/***************************************************************************
                          sigset_test.c  -  description
                             -------------------
    begin                : Wed Nov 16 2005
    copyright            : (C) 2005 by Qlusters Ltd
    email                : linux@qlusters.com
 ***************************************************************************/
#ifdef  DEF_KERNEL
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/signal.h>

static int sigset_test_init(void);
static void sigset_test_exit(void);

module_init(sigset_test_init);
module_exit(sigset_test_exit);
#define SIGADDSET sigaddset
#define SIGISMEMBER sigismember
//#define  SIGADDSET(x, y) set_bit(y, (long *)x)

#else
extern int printf(const char *format, ...);
#define printk printf
#define KERN_INFO
typedef struct {
	unsigned long sig[2];
} sigset_t;
#include <asm/signal.h>
#define _NSIG (64)
#define _NSIG_BPW (32)


static __inline__ int __const_sigismember(sigset_t *set, int _sig)
{
	unsigned long sig = _sig - 1;
	return 1 & (set->sig[sig / _NSIG_BPW] >> (sig % _NSIG_BPW));
}
static __inline__ int __gen_sigismember(sigset_t *set, int _sig)
{
	int ret;
	__asm__("btl %2,%1\n\tsbbl %0,%0"
		: "=r"(ret) : "m"(*set), "Ir"(_sig-1) : "cc");
	return ret;
}

#define SIGISMEMBER(set,sig)               \
	(__builtin_constant_p(sig) ?           \
	__const_sigismember((set),(sig)) :     \
	__gen_sigismember((set),(sig)))

#define SIGADDSET1(set,sig)                \
	(__builtin_constant_p(sig) ?           \
	__const_sigaddset((set),(sig)) :       \
	__gen_sigaddset((set),(sig)))

static __inline__ void __gen_sigaddset(sigset_t *set, int _sig)
{
	__asm__("btsl %1,%0" : "=m"(*set) : "Ir"(_sig-1) : "cc");
}

static __inline__ void __const_sigaddset(sigset_t *set, int _sig)
{
	unsigned long sig = _sig - 1;
	set->sig[sig / _NSIG_BPW] |= 1 << (sig % _NSIG_BPW);
}

#define SIGADDSET  __gen_sigaddset
//#define SIGADDSET  SIGADDSET1 /* fixes the problem */


#endif


sigset_t ssi_fatal_sigset;
static sigset_t ssi_stop_set;
static void print_pending_signals(sigset_t *pending, sigset_t *blocked);

void sigset_test_exit(void)
{
	return;
}

#ifdef  DEF_KERNEL
static int sigset_test_init()
#else
int main()
#endif
{
	sigset_t cleaned;

	cleaned = (sigset_t) { {0,  0} };
	/* these are non-fatal signals.  Other signals are if their action is SIG_DFL */
	SIGADDSET(&cleaned, SIGCONT);
	SIGADDSET(&cleaned, SIGCHLD);
	SIGADDSET(&cleaned, SIGWINCH);
	SIGADDSET(&cleaned, SIGURG);
	SIGADDSET(&cleaned, SIGTSTP);
	SIGADDSET(&cleaned, SIGTTIN);
	SIGADDSET(&cleaned, SIGTTOU);
	SIGADDSET(&cleaned, SIGTTOU);
	ssi_fatal_sigset =  (sigset_t) { {-1,  -1} };

	//uncomenting this line fixes the problem
	//printk(KERN_INFO "sigset_test: fatal %p, stop %p\n", &ssi_fatal_sigset, &ssi_stop_set);

	/* ssi_fatal_sigset is a mask of all signals that are fatal */
	//commenting the line below fixes the problem
	ssi_fatal_sigset = cleaned;

	ssi_stop_set = (sigset_t) { {0,  0} };
	printk(KERN_INFO "sigset_test after zeroing\n");
	print_pending_signals(&ssi_stop_set, NULL);

	SIGADDSET(&ssi_stop_set, SIGTSTP);
	printk(KERN_INFO "sigset_test after %d\n", SIGTSTP);
	print_pending_signals(&ssi_stop_set, NULL);

	SIGADDSET(&ssi_stop_set, SIGTTIN);
	printk(KERN_INFO "sigset_test after %d\n", SIGTTIN);
	print_pending_signals(&ssi_stop_set, NULL);

	SIGADDSET(&ssi_stop_set, SIGTTOU);
	printk(KERN_INFO "sigset_test after %d\n", SIGTTOU);
	print_pending_signals(&ssi_stop_set, NULL);

	SIGADDSET(&ssi_stop_set, SIGSTOP);
	printk(KERN_INFO "sigset_test after %d\n", SIGSTOP);
	print_pending_signals(&ssi_stop_set, NULL);
	return 1;
}

static void print_pending_signals(sigset_t *pending, sigset_t *blocked)
{
	int i;

	if(pending->sig[0] == 0 && pending->sig[1] == 0) {
		printk(KERN_INFO "sigset_t: no set signals\n");
		return;
	}
	if(blocked) {
		for(i = 0; i < _NSIG; i++) {
			if(SIGISMEMBER(pending, i+1)) {
				printk(KERN_INFO "sigset_test: set signal %d is%sblocked\n", i+1,  SIGISMEMBER(blocked, i+1) ? " " : " not ");
			}
		}
	} else {
		 for(i = 0; i < _NSIG; i++) {
			if(SIGISMEMBER(pending, i+1)) {
				printk(KERN_INFO "sigset_test: set signal %d\n", i+1);
			}
		}
	}
}