/*
 *  kernel_restorer.c
 *
 *  Testtool for UML
 *  This tool tests the kernels restorer code stubs.
 *  Also it checks, whether syscall restarting is skipped on
 *  return from sys_sigreturn() and sys_rt_sigreturn()
 *
 *  Copyright (C) 2004 Fujitsu Siemens Computers GmbH
 *  Author: Bodo Stroesser (bodo.stroesser@fujitsu-siemens.com)
 *
 *  Licensed under the GPL
 */

#define __KERNEL__
#include <asm/signal.h>
#include <asm/siginfo.h>
#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <unistd.h>
#include <errno.h>
#include <asm/unistd.h>

int counter;
int mod_eip;

void sighdlr( int sig)
{
	struct sigcontext * sc = (struct sigcontext *)(&sig + 1);

	printf("sighdlr(): signal %d caught\n", sig);
	if ( --counter )
		alarm(1);
	else if ( mod_eip )
		sc->eip -= 2;
}


void rt_sighdlr( int sig, siginfo_t * info, struct ucontext * uc)
{
	printf("rt_sighdlr(): signal %d caught\n", sig);
	if ( --counter )
		alarm(1);
	else if ( mod_eip )
		uc->uc_mcontext.eip -= 2;
}

_syscall4( int, rt_sigaction, int, signr, struct k_sigaction *, new, struct k_sigaction *, old, int, size)


void
prepare( struct k_sigaction *sa, void * hdlr, int count)
{
	int ret;

	counter = count;
	sa->sa.sa_handler = hdlr;
	sa->sa.sa_flags = SA_RESTART;
	if ( hdlr == rt_sighdlr )
		sa->sa.sa_flags |= SA_SIGINFO;
	ret = rt_sigaction( SIGALRM, sa, NULL, sizeof( sigset_t));
	if ( ret ) {
		perror("rt_sigaction()");
		exit(1);
	}
	
	alarm(1);
}


void
test_suspend( void)
{
	int ret, errno_sav;
	sigset_t set;

	memset( &set, 0, sizeof( sigset_t));

	ret = sigsuspend( &set);
	if ( ret ) {
		errno_sav=errno;
		perror("sigsuspend()");
		if ( errno_sav != EINTR ) {
			printf("ERROR: sigsuspend() didn't return -EINTR\n");
			exit(1);
		}
	} else {
		printf("ERROR: sigsuspend() returns O.K. --> this should never happen!\n");
		exit(1);
	}

	if ( counter ) {
		printf("ERROR: signal counter not counted down to 0, is %d\n", counter);
		exit(1);
	}
	printf("==> OK.\n");
}


void
test_loop( void)
{
	__asm__ volatile ("	call 1f	\n"
			"	jmp  2f	\n"
			"	ret	\n"
			"	nop	\n"
			"1:	jmp  1b	\n"
			"2:		\n"
				: : "a" (-ERESTARTSYS));

	alarm(0);

	if ( counter ) {
		printf("ERROR: signal counter not counted down to 0, is %d\n", counter);
		exit(1);
	}
	printf("==> OK.\n");
}


int
main( void)
{
	struct k_sigaction sa;

	sa.sa.sa_restorer = NULL;
	memset( sa.sa.sa_mask.sig, 0xff, sizeof( sigset_t));

	mod_eip = 0;

	printf("\nTesting kernels restorer for sigreturn(): this simply shouldn't crash\n\n");

	prepare( &sa, sighdlr, 1);

	test_suspend();

	printf("\nTesting kernels restorer for rt_sigreturn(): this simply shouldn't crash\n\n");

	prepare( &sa, rt_sighdlr, 1);

	test_suspend();

	mod_eip = 1;

	printf("\nTesting correct returncode-handling for sigreturn()\n");

	prepare( &sa, sighdlr, 3);

	test_loop();

	printf("\nTesting correct returncode-handling for rt_sigreturn()\n");

	prepare( &sa, rt_sighdlr, 3);

	test_loop();

	return 0;
}