fault_handler.c

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <unistd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <signal.h>

#include <sys/ucontext.h>
#include <ucontext.h>

void setHandler(void (*handler)(int,siginfo_t *,void *))
{
	struct sigaction action;
	action.sa_flags = SA_SIGINFO;
	action.sa_sigaction = handler;

	if (sigaction(SIGFPE, &action, NULL) == -1) {
		perror("sigusr: sigaction");
		_exit(1);
	}
	if (sigaction(SIGSEGV, &action, NULL) == -1) {
		perror("sigusr: sigaction");
		_exit(1);
	}
	if (sigaction(SIGILL, &action, NULL) == -1) {
		perror("sigusr: sigaction");
		_exit(1);
	}
	if (sigaction(SIGBUS, &action, NULL) == -1) {
		perror("sigusr: sigaction");
		_exit(1);
	}

}

void continue_after_crash(void)
{
	printf("normal running now\n");
	exit(0);
}

void catchit(int signo, siginfo_t *info, void *extra) 
{
	ucontext_t *p=(ucontext_t *)extra;
	int x;
	printf("Signal %d received from parent\n", signo);
	printf("siginfo address=%x\n",info->si_addr);

	x= p->uc_mcontext.gregs[REG_RIP];
//	x= p->uc_mcontext.arm_pc;

	printf("address = %x\n",x);

  // uncomment one of the following lines
  
	//p->uc_mcontext.gregs[REG_RIP] += 6;
	//setHandler(SIG_DFL);
	//p->uc_mcontext.gregs[REG_RIP] = (unsigned int)continue_after_crash;
	//abort();

}


int main()
{
	int x=9,y=0,z=10;
	int *p=NULL;

	setHandler(catchit);
	
	p=0x90; // put a wrong address
	
	*p=100;
	printf("Alive???\n");
	z=x/y;
	printf("%d\n",z);
	return 0;
}

Read the full post in My Blog

An interesting article and example. Gcc warns that those %x should be %p