none/tests/solaris/context_stack.c

   1 /* Test of correct simulation for active stack. */
   2
   3 #include <assert.h>
   4 #include <signal.h>
   5 #include <stdio.h>
   6 #include <ucontext.h>
   7
   8 static char altstack_map[8096];
   9 static volatile stack_t *sp;
  10
  11 static void sighandler(int sig)
  12 {
  13    /* Check that the alternate stack is active. */
  14    assert(sp->ss_sp == altstack_map);
  15    assert(sp->ss_size == sizeof(altstack_map));
  16    assert(sp->ss_flags == SS_ONSTACK);
  17 }
  18
  19 int main(void)
  20 {
  21    stack_t mainstack;
  22    stack_t altstack;
  23    struct sigaction sa;
  24    /* Obtain an address inside the stack using a dirty trick. */
  25    void *local = &sa;
  26
  27    /* Get an address for stack definition. */
  28    if (getustack((stack_t**)&sp)) {
  29       perror("getustack");
  30       return 1;
  31    }
  32
  33    /* Check the current stack. */
  34    assert(sp->ss_sp <= local);
  35    assert(local < (void*)((char*)sp->ss_sp + sp->ss_size));
  36    assert(sp->ss_flags == 0);
  37
  38    /* Backup the current stack. */
  39    mainstack = *sp;
  40
  41    /* Setup a signal handler. */
  42    sa.sa_handler = sighandler;
  43    sa.sa_flags = SA_ONSTACK;
  44    if (sigfillset(&sa.sa_mask)) {
  45       perror("sigfillset");
  46       return 1;
  47    }
  48    if (sigaction(SIGUSR1, &sa, NULL)) {
  49       perror("sigaction");
  50       return 1;
  51    }
  52
  53    /* Setup an alternate stack. */
  54    altstack.ss_sp = altstack_map;
  55    altstack.ss_size = sizeof(altstack_map);
  56    altstack.ss_flags = 0;
  57    if (sigaltstack(&altstack, NULL)) {
  58       perror("sigaltstack");
  59       return 1;
  60    }
  61
  62    /* Raise a signal. */
  63    raise(SIGUSR1);
  64
  65    /* Check the current stack. */
  66    assert(mainstack.ss_sp == sp->ss_sp);
  67    assert(mainstack.ss_size == sp->ss_size);
  68    assert(mainstack.ss_flags == sp->ss_flags);
  69
  70    return 0;
  71 }
  72