1/* This testcase is part of GDB, the GNU debugger. 2 3 Copyright 2004, 2007 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 Please email any bugs, comments, and/or additions to this file to: 19 bug-gdb@prep.ai.mit.edu */ 20 21#include <signal.h> 22#include <stdio.h> 23#include <stdlib.h> 24#include <string.h> 25#include <sys/time.h> 26 27enum level { MAIN, OUTER, INNER, LEAF, NR_LEVELS }; 28 29/* Levels completed flag. */ 30volatile enum level level = NR_LEVELS; 31 32void catcher (int signal); 33 34void 35thrower (enum level next_level, int sig, int itimer, int on_stack) 36{ 37 level = next_level; 38 /* Set up the signal handler. */ 39 { 40 struct sigaction act; 41 memset (&act, 0, sizeof (act)); 42 act.sa_handler = catcher; 43 act.sa_flags |= on_stack; 44 sigaction (sig, &act, NULL); 45 } 46 /* Set up a one-off timer. A timer, rather than SIGSEGV, is used as 47 after a timer handler finishes the interrupted code can safely 48 resume. */ 49 { 50 struct itimerval itime; 51 memset (&itime, 0, sizeof (itime)); 52 itime.it_value.tv_usec = 250 * 1000; 53 setitimer (itimer, &itime, NULL); 54 } 55 /* Wait. */ 56 while (level != LEAF); 57} 58 59void 60catcher (int signal) 61{ 62 /* Find the next level. */ 63 switch (level) 64 { 65 case MAIN: 66 thrower (OUTER, SIGALRM, ITIMER_REAL, SA_ONSTACK); 67 break; 68 case OUTER: 69 thrower (INNER, SIGVTALRM, ITIMER_VIRTUAL, SA_ONSTACK); 70 break; 71 case INNER: 72 level = LEAF; 73 return; 74 } 75} 76 77 78main () 79{ 80 /* Set up the altstack. */ 81 { 82 static char stack[SIGSTKSZ * NR_LEVELS]; 83 stack_t alt; 84 memset (&alt, 0, sizeof (alt)); 85 alt.ss_sp = stack; 86 alt.ss_size = SIGSTKSZ; 87 alt.ss_flags = 0; 88 if (sigaltstack (&alt, NULL) < 0) 89 { 90 perror ("sigaltstack"); 91 exit (0); 92 } 93 } 94 level = MAIN; 95 catcher (0); 96} 97