Avoid crash in print_ada_task_info

In MI mode, print_ada_task_info can crash in find_thread_ptid when
trying to print an Ada task that is no longer alive.  This patch
avoids the problem by checking for this case.

Because this is Ada-specific, and because Joel approved it internally,
I am checking it in.

gdb/ChangeLog
2019-11-22  Tom Tromey  <tromey@adacore.com>

	* ada-tasks.c (ada_task_is_alive): Make parameter const.
	(print_ada_task_info): Don't try to fetch thread id if task is not
	alive.

gdb/gdbserver/ChangeLog
2019-11-22  Tom Tromey  <tromey@adacore.com>

	* gdb.ada/tasks.exp: Add -ada-task-info regression test.
	* gdb.ada/tasks/foo.adb: Add another stopping location.

Change-Id: If25eae6507eebb7537eb8adbcbaa1fc1eec88f5c
This commit is contained in:
Tom Tromey 2019-11-21 09:05:10 -07:00
parent 987012b89b
commit c83d8d32c9
5 changed files with 29 additions and 6 deletions

View File

@ -1,3 +1,9 @@
2019-11-22 Tom Tromey <tromey@adacore.com>
* ada-tasks.c (ada_task_is_alive): Make parameter const.
(print_ada_task_info): Don't try to fetch thread id if task is not
alive.
2019-11-22 Christian Biesinger <cbiesinger@google.com>
* ada-exp.y: Update.

View File

@ -347,7 +347,7 @@ valid_task_id (int task_num)
task state. */
static int
ada_task_is_alive (struct ada_task_info *task_info)
ada_task_is_alive (const struct ada_task_info *task_info)
{
return (task_info->state != Terminated);
}
@ -1127,14 +1127,17 @@ print_ada_task_info (struct ui_out *uiout,
/* Print the associated Thread ID. */
if (uiout->is_mi_like_p ())
{
thread_info *thread = find_thread_ptid (task_info->ptid);
thread_info *thread = (ada_task_is_alive (task_info)
? find_thread_ptid (task_info->ptid)
: nullptr);
if (thread != NULL)
uiout->field_signed ("thread-id", thread->global_num);
else
/* This should never happen unless there is a bug somewhere,
but be resilient when that happens. */
uiout->field_skip ("thread-id");
{
/* This can happen if the thread is no longer alive. */
uiout->field_skip ("thread-id");
}
}
/* Print the ID of the parent task. */

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@ -1,3 +1,8 @@
2019-11-22 Tom Tromey <tromey@adacore.com>
* gdb.ada/tasks.exp: Add -ada-task-info regression test.
* gdb.ada/tasks/foo.adb: Add another stopping location.
2019-11-20 Luis Machado <luis.machado@linaro.org>
* linux-aarch64-low.c (is_sve_tdesc): Check against target feature

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@ -82,4 +82,10 @@ gdb_test "info tasks" \
# Now, resume the execution and make sure that GDB does not stop when
# task 4 hits the breakpoint. Continuing thus results in our program
# running to completion.
gdb_continue_to_end "" continue 1
set bp_location [gdb_get_line_number "STOP_HERE_2" ${testdir}/foo.adb]
gdb_breakpoint foo.adb:$bp_location
gdb_continue_to_breakpoint second ".*foo.adb:$bp_location.*null; -- STOP_HERE_2"
# A regression test for a crash caused by trying to find the thread
# for a terminated task.
gdb_test "interpreter-exec mi \"-ada-task-info\"" ".*"

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@ -65,4 +65,7 @@ begin
for J in Task_List'Range loop
Task_List (J).Finalize;
end loop;
null; -- STOP_HERE_2
end Foo;