[PATCH 11/18] gdbserver: fix killed-outside.exp

Pedro Alves
2015-10-14T15:36:43Z

killed-outside.exp regresses with "maint set target-non-stop on". The
logs show:

(gdb) continue
Continuing.
infrun: clear_proceed_status_thread (Thread 9028.9028)
infrun: proceed (addr=0xffffffffffffffff, signal=GDB_SIGNAL_DEFAULT)
infrun: proceed: resuming Thread 9028.9028
Sending packet: $Z0,3615a03966,1#4b... Notification received: Stop:X9;process:2344
Packet received: E01
Sending packet: $Z0,3615a13970,1#47...Packet received: E01
Sending packet: $Z0,3615a14891,1#4a...Packet received: E01
infrun: resume (step=0, signal=GDB_SIGNAL_0), trap_expected=0, current thread [Thread 9028.9028] at 0x4005e4
Sending packet: $vCont;c:p2344.2344#1a...Packet received: E.target not running.
Sending packet: $qXfer:threads:read::0,fff#03...Packet received: l<threads>\n</threads>\n
Sending packet: $vStopped#55...Packet received: OK
Unexpected vCont reply in non-stop mode: E.target not running.
(gdb) remote_async_inferior_event_handler
infrun: target_wait (-1.0.0, status) =
infrun: 9028.0.0 [process 9028],
infrun: status->kind = signalled, signal = GDB_SIGNAL_KILL
infrun: TARGET_WAITKIND_SIGNALLED

Program terminated with signal SIGKILL, Killed.
The program no longer exists.
infrun: stop_waiting
infrun: clear_step_over_info
infrun: stop_all_threads
remote_thread_exit_events(1)

Note the "Unexpected vCont reply" error.

I traced it to a problem in status_pending_p_callback. It resumes an
LWP when it shouldn't.

gdb/gdbserver/ChangeLog:
2015-10-14 Pedro Alves <palves@redhat.com>

* linux-low.c (thread_still_has_status_pending_p): Don't check
vCont;t here.
(lwp_resumed): New function.
(status_pending_p_callback): Return early if the LWP is not
supposed to be resumed.
---
gdb/gdbserver/linux-low.c | 27 +++++++++++++++++++++------
1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 1c447c2..af9ca22 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -1535,12 +1535,6 @@ thread_still_has_status_pending_p (struct thread_info *thread)
if (!lp->status_pending_p)
return 0;

- /* If we got a `vCont;t', but we haven't reported a stop yet, do
- report any status pending the LWP may have. */
- if (thread->last_resume_kind == resume_stop
- && thread->last_status.kind != TARGET_WAITKIND_IGNORE)
- return 0;
-
if (thread->last_resume_kind != resume_stop
&& (lp->stop_reason == TARGET_STOPPED_BY_SW_BREAKPOINT
|| lp->stop_reason == TARGET_STOPPED_BY_HW_BREAKPOINT))
@@ -1597,6 +1591,24 @@ thread_still_has_status_pending_p (struct thread_info *thread)
return 1;
}

+/* Returns true if LWP is resumed from the client's perspective. */
+
+static int
+lwp_resumed (struct lwp_info *lwp)
+{
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind != resume_stop)
+ return 1;
+
+ /* Did we get a `vCont;t', but we haven't reported a stop yet? */
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE)
+ return 1;
+
+ return 0;
+}
+
/* Return 1 if this lwp has an interesting status pending. */
static int
status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
@@ -1610,6 +1622,9 @@ status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
if (!ptid_match (ptid_of (thread), ptid))
return 0;

+ if (!lwp_resumed (lp))
+ return 0;
+
if (lp->status_pending_p
&& !thread_still_has_status_pending_p (thread))
{
--
1.9.3