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

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2009-2020 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 #include <features.h>
  34 #ifdef __UCLIBC__
  35 #if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
  36 #define HAS_NOMMU
  37 #endif
  38 #endif
  39
  40 #define STACK_SIZE 0x1000
  41
  42 static int
  43 fn_return (void *unused)
  44 {
  45   return 0;     /* at-fn_return */
  46 }
  47
  48 static int
  49 fn (void *unused)
  50 {
  51   int i;
  52   unsigned char *stack;
  53   int new_pid;
  54
  55   i = sleep (1);
  56   assert (i == 0);
  57
  58   stack = malloc (STACK_SIZE);
  59   assert (stack != NULL);
  60
  61   new_pid = clone (fn_return, stack + STACK_SIZE, CLONE_FILES
  62 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
  63                    | CLONE_VM
  64 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
  65                    , NULL, NULL, NULL, NULL);
  66   assert (new_pid > 0);
  67
  68   return 0;
  69 }
  70
  71 int
  72 main (int argc, char **argv)
  73 {
  74   unsigned char *stack;
  75   int new_pid;
  76
  77   stack = malloc (STACK_SIZE);
  78   assert (stack != NULL);
  79
  80   new_pid = clone (fn, stack + STACK_SIZE, CLONE_FILES
  81 #if defined(__UCLIBC__) && defined(HAS_NOMMU)
  82                    | CLONE_VM
  83 #endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
  84                    , NULL, NULL, NULL, NULL);
  85   assert (new_pid > 0);
  86
  87   return 0;
  88 }