gdb/testsuite/gdb.threads/watchpoint-fork-mt.c

   1 /* Test case for forgotten hw-watchpoints after fork()-off of a process.
   2
   3    Copyright 2012-2015 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include <assert.h>
  21 #include <unistd.h>
  22 #include <sys/wait.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25
  26 /* pthread_yield is a GNU extension.  */
  27 #define _GNU_SOURCE
  28 #include <pthread.h>
  29
  30 #include <asm/unistd.h>
  31 #include <unistd.h>
  32 #define gettid() syscall (__NR_gettid)
  33
  34 #include "watchpoint-fork.h"
  35
  36 /* Non-atomic `var++' should not hurt as we synchronize the threads by the STEP
  37    variable.  Hit-comments need to be duplicated there to catch both at-stops
  38    and behind-stops, depending on the target.  */
  39
  40 volatile int var;
  41
  42 void
  43 marker (void)
  44 {
  45 }
  46
  47 static void
  48 empty (void)
  49 {
  50 }
  51
  52 static void
  53 mark_exit (void)
  54 {
  55 }
  56
  57 pthread_t thread;
  58 volatile int step;
  59
  60 static void *
  61 start (void *arg)
  62 {
  63   int i;
  64
  65   if (step >= 3)
  66     goto step_3;
  67
  68   while (step != 1)
  69     {
  70       i = pthread_yield ();
  71       assert (i == 0);
  72     }
  73
  74   var++;        /* validity-thread-B */
  75   empty ();     /* validity-thread-B */
  76   step = 2;
  77   while (step != 3)
  78     {
  79       if (step == 99)
  80         goto step_99;
  81
  82       i = pthread_yield ();
  83       assert (i == 0);
  84     }
  85
  86 step_3:
  87   if (step >= 5)
  88     goto step_5;
  89
  90   var++;        /* after-fork1-B */
  91   empty ();     /* after-fork1-B */
  92   step = 4;
  93   while (step != 5)
  94     {
  95       if (step == 99)
  96         goto step_99;
  97
  98       i = pthread_yield ();
  99       assert (i == 0);
 100     }
 101
 102 step_5:
 103   var++;        /* after-fork2-B */
 104   empty ();     /* after-fork2-B */
 105   return (void *) 5UL;
 106
 107 step_99:
 108   /* We must not get caught here (against a forgotten breakpoint).  */
 109   var++;
 110   marker ();
 111   return (void *) 99UL;
 112 }
 113
 114 int
 115 main (void)
 116 {
 117   int i;
 118   void *thread_result;
 119
 120   setbuf (stdout, NULL);
 121   printf ("main: %d\n", (int) gettid ());
 122
 123   /* General hardware breakpoints and watchpoints validity.  */
 124   marker ();
 125   var++;        /* validity-first */
 126   empty ();     /* validity-first */
 127
 128   i = pthread_create (&thread, NULL, start, NULL);
 129   assert (i == 0);
 130
 131   var++;        /* validity-thread-A */
 132   empty ();     /* validity-thread-A */
 133   step = 1;
 134   while (step != 2)
 135     {
 136       i = pthread_yield ();
 137       assert (i == 0);
 138     }
 139
 140   /* Hardware watchpoints got disarmed here.  */
 141   forkoff (1);
 142
 143   var++;        /* after-fork1-A */
 144   empty ();     /* after-fork1-A */
 145   step = 3;
 146 #ifdef FOLLOW_CHILD
 147   /* Spawn new thread as it was deleted in the child of FORK.  */
 148   i = pthread_create (&thread, NULL, start, NULL);
 149   assert (i == 0);
 150 #endif
 151   while (step != 4)
 152     {
 153       i = pthread_yield ();
 154       assert (i == 0);
 155     }
 156
 157   /* A sanity check for double hardware watchpoints removal.  */
 158   forkoff (2);
 159
 160   var++;        /* after-fork2-A */
 161   empty ();     /* after-fork2-A */
 162   step = 5;
 163 #ifdef FOLLOW_CHILD
 164   /* Spawn new thread as it was deleted in the child of FORK.  */
 165   i = pthread_create (&thread, NULL, start, NULL);
 166   assert (i == 0);
 167 #endif
 168
 169   i = pthread_join (thread, &thread_result);
 170   assert (i == 0);
 171   assert (thread_result == (void *) 5UL);
 172
 173   mark_exit ();
 174   return 0;
 175 }