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

/* signal.c: FRV specific bits of signal handling
 *
 * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 * - Derived from arch/m68k/kernel/signal.c
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#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/personality.h>
#include <linux/freezer.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>

#define DEBUG_SIG 0

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

struct fdpic_func_descriptor {
	unsigned long	text;
	unsigned long	GOT;
};

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask)
{
	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	siginitset(&current->blocked, mask);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);
	return -ERESTARTNOHAND;
}

asmlinkage int sys_sigaction(int sig,
			     const struct old_sigaction __user *act,
			     struct old_sigaction __user *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

	if (act) {
		old_sigset_t mask;
		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
			return -EFAULT;
		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
		__get_user(mask, &act->sa_mask);
		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
			return -EFAULT;
		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	}

	return ret;
}

asmlinkage
int sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
{
	return do_sigaltstack(uss, uoss, __frame->sp);
}


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

struct sigframe
{
	__sigrestore_t pretcode;
	int sig;
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	uint32_t retcode[2];
};

struct rt_sigframe
{
	__sigrestore_t pretcode;
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	uint32_t retcode[2];
};

static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8)
{
	struct user_context *user = current->thread.user;
	unsigned long tbr, psr;

	tbr = user->i.tbr;
	psr = user->i.psr;
	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
		goto badframe;
	user->i.tbr = tbr;
	user->i.psr = psr;

	restore_user_regs(user);

	user->i.syscallno = -1;		/* disable syscall checks */

	*_gr8 = user->i.gr[8];
	return 0;

 badframe:
	return 1;
}

asmlinkage int sys_sigreturn(void)
{
	struct sigframe __user *frame = (struct sigframe __user *) __frame->sp;
	sigset_t set;
	int gr8;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
		goto badframe;

	if (_NSIG_WORDS > 1 &&
	    __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
		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(&frame->sc, &gr8))
		goto badframe;
	return gr8;

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

asmlinkage int sys_rt_sigreturn(void)
{
	struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp;
	sigset_t set;
	int gr8;

	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(&frame->uc.uc_mcontext, &gr8))
		goto badframe;

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

	return gr8;

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

/*
 * Set up a signal frame
 */
static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
{
	save_user_regs(current->thread.user);

	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
		goto badframe;

	/* non-iBCS2 extensions.. */
	if (__put_user(mask, &sc->sc_oldmask) < 0)
		goto badframe;

	return 0;

 badframe:
	return 1;
}

/*****************************************************************************/
/*
 * Determine which stack to use..
 */
static inline void __user *get_sigframe(struct k_sigaction *ka,
					size_t frame_size)
{
	unsigned long sp;

	/* Default to using normal stack */
	sp = __frame->sp;

	/* This is the X/Open sanctioned signal stack switching.  */
	if (ka->sa.sa_flags & SA_ONSTACK) {
		if (! sas_ss_flags(sp))
			sp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *) ((sp - frame_size) & ~7UL);

} /* end get_sigframe() */

/*****************************************************************************/
/*
 *
 */
static int setup_frame(int sig, struct k_sigaction *ka, sigset_t *set)
{
	struct sigframe __user *frame;
	int rsig;

	frame = get_sigframe(ka, sizeof(*frame));

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

	rsig = sig;
	if (sig < 32 &&
	    __current_thread_info->exec_domain &&
	    __current_thread_info->exec_domain->signal_invmap)
		rsig = __current_thread_info->exec_domain->signal_invmap[sig];

	if (__put_user(rsig, &frame->sig) < 0)
		goto give_sigsegv;

	if (setup_sigcontext(&frame->sc, set->sig[0]))
		goto give_sigsegv;

	if (_NSIG_WORDS > 1) {
		if (__copy_to_user(frame->extramask, &set->sig[1],
				   sizeof(frame->extramask)))
			goto give_sigsegv;
	}

	/* Set up to return from userspace.  If provided, use a stub
	 * already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
		if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
			goto give_sigsegv;
	}
	else {
		/* Set up the following code on the stack:
		 *	setlos	#__NR_sigreturn,gr7
		 *	tira	gr0,0
		 */
		if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
		    __put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) ||
		    __put_user(0xc0700000, &frame->retcode[1]))
			goto give_sigsegv;

		flush_icache_range((unsigned long) frame->retcode,
				   (unsigned long) (frame->retcode + 2));
	}

	/* set up registers for signal handler */
	__frame->sp   = (unsigned long) frame;
	__frame->lr   = (unsigned long) &frame->retcode;
	__frame->gr8  = sig;

	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
		__get_user(__frame->pc, &funcptr->text);
		__get_user(__frame->gr15, &funcptr->GOT);
	} else {
		__frame->pc   = (unsigned long) ka->sa.sa_handler;
		__frame->gr15 = 0;
	}

	set_fs(USER_DS);

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

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

	return 0;

give_sigsegv:
	force_sig(SIGSEGV, current);
	return -EFAULT;

} /* end setup_frame() */

/*****************************************************************************/
/*
 *
 */
static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
			  sigset_t *set)
{
	struct rt_sigframe __user *frame;
	int rsig;

	frame = get_sigframe(ka, sizeof(*frame));

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

	rsig = sig;
	if (sig < 32 &&
	    __current_thread_info->exec_domain &&
	    __current_thread_info->exec_domain->signal_invmap)
		rsig = __current_thread_info->exec_domain->signal_invmap[sig];

	if (__put_user(rsig,		&frame->sig) ||
	    __put_user(&frame->info,	&frame->pinfo) ||
	    __put_user(&frame->uc,	&frame->puc))
		goto give_sigsegv;

	if (copy_siginfo_to_user(&frame->info, info))
		goto give_sigsegv;

	/* Create the ucontext.  */
	if (__put_user(0, &frame->uc.uc_flags) ||
	    __put_user(NULL, &frame->uc.uc_link) ||
	    __put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) ||
	    __put_user(sas_ss_flags(__frame->sp), &frame->uc.uc_stack.ss_flags) ||
	    __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size))
		goto give_sigsegv;

	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
		goto give_sigsegv;

	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
		goto give_sigsegv;

	/* Set up to return from userspace.  If provided, use a stub
	 * already in userspace.  */
	if (ka->sa.sa_flags & SA_RESTORER) {
		if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
			goto give_sigsegv;
	}
	else {
		/* Set up the following code on the stack:
		 *	setlos	#__NR_sigreturn,gr7
		 *	tira	gr0,0
		 */
		if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) ||
		    __put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) ||
		    __put_user(0xc0700000, &frame->retcode[1]))
			goto give_sigsegv;

		flush_icache_range((unsigned long) frame->retcode,
				   (unsigned long) (frame->retcode + 2));
	}

	/* Set up registers for signal handler */
	__frame->sp  = (unsigned long) frame;
	__frame->lr   = (unsigned long) &frame->retcode;
	__frame->gr8 = sig;
	__frame->gr9 = (unsigned long) &frame->info;

	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
		__get_user(__frame->pc, &funcptr->text);
		__get_user(__frame->gr15, &funcptr->GOT);
	} else {
		__frame->pc   = (unsigned long) ka->sa.sa_handler;
		__frame->gr15 = 0;
	}

	set_fs(USER_DS);

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

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

	return 0;

give_sigsegv:
	force_sig(SIGSEGV, current);
	return -EFAULT;

} /* end setup_rt_frame() */

/*****************************************************************************/
/*
 * OK, we're invoking a handler
 */
static int handle_signal(unsigned long sig, siginfo_t *info,
			 struct k_sigaction *ka, sigset_t *oldset)
{
	int ret;

	/* Are we from a system call? */
	if (in_syscall(__frame)) {
		/* If so, check system call restarting.. */
		switch (__frame->gr8) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			__frame->gr8 = -EINTR;
			break;

		case -ERESTARTSYS:
			if (!(ka->sa.sa_flags & SA_RESTART)) {
				__frame->gr8 = -EINTR;
				break;
			}

			/* fallthrough */
		case -ERESTARTNOINTR:
			__frame->gr8 = __frame->orig_gr8;
			__frame->pc -= 4;
		}
	}

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

	if (ret == 0) {
		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 ret;

} /* end handle_signal() */

/*****************************************************************************/
/*
 * 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(void)
{
	struct k_sigaction ka;
	siginfo_t info;
	sigset_t *oldset;
	int signr;

	/*
	 * 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(__frame))
		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, __frame, NULL);
	if (signr > 0) {
		if (handle_signal(signr, &info, &ka, oldset) == 0) {
			/* 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 TIF_RESTORE_SIGMASK flag */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);
		}

		return;
	}

no_signal:
	/* Did we come from a system call? */
	if (__frame->syscallno >= 0) {
		/* Restart the system call - no handlers present */
		switch (__frame->gr8) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			__frame->gr8 = __frame->orig_gr8;
			__frame->pc -= 4;
			break;

		case -ERESTART_RESTARTBLOCK:
			__frame->gr8 = __NR_restart_syscall;
			__frame->pc -= 4;
			break;
		}
	}

	/* if there's no signal to deliver, we just put the saved sigmask
	 * back */
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}

} /* end do_signal() */

/*****************************************************************************/
/*
 * notification of userspace execution resumption
 * - triggered by the TIF_WORK_MASK flags
 */
asmlinkage void do_notify_resume(__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 | _TIF_RESTORE_SIGMASK))
		do_signal();

} /* end do_notify_resume() */
Commit	Line	Data
1da177e4 LT	1	/* signal.c: FRV specific bits of signal handling
	2	*
	3	* Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	* - Derived from arch/m68k/kernel/signal.c
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the License, or (at your option) any later version.
	11	*/
	12
	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/ptrace.h>
	21	#include <linux/unistd.h>
	22	#include <linux/personality.h>
7dfb7103	23	#include <linux/freezer.h>
1da177e4 LT	24	#include <asm/ucontext.h>
	25	#include <asm/uaccess.h>
	26	#include <asm/cacheflush.h>
	27
	28	#define DEBUG_SIG 0
	29
	30	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	31
	32	struct fdpic_func_descriptor {
	33	unsigned long text;
	34	unsigned long GOT;
	35	};
	36
1da177e4 LT	37	/*
	38	* Atomically swap in the new signal mask, and wait for a signal.
	39	*/
	40	asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask)
	41	{
1da177e4 LT	42	mask &= _BLOCKABLE;
1da177e4 LT	43	spin_lock_irq(&current->sighand->siglock);
a411aee9	44	current->saved_sigmask = current->blocked;
1da177e4 LT	45	siginitset(&current->blocked, mask);
	46	recalc_sigpending();
	47	spin_unlock_irq(&current->sighand->siglock);
	48
a411aee9 DH	49	current->state = TASK_INTERRUPTIBLE;
	50	schedule();
	51	set_thread_flag(TIF_RESTORE_SIGMASK);
	52	return -ERESTARTNOHAND;
1da177e4 LT	53	}
	54
	55	asmlinkage int sys_sigaction(int sig,
	56	const struct old_sigaction __user *act,
	57	struct old_sigaction __user *oact)
	58	{
	59	struct k_sigaction new_ka, old_ka;
	60	int ret;
	61
	62	if (act) {
	63	old_sigset_t mask;
	64	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	65	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
	66	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
	67	return -EFAULT;
	68	__get_user(new_ka.sa.sa_flags, &act->sa_flags);
	69	__get_user(mask, &act->sa_mask);
	70	siginitset(&new_ka.sa.sa_mask, mask);
	71	}
	72
	73	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	74
	75	if (!ret && oact) {
	76	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	77	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
	78	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
	79	return -EFAULT;
	80	__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	81	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	82	}
	83
	84	return ret;
	85	}
	86
	87	asmlinkage
	88	int sys_sigaltstack(const stack_t __user uss, stack_t __user uoss)
	89	{
	90	return do_sigaltstack(uss, uoss, __frame->sp);
	91	}
	92
	93
	94	/*
	95	* Do a signal return; undo the signal stack.
	96	*/
	97
	98	struct sigframe
	99	{
9e4d11f8	100	__sigrestore_t pretcode;
1da177e4 LT	101	int sig;
	102	struct sigcontext sc;
	103	unsigned long extramask[_NSIG_WORDS-1];
	104	uint32_t retcode[2];
	105	};
	106
	107	struct rt_sigframe
	108	{
9e4d11f8	109	__sigrestore_t pretcode;
1da177e4	110	int sig;
9e4d11f8 AV	111	struct siginfo __user *pinfo;
9e4d11f8 AV	112	void __user *puc;
1da177e4 LT	113	struct siginfo info;
	114	struct ucontext uc;
	115	uint32_t retcode[2];
	116	};
	117
	118	static int restore_sigcontext(struct sigcontext __user sc, int _gr8)
	119	{
	120	struct user_context *user = current->thread.user;
	121	unsigned long tbr, psr;
	122
	123	tbr = user->i.tbr;
	124	psr = user->i.psr;
	125	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
	126	goto badframe;
	127	user->i.tbr = tbr;
	128	user->i.psr = psr;
	129
	130	restore_user_regs(user);
	131
	132	user->i.syscallno = -1; /* disable syscall checks */
	133
	134	*_gr8 = user->i.gr[8];
	135	return 0;
	136
	137	badframe:
	138	return 1;
	139	}
	140
	141	asmlinkage int sys_sigreturn(void)
	142	{
	143	struct sigframe __user frame = (struct sigframe __user ) __frame->sp;
	144	sigset_t set;
	145	int gr8;
	146
	147	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	148	goto badframe;
	149	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
	150	goto badframe;
	151
	152	if (_NSIG_WORDS > 1 &&
	153	__copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
	154	goto badframe;
	155
	156	sigdelsetmask(&set, ~_BLOCKABLE);
	157	spin_lock_irq(&current->sighand->siglock);
	158	current->blocked = set;
	159	recalc_sigpending();
	160	spin_unlock_irq(&current->sighand->siglock);
	161
	162	if (restore_sigcontext(&frame->sc, &gr8))
	163	goto badframe;
	164	return gr8;
	165
	166	badframe:
	167	force_sig(SIGSEGV, current);
	168	return 0;
	169	}
	170
	171	asmlinkage int sys_rt_sigreturn(void)
	172	{
	173	struct rt_sigframe __user frame = (struct rt_sigframe __user ) __frame->sp;
	174	sigset_t set;
	175	int gr8;
	176
177	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
178	goto badframe;
179	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
180	goto badframe;
181
182	sigdelsetmask(&set, ~_BLOCKABLE);
183	spin_lock_irq(&current->sighand->siglock);
184	current->blocked = set;
185	recalc_sigpending();
186	spin_unlock_irq(&current->sighand->siglock);
187
188	if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
189	goto badframe;
190
191	if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT)
192	goto badframe;
193
194	return gr8;
195
196	badframe:
197	force_sig(SIGSEGV, current);
198	return 0;
199	}
200
201	/*
202	* Set up a signal frame
203	*/
204	static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
205	{
206	save_user_regs(current->thread.user);
207
208	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
209	goto badframe;
210
211	/* non-iBCS2 extensions.. */
212	if (__put_user(mask, &sc->sc_oldmask) < 0)
213	goto badframe;
214
215	return 0;
216
217	badframe:
218	return 1;
219	}
220
221	/*****************************************************************************/
222	/*
223	* Determine which stack to use..
224	*/
225	static inline void __user get_sigframe(struct k_sigaction ka,
1da177e4 LT	226	size_t frame_size)
	227	{
	228	unsigned long sp;
	229
	230	/* Default to using normal stack */
fef2b580	231	sp = __frame->sp;
1da177e4 LT	232
	233	/* This is the X/Open sanctioned signal stack switching. */
	234	if (ka->sa.sa_flags & SA_ONSTACK) {
d09042da	235	if (! sas_ss_flags(sp))
1da177e4 LT	236	sp = current->sas_ss_sp + current->sas_ss_size;
	237	}
	238
	239	return (void __user *) ((sp - frame_size) & ~7UL);
fef2b580	240
1da177e4 LT	241	} /* end get_sigframe() */
	242
	243	/*****************************************************************************/
	244	/*
	245	*
	246	*/
fef2b580	247	static int setup_frame(int sig, struct k_sigaction ka, sigset_t set)
1da177e4 LT	248	{
	249	struct sigframe __user *frame;
	250	int rsig;
	251
fef2b580	252	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	253
	254	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	255	goto give_sigsegv;
	256
	257	rsig = sig;
	258	if (sig < 32 &&
	259	__current_thread_info->exec_domain &&
	260	__current_thread_info->exec_domain->signal_invmap)
	261	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	262
	263	if (__put_user(rsig, &frame->sig) < 0)
	264	goto give_sigsegv;
	265
	266	if (setup_sigcontext(&frame->sc, set->sig[0]))
	267	goto give_sigsegv;
	268
	269	if (_NSIG_WORDS > 1) {
	270	if (__copy_to_user(frame->extramask, &set->sig[1],
	271	sizeof(frame->extramask)))
	272	goto give_sigsegv;
	273	}
	274
	275	/* Set up to return from userspace. If provided, use a stub
	276	* already in userspace. */
	277	if (ka->sa.sa_flags & SA_RESTORER) {
	278	if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
	279	goto give_sigsegv;
	280	}
	281	else {
	282	/* Set up the following code on the stack:
	283	* setlos #__NR_sigreturn,gr7
	284	* tira gr0,0
	285	*/
9e4d11f8	286	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	287	__put_user(0x8efc0000\|__NR_sigreturn, &frame->retcode[0]) \|\|
	288	__put_user(0xc0700000, &frame->retcode[1]))
	289	goto give_sigsegv;
	290
	291	flush_icache_range((unsigned long) frame->retcode,
	292	(unsigned long) (frame->retcode + 2));
	293	}
	294
	295	/* set up registers for signal handler */
fef2b580 DH	296	__frame->sp = (unsigned long) frame;
	297	__frame->lr = (unsigned long) &frame->retcode;
	298	__frame->gr8 = sig;
1da177e4	299
ecd0fa98	300	if (current->personality & FDPIC_FUNCPTRS) {
1da177e4	301	struct fdpic_func_descriptor __user *funcptr =
9e4d11f8	302	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
fef2b580 DH	303	__get_user(__frame->pc, &funcptr->text);
fef2b580 DH	304	__get_user(__frame->gr15, &funcptr->GOT);
1da177e4	305	} else {
fef2b580 DH	306	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	307	__frame->gr15 = 0;
1da177e4 LT	308	}
	309
	310	set_fs(USER_DS);
	311
8efc0ab5 DH	312	/* the tracer may want to single-step inside the handler */
	313	if (test_thread_flag(TIF_SINGLESTEP))
	314	ptrace_notify(SIGTRAP);
	315
1da177e4 LT	316	#if DEBUG_SIG
1da177e4 LT	317	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	318	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	319	frame->pretcode);
1da177e4 LT	320	#endif
1da177e4 LT	321
a411aee9	322	return 0;
1da177e4 LT	323
1da177e4 LT	324	give_sigsegv:
1da177e4	325	force_sig(SIGSEGV, current);
a411aee9	326	return -EFAULT;
8efc0ab5	327
1da177e4 LT	328	} /* end setup_frame() */
	329
	330	/*****************************************************************************/
	331	/*
	332	*
	333	*/
8efc0ab5	334	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
fef2b580	335	sigset_t *set)
1da177e4 LT	336	{
	337	struct rt_sigframe __user *frame;
	338	int rsig;
	339
fef2b580	340	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	341
	342	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	343	goto give_sigsegv;
	344
	345	rsig = sig;
	346	if (sig < 32 &&
	347	__current_thread_info->exec_domain &&
	348	__current_thread_info->exec_domain->signal_invmap)
	349	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	350
	351	if (__put_user(rsig, &frame->sig) \|\|
	352	__put_user(&frame->info, &frame->pinfo) \|\|
	353	__put_user(&frame->uc, &frame->puc))
	354	goto give_sigsegv;
	355
	356	if (copy_siginfo_to_user(&frame->info, info))
	357	goto give_sigsegv;
	358
	359	/* Create the ucontext. */
	360	if (__put_user(0, &frame->uc.uc_flags) \|\|
9e4d11f8 AV	361	__put_user(NULL, &frame->uc.uc_link) \|\|
9e4d11f8 AV	362	__put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) \|\|
fef2b580	363	__put_user(sas_ss_flags(__frame->sp), &frame->uc.uc_stack.ss_flags) \|\|
1da177e4 LT	364	__put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size))
	365	goto give_sigsegv;
	366
	367	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
	368	goto give_sigsegv;
	369
	370	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
	371	goto give_sigsegv;
	372
	373	/* Set up to return from userspace. If provided, use a stub
	374	* already in userspace. */
	375	if (ka->sa.sa_flags & SA_RESTORER) {
	376	if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
	377	goto give_sigsegv;
	378	}
	379	else {
	380	/* Set up the following code on the stack:
	381	* setlos #__NR_sigreturn,gr7
	382	* tira gr0,0
	383	*/
9e4d11f8	384	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	385	__put_user(0x8efc0000\|__NR_rt_sigreturn, &frame->retcode[0]) \|\|
	386	__put_user(0xc0700000, &frame->retcode[1]))
	387	goto give_sigsegv;
	388
	389	flush_icache_range((unsigned long) frame->retcode,
	390	(unsigned long) (frame->retcode + 2));
	391	}
	392
	393	/* Set up registers for signal handler */
fef2b580 DH	394	__frame->sp = (unsigned long) frame;
	395	__frame->lr = (unsigned long) &frame->retcode;
	396	__frame->gr8 = sig;
	397	__frame->gr9 = (unsigned long) &frame->info;
1da177e4	398
ecd0fa98	399	if (current->personality & FDPIC_FUNCPTRS) {
9e4d11f8	400	struct fdpic_func_descriptor __user *funcptr =
1da177e4	401	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
fef2b580 DH	402	__get_user(__frame->pc, &funcptr->text);
fef2b580 DH	403	__get_user(__frame->gr15, &funcptr->GOT);
1da177e4	404	} else {
fef2b580 DH	405	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	406	__frame->gr15 = 0;
1da177e4 LT	407	}
	408
	409	set_fs(USER_DS);
	410
8efc0ab5 DH	411	/* the tracer may want to single-step inside the handler */
	412	if (test_thread_flag(TIF_SINGLESTEP))
	413	ptrace_notify(SIGTRAP);
	414
1da177e4 LT	415	#if DEBUG_SIG
1da177e4 LT	416	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	417	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	418	frame->pretcode);
1da177e4 LT	419	#endif
1da177e4 LT	420
a411aee9	421	return 0;
1da177e4 LT	422
1da177e4 LT	423	give_sigsegv:
1da177e4	424	force_sig(SIGSEGV, current);
a411aee9	425	return -EFAULT;
1da177e4 LT	426
	427	} /* end setup_rt_frame() */
	428
	429	/*****************************************************************************/
	430	/*
	431	* OK, we're invoking a handler
	432	*/
8efc0ab5	433	static int handle_signal(unsigned long sig, siginfo_t *info,
fef2b580	434	struct k_sigaction ka, sigset_t oldset)
1da177e4	435	{
8efc0ab5 DH	436	int ret;
8efc0ab5 DH	437
1da177e4	438	/* Are we from a system call? */
fef2b580	439	if (in_syscall(__frame)) {
1da177e4	440	/* If so, check system call restarting.. */
fef2b580	441	switch (__frame->gr8) {
1da177e4 LT	442	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	443	case -ERESTARTNOHAND:
fef2b580	444	__frame->gr8 = -EINTR;
1da177e4 LT	445	break;
	446
	447	case -ERESTARTSYS:
	448	if (!(ka->sa.sa_flags & SA_RESTART)) {
fef2b580	449	__frame->gr8 = -EINTR;
1da177e4 LT	450	break;
1da177e4 LT	451	}
8efc0ab5	452
1da177e4 LT	453	/* fallthrough */
1da177e4 LT	454	case -ERESTARTNOINTR:
fef2b580 DH	455	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	456	__frame->pc -= 4;
1da177e4 LT	457	}
	458	}
	459
	460	/* Set up the stack frame */
	461	if (ka->sa.sa_flags & SA_SIGINFO)
fef2b580	462	ret = setup_rt_frame(sig, ka, info, oldset);
1da177e4	463	else
fef2b580	464	ret = setup_frame(sig, ka, oldset);
8efc0ab5	465
a411aee9	466	if (ret == 0) {
8efc0ab5 DH	467	spin_lock_irq(&current->sighand->siglock);
	468	sigorsets(&current->blocked, &current->blocked,
	469	&ka->sa.sa_mask);
	470	if (!(ka->sa.sa_flags & SA_NODEFER))
	471	sigaddset(&current->blocked, sig);
	472	recalc_sigpending();
	473	spin_unlock_irq(&current->sighand->siglock);
	474	}
	475
	476	return ret;
1da177e4	477
1da177e4 LT	478	} /* end handle_signal() */
	479
	480	/*****************************************************************************/
	481	/*
	482	* Note that 'init' is a special process: it doesn't get signals it doesn't
	483	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	484	* mistake.
	485	*/
a411aee9	486	static void do_signal(void)
1da177e4 LT	487	{
	488	struct k_sigaction ka;
	489	siginfo_t info;
a411aee9	490	sigset_t *oldset;
1da177e4 LT	491	int signr;
	492
	493	/*
	494	* We want the common case to go fast, which
	495	* is why we may in certain cases get here from
	496	* kernel mode. Just return without doing anything
	497	* if so.
	498	*/
fef2b580	499	if (!user_mode(__frame))
a411aee9	500	return;
1da177e4	501
3e1d1d28	502	if (try_to_freeze())
1da177e4	503	goto no_signal;
1da177e4	504
a411aee9 DH	505	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	506	oldset = &current->saved_sigmask;
	507	else
1da177e4 LT	508	oldset = &current->blocked;
1da177e4 LT	509
fef2b580	510	signr = get_signal_to_deliver(&info, &ka, __frame, NULL);
a411aee9 DH	511	if (signr > 0) {
	512	if (handle_signal(signr, &info, &ka, oldset) == 0) {
	513	/* a signal was successfully delivered; the saved
	514	* sigmask will have been stored in the signal frame,
	515	* and will be restored by sigreturn, so we can simply
	516	* clear the TIF_RESTORE_SIGMASK flag */
	517	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	518	clear_thread_flag(TIF_RESTORE_SIGMASK);
	519	}
	520
	521	return;
	522	}
1da177e4	523
8efc0ab5	524	no_signal:
1da177e4	525	/* Did we come from a system call? */
fef2b580	526	if (__frame->syscallno >= 0) {
1da177e4	527	/* Restart the system call - no handlers present */
a411aee9 DH	528	switch (__frame->gr8) {
	529	case -ERESTARTNOHAND:
	530	case -ERESTARTSYS:
	531	case -ERESTARTNOINTR:
fef2b580 DH	532	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	533	__frame->pc -= 4;
a411aee9	534	break;
1da177e4	535
a411aee9	536	case -ERESTART_RESTARTBLOCK:
fef2b580 DH	537	__frame->gr8 = __NR_restart_syscall;
fef2b580 DH	538	__frame->pc -= 4;
a411aee9	539	break;
1da177e4 LT	540	}
	541	}
	542
a411aee9 DH	543	/* if there's no signal to deliver, we just put the saved sigmask
	544	* back */
	545	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	546	clear_thread_flag(TIF_RESTORE_SIGMASK);
	547	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	548	}
8efc0ab5	549
1da177e4 LT	550	} /* end do_signal() */
	551
	552	/*****************************************************************************/
	553	/*
	554	* notification of userspace execution resumption
a411aee9	555	* - triggered by the TIF_WORK_MASK flags
1da177e4 LT	556	*/
	557	asmlinkage void do_notify_resume(__u32 thread_info_flags)
	558	{
	559	/* pending single-step? */
	560	if (thread_info_flags & _TIF_SINGLESTEP)
	561	clear_thread_flag(TIF_SINGLESTEP);
	562
	563	/* deal with pending signal delivery */
a411aee9 DH	564	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
a411aee9 DH	565	do_signal();
1da177e4 LT	566
1da177e4 LT	567	} /* end do_notify_resume() */