From: Pedro Alves <pedro@palves.net>
To: gdb-patches@sourceware.org
Subject: [PATCH 2/8] Ensure selected thread after thread exit stop
Date: Thu, 14 Dec 2023 20:22:32 +0000 [thread overview]
Message-ID: <20231214202238.1065676-3-pedro@palves.net> (raw)
In-Reply-To: <20231214202238.1065676-1-pedro@palves.net>
While making step over thread exit work properly on AMDGPU, I noticed
that if there's a breakpoint on top of the exit syscall, and,
displaced stepping is off, then when GDB reports "Command aborted,
thread exited.", GDB also switches focus to a random thread, instead
of leaving the exited thread as selected:
(gdb) thread
[Current thread is 6, lane 0 (AMDGPU Lane 1:4:1:1/0 (0,0,0)[0,0,0])]
(gdb) si
Command aborted, thread exited.
(gdb) thread
[Current thread is 5 (Thread 0x7ffff626f640 (LWP 3248392))]
(gdb)
The previous patch extended gdb.threads/step-over-thread-exit.exp to
exercise this on GNU/Linux (on the CPU side), and there, after that
"si", we always end up with the exiting thread as selected even
without this fix, but that's just a concidence, there's a code path
that happens to select the exiting thread for an unrelated reason.
This commit add the explict switch, fixing the latent problem for
GNU/Linux, and the actual problem on AMDGPU. I wrote a gdb.rocm/
testcase for this, but it can't be upstreamed yet, until more pieces
of the DWARF machinery are upstream as well.
Change-Id: I6ff57a79514ac0142bba35c749fe83d53d9e4e51
---
gdb/infrun.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/gdb/infrun.c b/gdb/infrun.c
index 45c1b4a79bb..6dc0a2bb9a5 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -5895,7 +5895,14 @@ handle_thread_exited (execution_control_state *ecs)
if (abort_cmd)
{
+ /* We're stopping for the thread exit event. Switch to the
+ event thread again, as finish_step_over may have switched
+ threads. */
+ switch_to_thread (ecs->event_thread);
+
+ /* Emit [Thread ... exited] notification. */
delete_thread (ecs->event_thread);
+
ecs->event_thread = nullptr;
return false;
}
--
2.43.0
next prev parent reply other threads:[~2023-12-14 20:22 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-12-14 20:22 [PATCH 0/8] Step over thread exit improvements/fixes + AMD GPU Pedro Alves
2023-12-14 20:22 ` [PATCH 1/8] gdb.threads/step-over-thread-exit.exp improvements Pedro Alves
2023-12-14 20:22 ` Pedro Alves [this message]
2023-12-14 20:22 ` [PATCH 3/8] displaced_step_finish: Don't fetch the regcache of exited threads Pedro Alves
2023-12-14 20:22 ` [PATCH 4/8] Step over thread exit, always delete the thread non-silently Pedro Alves
2023-12-14 20:22 ` [PATCH 5/8] Fix thread target ID of exited waves Pedro Alves
2023-12-15 10:51 ` Lancelot SIX
2023-12-14 20:22 ` [PATCH 6/8] Fix handling of vanishing threads that were stepping/stopping Pedro Alves
2023-12-15 10:51 ` Lancelot SIX
2023-12-14 20:22 ` [PATCH 7/8] Add tests for s_endpgm handling Pedro Alves
2023-12-14 20:22 ` [PATCH 8/8] Add tests for handling of vanishing threads that were stepping/stopping Pedro Alves
2023-12-20 21:24 ` [PATCH 0/8] Step over thread exit improvements/fixes + AMD GPU Pedro Alves
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