/* $Id: fault.c,v 1.5 2008/10/28 17:39:16 kostik Exp $ */

#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/ucontext.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>

extern char *fault_instr;
int run;

void
sigsegv_sigaction(int signo, siginfo_t *si, void *c)
{
	ucontext_t *uc;
	mcontext_t *mc;

	uc = c;
	mc = &uc->uc_mcontext;
	printf("SIGSEGV run %d err %x ds %x ss %x es %x fs %x gs %x\n",
	    run, mc->mc_err, mc->mc_ds, mc->mc_ss, mc->mc_es, mc->mc_fs,
	    mc->mc_gs);
	switch (run) {
	case 0:
		mc->mc_ds = 0x1111;
		break;
	case 1:
		mc->mc_es = 0x1111;
		break;
	case 2:
		mc->mc_fs = 0x1111;
		break;
	case 3:
		mc->mc_gs = 0x1111;
		break;
	case 4:
		mc->mc_ss = 0x1111;
		break;
	case 5:
		_exit(11);
	}
	run++;
}

void
fault(void)
{

	__asm__ volatile(".globl\tfault_instr;fault_instr:\ttestl\t$0,0\n");
}

int
main(int argc, char *argv[])
{
	struct sigaction sa;

	memset(&sa, 0, sizeof(sa));
	sa.sa_sigaction = sigsegv_sigaction;
	sa.sa_flags = SA_SIGINFO;
	if (sigaction(SIGSEGV, &sa, NULL) == -1) {
		fprintf(stderr, "sigaction: %s\n", strerror(errno));
		return (1);
	}
	if (sigaction(SIGBUS, &sa, NULL) == -1) {
		fprintf(stderr, "sigaction: %s\n", strerror(errno));
		return (1);
	}

	fault();

	return (0);
}