a2077e2540
If you have "set follow-fork child" set, then if you do "info threads" right after a fork, and before the child reports any other event to GDB core, you'll see: (gdb) info threads Id Target Id Frame * 1.1 Thread 0x7ffff7fc1740 (LWP 31875) "fork-plus-threa" (running) 2.1 process 31879 "fork-plus-threa" Selected thread is running. (gdb) The "Selected thread is running." bit is a bogus error. That was GDB trying to fetch the current frame of thread 2.1, because the external runnning state is "stopped", and then throwing an error because the thread is actually running. This actually affects all-stop + schedule-multiple as well. The problem here is that on a fork event, GDB doesn't update the external parent/child running states. New comprehensive test included. The "kill inferior 1" / "kill inferior 2" bits also trip on PR gdb/19494 (hang killing unfollowed fork children), which was fixed by the previous patch. gdb/ChangeLog: 2016-01-25 Pedro Alves <palves@redhat.com> PR threads/19461 * infrun.c (handle_inferior_event_1) <fork/vfork>: Update parent/child running states. gdb/testsuite/ChangeLog: 2016-01-25 Pedro Alves <palves@redhat.com> PR threads/19461 * gdb.base/fork-running-state.c: New file. * gdb.base/fork-running-state.exp: New file.
83 lines
1.8 KiB
C
83 lines
1.8 KiB
C
/* This testcase is part of GDB, the GNU debugger.
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Copyright 2015-2016 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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#include <unistd.h>
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#include <stdio.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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int save_parent;
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/* The fork child. Just runs forever. */
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static int
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fork_child (void)
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{
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while (1)
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{
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sleep (1);
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/* Exit if GDB kills the parent. */
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if (getppid () != save_parent)
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break;
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if (kill (getppid (), 0) != 0)
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break;
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}
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return 0;
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}
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/* The fork parent. Just runs forever waiting for the child to
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exit. */
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static int
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fork_parent (void)
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{
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if (wait (NULL) == -1)
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{
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perror ("wait");
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return 1;
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}
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return 0;
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}
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int
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main (void)
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{
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pid_t pid;
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save_parent = getpid ();
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/* Don't run forever. */
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alarm (180);
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/* The parent and child should basically run forever without
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tripping on any debug event. We want to check that GDB updates
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the parent and child running states correctly right after the
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fork. */
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pid = fork ();
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if (pid > 0)
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return fork_parent ();
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else if (pid == 0)
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return fork_child ();
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else
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{
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perror ("fork");
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return 1;
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}
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}
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