[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>

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

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;

	sigdelsetmask(&set, ~_BLOCKABLE);
	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))
		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);

	/* the tracer may want to single-step inside the handler */
	if (test_thread_flag(TIF_SINGLESTEP))
		ptrace_notify(SIGTRAP);

#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 */
#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)
{
	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 ret;

	block_sigmask(ka, sig);

	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.
 *
 * 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;
	sigset_t *oldset;
#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

	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;
	}

	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
	44	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	45
e513588f	46	asmlinkage long
2148daa9 MS	47	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	48	struct pt_regs *regs)
	49	{
	50	return do_sigaltstack(uss, uoss, regs->r1);
	51	}
	52
	53	/*
	54	* Do a signal return; undo the signal stack.
	55	*/
2148daa9 MS	56	struct sigframe {
	57	struct sigcontext sc;
	58	unsigned long extramask[_NSIG_WORDS-1];
	59	unsigned long tramp[2]; /* signal trampoline */
	60	};
	61
	62	struct rt_sigframe {
	63	struct siginfo info;
	64	struct ucontext uc;
	65	unsigned long tramp[2]; /* signal trampoline */
	66	};
	67
353b431b AB	68	static int restore_sigcontext(struct pt_regs *regs,
353b431b AB	69	struct sigcontext __user sc, int rval_p)
2148daa9 MS	70	{
	71	unsigned int err = 0;
	72
	73	#define COPY(x) {err \|= __get_user(regs->x, &sc->regs.x); }
	74	COPY(r0);
	75	COPY(r1);
	76	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	77	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	78	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	79	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	80	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	81	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	82	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	83	COPY(r30); COPY(r31);
	84	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	85	#undef COPY
	86
	87	*rval_p = regs->r3;
	88
	89	return err;
	90	}
	91
3183e068	92	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
2148daa9	93	{
353b431b	94	struct rt_sigframe __user *frame =
6e83557c	95	(struct rt_sigframe __user *)(regs->r1);
2921e2bd	96
2148daa9	97	sigset_t set;
2148daa9 MS	98	int rval;
2148daa9 MS	99
58e4257b AV	100	/* Always make any pending restarted system calls return -EINTR */
	101	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	102
2148daa9 MS	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);
60c59751	110	set_current_blocked(&set);
2148daa9 MS	111
	112	if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
	113	goto badframe;
	114
2148daa9 MS	115	/* It is more difficult to avoid calling this function than to
2148daa9 MS	116	call it and ignore errors. */
353b431b AB	117	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->r1))
353b431b AB	118	goto badframe;
2148daa9 MS	119
	120	return rval;
	121
	122	badframe:
	123	force_sig(SIGSEGV, current);
	124	return 0;
	125	}
	126
	127	/*
	128	* Set up a signal frame.
	129	*/
	130
	131	static int
353b431b	132	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
2148daa9 MS	133	unsigned long mask)
	134	{
	135	int err = 0;
	136
	137	#define COPY(x) {err \|= __put_user(regs->x, &sc->regs.x); }
	138	COPY(r0);
	139	COPY(r1);
	140	COPY(r2); COPY(r3); COPY(r4); COPY(r5);
	141	COPY(r6); COPY(r7); COPY(r8); COPY(r9);
	142	COPY(r10); COPY(r11); COPY(r12); COPY(r13);
	143	COPY(r14); COPY(r15); COPY(r16); COPY(r17);
	144	COPY(r18); COPY(r19); COPY(r20); COPY(r21);
	145	COPY(r22); COPY(r23); COPY(r24); COPY(r25);
	146	COPY(r26); COPY(r27); COPY(r28); COPY(r29);
	147	COPY(r30); COPY(r31);
	148	COPY(pc); COPY(ear); COPY(esr); COPY(fsr);
	149	#undef COPY
	150
	151	err \|= __put_user(mask, &sc->oldmask);
	152
	153	return err;
	154	}
	155
	156	/*
	157	* Determine which stack to use..
	158	*/
353b431b	159	static inline void __user *
2148daa9 MS	160	get_sigframe(struct k_sigaction ka, struct pt_regs regs, size_t frame_size)
	161	{
	162	/* Default to using normal stack */
	163	unsigned long sp = regs->r1;
	164
	165	if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && !on_sig_stack(sp))
	166	sp = current->sas_ss_sp + current->sas_ss_size;
	167
353b431b	168	return (void __user *)((sp - frame_size) & -8UL);
2148daa9 MS	169	}
2148daa9 MS	170
bcb8c8d0	171	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
2148daa9 MS	172	sigset_t set, struct pt_regs regs)
2148daa9 MS	173	{
353b431b	174	struct rt_sigframe __user *frame;
2148daa9 MS	175	int err = 0;
2148daa9 MS	176	int signal;
2ee2ff87 MS	177	unsigned long address = 0;
	178	#ifdef CONFIG_MMU
	179	pmd_t *pmdp;
	180	pte_t *ptep;
	181	#endif
2148daa9 MS	182
	183	frame = get_sigframe(ka, regs, sizeof(*frame));
	184
	185	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	186	goto give_sigsegv;
	187
	188	signal = current_thread_info()->exec_domain
	189	&& current_thread_info()->exec_domain->signal_invmap
	190	&& sig < 32
	191	? current_thread_info()->exec_domain->signal_invmap[sig]
	192	: sig;
	193
a6029d1c MS	194	if (info)
a6029d1c MS	195	err \|= copy_siginfo_to_user(&frame->info, info);
2148daa9 MS	196
	197	/* Create the ucontext. */
	198	err \|= __put_user(0, &frame->uc.uc_flags);
2cfedb97 MS	199	err \|= __put_user(NULL, &frame->uc.uc_link);
2cfedb97 MS	200	err \|= __put_user((void __user *)current->sas_ss_sp,
2148daa9 MS	201	&frame->uc.uc_stack.ss_sp);
	202	err \|= __put_user(sas_ss_flags(regs->r1),
	203	&frame->uc.uc_stack.ss_flags);
	204	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	205	err \|= setup_sigcontext(&frame->uc.uc_mcontext,
	206	regs, set->sig[0]);
	207	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	208
	209	/* Set up to return from userspace. If provided, use a stub
	210	already in userspace. */
	211	/* minus 8 is offset to cater for "rtsd r15,8" */
3183e068 AB	212	/* addi r12, r0, __NR_sigreturn */
	213	err \|= __put_user(0x31800000 \| __NR_rt_sigreturn ,
	214	frame->tramp + 0);
	215	/* brki r14, 0x8 */
	216	err \|= __put_user(0xb9cc0008, frame->tramp + 1);
	217
	218	/* Return from sighandler will jump to the tramp.
	219	Negative 8 offset because return is rtsd r15, 8 */
	220	regs->r15 = ((unsigned long)frame->tramp)-8;
	221
2ee2ff87 MS	222	address = ((unsigned long)frame->tramp);
	223	#ifdef CONFIG_MMU
	224	pmdp = pmd_offset(pud_offset(
	225	pgd_offset(current->mm, address),
	226	address), address);
	227
	228	preempt_disable();
	229	ptep = pte_offset_map(pmdp, address);
	230	if (pte_present(*ptep)) {
	231	address = (unsigned long) page_address(pte_page(*ptep));
	232	/* MS: I need add offset in page */
	233	address += ((unsigned long)frame->tramp) & ~PAGE_MASK;
	234	/* MS address is virtual */
	235	address = virt_to_phys(address);
	236	invalidate_icache_range(address, address + 8);
	237	flush_dcache_range(address, address + 8);
	238	}
	239	pte_unmap(ptep);
	240	preempt_enable();
	241	#else
	242	flush_icache_range(address, address + 8);
	243	flush_dcache_range(address, address + 8);
	244	#endif
2148daa9 MS	245	if (err)
	246	goto give_sigsegv;
	247
	248	/* Set up registers for signal handler */
6e83557c	249	regs->r1 = (unsigned long) frame;
2921e2bd	250
2148daa9 MS	251	/* Signal handler args: */
	252	regs->r5 = signal; /* arg 0: signum */
	253	regs->r6 = (unsigned long) &frame->info; /* arg 1: siginfo */
	254	regs->r7 = (unsigned long) &frame->uc; /* arg2: ucontext */
	255	/* Offset to handle microblaze rtid r14, 0 */
	256	regs->pc = (unsigned long)ka->sa.sa_handler;
	257
	258	set_fs(USER_DS);
	259
a01523cd MS	260	/* the tracer may want to single-step inside the handler */
	261	if (test_thread_flag(TIF_SINGLESTEP))
	262	ptrace_notify(SIGTRAP);
	263
2148daa9 MS	264	#ifdef DEBUG_SIG
	265	printk(KERN_INFO "SIG deliver (%s:%d): sp=%p pc=%08lx\n",
	266	current->comm, current->pid, frame, regs->pc);
	267	#endif
	268
bcb8c8d0	269	return 0;
2148daa9 MS	270
2148daa9 MS	271	give_sigsegv:
de8f2ddd	272	force_sigsegv(sig, current);
bcb8c8d0	273	return -EFAULT;
2148daa9 MS	274	}
	275
	276	/* Handle restarting system calls */
	277	static inline void
	278	handle_restart(struct pt_regs regs, struct k_sigaction ka, int has_handler)
	279	{
	280	switch (regs->r3) {
	281	case -ERESTART_RESTARTBLOCK:
	282	case -ERESTARTNOHAND:
	283	if (!has_handler)
	284	goto do_restart;
	285	regs->r3 = -EINTR;
	286	break;
	287	case -ERESTARTSYS:
	288	if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
	289	regs->r3 = -EINTR;
	290	break;
	291	}
	292	/* fallthrough */
	293	case -ERESTARTNOINTR:
	294	do_restart:
	295	/* offset of 4 bytes to re-execute trap (brki) instruction */
8b28626a	296	#ifndef CONFIG_MMU
2148daa9	297	regs->pc -= 4;
8b28626a MS	298	#else
	299	/* offset of 8 bytes required = 4 for rtbd
	300	offset, plus 4 for size of
	301	"brki r14,8"
	302	instruction. */
	303	regs->pc -= 8;
	304	#endif
2148daa9 MS	305	break;
	306	}
	307	}
	308
	309	/*
	310	* OK, we're invoking a handler
	311	*/
	312
3183e068	313	static int
2148daa9 MS	314	handle_signal(unsigned long sig, struct k_sigaction *ka,
	315	siginfo_t info, sigset_t oldset, struct pt_regs *regs)
	316	{
bcb8c8d0 MF	317	int ret;
bcb8c8d0 MF	318
2148daa9 MS	319	/* Set up the stack frame */
2148daa9 MS	320	if (ka->sa.sa_flags & SA_SIGINFO)
bcb8c8d0	321	ret = setup_rt_frame(sig, ka, info, oldset, regs);
2148daa9	322	else
bcb8c8d0 MF	323	ret = setup_rt_frame(sig, ka, NULL, oldset, regs);
	324
	325	if (ret)
	326	return ret;
2148daa9	327
60c59751	328	block_sigmask(ka, sig);
bcb8c8d0 MF	329
bcb8c8d0 MF	330	return 0;
2148daa9 MS	331	}
	332
	333	/*
	334	* Note that 'init' is a special process: it doesn't get signals it doesn't
	335	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	336	* mistake.
	337	*
	338	* Note that we go through the signals twice: once to check the signals that
	339	* the kernel can handle, and then we build all the user-level signal handling
	340	* stack-frames in one go after that.
	341	*/
83140191	342	static void do_signal(struct pt_regs *regs, int in_syscall)
2148daa9 MS	343	{
	344	siginfo_t info;
	345	int signr;
	346	struct k_sigaction ka;
83140191	347	sigset_t *oldset;
2148daa9	348	#ifdef DEBUG_SIG
83140191	349	printk(KERN_INFO "do signal: %p %d\n", regs, in_syscall);
2148daa9 MS	350	printk(KERN_INFO "do signal2: %lx %lx %ld [%lx]\n", regs->pc, regs->r1,
	351	regs->r12, current_thread_info()->flags);
	352	#endif
2148daa9	353
3183e068 AB	354	if (current_thread_info()->status & TS_RESTORE_SIGMASK)
	355	oldset = &current->saved_sigmask;
	356	else
2148daa9 MS	357	oldset = &current->blocked;
	358
	359	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	360	if (signr > 0) {
	361	/* Whee! Actually deliver the signal. */
	362	if (in_syscall)
	363	handle_restart(regs, &ka, 1);
bcb8c8d0	364	if (!handle_signal(signr, &ka, &info, oldset, regs)) {
3183e068 AB	365	/*
	366	* A signal was successfully delivered; the saved
	367	* sigmask will have been stored in the signal frame,
	368	* and will be restored by sigreturn, so we can simply
	369	* clear the TS_RESTORE_SIGMASK flag.
	370	*/
	371	current_thread_info()->status &=
	372	~TS_RESTORE_SIGMASK;
	373	}
83140191	374	return;
2148daa9 MS	375	}
	376
	377	if (in_syscall)
	378	handle_restart(regs, NULL, 0);
	379
3183e068 AB	380	/*
	381	* If there's no signal to deliver, we just put the saved sigmask
	382	* back.
	383	*/
51a7b448	384	restore_saved_sigmask();
2148daa9	385	}
969a9616	386
83140191	387	void do_notify_resume(struct pt_regs *regs, int in_syscall)
969a9616 AV	388	{
	389	/*
	390	* We want the common case to go fast, which
	391	* is why we may in certain cases get here from
	392	* kernel mode. Just return without doing anything
	393	* if so.
	394	*/
	395	if (kernel_mode(regs))
	396	return;
	397
	398	if (test_thread_flag(TIF_SIGPENDING))
83140191	399	do_signal(regs, in_syscall);
969a9616	400
a42c6ded	401	if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME))
969a9616	402	tracehook_notify_resume(regs);
969a9616	403	}