glibc/elf/tst-unwind-main.c
Jim Wilson 85bd1ddbdf
RISC-V: Fix elfutils testsuite unwind failures.
The clone.S patch fixes 2 elfutils testsuite unwind failures, where the
backtrace gets stuck repeating __thread_start until we hit the backtrace
limit.  This was confirmed by building and installing a patched glibc and
then building elfutils and running its testsuite.

Unfortunately, the testcase isn't working as expected and I don't know why.
The testcase passes even when my clone.S patch is not installed.  The testcase
looks logically similarly to the elfutils testcases that are failing.  Maybe
there is a subtle difference in how the glibc unwinding works versus the
elfutils unwinding?  I don't have good gdb pthread support yet, so I haven't
found a way to debug this.  Anyways, I don't know if the testcase is useful or
not.  If the testcase isn't useful then maybe the clone.S patch is OK without
a testcase?

Jim

	[BZ #24040]
	* elf/Makefile (CFLAGS-tst-unwind-main.c): Add -DUSE_PTHREADS=0.
	* elf/tst-unwind-main.c: If USE_PTHEADS, include pthread.h and error.h
	(func): New.
	(main): If USE_PTHREADS, call pthread_create to run func.  Otherwise
	call func directly.
	* nptl/Makefile (tests): Add tst-unwind-thread.
	(CFLAGS-tst-unwind-thread.c): Define.
	* nptl/tst-unwind-thread.c: New file.
	* sysdeps/unix/sysv/linux/riscv/clone.S (__thread_start): Mark ra
	as undefined.
2019-02-13 14:25:00 -08:00

61 lines
1.7 KiB
C

/* Test unwinding through main.
Copyright (C) 2018-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <unwind.h>
#include <unistd.h>
#include <support/test-driver.h>
#if USE_PTHREADS
# include <pthread.h>
# include <error.h>
#endif
static _Unwind_Reason_Code
callback (struct _Unwind_Context *ctx, void *arg)
{
return _URC_NO_REASON;
}
static void *
func (void *a)
{
/* Arrange for this test to be killed if _Unwind_Backtrace runs into an
endless loop. We cannot use the test driver because the complete
call chain needs to be compiled with -funwind-tables so that
_Unwind_Backtrace is able to reach the start routine. */
alarm (DEFAULT_TIMEOUT);
_Unwind_Backtrace (callback, 0);
return a;
}
int
main (void)
{
#if USE_PTHREADS
pthread_t thr;
int rc = pthread_create (&thr, NULL, &func, NULL);
if (rc)
error (1, rc, "pthread_create");
rc = pthread_join (thr, NULL);
if (rc)
error (1, rc, "pthread_join");
#else
func (NULL);
#endif
}