glibc/debug/tst-backtrace5.c
Adhemerval Zanella d0d7f85f66 nptl: Fix testcases for new pthread cancellation mechanism
With upcoming fix for BZ#12683, pthread cancellation does not act for:

  1. If syscall is blocked but with some side effects already having
     taken place (e.g. a partial read or write).
  2. After the syscall has returned.

The main change is due the fact programs need to act in syscalls with
side-effects (for instance, to avoid leak of allocated resources or
handle partial read/write).

This patch changes the NPTL testcase that assumes the old behavior and
also changes the tst-backtrace{5,6} to ignore the cancellable wrappers.

Checked on i686-linux-gnu, x86_64-linux-gnu, x86_64-linux-gnux32,
aarch64-linux-gnu, arm-linux-gnueabihf, powerpc64le-linux-gnu,
powerpc-linux-gnu, sparcv9-linux-gnu, and sparc64-linux-gnu.

	* debug/tst-backtrace5.c (handle_signal): Avoid cancellable wrappers
	in backtrace analysis.
	* nptl/tst-cancel4.c (tf_write): Handle cancelled syscall with
	side-effects.
	(tf_send): Likewise.
2019-01-03 18:38:09 -02:00

141 lines
3.2 KiB
C

/* Test backtrace and backtrace_symbols for signal frames, where a
system call was interrupted by a signal.
Copyright (C) 2011-2019 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 <execinfo.h>
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <signal.h>
#include <unistd.h>
#include "tst-backtrace.h"
#ifndef SIGACTION_FLAGS
# define SIGACTION_FLAGS 0
#endif
/* The backtrace should include at least handle_signal, a signal
trampoline, read, 3 * fn, and do_test. */
#define NUM_FUNCTIONS 7
void
handle_signal (int signum)
{
void *addresses[NUM_FUNCTIONS];
char **symbols;
int n;
int i;
/* Get the backtrace addresses. */
n = backtrace (addresses, sizeof (addresses) / sizeof (addresses[0]));
printf ("Obtained backtrace with %d functions\n", n);
/* Check that there are at least seven functions. */
if (n < NUM_FUNCTIONS)
{
FAIL ();
return;
}
/* Convert them to symbols. */
symbols = backtrace_symbols (addresses, n);
/* Check that symbols were obtained. */
if (symbols == NULL)
{
FAIL ();
return;
}
for (i = 0; i < n; ++i)
printf ("Function %d: %s\n", i, symbols[i]);
/* Check that the function names obtained are accurate. */
if (!match (symbols[0], "handle_signal"))
{
FAIL ();
return;
}
/* Do not check name for signal trampoline or cancellable syscall
wrappers (__syscall_cancel*). */
for (; i < n - 1; i++)
if (match (symbols[i], "read"))
break;
if (i == n - 1)
{
FAIL ();
return;
}
for (; i < n - 1; i++)
if (!match (symbols[i], "fn"))
{
FAIL ();
return;
}
/* Symbol names are not available for static functions, so we do not
check do_test. */
}
NO_INLINE int
fn (int c, int flags)
{
pid_t parent_pid, child_pid;
int pipefd[2];
char r[1];
struct sigaction act;
if (c > 0)
{
fn (c - 1, flags);
return x;
}
memset (&act, 0, sizeof (act));
act.sa_handler = handle_signal;
act.sa_flags = flags;
sigemptyset (&act.sa_mask);
sigaction (SIGUSR1, &act, NULL);
parent_pid = getpid ();
if (pipe (pipefd) == -1)
abort ();
child_pid = fork ();
if (child_pid == (pid_t) -1)
abort ();
else if (child_pid == 0)
{
sleep (1);
kill (parent_pid, SIGUSR1);
_exit (0);
}
/* In the parent. */
read (pipefd[0], r, 1);
return 0;
}
NO_INLINE int
do_test (void)
{
fn (2, SIGACTION_FLAGS);
return ret;
}
#include <support/test-driver.c>