[net-next-2.6.git] / arch / m32r / kernel / signal.c

/*
 *  linux/arch/m32r/kernel/signal.c
 *
 *  Copyright (c) 2003  Hitoshi Yamamoto
 *
 *  Taken from i386 version.
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/freezer.h>
#include <linux/tracehook.h>
#include <asm/cacheflush.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>

#define DEBUG_SIG 0

asmlinkage int
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
		unsigned long r2, unsigned long r3, unsigned long r4,
		unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
	return do_sigaltstack(uss, uoss, regs->spu);
}


/*
 * Do a signal return; undo the signal stack.
 */

struct rt_sigframe
{
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
//	struct _fpstate fpstate;
};

static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
		   int *r0_p)
{
	unsigned int err = 0;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

#define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	/* COPY(r0); Skip r0 */
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
#undef COPY

	regs->syscall_nr = -1;	/* disable syscall checks */
	err |= __get_user(*r0_p, &sc->sc_r0);

	return err;
}

asmlinkage int
sys_rt_sigreturn(unsigned long r0, unsigned long r1,
		 unsigned long r2, unsigned long r3, unsigned long r4,
		 unsigned long r5, unsigned long r6, struct pt_regs *regs)
{
	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
	sigset_t set;
	int result;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
		goto badframe;

	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
		goto badframe;

	return result;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

/*
 * Set up a signal frame.
 */

static int
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
	         unsigned long mask)
{
	int err = 0;

#define COPY(x)	err |= __put_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	COPY(r0);
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
#undef COPY

	err |= __put_user(mask, &sc->oldmask);

	return err;
}

/*
 * Determine which stack to use..
 */
static inline void __user *
get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
{
	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (sas_ss_flags(sp) == 0)
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *)((sp - frame_size) & -8ul);
}

static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
			   sigset_t *set, struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	int err = 0;
	int signal;

	frame = get_sigframe(ka, regs->spu, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto give_sigsegv;

	signal = current_thread_info()->exec_domain
		&& current_thread_info()->exec_domain->signal_invmap
		&& sig < 32
		? current_thread_info()->exec_domain->signal_invmap[sig]
		: sig;

	err |= __put_user(signal, &frame->sig);
	if (err)
		goto give_sigsegv;

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	if (err)
		goto give_sigsegv;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->spu),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		goto give_sigsegv;

	/* Set up to return from userspace.  */
	regs->lr = (unsigned long)ka->sa.sa_restorer;

	/* Set up registers for signal handler */
	regs->spu = (unsigned long)frame;
	regs->r0 = signal;	/* Arg for signal handler */
	regs->r1 = (unsigned long)&frame->info;
	regs->r2 = (unsigned long)&frame->uc;
	regs->bpc = (unsigned long)ka->sa.sa_handler;

	set_fs(USER_DS);

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
		current->comm, current->pid, frame, regs->pc);
#endif

	return 0;

give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
}

/*
 * OK, we're invoking a handler
 */

static int
handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
	      sigset_t *oldset, struct pt_regs *regs)
{
	unsigned short inst;

	/* Are we from a system call? */
	if (regs->syscall_nr >= 0) {
		/* If so, check system call restarting.. */
		switch (regs->r0) {
		        case -ERESTART_RESTARTBLOCK:
			case -ERESTARTNOHAND:
				regs->r0 = -EINTR;
				break;

			case -ERESTARTSYS:
				if (!(ka->sa.sa_flags & SA_RESTART)) {
					regs->r0 = -EINTR;
					break;
				}
			/* fallthrough */
			case -ERESTARTNOINTR:
				regs->r0 = regs->orig_r0;
				inst = *(unsigned short *)(regs->bpc - 2);
				if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
					regs->bpc -= 2;
				else
					regs->bpc -= 4;
				regs->syscall_nr = -1;
		}
	}

	/* Set up the stack frame */
	if (setup_rt_frame(sig, ka, info, oldset, regs))
		return -EFAULT;

	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
		sigaddset(&current->blocked,sig);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return 0;
}

/*
 * Note that 'init' is a special process: it doesn't get signals it doesn't
 * want to handle. Thus you cannot kill init even with a SIGKILL even by
 * mistake.
 */
static void do_signal(struct pt_regs *regs)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
	unsigned short inst;
	sigset_t *oldset;

	/*
	 * We want the common case to go fast, which
	 * is why we may in certain cases get here from
	 * kernel mode. Just return without doing anything
	 * if so.
	 */
	if (!user_mode(regs))
		return;

	if (try_to_freeze()) 
		goto no_signal;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		/* Re-enable any watchpoints before delivering the
		 * signal to user space. The processor register will
		 * have been cleared if the watchpoint triggered
		 * inside the kernel.
		 */

		/* Whee!  Actually deliver the signal.  */
		if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
			clear_thread_flag(TIF_RESTORE_SIGMASK);

		return;
	}

 no_signal:
	/* Did we come from a system call? */
	if (regs->syscall_nr >= 0) {
		/* Restart the system call - no handlers present */
		if (regs->r0 == -ERESTARTNOHAND ||
		    regs->r0 == -ERESTARTSYS ||
		    regs->r0 == -ERESTARTNOINTR) {
			regs->r0 = regs->orig_r0;
			inst = *(unsigned short *)(regs->bpc - 2);
			if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
				regs->bpc -= 2;
			else
				regs->bpc -= 4;
			regs->syscall_nr = -1;
		} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
			regs->r0 = regs->orig_r0;
			regs->r7 = __NR_restart_syscall;
			inst = *(unsigned short *)(regs->bpc - 2);
			if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
				regs->bpc -= 2;
			else
				regs->bpc -= 4;
			regs->syscall_nr = -1;
		}
	}
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
}

/*
 * notification of userspace execution resumption
 * - triggered by current->work.notify_resume
 */
void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
{
	/* Pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP)
		clear_thread_flag(TIF_SINGLESTEP);

	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
		do_signal(regs);

	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(regs);
		if (current->replacement_session_keyring)
			key_replace_session_keyring();
	}

	clear_thread_flag(TIF_IRET);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/m32r/kernel/signal.c
	3	*
	4	* Copyright (c) 2003 Hitoshi Yamamoto
	5	*
	6	* Taken from i386 version.
	7	* Copyright (C) 1991, 1992 Linus Torvalds
	8	*
	9	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	10	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	11	*/
	12
1da177e4 LT	13	#include <linux/sched.h>
	14	#include <linux/mm.h>
	15	#include <linux/smp.h>
1da177e4 LT	16	#include <linux/kernel.h>
	17	#include <linux/signal.h>
	18	#include <linux/errno.h>
	19	#include <linux/wait.h>
	20	#include <linux/unistd.h>
	21	#include <linux/stddef.h>
	22	#include <linux/personality.h>
7dfb7103	23	#include <linux/freezer.h>
733e5e4b	24	#include <linux/tracehook.h>
1da177e4 LT	25	#include <asm/cacheflush.h>
	26	#include <asm/ucontext.h>
	27	#include <asm/uaccess.h>
	28
	29	#define DEBUG_SIG 0
	30
1da177e4 LT	31	asmlinkage int
	32	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	33	unsigned long r2, unsigned long r3, unsigned long r4,
6ced13cd	34	unsigned long r5, unsigned long r6, struct pt_regs *regs)
1da177e4	35	{
6ced13cd	36	return do_sigaltstack(uss, uoss, regs->spu);
1da177e4 LT	37	}
	38
	39
	40	/*
	41	* Do a signal return; undo the signal stack.
	42	*/
	43
	44	struct rt_sigframe
	45	{
	46	int sig;
870e75a2 AV	47	struct siginfo __user *pinfo;
870e75a2 AV	48	void __user *puc;
1da177e4 LT	49	struct siginfo info;
	50	struct ucontext uc;
	51	// struct _fpstate fpstate;
	52	};
	53
	54	static int
	55	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc,
	56	int *r0_p)
	57	{
	58	unsigned int err = 0;
	59
	60	/* Always make any pending restarted system calls return -EINTR */
	61	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	62
	63	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	64	COPY(r4);
	65	COPY(r5);
	66	COPY(r6);
	67	COPY(pt_regs);
	68	/* COPY(r0); Skip r0 */
	69	COPY(r1);
	70	COPY(r2);
	71	COPY(r3);
	72	COPY(r7);
	73	COPY(r8);
	74	COPY(r9);
	75	COPY(r10);
	76	COPY(r11);
	77	COPY(r12);
1da177e4 LT	78	COPY(acc0h);
1da177e4 LT	79	COPY(acc0l);
9674dcf7 HT	80	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	81	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	82	COPY(psw);
	83	COPY(bpc);
	84	COPY(bbpsw);
	85	COPY(bbpc);
	86	COPY(spu);
	87	COPY(fp);
	88	COPY(lr);
	89	COPY(spi);
	90	#undef COPY
	91
	92	regs->syscall_nr = -1; /* disable syscall checks */
	93	err \|= __get_user(*r0_p, &sc->sc_r0);
	94
	95	return err;
	96	}
	97
	98	asmlinkage int
	99	sys_rt_sigreturn(unsigned long r0, unsigned long r1,
	100	unsigned long r2, unsigned long r3, unsigned long r4,
6ced13cd	101	unsigned long r5, unsigned long r6, struct pt_regs *regs)
1da177e4	102	{
6ced13cd	103	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->spu;
1da177e4	104	sigset_t set;
1da177e4 LT	105	int result;
	106
	107	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	108	goto badframe;
	109	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	110	goto badframe;
	111
	112	sigdelsetmask(&set, ~_BLOCKABLE);
	113	spin_lock_irq(&current->sighand->siglock);
	114	current->blocked = set;
	115	recalc_sigpending();
	116	spin_unlock_irq(&current->sighand->siglock);
	117
6ced13cd	118	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &result))
1da177e4 LT	119	goto badframe;
1da177e4 LT	120
6ced13cd	121	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
1da177e4	122	goto badframe;
1da177e4 LT	123
	124	return result;
	125
	126	badframe:
	127	force_sig(SIGSEGV, current);
	128	return 0;
	129	}
	130
	131	/*
	132	* Set up a signal frame.
	133	*/
	134
	135	static int
	136	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	137	unsigned long mask)
	138	{
	139	int err = 0;
	140
	141	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	142	COPY(r4);
	143	COPY(r5);
	144	COPY(r6);
	145	COPY(pt_regs);
	146	COPY(r0);
	147	COPY(r1);
	148	COPY(r2);
	149	COPY(r3);
	150	COPY(r7);
	151	COPY(r8);
	152	COPY(r9);
	153	COPY(r10);
	154	COPY(r11);
	155	COPY(r12);
1da177e4 LT	156	COPY(acc0h);
1da177e4 LT	157	COPY(acc0l);
9674dcf7 HT	158	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
9674dcf7 HT	159	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
1da177e4 LT	160	COPY(psw);
	161	COPY(bpc);
	162	COPY(bbpsw);
	163	COPY(bbpc);
	164	COPY(spu);
	165	COPY(fp);
	166	COPY(lr);
	167	COPY(spi);
	168	#undef COPY
	169
	170	err \|= __put_user(mask, &sc->oldmask);
	171
	172	return err;
	173	}
	174
	175	/*
	176	* Determine which stack to use..
	177	*/
	178	static inline void __user *
	179	get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
	180	{
	181	/* This is the X/Open sanctioned signal stack switching. */
	182	if (ka->sa.sa_flags & SA_ONSTACK) {
	183	if (sas_ss_flags(sp) == 0)
	184	sp = current->sas_ss_sp + current->sas_ss_size;
	185	}
	186
	187	return (void __user *)((sp - frame_size) & -8ul);
	188	}
	189
a05c4e1d	190	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
1da177e4 LT	191	sigset_t set, struct pt_regs regs)
	192	{
	193	struct rt_sigframe __user *frame;
	194	int err = 0;
	195	int signal;
	196
	197	frame = get_sigframe(ka, regs->spu, sizeof(*frame));
	198
	199	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	200	goto give_sigsegv;
	201
	202	signal = current_thread_info()->exec_domain
	203	&& current_thread_info()->exec_domain->signal_invmap
	204	&& sig < 32
	205	? current_thread_info()->exec_domain->signal_invmap[sig]
	206	: sig;
	207
	208	err \|= __put_user(signal, &frame->sig);
	209	if (err)
	210	goto give_sigsegv;
	211
	212	err \|= __put_user(&frame->info, &frame->pinfo);
	213	err \|= __put_user(&frame->uc, &frame->puc);
	214	err \|= copy_siginfo_to_user(&frame->info, info);
	215	if (err)
	216	goto give_sigsegv;
	217
	218	/* Create the ucontext. */
	219	err \|= __put_user(0, &frame->uc.uc_flags);
	220	err \|= __put_user(0, &frame->uc.uc_link);
	221	err \|= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	222	err \|= __put_user(sas_ss_flags(regs->spu),
	223	&frame->uc.uc_stack.ss_flags);
	224	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	225	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	226	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	227	if (err)
	228	goto give_sigsegv;
	229
	230	/* Set up to return from userspace. */
	231	regs->lr = (unsigned long)ka->sa.sa_restorer;
	232
	233	/* Set up registers for signal handler */
	234	regs->spu = (unsigned long)frame;
	235	regs->r0 = signal; /* Arg for signal handler */
	236	regs->r1 = (unsigned long)&frame->info;
	237	regs->r2 = (unsigned long)&frame->uc;
	238	regs->bpc = (unsigned long)ka->sa.sa_handler;
	239
	240	set_fs(USER_DS);
	241
	242	#if DEBUG_SIG
	243	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
	244	current->comm, current->pid, frame, regs->pc);
	245	#endif
	246
a05c4e1d	247	return 0;
1da177e4 LT	248
	249	give_sigsegv:
	250	force_sigsegv(sig, current);
a05c4e1d	251	return -EFAULT;
1da177e4 LT	252	}
	253
	254	/*
	255	* OK, we're invoking a handler
	256	*/
	257
a05c4e1d	258	static int
1da177e4 LT	259	handle_signal(unsigned long sig, struct k_sigaction ka, siginfo_t info,
	260	sigset_t oldset, struct pt_regs regs)
	261	{
	262	unsigned short inst;
	263
	264	/* Are we from a system call? */
	265	if (regs->syscall_nr >= 0) {
	266	/* If so, check system call restarting.. */
	267	switch (regs->r0) {
	268	case -ERESTART_RESTARTBLOCK:
	269	case -ERESTARTNOHAND:
	270	regs->r0 = -EINTR;
	271	break;
	272
	273	case -ERESTARTSYS:
	274	if (!(ka->sa.sa_flags & SA_RESTART)) {
	275	regs->r0 = -EINTR;
	276	break;
	277	}
	278	/* fallthrough */
	279	case -ERESTARTNOINTR:
	280	regs->r0 = regs->orig_r0;
	281	inst = (unsigned short )(regs->bpc - 2);
	282	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	283	regs->bpc -= 2;
	284	else
	285	regs->bpc -= 4;
a7481024	286	regs->syscall_nr = -1;
1da177e4 LT	287	}
	288	}
	289
	290	/* Set up the stack frame */
a05c4e1d AV	291	if (setup_rt_frame(sig, ka, info, oldset, regs))
a05c4e1d AV	292	return -EFAULT;
1da177e4	293
69be8f18 SR	294	spin_lock_irq(&current->sighand->siglock);
	295	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	296	if (!(ka->sa.sa_flags & SA_NODEFER))
1da177e4	297	sigaddset(&current->blocked,sig);
69be8f18 SR	298	recalc_sigpending();
69be8f18 SR	299	spin_unlock_irq(&current->sighand->siglock);
a05c4e1d	300	return 0;
1da177e4 LT	301	}
	302
	303	/*
	304	* Note that 'init' is a special process: it doesn't get signals it doesn't
	305	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	306	* mistake.
	307	*/
a05c4e1d	308	static void do_signal(struct pt_regs *regs)
1da177e4 LT	309	{
	310	siginfo_t info;
	311	int signr;
	312	struct k_sigaction ka;
	313	unsigned short inst;
a7f8388e	314	sigset_t *oldset;
1da177e4 LT	315
	316	/*
	317	* We want the common case to go fast, which
	318	* is why we may in certain cases get here from
	319	* kernel mode. Just return without doing anything
	320	* if so.
	321	*/
	322	if (!user_mode(regs))
a05c4e1d	323	return;
1da177e4	324
3e1d1d28	325	if (try_to_freeze())
1da177e4	326	goto no_signal;
1da177e4	327
a7f8388e AV	328	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	329	oldset = &current->saved_sigmask;
	330	else
1da177e4 LT	331	oldset = &current->blocked;
	332
	333	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	334	if (signr > 0) {
5aa8b6c1	335	/* Re-enable any watchpoints before delivering the
1da177e4 LT	336	* signal to user space. The processor register will
	337	* have been cleared if the watchpoint triggered
	338	* inside the kernel.
	339	*/
	340
	341	/* Whee! Actually deliver the signal. */
a05c4e1d AV	342	if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
	343	clear_thread_flag(TIF_RESTORE_SIGMASK);
	344
	345	return;
1da177e4 LT	346	}
	347
	348	no_signal:
	349	/* Did we come from a system call? */
	350	if (regs->syscall_nr >= 0) {
	351	/* Restart the system call - no handlers present */
	352	if (regs->r0 == -ERESTARTNOHAND \|\|
	353	regs->r0 == -ERESTARTSYS \|\|
	354	regs->r0 == -ERESTARTNOINTR) {
	355	regs->r0 = regs->orig_r0;
	356	inst = (unsigned short )(regs->bpc - 2);
	357	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	358	regs->bpc -= 2;
	359	else
	360	regs->bpc -= 4;
a7481024 AV	361	regs->syscall_nr = -1;
a7481024 AV	362	} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
1da177e4 LT	363	regs->r0 = regs->orig_r0;
	364	regs->r7 = __NR_restart_syscall;
	365	inst = (unsigned short )(regs->bpc - 2);
	366	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	367	regs->bpc -= 2;
	368	else
	369	regs->bpc -= 4;
a7481024	370	regs->syscall_nr = -1;
1da177e4 LT	371	}
1da177e4 LT	372	}
a7f8388e AV	373	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	374	clear_thread_flag(TIF_RESTORE_SIGMASK);
	375	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	376	}
1da177e4 LT	377	}
	378
	379	/*
	380	* notification of userspace execution resumption
	381	* - triggered by current->work.notify_resume
	382	*/
a7f8388e	383	void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
1da177e4 LT	384	{
	385	/* Pending single-step? */
	386	if (thread_info_flags & _TIF_SINGLESTEP)
	387	clear_thread_flag(TIF_SINGLESTEP);
	388
	389	/* deal with pending signal delivery */
	390	if (thread_info_flags & _TIF_SIGPENDING)
a7f8388e	391	do_signal(regs);
1da177e4	392
d0420c83 DH	393	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	394	clear_thread_flag(TIF_NOTIFY_RESUME);
	395	tracehook_notify_resume(regs);
ee18d64c DH	396	if (current->replacement_session_keyring)
ee18d64c DH	397	key_replace_session_keyring();
d0420c83 DH	398	}
d0420c83 DH	399
1da177e4 LT	400	clear_thread_flag(TIF_IRET);
1da177e4 LT	401	}