[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 <linux/tracehook.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;

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

	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;

	set_fs(USER_DS);

	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 the signal handler */
	if (current->personality & FDPIC_FUNCPTRS) {
		struct fdpic_func_descriptor __user *funcptr =
			(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
		struct fdpic_func_descriptor desc;
		if (copy_from_user(&desc, funcptr, sizeof(desc)))
			goto give_sigsegv;
		__frame->pc = desc.text;
		__frame->gr15 = desc.GOT;
	} else {
		__frame->pc   = (unsigned long) ka->sa.sa_handler;
		__frame->gr15 = 0;
	}

	__frame->sp   = (unsigned long) frame;
	__frame->lr   = (unsigned long) &frame->retcode;
	__frame->gr8  = sig;

	/* 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_sigsegv(sig, 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;

	set_fs(USER_DS);

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

	__frame->sp  = (unsigned long) frame;
	__frame->lr  = (unsigned long) &frame->retcode;
	__frame->gr8 = sig;
	__frame->gr9 = (unsigned long) &frame->info;

	/* 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_sigsegv(sig, 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);

			tracehook_signal_handler(signr, &info, &ka, __frame,
						 test_thread_flag(TIF_SINGLESTEP));
		}

		return;
	}

no_signal:
	/* Did we come from a system call? */
	if (__frame->syscallno != -1) {
		/* 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();

	/* deal with notification on about to resume userspace execution */
	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(__frame);
		if (current->replacement_session_keyring)
			key_replace_session_keyring();
	}

} /* 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>
4a3b9893	24	#include <linux/tracehook.h>
1da177e4 LT	25	#include <asm/ucontext.h>
	26	#include <asm/uaccess.h>
	27	#include <asm/cacheflush.h>
	28
	29	#define DEBUG_SIG 0
	30
	31	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	32
	33	struct fdpic_func_descriptor {
	34	unsigned long text;
	35	unsigned long GOT;
	36	};
	37
1da177e4 LT	38	/*
	39	* Atomically swap in the new signal mask, and wait for a signal.
	40	*/
	41	asmlinkage int sys_sigsuspend(int history0, int history1, old_sigset_t mask)
	42	{
1da177e4 LT	43	mask &= _BLOCKABLE;
1da177e4 LT	44	spin_lock_irq(&current->sighand->siglock);
a411aee9	45	current->saved_sigmask = current->blocked;
1da177e4 LT	46	siginitset(&current->blocked, mask);
	47	recalc_sigpending();
	48	spin_unlock_irq(&current->sighand->siglock);
	49
a411aee9 DH	50	current->state = TASK_INTERRUPTIBLE;
	51	schedule();
	52	set_thread_flag(TIF_RESTORE_SIGMASK);
	53	return -ERESTARTNOHAND;
1da177e4 LT	54	}
	55
	56	asmlinkage int sys_sigaction(int sig,
	57	const struct old_sigaction __user *act,
	58	struct old_sigaction __user *oact)
	59	{
	60	struct k_sigaction new_ka, old_ka;
	61	int ret;
	62
	63	if (act) {
	64	old_sigset_t mask;
	65	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	66	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
	67	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
	68	return -EFAULT;
	69	__get_user(new_ka.sa.sa_flags, &act->sa_flags);
	70	__get_user(mask, &act->sa_mask);
	71	siginitset(&new_ka.sa.sa_mask, mask);
	72	}
	73
	74	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	75
	76	if (!ret && oact) {
	77	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	78	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
	79	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
	80	return -EFAULT;
	81	__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	82	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	83	}
	84
	85	return ret;
	86	}
	87
	88	asmlinkage
	89	int sys_sigaltstack(const stack_t __user uss, stack_t __user uoss)
	90	{
	91	return do_sigaltstack(uss, uoss, __frame->sp);
	92	}
	93
	94
	95	/*
	96	* Do a signal return; undo the signal stack.
	97	*/
	98
	99	struct sigframe
	100	{
9e4d11f8	101	__sigrestore_t pretcode;
1da177e4 LT	102	int sig;
	103	struct sigcontext sc;
	104	unsigned long extramask[_NSIG_WORDS-1];
	105	uint32_t retcode[2];
	106	};
	107
	108	struct rt_sigframe
	109	{
9e4d11f8	110	__sigrestore_t pretcode;
1da177e4	111	int sig;
9e4d11f8 AV	112	struct siginfo __user *pinfo;
9e4d11f8 AV	113	void __user *puc;
1da177e4 LT	114	struct siginfo info;
	115	struct ucontext uc;
	116	uint32_t retcode[2];
	117	};
	118
	119	static int restore_sigcontext(struct sigcontext __user sc, int _gr8)
	120	{
	121	struct user_context *user = current->thread.user;
	122	unsigned long tbr, psr;
	123
20cd514d AV	124	/* Always make any pending restarted system calls return -EINTR */
	125	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	126
1da177e4 LT	127	tbr = user->i.tbr;
	128	psr = user->i.psr;
	129	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
	130	goto badframe;
	131	user->i.tbr = tbr;
	132	user->i.psr = psr;
	133
	134	restore_user_regs(user);
	135
	136	user->i.syscallno = -1; /* disable syscall checks */
	137
	138	*_gr8 = user->i.gr[8];
	139	return 0;
	140
	141	badframe:
	142	return 1;
	143	}
	144
	145	asmlinkage int sys_sigreturn(void)
	146	{
	147	struct sigframe __user frame = (struct sigframe __user ) __frame->sp;
	148	sigset_t set;
	149	int gr8;
	150
	151	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	152	goto badframe;
	153	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
	154	goto badframe;
	155
	156	if (_NSIG_WORDS > 1 &&
	157	__copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
	158	goto badframe;
	159
	160	sigdelsetmask(&set, ~_BLOCKABLE);
	161	spin_lock_irq(&current->sighand->siglock);
	162	current->blocked = set;
	163	recalc_sigpending();
	164	spin_unlock_irq(&current->sighand->siglock);
	165
	166	if (restore_sigcontext(&frame->sc, &gr8))
	167	goto badframe;
	168	return gr8;
	169
	170	badframe:
	171	force_sig(SIGSEGV, current);
	172	return 0;
	173	}
	174
	175	asmlinkage int sys_rt_sigreturn(void)
	176	{
	177	struct rt_sigframe __user frame = (struct rt_sigframe __user ) __frame->sp;
	178	sigset_t set;
	179	int gr8;
	180
	181	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	182	goto badframe;
	183	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	184	goto badframe;
	185
	186	sigdelsetmask(&set, ~_BLOCKABLE);
	187	spin_lock_irq(&current->sighand->siglock);
	188	current->blocked = set;
	189	recalc_sigpending();
	190	spin_unlock_irq(&current->sighand->siglock);
191
192	if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
193	goto badframe;
194
195	if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT)
196	goto badframe;
197
198	return gr8;
199
200	badframe:
201	force_sig(SIGSEGV, current);
202	return 0;
203	}
204
205	/*
206	* Set up a signal frame
207	*/
208	static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
209	{
210	save_user_regs(current->thread.user);
211
212	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
213	goto badframe;
214
215	/* non-iBCS2 extensions.. */
216	if (__put_user(mask, &sc->sc_oldmask) < 0)
217	goto badframe;
218
219	return 0;
220
221	badframe:
222	return 1;
223	}
224
225	/*****************************************************************************/
226	/*
227	* Determine which stack to use..
228	*/
229	static inline void __user get_sigframe(struct k_sigaction ka,
1da177e4 LT	230	size_t frame_size)
	231	{
	232	unsigned long sp;
	233
	234	/* Default to using normal stack */
fef2b580	235	sp = __frame->sp;
1da177e4 LT	236
	237	/* This is the X/Open sanctioned signal stack switching. */
	238	if (ka->sa.sa_flags & SA_ONSTACK) {
d09042da	239	if (! sas_ss_flags(sp))
1da177e4 LT	240	sp = current->sas_ss_sp + current->sas_ss_size;
	241	}
	242
	243	return (void __user *) ((sp - frame_size) & ~7UL);
fef2b580	244
1da177e4 LT	245	} /* end get_sigframe() */
	246
	247	/*****************************************************************************/
	248	/*
	249	*
	250	*/
fef2b580	251	static int setup_frame(int sig, struct k_sigaction ka, sigset_t set)
1da177e4 LT	252	{
	253	struct sigframe __user *frame;
	254	int rsig;
	255
5f4ad04a AV	256	set_fs(USER_DS);
5f4ad04a AV	257
fef2b580	258	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	259
	260	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	261	goto give_sigsegv;
	262
	263	rsig = sig;
	264	if (sig < 32 &&
	265	__current_thread_info->exec_domain &&
	266	__current_thread_info->exec_domain->signal_invmap)
	267	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	268
	269	if (__put_user(rsig, &frame->sig) < 0)
	270	goto give_sigsegv;
	271
	272	if (setup_sigcontext(&frame->sc, set->sig[0]))
	273	goto give_sigsegv;
	274
	275	if (_NSIG_WORDS > 1) {
	276	if (__copy_to_user(frame->extramask, &set->sig[1],
	277	sizeof(frame->extramask)))
	278	goto give_sigsegv;
	279	}
	280
	281	/* Set up to return from userspace. If provided, use a stub
	282	* already in userspace. */
	283	if (ka->sa.sa_flags & SA_RESTORER) {
	284	if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
	285	goto give_sigsegv;
	286	}
	287	else {
	288	/* Set up the following code on the stack:
	289	* setlos #__NR_sigreturn,gr7
	290	* tira gr0,0
	291	*/
9e4d11f8	292	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	293	__put_user(0x8efc0000\|__NR_sigreturn, &frame->retcode[0]) \|\|
	294	__put_user(0xc0700000, &frame->retcode[1]))
	295	goto give_sigsegv;
	296
	297	flush_icache_range((unsigned long) frame->retcode,
	298	(unsigned long) (frame->retcode + 2));
	299	}
	300
5f4ad04a	301	/* Set up registers for the signal handler */
ecd0fa98	302	if (current->personality & FDPIC_FUNCPTRS) {
1da177e4	303	struct fdpic_func_descriptor __user *funcptr =
9e4d11f8	304	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
5f4ad04a AV	305	struct fdpic_func_descriptor desc;
	306	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	307	goto give_sigsegv;
	308	__frame->pc = desc.text;
	309	__frame->gr15 = desc.GOT;
1da177e4	310	} else {
fef2b580 DH	311	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	312	__frame->gr15 = 0;
1da177e4 LT	313	}
1da177e4 LT	314
5f4ad04a AV	315	__frame->sp = (unsigned long) frame;
	316	__frame->lr = (unsigned long) &frame->retcode;
	317	__frame->gr8 = sig;
1da177e4	318
8efc0ab5 DH	319	/* the tracer may want to single-step inside the handler */
	320	if (test_thread_flag(TIF_SINGLESTEP))
	321	ptrace_notify(SIGTRAP);
	322
1da177e4 LT	323	#if DEBUG_SIG
1da177e4 LT	324	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	325	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	326	frame->pretcode);
1da177e4 LT	327	#endif
1da177e4 LT	328
a411aee9	329	return 0;
1da177e4 LT	330
1da177e4 LT	331	give_sigsegv:
ad0acab4	332	force_sigsegv(sig, current);
a411aee9	333	return -EFAULT;
8efc0ab5	334
1da177e4 LT	335	} /* end setup_frame() */
	336
	337	/*****************************************************************************/
	338	/*
	339	*
	340	*/
8efc0ab5	341	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
fef2b580	342	sigset_t *set)
1da177e4 LT	343	{
	344	struct rt_sigframe __user *frame;
	345	int rsig;
	346
5f4ad04a AV	347	set_fs(USER_DS);
5f4ad04a AV	348
fef2b580	349	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	350
	351	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	352	goto give_sigsegv;
	353
	354	rsig = sig;
	355	if (sig < 32 &&
	356	__current_thread_info->exec_domain &&
	357	__current_thread_info->exec_domain->signal_invmap)
	358	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	359
	360	if (__put_user(rsig, &frame->sig) \|\|
	361	__put_user(&frame->info, &frame->pinfo) \|\|
	362	__put_user(&frame->uc, &frame->puc))
	363	goto give_sigsegv;
	364
	365	if (copy_siginfo_to_user(&frame->info, info))
	366	goto give_sigsegv;
	367
	368	/* Create the ucontext. */
	369	if (__put_user(0, &frame->uc.uc_flags) \|\|
9e4d11f8 AV	370	__put_user(NULL, &frame->uc.uc_link) \|\|
9e4d11f8 AV	371	__put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) \|\|
fef2b580	372	__put_user(sas_ss_flags(__frame->sp), &frame->uc.uc_stack.ss_flags) \|\|
1da177e4 LT	373	__put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size))
	374	goto give_sigsegv;
	375
	376	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
	377	goto give_sigsegv;
	378
	379	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
	380	goto give_sigsegv;
	381
	382	/* Set up to return from userspace. If provided, use a stub
	383	* already in userspace. */
	384	if (ka->sa.sa_flags & SA_RESTORER) {
	385	if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
	386	goto give_sigsegv;
	387	}
	388	else {
	389	/* Set up the following code on the stack:
	390	* setlos #__NR_sigreturn,gr7
	391	* tira gr0,0
	392	*/
9e4d11f8	393	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	394	__put_user(0x8efc0000\|__NR_rt_sigreturn, &frame->retcode[0]) \|\|
	395	__put_user(0xc0700000, &frame->retcode[1]))
	396	goto give_sigsegv;
	397
	398	flush_icache_range((unsigned long) frame->retcode,
	399	(unsigned long) (frame->retcode + 2));
	400	}
	401
	402	/* Set up registers for signal handler */
ecd0fa98	403	if (current->personality & FDPIC_FUNCPTRS) {
9e4d11f8	404	struct fdpic_func_descriptor __user *funcptr =
1da177e4	405	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
5f4ad04a AV	406	struct fdpic_func_descriptor desc;
	407	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	408	goto give_sigsegv;
	409	__frame->pc = desc.text;
	410	__frame->gr15 = desc.GOT;
1da177e4	411	} else {
fef2b580 DH	412	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	413	__frame->gr15 = 0;
1da177e4 LT	414	}
1da177e4 LT	415
5f4ad04a AV	416	__frame->sp = (unsigned long) frame;
	417	__frame->lr = (unsigned long) &frame->retcode;
	418	__frame->gr8 = sig;
	419	__frame->gr9 = (unsigned long) &frame->info;
1da177e4	420
8efc0ab5 DH	421	/* the tracer may want to single-step inside the handler */
	422	if (test_thread_flag(TIF_SINGLESTEP))
	423	ptrace_notify(SIGTRAP);
	424
1da177e4 LT	425	#if DEBUG_SIG
1da177e4 LT	426	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	427	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	428	frame->pretcode);
1da177e4 LT	429	#endif
1da177e4 LT	430
a411aee9	431	return 0;
1da177e4 LT	432
1da177e4 LT	433	give_sigsegv:
ad0acab4	434	force_sigsegv(sig, current);
a411aee9	435	return -EFAULT;
1da177e4 LT	436
	437	} /* end setup_rt_frame() */
	438
	439	/*****************************************************************************/
	440	/*
	441	* OK, we're invoking a handler
	442	*/
8efc0ab5	443	static int handle_signal(unsigned long sig, siginfo_t *info,
fef2b580	444	struct k_sigaction ka, sigset_t oldset)
1da177e4	445	{
8efc0ab5 DH	446	int ret;
8efc0ab5 DH	447
1da177e4	448	/* Are we from a system call? */
fef2b580	449	if (in_syscall(__frame)) {
1da177e4	450	/* If so, check system call restarting.. */
fef2b580	451	switch (__frame->gr8) {
1da177e4 LT	452	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	453	case -ERESTARTNOHAND:
fef2b580	454	__frame->gr8 = -EINTR;
1da177e4 LT	455	break;
	456
	457	case -ERESTARTSYS:
	458	if (!(ka->sa.sa_flags & SA_RESTART)) {
fef2b580	459	__frame->gr8 = -EINTR;
1da177e4 LT	460	break;
1da177e4 LT	461	}
8efc0ab5	462
1da177e4 LT	463	/* fallthrough */
1da177e4 LT	464	case -ERESTARTNOINTR:
fef2b580 DH	465	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	466	__frame->pc -= 4;
1da177e4 LT	467	}
	468	}
	469
	470	/* Set up the stack frame */
	471	if (ka->sa.sa_flags & SA_SIGINFO)
fef2b580	472	ret = setup_rt_frame(sig, ka, info, oldset);
1da177e4	473	else
fef2b580	474	ret = setup_frame(sig, ka, oldset);
8efc0ab5	475
a411aee9	476	if (ret == 0) {
8efc0ab5 DH	477	spin_lock_irq(&current->sighand->siglock);
	478	sigorsets(&current->blocked, &current->blocked,
	479	&ka->sa.sa_mask);
	480	if (!(ka->sa.sa_flags & SA_NODEFER))
	481	sigaddset(&current->blocked, sig);
	482	recalc_sigpending();
	483	spin_unlock_irq(&current->sighand->siglock);
	484	}
	485
	486	return ret;
1da177e4	487
1da177e4 LT	488	} /* end handle_signal() */
	489
	490	/*****************************************************************************/
	491	/*
	492	* Note that 'init' is a special process: it doesn't get signals it doesn't
	493	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	494	* mistake.
	495	*/
a411aee9	496	static void do_signal(void)
1da177e4 LT	497	{
	498	struct k_sigaction ka;
	499	siginfo_t info;
a411aee9	500	sigset_t *oldset;
1da177e4 LT	501	int signr;
	502
	503	/*
	504	* We want the common case to go fast, which
	505	* is why we may in certain cases get here from
	506	* kernel mode. Just return without doing anything
	507	* if so.
	508	*/
fef2b580	509	if (!user_mode(__frame))
a411aee9	510	return;
1da177e4	511
3e1d1d28	512	if (try_to_freeze())
1da177e4	513	goto no_signal;
1da177e4	514
a411aee9 DH	515	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	516	oldset = &current->saved_sigmask;
	517	else
1da177e4 LT	518	oldset = &current->blocked;
1da177e4 LT	519
fef2b580	520	signr = get_signal_to_deliver(&info, &ka, __frame, NULL);
a411aee9 DH	521	if (signr > 0) {
	522	if (handle_signal(signr, &info, &ka, oldset) == 0) {
	523	/* a signal was successfully delivered; the saved
	524	* sigmask will have been stored in the signal frame,
	525	* and will be restored by sigreturn, so we can simply
	526	* clear the TIF_RESTORE_SIGMASK flag */
	527	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	528	clear_thread_flag(TIF_RESTORE_SIGMASK);
4a3b9893 DH	529
	530	tracehook_signal_handler(signr, &info, &ka, __frame,
	531	test_thread_flag(TIF_SINGLESTEP));
a411aee9 DH	532	}
	533
	534	return;
	535	}
1da177e4	536
8efc0ab5	537	no_signal:
1da177e4	538	/* Did we come from a system call? */
c896a2e0	539	if (__frame->syscallno != -1) {
1da177e4	540	/* Restart the system call - no handlers present */
a411aee9 DH	541	switch (__frame->gr8) {
	542	case -ERESTARTNOHAND:
	543	case -ERESTARTSYS:
	544	case -ERESTARTNOINTR:
fef2b580 DH	545	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	546	__frame->pc -= 4;
a411aee9	547	break;
1da177e4	548
a411aee9	549	case -ERESTART_RESTARTBLOCK:
fef2b580 DH	550	__frame->gr8 = __NR_restart_syscall;
fef2b580 DH	551	__frame->pc -= 4;
a411aee9	552	break;
1da177e4 LT	553	}
	554	}
	555
a411aee9 DH	556	/* if there's no signal to deliver, we just put the saved sigmask
	557	* back */
	558	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	559	clear_thread_flag(TIF_RESTORE_SIGMASK);
	560	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	561	}
8efc0ab5	562
1da177e4 LT	563	} /* end do_signal() */
	564
	565	/*****************************************************************************/
	566	/*
	567	* notification of userspace execution resumption
a411aee9	568	* - triggered by the TIF_WORK_MASK flags
1da177e4 LT	569	*/
	570	asmlinkage void do_notify_resume(__u32 thread_info_flags)
	571	{
	572	/* pending single-step? */
	573	if (thread_info_flags & _TIF_SINGLESTEP)
	574	clear_thread_flag(TIF_SINGLESTEP);
	575
	576	/* deal with pending signal delivery */
a411aee9 DH	577	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
a411aee9 DH	578	do_signal();
1da177e4	579
b7bab880 DH	580	/* deal with notification on about to resume userspace execution */
	581	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	582	clear_thread_flag(TIF_NOTIFY_RESUME);
4a3b9893	583	tracehook_notify_resume(__frame);
ee18d64c DH	584	if (current->replacement_session_keyring)
ee18d64c DH	585	key_replace_session_keyring();
b7bab880 DH	586	}
b7bab880 DH	587
1da177e4	588	} /* end do_notify_resume() */