/* set up signal_handler as the handler for signal "sig" */
static void
intercept_signal(int sig, handler_t handler)
{
int rc;
struct sigaction act;
act.sa_sigaction = (handler_3_t) handler;
rc = sigfillset(&act.sa_mask); /* block all signals within handler */
ASSERT_NOERR(rc);
act.sa_flags = SA_ONSTACK;
/* arm the signal */
rc = sigaction(sig, &act, NULL);
ASSERT_NOERR(rc);
}
/* set up signal_handler as the handler for signal "sig" */
void
intercept_signal(int sig, handler_3_t handler, bool sigstack)
{
int rc;
struct sigaction act;
act.sa_sigaction = (void (*)(int, siginfo_t *, void *)) handler;
rc = sigfillset(&act.sa_mask); /* block all signals within handler */
ASSERT_NOERR(rc);
act.sa_flags = SA_SIGINFO;
if (sigstack)
act.sa_flags = SA_ONSTACK;
/* arm the signal */
rc = sigaction(sig, &act, NULL);
ASSERT_NOERR(rc);
}
/* set up signal_handler as the handler for signal "sig" */
static void
intercept_signal(int sig, handler_t handler)
{
int rc;
struct sigaction act;
act.sa_sigaction = handler;
#if BLOCK_IN_HANDLER
rc = sigfillset(&act.sa_mask); /* block all signals within handler */
#else
rc = sigemptyset(&act.sa_mask); /* no signals are blocked within handler */
#endif
ASSERT_NOERR(rc);
act.sa_flags = SA_SIGINFO | SA_ONSTACK; /* send 3 args to handler */
/* arm the signal */
rc = sigaction(sig, &act, NULL);
ASSERT_NOERR(rc);
}
/* set up signal_handler as the handler for signal "sig" */
static void
intercept_signal(int sig, handler_t handler)
{
int rc;
struct sigaction act;
act.sa_sigaction = (handler_3_t) handler;
/* FIXME: due to DR bug 840 we cannot block ourself in the handler
* since the handler does not end in a sigreturn, so we have an empty mask
* and we use SA_NOMASK
*/
rc = sigemptyset(&act.sa_mask); /* block no signals within handler */
ASSERT_NOERR(rc);
/* FIXME: due to DR bug #654 we use SA_SIGINFO -- change it once DR works */
act.sa_flags = SA_NOMASK | SA_SIGINFO | SA_ONSTACK;
/* arm the signal */
rc = sigaction(sig, &act, NULL);
ASSERT_NOERR(rc);
}
int main(int argc, char *argv[])
{
double res = 0.;
int i, j;
#if defined(USE_DYNAMO) || USE_TIMER || USE_SIGSTACK
int rc;
#endif
#if USE_SIGSTACK
stack_t sigstack;
#endif
#if USE_TIMER
struct itimerval t;
#endif
#ifdef USE_DYNAMO
rc = dynamorio_app_init();
ASSERT_NOERR(rc);
dynamorio_app_start();
#endif
#if USE_TIMER
intercept_signal(SIGVTALRM, (handler_t) signal_handler);
t.it_interval.tv_sec = 0;
t.it_interval.tv_usec = 10000;
t.it_value.tv_sec = 0;
t.it_value.tv_usec = 10000;
rc = setitimer(ITIMER_VIRTUAL, &t, NULL);
ASSERT_NOERR(rc);
#endif
#if USE_SIGSTACK
sigstack.ss_sp = (char *) malloc(ALT_STACK_SIZE);
sigstack.ss_size = ALT_STACK_SIZE;
sigstack.ss_flags = SS_ONSTACK;
rc = sigaltstack(&sigstack, NULL);
ASSERT_NOERR(rc);
# if VERBOSE
fprintf(stderr, "Set up sigstack: 0x%08x - 0x%08x\n",
sigstack.ss_sp, sigstack.ss_sp + sigstack.ss_size);
# endif
#endif
intercept_signal(SIGSEGV, (handler_t) signal_handler);
intercept_signal(SIGUSR1, (handler_t) signal_handler);
intercept_signal(SIGUSR2, (handler_t) SIG_IGN);
res = cos(0.56);
fprintf(stderr, "Sending SIGUSR2\n");
kill(getpid(), SIGUSR2);
fprintf(stderr, "Sending SIGUSR1\n");
kill(getpid(), SIGUSR1);
#if USE_SIGSTACK
/* now remove alt stack */
free(sigstack.ss_sp);
sigstack.ss_sp = 0;
sigstack.ss_size = 0;
sigstack.ss_flags = SS_DISABLE;
rc = sigaltstack(&sigstack, NULL);
ASSERT_NOERR(rc);
#endif
fprintf(stderr, "Generating SIGSEGV\n");
#if USE_LONGJMP
res = setjmp(env);
if (res == 0) {
*((int *)0) = 4;
}
#else
kill(getpid(), SIGSEGV);
#endif
for (i=0; i<ITERS; i++) {
if (i % 2 == 0) {
res += cos(1./(double)(i+1));
} else {
res += sin(1./(double)(i+1));
}
j = (i << 4) / (i | 0x38);
a[i] += j;
}
fprintf(stderr, "%f\n", res);
#if USE_TIMER
memset(&t, 0, sizeof(t));
rc = setitimer(ITIMER_VIRTUAL, &t, NULL);
ASSERT_NOERR(rc);
if (timer_hits == 0)
fprintf(stderr, "Got 0 timer hits!\n");
else
fprintf(stderr, "Got some timer hits!\n");
#endif
#ifdef USE_DYNAMO
dynamorio_app_stop();
dynamorio_app_exit();
#endif
return 0;
}
static void
signal_handler(int sig, siginfo_t *siginfo, ucontext_t *ucxt)
{
#if VERBOSE
fprintf(stderr, "signal_handler: sig=%d, retaddr=0x%08x, fpregs=0x%08x\n",
sig, *(&sig - 1), ucxt->uc_mcontext.fpregs);
#else
# if USE_TIMER
if (sig != SIGVTALRM)
# endif
fprintf(stderr, "signal_handler: sig=%d\n", sig);
#endif
switch (sig) {
case SIGSEGV: {
#if VERBOSE
struct sigcontext *sc = (struct sigcontext *) &(ucxt->uc_mcontext);
void *pc = (void *) sc->SC_XIP;
#endif
#if USE_LONGJMP && BLOCK_IN_HANDLER
sigset_t set;
int rc;
#endif
#if VERBOSE
fprintf(stderr, "Got SIGSEGV @ 0x%08x\n", pc);
#else
fprintf(stderr, "Got SIGSEGV\n");
#endif
#if USE_LONGJMP
# if BLOCK_IN_HANDLER
/* longjmp will bypass sigreturn, and sigreturn is what resets
* the set of blocked signals, so we have to unblock them here
*/
rc = sigemptyset(&set); /* reset blocked signals */
ASSERT_NOERR(rc);
sigprocmask(SIG_SETMASK, &set, NULL);
# endif
longjmp(env, 1);
#endif
break;
}
case SIGUSR1: {
#if VERBOSE
struct sigcontext *sc = (struct sigcontext *) &(ucxt->uc_mcontext);
void *pc = (void *) sc->SC_XIP;
fprintf(stderr, "Got SIGUSR1 @ 0x%08x\n", pc);
#else
fprintf(stderr, "Got SIGUSR1\n");
#endif
break;
}
#if USE_TIMER
case SIGVTALRM: {
struct sigcontext *sc = (struct sigcontext *) &(ucxt->uc_mcontext);
void *pc = (void *) sc->SC_XIP;
#if VERBOSE
fprintf(stderr, "Got SIGVTALRM @ 0x%08x\n", pc);
#endif
timer_hits++;
break;
}
#endif
default:
assert(0);
}
}
