1 #include <inttypes.h>
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <signal.h>
5 #include "tests/sys_mman.h"
6
sig_handler(int sig)7 void sig_handler(int sig){
8 int var;
9 fprintf(stderr, "caught signal, local var is on %#" PRIxPTR "\n",
10 (uintptr_t)&var);
11 }
12
main(int argv,char ** argc)13 int main(int argv, char** argc) {
14 int res, i;
15 stack_t sigstk;
16 struct sigaction act;
17 static const int size = SIGSTKSZ*2;
18 // We give EXEC permissions because this won't work on ppc32 unless you
19 // ask for an alt stack with EXEC permissions,
20 // since signal returning requires execution of code on the stack.
21 char *stk = (char *)mmap(0, size, PROT_READ|PROT_WRITE|PROT_EXEC,
22 MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
23 sigstk.ss_sp = stk;
24
25 sigstk.ss_size = size;
26 sigstk.ss_flags = 0;
27 fprintf(stderr, "calling sigaltstack, stack base is %#" PRIxPTR "\n",
28 (uintptr_t)sigstk.ss_sp);
29 if (sigaltstack(&sigstk,0)<0) perror("sigaltstack");
30
31 fprintf(stderr,"setting sigaction\n");
32 act.sa_flags=SA_ONSTACK;
33 act.sa_handler=&sig_handler;
34 sigemptyset(&act.sa_mask);
35 res = sigaction(SIGUSR1,&act,0);
36 fprintf(stderr, "res = %d\n", res);
37 fprintf(stderr, "raising the signal\n");
38 raise(SIGUSR1);
39
40 /* Loop long enough so valgrind has a forced context switch and
41 actually delivers the signal before the thread exits. */
42 for (i = 0; i < 1000000; i++) ;
43
44 fprintf(stderr, "done\n");
45 return 0;
46 }
47