.
+
+if $tracelevel then {
+ strace $tracelevel
+}
+
+set prms_id 0
+set bug_id 0
+
+# This test only works on Linux
+if { ![istarget "*-*-linux-gnu*"] } {
+ return 0
+}
+
+set testfile "attachstop"
+set srcfile ${testfile}.c
+set binfile ${objdir}/${subdir}/${testfile}
+set escapedbinfile [string_to_regexp ${objdir}/${subdir}/${testfile}]
+
+#execute_anywhere "rm -f ${binfile}"
+remote_exec build "rm -f ${binfile}"
+# For debugging this test
+#
+#log_user 1
+
+proc corefunc { threadtype } {
+ global srcfile
+ global binfile
+ global escapedbinfile
+ global srcdir
+ global subdir
+ global gdb_prompt
+
+ if [get_compiler_info ${binfile}] {
+ return -1
+ }
+
+ # Start the program running and then wait for a bit, to be sure
+ # that it can be attached to.
+
+ set testpid [eval exec $binfile &]
+ exec sleep 2
+
+ # Stop the program
+ remote_exec build "kill -s STOP ${testpid}"
+
+ # Start with clean gdb
+ gdb_exit
+ gdb_start
+ gdb_reinitialize_dir $srcdir/$subdir
+ gdb_load ${binfile}
+
+ # Verify that we can attach to the process by first giving its
+ # executable name via the file command, and using attach with the
+ # process ID.
+
+ set test "$threadtype: set file, before attach1 to stopped process"
+ gdb_test_multiple "file $binfile" "$test" {
+ -re "Load new symbol table from.*y or n. $" {
+ gdb_test "y" "Reading symbols from $escapedbinfile\.\.\.*done." \
+ "$test (re-read)"
+ }
+ -re "Reading symbols from $escapedbinfile\.\.\.*done.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+
+ set test "$threadtype: attach1 to stopped, after setting file"
+ gdb_test_multiple "attach $testpid" "$test" {
+ -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+
+ if {[string equal $threadtype threaded]} {
+ gdb_test "thread apply all bt" ".*sleep.*clone.*" "$threadtype: attach1 to stopped bt"
+ } else {
+ gdb_test "bt" ".*sleep.*main.*" "$threadtype: attach1 to stopped bt"
+ }
+
+ # Exit and detach the process.
+
+ gdb_exit
+
+ set fileid [open /proc/${testpid}/status r];
+ gets $fileid line1;
+ gets $fileid line2;
+ close $fileid;
+
+ set test "$threadtype: attach1, exit leaves process stopped"
+ if {[string match "*(stopped)*" $line2]} {
+ pass $test
+ } else {
+ fail $test
+ }
+
+ # At this point, the process should still be stopped
+
+ gdb_start
+ gdb_reinitialize_dir $srcdir/$subdir
+ gdb_load ${binfile}
+
+ # Verify that we can attach to the process just by giving the
+ # process ID.
+
+ set test "$threadtype: attach2 to stopped, after setting file"
+ gdb_test_multiple "attach $testpid" "$test" {
+ -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" {
+ pass "$test"
+ }
+ }
+
+ if {[string equal $threadtype threaded]} {
+ gdb_test "thread apply all bt" ".*sleep.*clone.*" "$threadtype: attach2 to stopped bt"
+ } else {
+ gdb_test "bt" ".*sleep.*main.*" "$threadtype: attach2 to stopped bt"
+ }
+ gdb_breakpoint [gdb_get_line_number "$threadtype: Second sleep"]
+ set test "$threadtype: attach2 continue"
+ send_gdb "continue\n"
+ gdb_expect {
+ -re "Continuing"
+ { pass "continue ($test)" }
+ timeout
+ { fail "continue ($test) (timeout)" }
+ }
+
+ # For this to work we must be sure to consume the "Continuing."
+ # message first, or GDB's signal handler may not be in place.
+ after 1000 {send_gdb "\003"}
+ set test "$threadtype: attach2 stop unbreakable interrupt"
+ gdb_expect 4 {
+ -re "Program received signal SIGINT.*$gdb_prompt $"
+ {
+ fail "$test (broke into)"
+ }
+ -re "Breakpoint \[0-9\].*$srcfile.*$gdb_prompt $"
+ {
+ fail "$test (broke into)"
+ }
+ timeout
+ {
+ pass $test
+ }
+ }
+
+ # Continue the program
+ remote_exec build "kill -s CONT ${testpid}"
+
+ # Already sent before: after 1000 {send_gdb "\003"}
+ set test "$threadtype: attach2 stop by interrupt"
+ gdb_expect {
+ -re "Program received signal SIGSTOP,.*$gdb_prompt $"
+ {
+ pass $test
+ }
+ -re "Breakpoint \[0-9\].*$srcfile.*$gdb_prompt $"
+ {
+ pass $test
+ }
+ timeout
+ {
+ fail "$test (timeout)"
+ }
+ }
+
+ gdb_exit
+
+ # Avoid some race:
+ exec sleep 2
+
+ # At this point, the process should be sleeping
+
+ set fileid2 [open /proc/${testpid}/status r];
+ gets $fileid2 line1;
+ gets $fileid2 line2;
+ close $fileid2;
+
+ set test "$threadtype: attach2, exit leaves process sleeping"
+ if {[string match "*(sleeping)*" $line2]} {
+ pass $test
+ } else {
+ fail $test
+ }
+
+ # Make sure we don't leave a process around to confuse
+ # the next test run (and prevent the compile by keeping
+ # the text file busy), in case the "set should_exit" didn't
+ # work.
+
+ remote_exec build "kill -9 ${testpid}"
+}
+
+# build the test case first without threads
+#
+if { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+ gdb_suppress_entire_file "Testcase nonthraded compile failed, so all tests in this file will automatically fail."
+}
+
+corefunc nonthreaded
+
+# build the test case first without threads
+#
+if { [gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug additional_flags=-DUSE_THREADS}] != "" } {
+ gdb_suppress_entire_file "Testcase threaded compile failed, so all tests in this file will automatically fail."
+}
+
+corefunc threaded
+
+return 0