signest.c

#include <stdio.h>
#include <stdlib.h>
#include <signal.h>
#include <execinfo.h>

volatile static int *x = NULL;
volatile static int action = 0;

void bt()
{
	int n = 10;
	void *buffer[n];
	backtrace((void **)&buffer, n);
	backtrace_symbols_fd(buffer, n, 2);
}

void crash(int signo)
{
	bt();
	exit(0);
}

void handler2()
{
	bt();
}

void handler1(int signo)
{
	volatile int boom;

	switch(action) {
	case 0:
		boom = *x;
		break;
	case 1:
		kill(getpid(), SIGUSR2);
		break;
	default:
		break;
	}
}

int main(int argc, char **argv)
{
	if (argc == 2)
		action = atoi(argv[1]);
	printf("action=%d\n", action);
	signal(SIGUSR1, handler1);
	signal(SIGUSR2, handler2);
	signal(SIGSEGV, crash);
	kill(getpid(), SIGUSR1);
	printf("bye\n");
}