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

   1 /* Test case for forgotten hw-watchpoints after fork()-off of a process.
   2
   3    Copyright 2012-2020 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 "watchpoint-fork.h"
  21
  22 #include <assert.h>
  23 #include <unistd.h>
  24 #include <sys/wait.h>
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <pthread.h>
  28
  29 #include <asm/unistd.h>
  30 #include <unistd.h>
  31 #define gettid() syscall (__NR_gettid)
  32
  33 /* Non-atomic `var++' should not hurt as we synchronize the threads by the STEP
  34    variable.  Hit-comments need to be duplicated there to catch both at-stops
  35    and behind-stops, depending on the target.  */
  36
  37 volatile int var;
  38
  39 void
  40 marker (void)
  41 {
  42 }
  43
  44 static void
  45 empty (void)
  46 {
  47 }
  48
  49 static void
  50 mark_exit (void)
  51 {
  52 }
  53
  54 pthread_t thread;
  55 volatile int step;
  56
  57 static void *
  58 start (void *arg)
  59 {
  60   int i;
  61
  62   if (step >= 3)
  63     goto step_3;
  64
  65   while (step != 1)
  66     {
  67       i = pthread_yield ();
  68       assert (i == 0);
  69     }
  70
  71   var++;        /* validity-thread-B */
  72   empty ();     /* validity-thread-B */
  73   step = 2;
  74   while (step != 3)
  75     {
  76       if (step == 99)
  77         goto step_99;
  78
  79       i = pthread_yield ();
  80       assert (i == 0);
  81     }
  82
  83 step_3:
  84   if (step >= 5)
  85     goto step_5;
  86
  87   var++;        /* after-fork1-B */
  88   empty ();     /* after-fork1-B */
  89   step = 4;
  90   while (step != 5)
  91     {
  92       if (step == 99)
  93         goto step_99;
  94
  95       i = pthread_yield ();
  96       assert (i == 0);
  97     }
  98
  99 step_5:
 100   var++;        /* after-fork2-B */
 101   empty ();     /* after-fork2-B */
 102   return (void *) 5UL;
 103
 104 step_99:
 105   /* We must not get caught here (against a forgotten breakpoint).  */
 106   var++;
 107   marker ();
 108   return (void *) 99UL;
 109 }
 110
 111 int
 112 main (void)
 113 {
 114   int i;
 115   void *thread_result;
 116
 117 #if DEBUG
 118   setbuf (stdout, NULL);
 119   printf ("main: %d\n", (int) gettid ());
 120 #endif
 121
 122   /* General hardware breakpoints and watchpoints validity.  */
 123   marker ();
 124   var++;        /* validity-first */
 125   empty ();     /* validity-first */
 126
 127   i = pthread_create (&thread, NULL, start, NULL);
 128   assert (i == 0);
 129
 130   var++;        /* validity-thread-A */
 131   empty ();     /* validity-thread-A */
 132   step = 1;
 133   while (step != 2)
 134     {
 135       i = pthread_yield ();
 136       assert (i == 0);
 137     }
 138
 139   /* Hardware watchpoints got disarmed here.  */
 140   forkoff (1);
 141
 142   var++;        /* after-fork1-A */
 143   empty ();     /* after-fork1-A */
 144   step = 3;
 145 #ifdef FOLLOW_CHILD
 146   /* Spawn new thread as it was deleted in the child of FORK.  */
 147   i = pthread_create (&thread, NULL, start, NULL);
 148   assert (i == 0);
 149 #endif
 150   while (step != 4)
 151     {
 152       i = pthread_yield ();
 153       assert (i == 0);
 154     }
 155
 156   /* A sanity check for double hardware watchpoints removal.  */
 157   forkoff (2);
 158
 159   var++;        /* after-fork2-A */
 160   empty ();     /* after-fork2-A */
 161   step = 5;
 162 #ifdef FOLLOW_CHILD
 163   /* Spawn new thread as it was deleted in the child of FORK.  */
 164   i = pthread_create (&thread, NULL, start, NULL);
 165   assert (i == 0);
 166 #endif
 167
 168   i = pthread_join (thread, &thread_result);
 169   assert (i == 0);
 170   assert (thread_result == (void *) 5UL);
 171
 172   mark_exit ();
 173   return 0;
 174 }