binutils-gdb/gdb/testsuite/gdb.btrace/enable-running.c
Markus Metzger cd4007e434 btrace: allow recording to be started (and stopped) for running threads
When recording is started for a running thread, GDB was able to start tracing
but then failed to read registers to insert the initial entry for the current
PC.  We don't really need that initial entry if we don't know where exactly we
started recording.  Skip that step to allow recording to be started while
threads are running.

If we do run into errors, we need to undo the tracing enable to not leak this
thread.  The operation did not complete so our caller won't clean up this
thread.

For the BTRACE_FORMAT_PT btrace format, we don't need that initial entry since
it will be recorded in the trace.  We can omit the call to btrace_add_pc.

gdb/
	* btrace.c (btrace_enable): Do not call btrace_add_pc for
	BTRACE_FORMAT_PT or if can_access_registers_ptid returns false.
	(btrace_fetch): Assert can_access_registers_ptid.
	* record-btrace.c (require_btrace_thread, record_btrace_info): Call
	validate_registers_access.

testsuite/
	* gdb.btrace/enable-running.c: New.
	* gdb.btrace/enable-running.exp: New.
2017-02-01 14:37:07 +01:00

49 lines
1.2 KiB
C

/* This testcase is part of GDB, the GNU debugger.
Copyright 2017 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include <pthread.h>
#include <unistd.h>
#define NTHREADS 3
static void *
test (void *arg)
{
/* Let's hope this is long enough for GDB to enable tracing and check that
everything is working as expected. */
sleep (10);
return arg;
}
int
main (void)
{
pthread_t th[NTHREADS];
int i;
for (i = 0; i < NTHREADS; ++i)
pthread_create (&th[i], NULL, test, NULL);
test (NULL); /* bp.1 */
for (i = 0; i < NTHREADS; ++i)
pthread_join (th[i], NULL);
return 0;
}