gdb/testsuite/gdb.base/sigaltstack.c

   1 /* This testcase is part of GDB, the GNU debugger.
   2
   3    Copyright 2004, 2007, 2008, 2009 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 #include <signal.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <sys/time.h>
  23
  24 enum level { MAIN, OUTER, INNER, LEAF, NR_LEVELS };
  25
  26 /* Levels completed flag.  */
  27 volatile enum level level = NR_LEVELS;
  28
  29 void catcher (int signal);
  30
  31 void
  32 thrower (enum level next_level, int sig, int itimer, int on_stack)
  33 {
  34   level = next_level;
  35   /* Set up the signal handler.  */
  36   {
  37     struct sigaction act;
  38     memset (&act, 0, sizeof (act));
  39     act.sa_handler = catcher;
  40     act.sa_flags |= on_stack;
  41     sigaction (sig, &act, NULL);
  42   }
  43   /* Set up a one-off timer.  A timer, rather than SIGSEGV, is used as
  44      after a timer handler finishes the interrupted code can safely
  45      resume.  */
  46   {
  47     struct itimerval itime;
  48     memset (&itime, 0, sizeof (itime));
  49     itime.it_value.tv_usec = 250 * 1000;
  50     setitimer (itimer, &itime, NULL);
  51   }
  52   /* Wait.  */
  53   while (level != LEAF);
  54 }
  55
  56 void
  57 catcher (int signal)
  58 {
  59   /* Find the next level.  */
  60   switch (level)
  61     {
  62     case MAIN:
  63       thrower (OUTER, SIGALRM, ITIMER_REAL, SA_ONSTACK);
  64       break;
  65     case OUTER:
  66       thrower (INNER, SIGVTALRM, ITIMER_VIRTUAL, SA_ONSTACK);
  67       break;
  68     case INNER:
  69       level = LEAF;
  70       return;
  71     }
  72 }
  73
  74
  75 main ()
  76 {
  77   /* Set up the altstack.  */
  78   {
  79     static char stack[SIGSTKSZ * NR_LEVELS];
  80     stack_t alt;
  81     memset (&alt, 0, sizeof (alt));
  82     alt.ss_sp = stack;
  83     alt.ss_size = SIGSTKSZ;
  84     alt.ss_flags = 0;
  85     if (sigaltstack (&alt, NULL) < 0)
  86       {
  87         perror ("sigaltstack");
  88         exit (0);
  89       }
  90   }
  91   level = MAIN;
  92   catcher (0);
  93 }