Attachment 181161 Details for Bug 248532 – New testcase.

New testcase.

stopped-sigcont-hang-1.c (text/plain), 3.56 KB, created by Jan Kratochvil on 2007-08-30 14:28:37 UTC

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Creator: Jan Kratochvil

Created: 2007-08-30 14:28:37 UTC

Size: 3.56 KB

patch

obsolete

>/* Copyright 2007 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 2 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, write to the Free Software
>   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
>
>#define _GNU_SOURCE
>#include <signal.h>
>#include <unistd.h>
>#include <string.h>
>#include <stdio.h>
>#include <stdlib.h>
>#include <errno.h>
>#include <sys/wait.h>
>#include <sys/ptrace.h>
>#include <assert.h>
>#include <fcntl.h>
>#include <limits.h>
>#include <ctype.h>
>#include <linux/ptrace.h>
>
>#include <asm/unistd.h>
>#include <unistd.h>
>#define tkill(tid, sig) syscall (__NR_tkill, (tid), (sig))
>
>#define LOOPS 10000
>#define SIGSTOPS 100
>
>static pid_t child;
>
>static void
>cleanup (void)
>{
>  if (child != 0)
>    kill (child, SIGKILL);
>}
>
>static void
>handler_fail (int signo)
>{
>  cleanup ();
>
>  signal (SIGABRT, SIG_DFL);
>  abort ();
>}
>
>int main (void)
>{
>  pid_t got_pid;
>  int status;
>  int sigstops;
>  int loops;
>
>  setbuf (stdout, NULL);
>  atexit (cleanup);
>  signal (SIGABRT, handler_fail);
>  signal (SIGALRM, handler_fail);
>
>  sigstops = 0;
>  loops = 0;
>  for (loops = 0; sigstops < SIGSTOPS; loops++)
>    {
>      if (loops >= LOOPS)
>	{
>	  fprintf (stderr,
>		   "UNRESOLVED: %d SIGSTOPs, required %d, in %d loops\n",
>		   sigstops, SIGSTOPS, loops);
>	  exit (77);
>	}
>
>      child = fork ();
>      switch (child)
>	{
>	  case -1:
>	    abort ();
>	  case 0:
>	    raise (SIGSTOP);
>	    for (;;)
>	      pause ();
>	    /* NOTREACHED */
>	  default:
>	    break;
>	}
>      alarm (1);
>
>      /* We must never WAITPID/WAITID on the child for this testcase.  */
>
>      /* Here is a point where we - as a debugger - start to attach.  */
>      errno = 0;
>      ptrace (PTRACE_ATTACH, child, NULL, NULL);
>      assert_perror (errno);
>
>      /* `PTRACE_CONT, SIGSTOP' does not work in 100% cases as sometimes SIGSTOP
>	 gets remembered by kernel during the first PTRACE_CONT later and we get
>	 spurious SIGSTOP event.  Expecting the signal may get delivered to
>	 a different task of the thread group.
>	 `tkill (SIGSTOP)' has no effect in this moment (it is already stopped).  */
>      errno = 0;
>      tkill (child, SIGCONT);
>      assert_perror (errno);
>
>      got_pid = waitpid (child, &status, 0);
>      assert (got_pid == child);
>      assert (WIFSTOPPED (status));
>      /* We may randomly get SIGCONT or SIGSTOP.  */
>      assert (WSTOPSIG (status) == SIGCONT || WSTOPSIG (status) == SIGSTOP);
>      if (WSTOPSIG (status) == SIGSTOP)
>        sigstops++;
>
>      alarm (0);
>
>      /* At this moment we should be already able to ptrace(2) the inferior.
>	 If we got SIGCONT above ptrace(2) always works.
>	 But if we got SIGSTOP above there was a regression on the patch
>	    https://bugzilla.redhat.com/show_bug.cgi?id=248532#c5
>	 that we occasionally got ESRCH.  */
>      errno = 0;
>      ptrace (PTRACE_PEEKUSR, child, (void *) 0UL, NULL);
>      assert_perror (errno);
>
>      /* Cleanup.  */
>      errno = 0;
>      kill (child, SIGKILL);
>      assert_perror (errno);
>
>      got_pid = waitpid (child, &status, 0);
>      assert (got_pid == child);
>
>      alarm (0);
>    }
>
>  puts ("PASS");
>  return 0;
>}

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Attachments on bug 248532: 159411 | 179961 | 181161 | 182321 | 182381 | 185931 | 187231 | 191741