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| author | Yao Qi <yao.qi@linaro.org> | 2016-06-17 10:25:12 +0100 |
|---|---|---|
| committer | Yao Qi <yao.qi@linaro.org> | 2016-06-17 10:38:55 +0100 |
| commit | f50bf8e5153e3cdddd1ad5d3f7d16f2b4e5adb3c (patch) | |
| tree | ac0815d07b13c8d80b7ee797b0a7d32333743abe /gdb/gdbserver/ChangeLog | |
| parent | 8376a3cbf73ca8b623db1daa8f9c49fb83ac54bd (diff) | |
| download | gdb-f50bf8e5153e3cdddd1ad5d3f7d16f2b4e5adb3c.zip gdb-f50bf8e5153e3cdddd1ad5d3f7d16f2b4e5adb3c.tar.gz gdb-f50bf8e5153e3cdddd1ad5d3f7d16f2b4e5adb3c.tar.bz2 | |
Step over exit with reinsert breakpoints
This patch fixes a GDBserver crash when one thread is stepping over
a syscall instruction which is exit. Step-over isn't finished due
to the exit, but GDBserver doesn't clean up the state of step-over,
so in the wait next time, GDBserver will wait on step_over_bkpt,
which is already exited, and GDBserver crashes because
'requested_child' is NULL. See gdbserver logs below,
Need step over [LWP 14858]? yes, found breakpoint at 0x2aaaaad91307^M
proceed_all_lwps: found thread 14858 needing a step-over^M
Starting step-over on LWP 14858. Stopping all threads^M
>>>> entering void stop_all_lwps(int, lwp_info*)
....
<<<< exiting void stop_all_lwps(int, lwp_info*)^M
Done stopping all threads for step-over.^M
pc is 0x2aaaaad91307^M
Writing 0f to 0x2aaaaad91307 in process 14858^M
Could not find fast tracepoint jump at 0x2aaaaad91307 in list (uninserting).^M
pending reinsert at 0x2aaaaad91307^M
step from pc 0x2aaaaad91307^M
Resuming lwp 14858 (step, signal 0, stop not expected)^M
# Start step-over for LWP 14858
>>>> entering ptid_t linux_wait_1(ptid_t, target_waitstatus*, int)
....
LLFE: 14858 exited.
...
<<<< exiting ptid_t linux_wait_1(ptid_t, target_waitstatus*, int)
# LWP 14858 exited
.....
>>>> entering ptid_t linux_wait_1(ptid_t, target_waitstatus*, int)^M
linux_wait_1: [<all threads>]^M
step_over_bkpt set [LWP 14858.14858], doing a blocking wait
# but step_over_bkpt is still LWP 14858, which is wrong
The fix is to finish step-over if it is ongoing, and unsuspend other
threads. Without the fix in linux-low.c, GDBserver will crash in
with running gdb.base/step-over-exit.exp.
gdb/gdbserver:
2016-06-17 Yao Qi <yao.qi@linaro.org>
* linux-low.c (unsuspend_all_lwps): Declare.
(linux_low_filter_event): If thread exited, call finish_step_over.
If step-over is finished, unsuspend other threads.
gdb/testsuite:
2016-06-17 Yao Qi <yao.qi@linaro.org>
* gdb.base/step-over-exit.c: New.
* gdb.base/step-over-exit.exp: New.
Diffstat (limited to 'gdb/gdbserver/ChangeLog')
| -rw-r--r-- | gdb/gdbserver/ChangeLog | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index c7a9595..fd70f59 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,5 +1,11 @@ 2016-06-17 Yao Qi <yao.qi@linaro.org> + * linux-low.c (unsuspend_all_lwps): Declare. + (linux_low_filter_event): If thread exited, call finish_step_over. + If step-over is finished, unsuspend other threads. + +2016-06-17 Yao Qi <yao.qi@linaro.org> + * linux-low.c (linux_resume_one_lwp_throw): Assert has_reinsert_breakpoints returns false. * mem-break.c (delete_disabled_breakpoints): Assert |