[deliverable/linux.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)
{
	sigset_t blocked;
	siginitset(&blocked, mask);
	return sigsuspend(&blocked);
}

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) ||
		    __get_user(new_ka.sa.sa_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		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) ||
		    __put_user(old_ka.sa.sa_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
	}

	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);
	set_current_blocked(&set);

	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);
	set_current_blocked(&set);

	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 (__frame->syscallno != -1) {
		/* 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;
		}
		__frame->syscallno = -1;
	}

	/* 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)
		block_sigmask(ka, sig);

	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->gr7 = __NR_restart_syscall;
			__frame->pc -= 4;
			break;
		}
		__frame->syscallno = -1;
	}

	/* 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);
	}

} /* 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	{
68f3f16d AV	43	sigset_t blocked;
	44	siginitset(&blocked, mask);
	45	return sigsuspend(&blocked);
1da177e4 LT	46	}
	47
	48	asmlinkage int sys_sigaction(int sig,
	49	const struct old_sigaction __user *act,
	50	struct old_sigaction __user *oact)
	51	{
	52	struct k_sigaction new_ka, old_ka;
	53	int ret;
	54
	55	if (act) {
	56	old_sigset_t mask;
	57	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	58	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
f0c22cdd AV	59	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer) \|\|
	60	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
	61	__get_user(mask, &act->sa_mask))
1da177e4	62	return -EFAULT;
1da177e4 LT	63	siginitset(&new_ka.sa.sa_mask, mask);
	64	}
	65
	66	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	67
	68	if (!ret && oact) {
	69	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	70	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
f0c22cdd AV	71	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer) \|\|
	72	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
	73	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	74	return -EFAULT;
1da177e4 LT	75	}
	76
	77	return ret;
	78	}
	79
	80	asmlinkage
	81	int sys_sigaltstack(const stack_t __user uss, stack_t __user uoss)
	82	{
	83	return do_sigaltstack(uss, uoss, __frame->sp);
	84	}
	85
	86
	87	/*
	88	* Do a signal return; undo the signal stack.
	89	*/
	90
	91	struct sigframe
	92	{
9e4d11f8	93	__sigrestore_t pretcode;
1da177e4 LT	94	int sig;
	95	struct sigcontext sc;
	96	unsigned long extramask[_NSIG_WORDS-1];
	97	uint32_t retcode[2];
	98	};
	99
	100	struct rt_sigframe
	101	{
9e4d11f8	102	__sigrestore_t pretcode;
1da177e4	103	int sig;
9e4d11f8 AV	104	struct siginfo __user *pinfo;
9e4d11f8 AV	105	void __user *puc;
1da177e4 LT	106	struct siginfo info;
	107	struct ucontext uc;
	108	uint32_t retcode[2];
	109	};
	110
	111	static int restore_sigcontext(struct sigcontext __user sc, int _gr8)
	112	{
	113	struct user_context *user = current->thread.user;
	114	unsigned long tbr, psr;
	115
20cd514d AV	116	/* Always make any pending restarted system calls return -EINTR */
	117	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	118
1da177e4 LT	119	tbr = user->i.tbr;
	120	psr = user->i.psr;
	121	if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context)))
	122	goto badframe;
	123	user->i.tbr = tbr;
	124	user->i.psr = psr;
	125
	126	restore_user_regs(user);
	127
	128	user->i.syscallno = -1; /* disable syscall checks */
	129
	130	*_gr8 = user->i.gr[8];
	131	return 0;
	132
	133	badframe:
	134	return 1;
	135	}
	136
	137	asmlinkage int sys_sigreturn(void)
	138	{
	139	struct sigframe __user frame = (struct sigframe __user ) __frame->sp;
	140	sigset_t set;
	141	int gr8;
	142
	143	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	144	goto badframe;
	145	if (__get_user(set.sig[0], &frame->sc.sc_oldmask))
	146	goto badframe;
	147
	148	if (_NSIG_WORDS > 1 &&
	149	__copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask)))
	150	goto badframe;
	151
	152	sigdelsetmask(&set, ~_BLOCKABLE);
7ebe0c5d	153	set_current_blocked(&set);
1da177e4 LT	154
	155	if (restore_sigcontext(&frame->sc, &gr8))
	156	goto badframe;
	157	return gr8;
	158
	159	badframe:
	160	force_sig(SIGSEGV, current);
	161	return 0;
	162	}
	163
	164	asmlinkage int sys_rt_sigreturn(void)
	165	{
	166	struct rt_sigframe __user frame = (struct rt_sigframe __user ) __frame->sp;
	167	sigset_t set;
	168	int gr8;
	169
	170	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	171	goto badframe;
	172	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	173	goto badframe;
	174
	175	sigdelsetmask(&set, ~_BLOCKABLE);
7ebe0c5d	176	set_current_blocked(&set);
1da177e4 LT	177
	178	if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8))
	179	goto badframe;
	180
	181	if (do_sigaltstack(&frame->uc.uc_stack, NULL, __frame->sp) == -EFAULT)
	182	goto badframe;
	183
	184	return gr8;
	185
	186	badframe:
	187	force_sig(SIGSEGV, current);
	188	return 0;
	189	}
	190
	191	/*
	192	* Set up a signal frame
	193	*/
	194	static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask)
	195	{
	196	save_user_regs(current->thread.user);
	197
	198	if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0)
	199	goto badframe;
	200
	201	/* non-iBCS2 extensions.. */
	202	if (__put_user(mask, &sc->sc_oldmask) < 0)
	203	goto badframe;
	204
	205	return 0;
	206
	207	badframe:
	208	return 1;
	209	}
	210
	211	/*****************************************************************************/
	212	/*
	213	* Determine which stack to use..
	214	*/
	215	static inline void __user get_sigframe(struct k_sigaction ka,
1da177e4 LT	216	size_t frame_size)
	217	{
	218	unsigned long sp;
	219
	220	/* Default to using normal stack */
fef2b580	221	sp = __frame->sp;
1da177e4 LT	222
	223	/* This is the X/Open sanctioned signal stack switching. */
	224	if (ka->sa.sa_flags & SA_ONSTACK) {
d09042da	225	if (! sas_ss_flags(sp))
1da177e4 LT	226	sp = current->sas_ss_sp + current->sas_ss_size;
	227	}
	228
	229	return (void __user *) ((sp - frame_size) & ~7UL);
fef2b580	230
1da177e4 LT	231	} /* end get_sigframe() */
	232
	233	/*****************************************************************************/
	234	/*
	235	*
	236	*/
fef2b580	237	static int setup_frame(int sig, struct k_sigaction ka, sigset_t set)
1da177e4 LT	238	{
	239	struct sigframe __user *frame;
	240	int rsig;
	241
5f4ad04a AV	242	set_fs(USER_DS);
5f4ad04a AV	243
fef2b580	244	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	245
	246	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	247	goto give_sigsegv;
	248
	249	rsig = sig;
	250	if (sig < 32 &&
	251	__current_thread_info->exec_domain &&
	252	__current_thread_info->exec_domain->signal_invmap)
	253	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	254
	255	if (__put_user(rsig, &frame->sig) < 0)
	256	goto give_sigsegv;
	257
	258	if (setup_sigcontext(&frame->sc, set->sig[0]))
	259	goto give_sigsegv;
	260
	261	if (_NSIG_WORDS > 1) {
	262	if (__copy_to_user(frame->extramask, &set->sig[1],
	263	sizeof(frame->extramask)))
	264	goto give_sigsegv;
	265	}
	266
	267	/* Set up to return from userspace. If provided, use a stub
	268	* already in userspace. */
	269	if (ka->sa.sa_flags & SA_RESTORER) {
	270	if (__put_user(ka->sa.sa_restorer, &frame->pretcode) < 0)
	271	goto give_sigsegv;
	272	}
	273	else {
	274	/* Set up the following code on the stack:
	275	* setlos #__NR_sigreturn,gr7
	276	* tira gr0,0
	277	*/
9e4d11f8	278	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	279	__put_user(0x8efc0000\|__NR_sigreturn, &frame->retcode[0]) \|\|
	280	__put_user(0xc0700000, &frame->retcode[1]))
	281	goto give_sigsegv;
	282
	283	flush_icache_range((unsigned long) frame->retcode,
	284	(unsigned long) (frame->retcode + 2));
	285	}
	286
5f4ad04a	287	/* Set up registers for the signal handler */
ecd0fa98	288	if (current->personality & FDPIC_FUNCPTRS) {
1da177e4	289	struct fdpic_func_descriptor __user *funcptr =
9e4d11f8	290	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
5f4ad04a AV	291	struct fdpic_func_descriptor desc;
	292	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	293	goto give_sigsegv;
	294	__frame->pc = desc.text;
	295	__frame->gr15 = desc.GOT;
1da177e4	296	} else {
fef2b580 DH	297	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	298	__frame->gr15 = 0;
1da177e4 LT	299	}
1da177e4 LT	300
5f4ad04a AV	301	__frame->sp = (unsigned long) frame;
	302	__frame->lr = (unsigned long) &frame->retcode;
	303	__frame->gr8 = sig;
1da177e4	304
8efc0ab5 DH	305	/* the tracer may want to single-step inside the handler */
	306	if (test_thread_flag(TIF_SINGLESTEP))
	307	ptrace_notify(SIGTRAP);
	308
1da177e4 LT	309	#if DEBUG_SIG
1da177e4 LT	310	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	311	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	312	frame->pretcode);
1da177e4 LT	313	#endif
1da177e4 LT	314
a411aee9	315	return 0;
1da177e4 LT	316
1da177e4 LT	317	give_sigsegv:
ad0acab4	318	force_sigsegv(sig, current);
a411aee9	319	return -EFAULT;
8efc0ab5	320
1da177e4 LT	321	} /* end setup_frame() */
	322
	323	/*****************************************************************************/
	324	/*
	325	*
	326	*/
8efc0ab5	327	static int setup_rt_frame(int sig, struct k_sigaction ka, siginfo_t info,
fef2b580	328	sigset_t *set)
1da177e4 LT	329	{
	330	struct rt_sigframe __user *frame;
	331	int rsig;
	332
5f4ad04a AV	333	set_fs(USER_DS);
5f4ad04a AV	334
fef2b580	335	frame = get_sigframe(ka, sizeof(*frame));
1da177e4 LT	336
	337	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	338	goto give_sigsegv;
	339
	340	rsig = sig;
	341	if (sig < 32 &&
	342	__current_thread_info->exec_domain &&
	343	__current_thread_info->exec_domain->signal_invmap)
	344	rsig = __current_thread_info->exec_domain->signal_invmap[sig];
	345
	346	if (__put_user(rsig, &frame->sig) \|\|
	347	__put_user(&frame->info, &frame->pinfo) \|\|
	348	__put_user(&frame->uc, &frame->puc))
	349	goto give_sigsegv;
	350
	351	if (copy_siginfo_to_user(&frame->info, info))
	352	goto give_sigsegv;
	353
	354	/* Create the ucontext. */
	355	if (__put_user(0, &frame->uc.uc_flags) \|\|
9e4d11f8 AV	356	__put_user(NULL, &frame->uc.uc_link) \|\|
9e4d11f8 AV	357	__put_user((void __user *)current->sas_ss_sp, &frame->uc.uc_stack.ss_sp) \|\|
fef2b580	358	__put_user(sas_ss_flags(__frame->sp), &frame->uc.uc_stack.ss_flags) \|\|
1da177e4 LT	359	__put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size))
	360	goto give_sigsegv;
	361
	362	if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0]))
	363	goto give_sigsegv;
	364
	365	if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)))
	366	goto give_sigsegv;
	367
	368	/* Set up to return from userspace. If provided, use a stub
	369	* already in userspace. */
	370	if (ka->sa.sa_flags & SA_RESTORER) {
	371	if (__put_user(ka->sa.sa_restorer, &frame->pretcode))
	372	goto give_sigsegv;
	373	}
	374	else {
	375	/* Set up the following code on the stack:
	376	* setlos #__NR_sigreturn,gr7
	377	* tira gr0,0
	378	*/
9e4d11f8	379	if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) \|\|
1da177e4 LT	380	__put_user(0x8efc0000\|__NR_rt_sigreturn, &frame->retcode[0]) \|\|
	381	__put_user(0xc0700000, &frame->retcode[1]))
	382	goto give_sigsegv;
	383
	384	flush_icache_range((unsigned long) frame->retcode,
	385	(unsigned long) (frame->retcode + 2));
	386	}
	387
	388	/* Set up registers for signal handler */
ecd0fa98	389	if (current->personality & FDPIC_FUNCPTRS) {
9e4d11f8	390	struct fdpic_func_descriptor __user *funcptr =
1da177e4	391	(struct fdpic_func_descriptor __user *) ka->sa.sa_handler;
5f4ad04a AV	392	struct fdpic_func_descriptor desc;
	393	if (copy_from_user(&desc, funcptr, sizeof(desc)))
	394	goto give_sigsegv;
	395	__frame->pc = desc.text;
	396	__frame->gr15 = desc.GOT;
1da177e4	397	} else {
fef2b580 DH	398	__frame->pc = (unsigned long) ka->sa.sa_handler;
fef2b580 DH	399	__frame->gr15 = 0;
1da177e4 LT	400	}
1da177e4 LT	401
5f4ad04a AV	402	__frame->sp = (unsigned long) frame;
	403	__frame->lr = (unsigned long) &frame->retcode;
	404	__frame->gr8 = sig;
	405	__frame->gr9 = (unsigned long) &frame->info;
1da177e4	406
8efc0ab5 DH	407	/* the tracer may want to single-step inside the handler */
	408	if (test_thread_flag(TIF_SINGLESTEP))
	409	ptrace_notify(SIGTRAP);
	410
1da177e4 LT	411	#if DEBUG_SIG
1da177e4 LT	412	printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n",
fef2b580	413	sig, current->comm, current->pid, frame, __frame->pc,
8efc0ab5	414	frame->pretcode);
1da177e4 LT	415	#endif
1da177e4 LT	416
a411aee9	417	return 0;
1da177e4 LT	418
1da177e4 LT	419	give_sigsegv:
ad0acab4	420	force_sigsegv(sig, current);
a411aee9	421	return -EFAULT;
1da177e4 LT	422
	423	} /* end setup_rt_frame() */
	424
	425	/*****************************************************************************/
	426	/*
	427	* OK, we're invoking a handler
	428	*/
8efc0ab5	429	static int handle_signal(unsigned long sig, siginfo_t *info,
fef2b580	430	struct k_sigaction ka, sigset_t oldset)
1da177e4	431	{
8efc0ab5 DH	432	int ret;
8efc0ab5 DH	433
1da177e4	434	/* Are we from a system call? */
ed1cde68	435	if (__frame->syscallno != -1) {
1da177e4	436	/* If so, check system call restarting.. */
fef2b580	437	switch (__frame->gr8) {
1da177e4 LT	438	case -ERESTART_RESTARTBLOCK:
1da177e4 LT	439	case -ERESTARTNOHAND:
fef2b580	440	__frame->gr8 = -EINTR;
1da177e4 LT	441	break;
	442
	443	case -ERESTARTSYS:
	444	if (!(ka->sa.sa_flags & SA_RESTART)) {
fef2b580	445	__frame->gr8 = -EINTR;
1da177e4 LT	446	break;
1da177e4 LT	447	}
8efc0ab5	448
1da177e4 LT	449	/* fallthrough */
1da177e4 LT	450	case -ERESTARTNOINTR:
fef2b580 DH	451	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	452	__frame->pc -= 4;
1da177e4	453	}
ed1cde68	454	__frame->syscallno = -1;
1da177e4 LT	455	}
	456
	457	/* Set up the stack frame */
	458	if (ka->sa.sa_flags & SA_SIGINFO)
fef2b580	459	ret = setup_rt_frame(sig, ka, info, oldset);
1da177e4	460	else
fef2b580	461	ret = setup_frame(sig, ka, oldset);
8efc0ab5	462
7ebe0c5d MF	463	if (ret == 0)
7ebe0c5d MF	464	block_sigmask(ka, sig);
8efc0ab5 DH	465
8efc0ab5 DH	466	return ret;
1da177e4	467
1da177e4 LT	468	} /* end handle_signal() */
	469
	470	/*****************************************************************************/
	471	/*
	472	* Note that 'init' is a special process: it doesn't get signals it doesn't
	473	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	474	* mistake.
	475	*/
a411aee9	476	static void do_signal(void)
1da177e4 LT	477	{
	478	struct k_sigaction ka;
	479	siginfo_t info;
a411aee9	480	sigset_t *oldset;
1da177e4 LT	481	int signr;
	482
	483	/*
	484	* We want the common case to go fast, which
	485	* is why we may in certain cases get here from
	486	* kernel mode. Just return without doing anything
	487	* if so.
	488	*/
fef2b580	489	if (!user_mode(__frame))
a411aee9	490	return;
1da177e4	491
3e1d1d28	492	if (try_to_freeze())
1da177e4	493	goto no_signal;
1da177e4	494
a411aee9 DH	495	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	496	oldset = &current->saved_sigmask;
	497	else
1da177e4 LT	498	oldset = &current->blocked;
1da177e4 LT	499
fef2b580	500	signr = get_signal_to_deliver(&info, &ka, __frame, NULL);
a411aee9 DH	501	if (signr > 0) {
	502	if (handle_signal(signr, &info, &ka, oldset) == 0) {
	503	/* a signal was successfully delivered; the saved
	504	* sigmask will have been stored in the signal frame,
	505	* and will be restored by sigreturn, so we can simply
	506	* clear the TIF_RESTORE_SIGMASK flag */
	507	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	508	clear_thread_flag(TIF_RESTORE_SIGMASK);
4a3b9893 DH	509
	510	tracehook_signal_handler(signr, &info, &ka, __frame,
	511	test_thread_flag(TIF_SINGLESTEP));
a411aee9 DH	512	}
	513
	514	return;
	515	}
1da177e4	516
8efc0ab5	517	no_signal:
1da177e4	518	/* Did we come from a system call? */
c896a2e0	519	if (__frame->syscallno != -1) {
1da177e4	520	/* Restart the system call - no handlers present */
a411aee9 DH	521	switch (__frame->gr8) {
	522	case -ERESTARTNOHAND:
	523	case -ERESTARTSYS:
	524	case -ERESTARTNOINTR:
fef2b580 DH	525	__frame->gr8 = __frame->orig_gr8;
fef2b580 DH	526	__frame->pc -= 4;
a411aee9	527	break;
1da177e4	528
a411aee9	529	case -ERESTART_RESTARTBLOCK:
44c7afff	530	__frame->gr7 = __NR_restart_syscall;
fef2b580	531	__frame->pc -= 4;
a411aee9	532	break;
1da177e4	533	}
ed1cde68	534	__frame->syscallno = -1;
1da177e4 LT	535	}
1da177e4 LT	536
a411aee9 DH	537	/* if there's no signal to deliver, we just put the saved sigmask
	538	* back */
	539	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	540	clear_thread_flag(TIF_RESTORE_SIGMASK);
	541	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	542	}
8efc0ab5	543
1da177e4 LT	544	} /* end do_signal() */
	545
	546	/*****************************************************************************/
	547	/*
	548	* notification of userspace execution resumption
a411aee9	549	* - triggered by the TIF_WORK_MASK flags
1da177e4 LT	550	*/
	551	asmlinkage void do_notify_resume(__u32 thread_info_flags)
	552	{
	553	/* pending single-step? */
	554	if (thread_info_flags & _TIF_SINGLESTEP)
	555	clear_thread_flag(TIF_SINGLESTEP);
	556
	557	/* deal with pending signal delivery */
a411aee9 DH	558	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
a411aee9 DH	559	do_signal();
1da177e4	560
b7bab880 DH	561	/* deal with notification on about to resume userspace execution */
	562	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	563	clear_thread_flag(TIF_NOTIFY_RESUME);
4a3b9893	564	tracehook_notify_resume(__frame);
b7bab880 DH	565	}
b7bab880 DH	566
1da177e4	567	} /* end do_notify_resume() */