[deliverable/linux.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/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 <linux/tracehook.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>

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);

	sigset_t set;
	int rval;

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

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;

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

	set_current_blocked(&set);

	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) == -EFAULT)
		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 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;
	unsigned long address = 0;
#ifdef CONFIG_MMU
	pmd_t *pmdp;
	pte_t *ptep;
#endif

	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(NULL, &frame->uc.uc_link);
	err |= __put_user((void __user *)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;

	address = ((unsigned long)frame->tramp);
#ifdef CONFIG_MMU
	pmdp = pmd_offset(pud_offset(
			pgd_offset(current->mm, address),
					address), address);

	preempt_disable();
	ptep = pte_offset_map(pmdp, address);
	if (pte_present(*ptep)) {
		address = (unsigned long) page_address(pte_page(*ptep));
		/* MS: I need add offset in page */
		address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
		/* MS address is virtual */
		address = virt_to_phys(address);
		invalidate_icache_range(address, address + 8);
		flush_dcache_range(address, address + 8);
	}
	pte_unmap(ptep);
	preempt_enable();
#else
	flush_icache_range(address, address + 8);
	flush_dcache_range(address, address + 8);
#endif
	if (err)
		goto give_sigsegv;

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

	/* 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 0;

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

/* 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 */
		regs->pc -= 4;
		break;
	}
}

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

static void
handle_signal(unsigned long sig, struct k_sigaction *ka,
		siginfo_t *info, struct pt_regs *regs)
{
	sigset_t *oldset = sigmask_to_save();
	int ret;

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

	if (ret)
		return;

	signal_delivered(sig, info, ka, regs,
			test_thread_flag(TIF_SINGLESTEP));
}

/*
 * 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.
 */
static void do_signal(struct pt_regs *regs, int in_syscall)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
#ifdef DEBUG_SIG
	printk(KERN_INFO "do signal: %p %d\n", regs, in_syscall);
	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
			regs->r12, current_thread_info()->flags);
#endif

	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);
		handle_signal(signr, &ka, &info, regs);
		return;
	}

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

	/*
	 * If there's no signal to deliver, we just put the saved sigmask
	 * back.
	 */
	restore_saved_sigmask();
}

void do_notify_resume(struct pt_regs *regs, int in_syscall)
{
	/*
	 * 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;

	if (test_thread_flag(TIF_SIGPENDING))
		do_signal(regs, in_syscall);

	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
		tracehook_notify_resume(regs);
}
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>
2148daa9 MS	24	#include <linux/kernel.h>
	25	#include <linux/signal.h>
	26	#include <linux/errno.h>
	27	#include <linux/wait.h>
	28	#include <linux/ptrace.h>
	29	#include <linux/unistd.h>
	30	#include <linux/stddef.h>
	31	#include <linux/personality.h>
	32	#include <linux/percpu.h>
	33	#include <linux/linkage.h>
969a9616	34	#include <linux/tracehook.h>
2148daa9 MS	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
e513588f	44	asmlinkage long
2148daa9 MS	45	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	46	struct pt_regs *regs)
	47	{
	48	return do_sigaltstack(uss, uoss, regs->r1);
	49	}
	50
	51	/*
	52	* Do a signal return; undo the signal stack.
	53	*/
2148daa9 MS	54	struct sigframe {
	55	struct sigcontext sc;
	56	unsigned long extramask[_NSIG_WORDS-1];
	57	unsigned long tramp[2]; /* signal trampoline */
	58	};
	59
	60	struct rt_sigframe {
	61	struct siginfo info;
	62	struct ucontext uc;
	63	unsigned long tramp[2]; /* signal trampoline */
	64	};
	65
353b431b AB	66	static int restore_sigcontext(struct pt_regs *regs,
353b431b AB	67	struct sigcontext __user sc, int rval_p)
2148daa9 MS	68	{
	69	unsigned int err = 0;
	70
	71	#define COPY(x) {err \|= __get_user(regs->x, &sc->regs.x); }
	72	COPY(r0);
	73	COPY(r1);
	74	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	75	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	76	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	77	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	78	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	79	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	80	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	81	COPY(r30); COPY(r31);
	82	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	83	#undef COPY
	84
	85	*rval_p = regs->r3;
	86
	87	return err;
	88	}
	89
3183e068	90	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
2148daa9	91	{
353b431b	92	struct rt_sigframe __user *frame =
6e83557c	93	(struct rt_sigframe __user *)(regs->r1);
2921e2bd	94
2148daa9	95	sigset_t set;
2148daa9 MS	96	int rval;
2148daa9 MS	97
58e4257b AV	98	/* Always make any pending restarted system calls return -EINTR */
	99	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	100
2148daa9 MS	101	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	102	goto badframe;
	103
	104	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	105	goto badframe;
	106
60c59751	107	set_current_blocked(&set);
2148daa9 MS	108
	109	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
	110	goto badframe;
	111
2148daa9 MS	112	/* It is more difficult to avoid calling this function than to
2148daa9 MS	113	call it and ignore errors. */
02232f8d	114	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1) == -EFAULT)
353b431b	115	goto badframe;
2148daa9 MS	116
	117	return rval;
	118
	119	badframe:
	120	force_sig(SIGSEGV, current);
	121	return 0;
	122	}
	123
	124	/*
	125	* Set up a signal frame.
	126	*/
	127
	128	static int
353b431b	129	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
2148daa9 MS	130	unsigned long mask)
	131	{
	132	int err = 0;
	133
	134	#define COPY(x) {err \|= __put_user(regs->x, &sc->regs.x); }
	135	COPY(r0);
	136	COPY(r1);
	137	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	138	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	139	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	140	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	141	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	142	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	143	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	144	COPY(r30); COPY(r31);
	145	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	146	#undef COPY
	147
	148	err \|= __put_user(mask, &sc->oldmask);
	149
	150	return err;
	151	}
	152
	153	/*
	154	* Determine which stack to use..
	155	*/
353b431b	156	static inline void __user *
2148daa9 MS	157	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	158	{
	159	/* Default to using normal stack */
	160	unsigned long sp = regs->r1;
	161
	162	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp))
	163	sp = current->sas_ss_sp + current->sas_ss_size;
	164
353b431b	165	return (void __user *)((sp - frame_size) & -8UL);
2148daa9 MS	166	}
2148daa9 MS	167
bcb8c8d0	168	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
2148daa9 MS	169	sigset_t set, struct pt_regs regs)
2148daa9 MS	170	{
353b431b	171	struct rt_sigframe __user *frame;
2148daa9 MS	172	int err = 0;
2148daa9 MS	173	int signal;
2ee2ff87 MS	174	unsigned long address = 0;
	175	#ifdef CONFIG_MMU
	176	pmd_t *pmdp;
	177	pte_t *ptep;
	178	#endif
2148daa9 MS	179
	180	frame = get_sigframe(ka, regs, sizeof(*frame));
	181
	182	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	183	goto give_sigsegv;
	184
	185	signal = current_thread_info()->exec_domain
	186	&& current_thread_info()->exec_domain->signal_invmap
	187	&& sig < 32
	188	? current_thread_info()->exec_domain->signal_invmap[sig]
	189	: sig;
	190
a6029d1c MS	191	if (info)
a6029d1c MS	192	err \|= copy_siginfo_to_user(&frame->info, info);
2148daa9 MS	193
	194	/* Create the ucontext. */
	195	err \|= __put_user(0, &frame->uc.uc_flags);
2cfedb97 MS	196	err \|= __put_user(NULL, &frame->uc.uc_link);
2cfedb97 MS	197	err \|= __put_user((void __user *)current->sas_ss_sp,
2148daa9 MS	198	&frame->uc.uc_stack.ss_sp);
	199	err \|= __put_user(sas_ss_flags(regs->r1),
	200	&frame->uc.uc_stack.ss_flags);
	201	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	202	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	203	regs, set->sig[0]);
	204	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	205
	206	/* Set up to return from userspace. If provided, use a stub
	207	already in userspace. */
	208	/* minus 8 is offset to cater for "rtsd r15,8" */
3183e068 AB	209	/* addi r12, r0, __NR_sigreturn */
	210	err \|= __put_user(0x31800000 \| __NR_rt_sigreturn ,
	211	frame->tramp + 0);
	212	/* brki r14, 0x8 */
	213	err \|= __put_user(0xb9cc0008, frame->tramp + 1);
	214
	215	/* Return from sighandler will jump to the tramp.
	216	Negative 8 offset because return is rtsd r15, 8 */
	217	regs->r15 = ((unsigned long)frame->tramp)-8;
	218
2ee2ff87 MS	219	address = ((unsigned long)frame->tramp);
	220	#ifdef CONFIG_MMU
	221	pmdp = pmd_offset(pud_offset(
	222	pgd_offset(current->mm, address),
	223	address), address);
	224
	225	preempt_disable();
	226	ptep = pte_offset_map(pmdp, address);
	227	if (pte_present(*ptep)) {
	228	address = (unsigned long) page_address(pte_page(*ptep));
	229	/* MS: I need add offset in page */
	230	address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
	231	/* MS address is virtual */
	232	address = virt_to_phys(address);
	233	invalidate_icache_range(address, address + 8);
	234	flush_dcache_range(address, address + 8);
	235	}
	236	pte_unmap(ptep);
	237	preempt_enable();
	238	#else
	239	flush_icache_range(address, address + 8);
	240	flush_dcache_range(address, address + 8);
	241	#endif
2148daa9 MS	242	if (err)
	243	goto give_sigsegv;
	244
	245	/* Set up registers for signal handler */
6e83557c	246	regs->r1 = (unsigned long) frame;
2921e2bd	247
2148daa9 MS	248	/* Signal handler args: */
	249	regs->r5 = signal; /* arg 0: signum */
	250	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	251	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	252	/* Offset to handle microblaze rtid r14, 0 */
	253	regs->pc = (unsigned long)ka->sa.sa_handler;
	254
	255	set_fs(USER_DS);
	256
	257	#ifdef DEBUG_SIG
	258	printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
	259	current->comm, current->pid, frame, regs->pc);
	260	#endif
	261
bcb8c8d0	262	return 0;
2148daa9 MS	263
2148daa9 MS	264	give_sigsegv:
de8f2ddd	265	force_sigsegv(sig, current);
bcb8c8d0	266	return -EFAULT;
2148daa9 MS	267	}
	268
	269	/* Handle restarting system calls */
	270	static inline void
	271	handle_restart(struct pt_regs regs, struct k_sigaction ka, int has_handler)
	272	{
	273	switch (regs->r3) {
	274	case -ERESTART_RESTARTBLOCK:
	275	case -ERESTARTNOHAND:
	276	if (!has_handler)
	277	goto do_restart;
	278	regs->r3 = -EINTR;
	279	break;
	280	case -ERESTARTSYS:
	281	if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
	282	regs->r3 = -EINTR;
	283	break;
	284	}
	285	/* fallthrough */
	286	case -ERESTARTNOINTR:
	287	do_restart:
	288	/* offset of 4 bytes to re-execute trap (brki) instruction */
	289	regs->pc -= 4;
	290	break;
	291	}
	292	}
	293
	294	/*
	295	* OK, we're invoking a handler
	296	*/
	297
a610d6e6	298	static void
2148daa9	299	handle_signal(unsigned long sig, struct k_sigaction *ka,
b7f9a11a	300	siginfo_t info, struct pt_regs regs)
2148daa9	301	{
b7f9a11a	302	sigset_t *oldset = sigmask_to_save();
bcb8c8d0 MF	303	int ret;
bcb8c8d0 MF	304
2148daa9 MS	305	/* Set up the stack frame */
2148daa9 MS	306	if (ka->sa.sa_flags & SA_SIGINFO)
bcb8c8d0	307	ret = setup_rt_frame(sig, ka, info, oldset, regs);
2148daa9	308	else
bcb8c8d0 MF	309	ret = setup_rt_frame(sig, ka, NULL, oldset, regs);
	310
	311	if (ret)
a610d6e6	312	return;
2148daa9	313
7f1c6168 AV	314	signal_delivered(sig, info, ka, regs,
7f1c6168 AV	315	test_thread_flag(TIF_SINGLESTEP));
2148daa9 MS	316	}
	317
	318	/*
	319	* Note that 'init' is a special process: it doesn't get signals it doesn't
	320	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	321	* mistake.
	322	*
	323	* Note that we go through the signals twice: once to check the signals that
	324	* the kernel can handle, and then we build all the user-level signal handling
	325	* stack-frames in one go after that.
	326	*/
83140191	327	static void do_signal(struct pt_regs *regs, int in_syscall)
2148daa9 MS	328	{
	329	siginfo_t info;
	330	int signr;
	331	struct k_sigaction ka;
	332	#ifdef DEBUG_SIG
83140191	333	printk(KERN_INFO "do signal: %p %d\n", regs, in_syscall);
2148daa9 MS	334	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
	335	regs->r12, current_thread_info()->flags);
	336	#endif
2148daa9	337
2148daa9 MS	338	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	339	if (signr > 0) {
	340	/* Whee! Actually deliver the signal. */
	341	if (in_syscall)
	342	handle_restart(regs, &ka, 1);
a610d6e6	343	handle_signal(signr, &ka, &info, regs);
83140191	344	return;
2148daa9 MS	345	}
	346
	347	if (in_syscall)
	348	handle_restart(regs, NULL, 0);
	349
3183e068 AB	350	/*
	351	* If there's no signal to deliver, we just put the saved sigmask
	352	* back.
	353	*/
51a7b448	354	restore_saved_sigmask();
2148daa9	355	}
969a9616	356
83140191	357	void do_notify_resume(struct pt_regs *regs, int in_syscall)
969a9616 AV	358	{
	359	/*
	360	* We want the common case to go fast, which
	361	* is why we may in certain cases get here from
	362	* kernel mode. Just return without doing anything
	363	* if so.
	364	*/
	365	if (kernel_mode(regs))
	366	return;
	367
	368	if (test_thread_flag(TIF_SIGPENDING))
83140191	369	do_signal(regs, in_syscall);
969a9616	370
a42c6ded	371	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
969a9616	372	tracehook_notify_resume(regs);
969a9616	373	}