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

/*
 * Signal handling
 *
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
 * Copyright (C) 2001 NEC Corporation
 * Copyright (C) 2001 Miles Bader <miles@gnu.org>
 * Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
 * Copyright (C) 1991,1992 Linus Torvalds
 *
 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
 *
 * This file was was derived from the sh version, arch/sh/kernel/signal.c
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file COPYING in the main directory of this
 * archive for more details.
 */

#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/percpu.h>
#include <linux/linkage.h>
#include <asm/entry.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <linux/syscalls.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>

#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_sycall);


asmlinkage long
sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
		struct pt_regs *regs)
{
	return do_sigaltstack(uss, uoss, regs->r1);
}

/*
 * Do a signal return; undo the signal stack.
 */
struct sigframe {
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	unsigned long tramp[2];	/* signal trampoline */
};

struct rt_sigframe {
	struct siginfo info;
	struct ucontext uc;
	unsigned long tramp[2];	/* signal trampoline */
};

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

#define COPY(x)		{err |= __get_user(regs->x, &sc->regs.x); }
	COPY(r0);
	COPY(r1);
	COPY(r2);	COPY(r3);	COPY(r4);	COPY(r5);
	COPY(r6);	COPY(r7);	COPY(r8);	COPY(r9);
	COPY(r10);	COPY(r11);	COPY(r12);	COPY(r13);
	COPY(r14);	COPY(r15);	COPY(r16);	COPY(r17);
	COPY(r18);	COPY(r19);	COPY(r20);	COPY(r21);
	COPY(r22);	COPY(r23);	COPY(r24);	COPY(r25);
	COPY(r26);	COPY(r27);	COPY(r28);	COPY(r29);
	COPY(r30);	COPY(r31);
	COPY(pc);	COPY(ear);	COPY(esr);	COPY(fsr);
#undef COPY

	*rval_p = regs->r3;

	return err;
}

asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_sigframe __user *frame =
		(struct rt_sigframe __user *)(regs->r1 + STATE_SAVE_ARG_SPACE);

	sigset_t set;
	int rval;

	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, &rval))
		goto badframe;

	/* It is more difficult to avoid calling this function than to
	 call it and ignore errors. */
	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1))
		goto badframe;

	return rval;

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->regs.x); }
	COPY(r0);
	COPY(r1);
	COPY(r2);	COPY(r3);	COPY(r4);	COPY(r5);
	COPY(r6);	COPY(r7);	COPY(r8);	COPY(r9);
	COPY(r10);	COPY(r11);	COPY(r12);	COPY(r13);
	COPY(r14);	COPY(r15);	COPY(r16);	COPY(r17);
	COPY(r18);	COPY(r19);	COPY(r20);	COPY(r21);
	COPY(r22);	COPY(r23);	COPY(r24);	COPY(r25);
	COPY(r26);	COPY(r27);	COPY(r28);	COPY(r29);
	COPY(r30);	COPY(r31);
	COPY(pc);	COPY(ear);	COPY(esr);	COPY(fsr);
#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, struct pt_regs *regs, size_t frame_size)
{
	/* Default to using normal stack */
	unsigned long sp = regs->r1;

	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp))
		sp = current->sas_ss_sp + current->sas_ss_size;

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

static void 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, 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;

	if (info)
		err |= copy_siginfo_to_user(&frame->info, info);

	/* Create the ucontext. */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user((void *)current->sas_ss_sp,
			&frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->r1),
			&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));

	/* Set up to return from userspace. If provided, use a stub
	 already in userspace. */
	/* minus 8 is offset to cater for "rtsd r15,8" */
	/* addi r12, r0, __NR_sigreturn */
	err |= __put_user(0x31800000 | __NR_rt_sigreturn ,
			frame->tramp + 0);
	/* brki r14, 0x8 */
	err |= __put_user(0xb9cc0008, frame->tramp + 1);

	/* Return from sighandler will jump to the tramp.
	 Negative 8 offset because return is rtsd r15, 8 */
	regs->r15 = ((unsigned long)frame->tramp)-8;

	__invalidate_cache_sigtramp((unsigned long)frame->tramp);

	if (err)
		goto give_sigsegv;

	/* Set up registers for signal handler */
	regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE;

	/* Signal handler args: */
	regs->r5 = signal; /* arg 0: signum */
	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	/* Offset to handle microblaze rtid r14, 0 */
	regs->pc = (unsigned long)ka->sa.sa_handler;

	set_fs(USER_DS);

#ifdef DEBUG_SIG
	printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
		current->comm, current->pid, frame, regs->pc);
#endif

	return;

give_sigsegv:
	if (sig == SIGSEGV)
		ka->sa.sa_handler = SIG_DFL;
	force_sig(SIGSEGV, current);
}

/* Handle restarting system calls */
static inline void
handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
{
	switch (regs->r3) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
		if (!has_handler)
			goto do_restart;
		regs->r3 = -EINTR;
		break;
	case -ERESTARTSYS:
		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
			regs->r3 = -EINTR;
			break;
	}
	/* fallthrough */
	case -ERESTARTNOINTR:
do_restart:
		/* offset of 4 bytes to re-execute trap (brki) instruction */
#ifndef CONFIG_MMU
		regs->pc -= 4;
#else
		/* offset of 8 bytes required = 4 for rtbd
		   offset, plus 4 for size of
			"brki r14,8"
		   instruction. */
		regs->pc -= 8;
#endif
		break;
	}
}

/*
 * 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)
{
	/* Set up the stack frame */
	if (ka->sa.sa_flags & SA_SIGINFO)
		setup_rt_frame(sig, ka, info, oldset, regs);
	else
		setup_rt_frame(sig, ka, NULL, oldset, regs);

	if (ka->sa.sa_flags & SA_ONESHOT)
		ka->sa.sa_handler = SIG_DFL;

	if (!(ka->sa.sa_flags & SA_NODEFER)) {
		spin_lock_irq(&current->sighand->siglock);
		sigorsets(&current->blocked,
				&current->blocked, &ka->sa.sa_mask);
		sigaddset(&current->blocked, sig);
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}
	return 1;
}

/*
 * 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.
 *
 * Note that we go through the signals twice: once to check the signals that
 * the kernel can handle, and then we build all the user-level signal handling
 * stack-frames in one go after that.
 */
int do_signal(struct pt_regs *regs, sigset_t *oldset, int in_syscall)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
#ifdef DEBUG_SIG
	printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall);
	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
			regs->r12, current_thread_info()->flags);
#endif
	/*
	 * 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 (kernel_mode(regs))
		return 1;

	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		/* Whee! Actually deliver the signal. */
		if (in_syscall)
			handle_restart(regs, &ka, 1);
		if (handle_signal(signr, &ka, &info, oldset, regs)) {
			/*
			 * A signal was successfully delivered; the saved
			 * sigmask will have been stored in the signal frame,
			 * and will be restored by sigreturn, so we can simply
			 * clear the TS_RESTORE_SIGMASK flag.
			 */
			current_thread_info()->status &=
			    ~TS_RESTORE_SIGMASK;
		}
		return 1;
	}

	if (in_syscall)
		handle_restart(regs, NULL, 0);

	/*
	 * If there's no signal to deliver, we just put the saved sigmask
	 * back.
	 */
	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
		current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}

	/* Did we come from a system call? */
	return 0;
}
Commit	Line	Data
2148daa9 MS	1	/*
	2	* Signal handling
	3	*
	4	* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
	5	* Copyright (C) 2008-2009 PetaLogix
	6	* Copyright (C) 2003,2004 John Williams <jwilliams@itee.uq.edu.au>
	7	* Copyright (C) 2001 NEC Corporation
	8	* Copyright (C) 2001 Miles Bader <miles@gnu.org>
	9	* Copyright (C) 1999,2000 Niibe Yutaka & Kaz Kojima
	10	* Copyright (C) 1991,1992 Linus Torvalds
	11	*
	12	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	13	*
	14	* This file was was derived from the sh version, arch/sh/kernel/signal.c
	15	*
	16	* This file is subject to the terms and conditions of the GNU General
	17	* Public License. See the file COPYING in the main directory of this
	18	* archive for more details.
	19	*/
	20
	21	#include <linux/sched.h>
	22	#include <linux/mm.h>
	23	#include <linux/smp.h>
	24	#include <linux/smp_lock.h>
	25	#include <linux/kernel.h>
	26	#include <linux/signal.h>
	27	#include <linux/errno.h>
	28	#include <linux/wait.h>
	29	#include <linux/ptrace.h>
	30	#include <linux/unistd.h>
	31	#include <linux/stddef.h>
	32	#include <linux/personality.h>
	33	#include <linux/percpu.h>
	34	#include <linux/linkage.h>
	35	#include <asm/entry.h>
	36	#include <asm/ucontext.h>
	37	#include <linux/uaccess.h>
	38	#include <asm/pgtable.h>
	39	#include <asm/pgalloc.h>
2148daa9 MS	40	#include <linux/syscalls.h>
	41	#include <asm/cacheflush.h>
	42	#include <asm/syscalls.h>
	43
	44	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	45
	46	asmlinkage int do_signal(struct pt_regs regs, sigset_t oldset, int in_sycall);
	47
2148daa9	48
e513588f	49	asmlinkage long
2148daa9 MS	50	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	51	struct pt_regs *regs)
	52	{
	53	return do_sigaltstack(uss, uoss, regs->r1);
	54	}
	55
	56	/*
	57	* Do a signal return; undo the signal stack.
	58	*/
2148daa9 MS	59	struct sigframe {
	60	struct sigcontext sc;
	61	unsigned long extramask[_NSIG_WORDS-1];
	62	unsigned long tramp[2]; /* signal trampoline */
	63	};
	64
	65	struct rt_sigframe {
	66	struct siginfo info;
	67	struct ucontext uc;
	68	unsigned long tramp[2]; /* signal trampoline */
	69	};
	70
353b431b AB	71	static int restore_sigcontext(struct pt_regs *regs,
353b431b AB	72	struct sigcontext __user sc, int rval_p)
2148daa9 MS	73	{
	74	unsigned int err = 0;
	75
	76	#define COPY(x) {err \|= __get_user(regs->x, &sc->regs.x); }
	77	COPY(r0);
	78	COPY(r1);
	79	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	80	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	81	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	82	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	83	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	84	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	85	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	86	COPY(r30); COPY(r31);
	87	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	88	#undef COPY
	89
	90	*rval_p = regs->r3;
	91
	92	return err;
	93	}
	94
3183e068	95	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
2148daa9	96	{
353b431b AB	97	struct rt_sigframe __user *frame =
353b431b AB	98	(struct rt_sigframe __user *)(regs->r1 + STATE_SAVE_ARG_SPACE);
2921e2bd	99
2148daa9	100	sigset_t set;
2148daa9 MS	101	int rval;
	102
	103	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	104	goto badframe;
	105
	106	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	107	goto badframe;
	108
	109	sigdelsetmask(&set, ~_BLOCKABLE);
	110	spin_lock_irq(&current->sighand->siglock);
	111	current->blocked = set;
	112	recalc_sigpending();
	113	spin_unlock_irq(&current->sighand->siglock);
	114
	115	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
	116	goto badframe;
	117
2148daa9 MS	118	/* It is more difficult to avoid calling this function than to
2148daa9 MS	119	call it and ignore errors. */
353b431b AB	120	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1))
353b431b AB	121	goto badframe;
2148daa9 MS	122
	123	return rval;
	124
	125	badframe:
	126	force_sig(SIGSEGV, current);
	127	return 0;
	128	}
	129
	130	/*
	131	* Set up a signal frame.
	132	*/
	133
	134	static int
353b431b	135	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
2148daa9 MS	136	unsigned long mask)
	137	{
	138	int err = 0;
	139
	140	#define COPY(x) {err \|= __put_user(regs->x, &sc->regs.x); }
	141	COPY(r0);
	142	COPY(r1);
	143	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	144	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	145	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	146	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	147	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	148	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	149	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	150	COPY(r30); COPY(r31);
	151	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	152	#undef COPY
	153
	154	err \|= __put_user(mask, &sc->oldmask);
	155
	156	return err;
	157	}
	158
	159	/*
	160	* Determine which stack to use..
	161	*/
353b431b	162	static inline void __user *
2148daa9 MS	163	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	164	{
	165	/* Default to using normal stack */
	166	unsigned long sp = regs->r1;
	167
	168	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp))
	169	sp = current->sas_ss_sp + current->sas_ss_size;
	170
353b431b	171	return (void __user *)((sp - frame_size) & -8UL);
2148daa9 MS	172	}
2148daa9 MS	173
2148daa9 MS	174	static void setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
	175	sigset_t set, struct pt_regs regs)
	176	{
353b431b	177	struct rt_sigframe __user *frame;
2148daa9 MS	178	int err = 0;
	179	int signal;
	180
	181	frame = get_sigframe(ka, regs, sizeof(*frame));
	182
	183	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	184	goto give_sigsegv;
	185
	186	signal = current_thread_info()->exec_domain
	187	&& current_thread_info()->exec_domain->signal_invmap
	188	&& sig < 32
	189	? current_thread_info()->exec_domain->signal_invmap[sig]
	190	: sig;
	191
a6029d1c MS	192	if (info)
a6029d1c MS	193	err \|= copy_siginfo_to_user(&frame->info, info);
2148daa9 MS	194
	195	/* Create the ucontext. */
	196	err \|= __put_user(0, &frame->uc.uc_flags);
	197	err \|= __put_user(0, &frame->uc.uc_link);
	198	err \|= __put_user((void *)current->sas_ss_sp,
	199	&frame->uc.uc_stack.ss_sp);
	200	err \|= __put_user(sas_ss_flags(regs->r1),
	201	&frame->uc.uc_stack.ss_flags);
	202	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	203	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	204	regs, set->sig[0]);
	205	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	206
	207	/* Set up to return from userspace. If provided, use a stub
	208	already in userspace. */
	209	/* minus 8 is offset to cater for "rtsd r15,8" */
3183e068 AB	210	/* addi r12, r0, __NR_sigreturn */
	211	err \|= __put_user(0x31800000 \| __NR_rt_sigreturn ,
	212	frame->tramp + 0);
	213	/* brki r14, 0x8 */
	214	err \|= __put_user(0xb9cc0008, frame->tramp + 1);
	215
	216	/* Return from sighandler will jump to the tramp.
	217	Negative 8 offset because return is rtsd r15, 8 */
	218	regs->r15 = ((unsigned long)frame->tramp)-8;
	219
	220	__invalidate_cache_sigtramp((unsigned long)frame->tramp);
2148daa9 MS	221
	222	if (err)
	223	goto give_sigsegv;
	224
	225	/* Set up registers for signal handler */
2921e2bd MS	226	regs->r1 = (unsigned long) frame - STATE_SAVE_ARG_SPACE;
2921e2bd MS	227
2148daa9 MS	228	/* Signal handler args: */
	229	regs->r5 = signal; /* arg 0: signum */
	230	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	231	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	232	/* Offset to handle microblaze rtid r14, 0 */
	233	regs->pc = (unsigned long)ka->sa.sa_handler;
	234
	235	set_fs(USER_DS);
	236
	237	#ifdef DEBUG_SIG
	238	printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
	239	current->comm, current->pid, frame, regs->pc);
	240	#endif
	241
	242	return;
	243
	244	give_sigsegv:
	245	if (sig == SIGSEGV)
	246	ka->sa.sa_handler = SIG_DFL;
	247	force_sig(SIGSEGV, current);
	248	}
	249
	250	/* Handle restarting system calls */
	251	static inline void
	252	handle_restart(struct pt_regs regs, struct k_sigaction ka, int has_handler)
	253	{
	254	switch (regs->r3) {
	255	case -ERESTART_RESTARTBLOCK:
	256	case -ERESTARTNOHAND:
	257	if (!has_handler)
	258	goto do_restart;
	259	regs->r3 = -EINTR;
	260	break;
	261	case -ERESTARTSYS:
	262	if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
	263	regs->r3 = -EINTR;
	264	break;
	265	}
	266	/* fallthrough */
	267	case -ERESTARTNOINTR:
	268	do_restart:
	269	/* offset of 4 bytes to re-execute trap (brki) instruction */
8b28626a	270	#ifndef CONFIG_MMU
2148daa9	271	regs->pc -= 4;
8b28626a MS	272	#else
	273	/* offset of 8 bytes required = 4 for rtbd
	274	offset, plus 4 for size of
	275	"brki r14,8"
	276	instruction. */
	277	regs->pc -= 8;
	278	#endif
2148daa9 MS	279	break;
	280	}
	281	}
	282
	283	/*
	284	* OK, we're invoking a handler
	285	*/
	286
3183e068	287	static int
2148daa9 MS	288	handle_signal(unsigned long sig, struct k_sigaction *ka,
	289	siginfo_t info, sigset_t oldset, struct pt_regs *regs)
	290	{
	291	/* Set up the stack frame */
	292	if (ka->sa.sa_flags & SA_SIGINFO)
	293	setup_rt_frame(sig, ka, info, oldset, regs);
	294	else
a6029d1c	295	setup_rt_frame(sig, ka, NULL, oldset, regs);
2148daa9 MS	296
	297	if (ka->sa.sa_flags & SA_ONESHOT)
	298	ka->sa.sa_handler = SIG_DFL;
	299
	300	if (!(ka->sa.sa_flags & SA_NODEFER)) {
	301	spin_lock_irq(&current->sighand->siglock);
	302	sigorsets(&current->blocked,
	303	&current->blocked, &ka->sa.sa_mask);
	304	sigaddset(&current->blocked, sig);
	305	recalc_sigpending();
	306	spin_unlock_irq(&current->sighand->siglock);
	307	}
3183e068	308	return 1;
2148daa9 MS	309	}
	310
	311	/*
	312	* Note that 'init' is a special process: it doesn't get signals it doesn't
	313	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	314	* mistake.
	315	*
	316	* Note that we go through the signals twice: once to check the signals that
	317	* the kernel can handle, and then we build all the user-level signal handling
	318	* stack-frames in one go after that.
	319	*/
	320	int do_signal(struct pt_regs regs, sigset_t oldset, int in_syscall)
	321	{
	322	siginfo_t info;
	323	int signr;
	324	struct k_sigaction ka;
	325	#ifdef DEBUG_SIG
	326	printk(KERN_INFO "do signal: %p %p %d\n", regs, oldset, in_syscall);
	327	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
	328	regs->r12, current_thread_info()->flags);
	329	#endif
	330	/*
	331	* We want the common case to go fast, which
	332	* is why we may in certain cases get here from
	333	* kernel mode. Just return without doing anything
	334	* if so.
	335	*/
	336	if (kernel_mode(regs))
	337	return 1;
	338
3183e068 AB	339	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
	340	oldset = &current->saved_sigmask;
	341	else
2148daa9 MS	342	oldset = &current->blocked;
	343
	344	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	345	if (signr > 0) {
	346	/* Whee! Actually deliver the signal. */
	347	if (in_syscall)
	348	handle_restart(regs, &ka, 1);
3183e068 AB	349	if (handle_signal(signr, &ka, &info, oldset, regs)) {
	350	/*
	351	* A signal was successfully delivered; the saved
	352	* sigmask will have been stored in the signal frame,
	353	* and will be restored by sigreturn, so we can simply
	354	* clear the TS_RESTORE_SIGMASK flag.
	355	*/
	356	current_thread_info()->status &=
	357	~TS_RESTORE_SIGMASK;
	358	}
2148daa9 MS	359	return 1;
	360	}
	361
	362	if (in_syscall)
	363	handle_restart(regs, NULL, 0);
	364
3183e068 AB	365	/*
	366	* If there's no signal to deliver, we just put the saved sigmask
	367	* back.
	368	*/
	369	if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
	370	current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
	371	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	372	}
	373
2148daa9 MS	374	/* Did we come from a system call? */
	375	return 0;
	376	}