gdb/testsuite/gdb.threads/current-lwp-dead.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2009, 2010 Free Software Foundation, Inc.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18    Do not use threads as we need to exploit a bug in LWP code masked by the
  19    threads code otherwise.
  20
  21    INFERIOR_PTID must point to exited LWP.  Here we use the initial LWP as it
  22    is automatically INFERIOR_PTID for GDB.
  23
  24    Finally we need to call target_resume (RESUME_ALL, ...) which we invoke by
  25    NEW_THREAD_EVENT (called from the new LWP as initial LWP is exited now).  */
  26
  27 #define _GNU_SOURCE
  28 #include <sched.h>
  29 #include <assert.h>
  30 #include <unistd.h>
  31 #include <stdlib.h>
  32
  33 #define STACK_SIZE 0x1000
  34
  35 static int
  36 fn_return (void *unused)
  37 {
  38   return 0;     /* at-fn_return */
  39 }
  40
  41 static int
  42 fn (void *unused)
  43 {
  44   int i;
  45   unsigned char *stack;
  46   int new_pid;
  47
  48   i = sleep (1);
  49   assert (i == 0);
  50
  51   stack = malloc (STACK_SIZE);
  52   assert (stack != NULL);
  53
  54   new_pid = clone (fn_return, stack + STACK_SIZE, CLONE_FILES | CLONE_VM, NULL,
  55                    NULL, NULL, NULL);
  56   assert (new_pid > 0);
  57
  58   return 0;
  59 }
  60
  61 int
  62 main (int argc, char **argv)
  63 {
  64   unsigned char *stack;
  65   int new_pid;
  66
  67   stack = malloc (STACK_SIZE);
  68   assert (stack != NULL);
  69
  70   new_pid = clone (fn, stack + STACK_SIZE, CLONE_FILES | CLONE_VM, NULL, NULL,
  71                    NULL, NULL);
  72   assert (new_pid > 0);
  73
  74   return 0;
  75 }