[PATCH] gdbserver: Install single-step breakpoint for a pending thread whose last_resume_kind is resume_step

zhiyong.yan
2023-07-12T03:26:04Z

From: Zhiyong Yan <zhiyong.yan@windriver.com>

Gdb should not assume pending threads always generate “a non-gdbserver trap event”, for example “Signal 17” event could happen. Now that resume_stopped_resumed_lwps() -> may_hw_step() assumes that the break point must already exist, resume_one_thread() should ensure the software breaking point is installed although the thread is pending.

Signed-off-by: Zhiyong Yan zhiyong.yan@windriver.com
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30387
---
gdbserver/linux-low.cc | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/gdbserver/linux-low.cc b/gdbserver/linux-low.cc
index e6a39202a98..d29881174db 100644
--- a/gdbserver/linux-low.cc
+++ b/gdbserver/linux-low.cc
@@ -4671,7 +4671,16 @@ linux_process_target::resume_one_thread (thread_info *thread,
proceed_one_lwp (thread, NULL);
}
else
- threads_debug_printf ("leaving LWP %ld stopped", lwpid_of (thread));
+ {
+ threads_debug_printf ("leaving LWP %ld stopped", lwpid_of (thread));
+ if (thread->last_resume_kind == resume_step)
+ {
+ /* If resume_step is required by GDB,
+ install single-step breakpoint. */
+ if (supports_software_single_step ())
+ install_software_single_step_breakpoints (lwp);
+ }
+ }

thread->last_status.set_ignore ();
lwp->resume = NULL;
--
2.25.1