[linux-block.git] / arch / cris / arch-v10 / kernel / signal.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/cris/kernel/signal.c
 *
 *  Based on arch/i386/kernel/signal.c by
 *     Copyright (C) 1991, 1992  Linus Torvalds
 *     1997-11-28  Modified for POSIX.1b signals by Richard Henderson *
 *
 *  Ideas also taken from arch/arm.
 *
 *  Copyright (C) 2000-2007 Axis Communications AB
 *
 *  Authors:  Bjorn Wesen (bjornw@axis.com)
 *
 */

#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/stddef.h>

#include <asm/processor.h>
#include <asm/ucontext.h>
#include <linux/uaccess.h>
#include <arch/system.h>

#define DEBUG_SIG 0

/* a syscall in Linux/CRIS is a break 13 instruction which is 2 bytes */
/* manipulate regs so that upon return, it will be re-executed */

/* We rely on that pc points to the instruction after "break 13", so the
 * library must never do strange things like putting it in a delay slot.
 */
#define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->irp -= 2;

void do_signal(int canrestart, struct pt_regs *regs);

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

struct sigframe {
	struct sigcontext sc;
	unsigned long extramask[_NSIG_WORDS-1];
	unsigned char retcode[8];  /* trampoline code */
};

struct rt_sigframe {
	struct siginfo *pinfo;
	void *puc;
	struct siginfo info;
	struct ucontext uc;
	unsigned char retcode[8];  /* trampoline code */
};


static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
	unsigned int err = 0;
	unsigned long old_usp;

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

	/* restore the regs from &sc->regs (same as sc, since regs is first)
	 * (sc is already checked for VERIFY_READ since the sigframe was
	 *  checked in sys_sigreturn previously)
	 */

	if (__copy_from_user(regs, sc, sizeof(struct pt_regs)))
                goto badframe;

	/* make sure the U-flag is set so user-mode cannot fool us */

	regs->dccr |= 1 << 8;

	/* restore the old USP as it was before we stacked the sc etc.
	 * (we cannot just pop the sigcontext since we aligned the sp and
	 *  stuff after pushing it)
	 */

	err |= __get_user(old_usp, &sc->usp);

	wrusp(old_usp);

	/* TODO: the other ports use regs->orig_XX to disable syscall checks
	 * after this completes, but we don't use that mechanism. maybe we can
	 * use it now ?
	 */

	return err;

badframe:
	return 1;
}

asmlinkage int sys_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct sigframe __user *frame = (struct sigframe *)rdusp();
	sigset_t set;

        /*
         * Since we stacked the signal on a dword boundary,
         * then frame should be dword aligned here.  If it's
         * not, then the user is trying to mess with us.
         */
        if (((long)frame) & 3)
                goto badframe;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__get_user(set.sig[0], &frame->sc.oldmask)
	    || (_NSIG_WORDS > 1
		&& __copy_from_user(&set.sig[1], frame->extramask,
				    sizeof(frame->extramask))))
		goto badframe;

	set_current_blocked(&set);

	if (restore_sigcontext(regs, &frame->sc))
		goto badframe;

	/* TODO: SIGTRAP when single-stepping as in arm ? */

	return regs->r10;

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

asmlinkage int sys_rt_sigreturn(void)
{
	struct pt_regs *regs = current_pt_regs();
	struct rt_sigframe __user *frame = (struct rt_sigframe *)rdusp();
	sigset_t set;

        /*
         * Since we stacked the signal on a dword boundary,
         * then frame should be dword aligned here.  If it's
         * not, then the user is trying to mess with us.
         */
        if (((long)frame) & 3)
                goto badframe;

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

	set_current_blocked(&set);

	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
		goto badframe;

	if (restore_altstack(&frame->uc.uc_stack))
		goto badframe;

	return regs->r10;

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

/*
 * Set up a signal frame.
 */

static int setup_sigcontext(struct sigcontext __user *sc,
	struct pt_regs *regs, unsigned long mask)
{
	int err = 0;
	unsigned long usp = rdusp();

	/* copy the regs. they are first in sc so we can use sc directly */

	err |= __copy_to_user(sc, regs, sizeof(struct pt_regs));

        /* Set the frametype to CRIS_FRAME_NORMAL for the execution of
           the signal handler. The frametype will be restored to its previous
           value in restore_sigcontext. */
        regs->frametype = CRIS_FRAME_NORMAL;

	/* then some other stuff */

	err |= __put_user(mask, &sc->oldmask);

	err |= __put_user(usp, &sc->usp);

	return err;
}

/* Figure out where we want to put the new signal frame
 * - usually on the stack. */

static inline void __user *
get_sigframe(struct ksignal *ksig, size_t frame_size)
{
	unsigned long sp = sigsp(rdusp(), ksig);

	/* make sure the frame is dword-aligned */

	sp &= ~3;

	return (void __user*)(sp - frame_size);
}

/* grab and setup a signal frame.
 *
 * basically we stack a lot of state info, and arrange for the
 * user-mode program to return to the kernel using either a
 * trampoline which performs the syscall sigreturn, or a provided
 * user-mode trampoline.
 */

static int setup_frame(struct ksignal *ksig, sigset_t *set,
		       struct pt_regs *regs)
{
	struct sigframe __user *frame;
	unsigned long return_ip;
	int err = 0;

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
	if (err)
		return -EFAULT;

	if (_NSIG_WORDS > 1) {
		err |= __copy_to_user(frame->extramask, &set->sig[1],
				      sizeof(frame->extramask));
	}
	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
	} else {
		/* trampoline - the desired return ip is the retcode itself */
		return_ip = (unsigned long)&frame->retcode;
		/* This is movu.w __NR_sigreturn, r9; break 13; */
		err |= __put_user(0x9c5f,         (short __user*)(frame->retcode+0));
		err |= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2));
		err |= __put_user(0xe93d,         (short __user*)(frame->retcode+4));
	}

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */

	regs->irp = (unsigned long) ksig->ka.sa.sa_handler;  /* what we enter NOW   */
	regs->srp = return_ip;                          /* what we enter LATER */
	regs->r10 = ksig->sig;                                /* first argument is signo */

	/* actually move the usp to reflect the stacked frame */

	wrusp((unsigned long)frame);

	return 0;
}

static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
			  struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	unsigned long return_ip;
	int err = 0;

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

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, &ksig->info);
	if (err)
		return -EFAULT;

	/* Clear all the bits of the ucontext we don't use.  */
        err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));

	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);

	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	err |= __save_altstack(&frame->uc.uc_stack, rdusp());

	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
		return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
	} else {
		/* trampoline - the desired return ip is the retcode itself */
		return_ip = (unsigned long)&frame->retcode;
		/* This is movu.w __NR_rt_sigreturn, r9; break 13; */
		err |= __put_user(0x9c5f, (short __user *)(frame->retcode+0));
		err |= __put_user(__NR_rt_sigreturn,
			(short __user *)(frame->retcode+2));
		err |= __put_user(0xe93d, (short __user *)(frame->retcode+4));
	}

	if (err)
		return -EFAULT;

	/* Set up registers for signal handler */

	/* What we enter NOW   */
	regs->irp = (unsigned long) ksig->ka.sa.sa_handler;
	/* What we enter LATER */
	regs->srp = return_ip;
	/* First argument is signo */
	regs->r10 = ksig->sig;
	/* Second argument is (siginfo_t *) */
	regs->r11 = (unsigned long)&frame->info;
	/* Third argument is unused */
	regs->r12 = 0;

	/* Actually move the usp to reflect the stacked frame */
	wrusp((unsigned long)frame);

	return 0;
}

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

static inline void handle_signal(int canrestart, struct ksignal *ksig,
				 struct pt_regs *regs)
{
	sigset_t *oldset = sigmask_to_save();
	int ret;

	/* Are we from a system call? */
	if (canrestart) {
		/* If so, check system call restarting.. */
		switch (regs->r10) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			/* ERESTARTNOHAND means that the syscall should
			 * only be restarted if there was no handler for
			 * the signal, and since we only get here if there
			 * is a handler, we don't restart */
			regs->r10 = -EINTR;
			break;
		case -ERESTARTSYS:
			/* ERESTARTSYS means to restart the syscall if
			 * there is no handler or the handler was
			 * registered with SA_RESTART */
			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
				regs->r10 = -EINTR;
				break;
			}
		/* fallthrough */
		case -ERESTARTNOINTR:
			/* ERESTARTNOINTR means that the syscall should
			 * be called again after the signal handler returns. */
			RESTART_CRIS_SYS(regs);
		}
	}

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

	signal_setup_done(ret, ksig, 0);
}

/*
 * Note that 'init' is a special process: it doesn't get signals it doesn't
 * want to handle. Thus you cannot kill init even with a SIGKILL even by
 * mistake.
 *
 * Also note that the regs structure given here as an argument, is the latest
 * pushed pt_regs. It may or may not be the same as the first pushed registers
 * when the initial usermode->kernelmode transition took place. Therefore
 * we can use user_mode(regs) to see if we came directly from kernel or user
 * mode below.
 */

void do_signal(int canrestart, struct pt_regs *regs)
{
	struct ksignal ksig;

	/*
	 * 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(regs))
		return;

	if (get_signal(&ksig)) {
		/* Whee!  Actually deliver the signal.  */
		handle_signal(canrestart, &ksig, regs);
		return;
	}

	/* Did we come from a system call? */
	if (canrestart) {
		/* Restart the system call - no handlers present */
		if (regs->r10 == -ERESTARTNOHAND ||
		    regs->r10 == -ERESTARTSYS ||
		    regs->r10 == -ERESTARTNOINTR) {
			RESTART_CRIS_SYS(regs);
		}
		if (regs->r10 == -ERESTART_RESTARTBLOCK) {
			regs->r9 = __NR_restart_syscall;
			regs->irp -= 2;
		}
	}

	/* if there's no signal to deliver, we just put the saved sigmask
	 * back */
	restore_saved_sigmask();
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
1da177e4 LT	2	/*
	3	* linux/arch/cris/kernel/signal.c
	4	*
	5	* Based on arch/i386/kernel/signal.c by
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson *
	8	*
	9	* Ideas also taken from arch/arm.
	10	*
a4858d4d	11	* Copyright (C) 2000-2007 Axis Communications AB
1da177e4 LT	12	*
	13	* Authors: Bjorn Wesen (bjornw@axis.com)
	14	*
	15	*/
	16
	17	#include <linux/sched.h>
68db0cf1	18	#include <linux/sched/task_stack.h>
1da177e4 LT	19	#include <linux/mm.h>
1da177e4 LT	20	#include <linux/smp.h>
1da177e4 LT	21	#include <linux/kernel.h>
	22	#include <linux/signal.h>
	23	#include <linux/errno.h>
	24	#include <linux/wait.h>
	25	#include <linux/ptrace.h>
	26	#include <linux/unistd.h>
	27	#include <linux/stddef.h>
	28
	29	#include <asm/processor.h>
	30	#include <asm/ucontext.h>
7c0f6ba6	31	#include <linux/uaccess.h>
b1a154db	32	#include <arch/system.h>
1da177e4 LT	33
	34	#define DEBUG_SIG 0
	35
1da177e4 LT	36	/* a syscall in Linux/CRIS is a break 13 instruction which is 2 bytes */
	37	/* manipulate regs so that upon return, it will be re-executed */
	38
	39	/* We rely on that pc points to the instruction after "break 13", so the
	40	* library must never do strange things like putting it in a delay slot.
	41	*/
	42	#define RESTART_CRIS_SYS(regs) regs->r10 = regs->orig_r10; regs->irp -= 2;
	43
a4858d4d	44	void do_signal(int canrestart, struct pt_regs *regs);
1da177e4	45
1da177e4 LT	46	/*
	47	* Do a signal return; undo the signal stack.
	48	*/
	49
	50	struct sigframe {
	51	struct sigcontext sc;
	52	unsigned long extramask[_NSIG_WORDS-1];
	53	unsigned char retcode[8]; /* trampoline code */
	54	};
	55
	56	struct rt_sigframe {
	57	struct siginfo *pinfo;
	58	void *puc;
	59	struct siginfo info;
	60	struct ucontext uc;
	61	unsigned char retcode[8]; /* trampoline code */
	62	};
	63
	64
	65	static int
	66	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	67	{
	68	unsigned int err = 0;
	69	unsigned long old_usp;
	70
	71	/* Always make any pending restarted system calls return -EINTR */
f56141e3	72	current->restart_block.fn = do_no_restart_syscall;
1da177e4 LT	73
	74	/* restore the regs from &sc->regs (same as sc, since regs is first)
	75	* (sc is already checked for VERIFY_READ since the sigframe was
	76	* checked in sys_sigreturn previously)
	77	*/
	78
	79	if (__copy_from_user(regs, sc, sizeof(struct pt_regs)))
	80	goto badframe;
	81
	82	/* make sure the U-flag is set so user-mode cannot fool us */
	83
	84	regs->dccr \|= 1 << 8;
	85
	86	/* restore the old USP as it was before we stacked the sc etc.
	87	* (we cannot just pop the sigcontext since we aligned the sp and
	88	* stuff after pushing it)
	89	*/
	90
	91	err \|= __get_user(old_usp, &sc->usp);
	92
	93	wrusp(old_usp);
	94
	95	/* TODO: the other ports use regs->orig_XX to disable syscall checks
	96	* after this completes, but we don't use that mechanism. maybe we can
a4858d4d	97	* use it now ?
1da177e4 LT	98	*/
	99
	100	return err;
	101
	102	badframe:
	103	return 1;
	104	}
	105
e6a6d210	106	asmlinkage int sys_sigreturn(void)
1da177e4	107	{
e6a6d210	108	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	109	struct sigframe __user frame = (struct sigframe )rdusp();
	110	sigset_t set;
	111
	112	/*
	113	* Since we stacked the signal on a dword boundary,
	114	* then frame should be dword aligned here. If it's
	115	* not, then the user is trying to mess with us.
	116	*/
	117	if (((long)frame) & 3)
	118	goto badframe;
	119
	120	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	121	goto badframe;
	122	if (__get_user(set.sig[0], &frame->sc.oldmask)
	123	\|\| (_NSIG_WORDS > 1
	124	&& __copy_from_user(&set.sig[1], frame->extramask,
	125	sizeof(frame->extramask))))
	126	goto badframe;
	127
f3b5e822	128	set_current_blocked(&set);
a4858d4d	129
1da177e4 LT	130	if (restore_sigcontext(regs, &frame->sc))
	131	goto badframe;
	132
	133	/* TODO: SIGTRAP when single-stepping as in arm ? */
	134
	135	return regs->r10;
	136
	137	badframe:
	138	force_sig(SIGSEGV, current);
	139	return 0;
a4858d4d	140	}
1da177e4	141
e6a6d210	142	asmlinkage int sys_rt_sigreturn(void)
1da177e4	143	{
e6a6d210	144	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	145	struct rt_sigframe __user frame = (struct rt_sigframe )rdusp();
	146	sigset_t set;
	147
	148	/*
	149	* Since we stacked the signal on a dword boundary,
	150	* then frame should be dword aligned here. If it's
	151	* not, then the user is trying to mess with us.
	152	*/
	153	if (((long)frame) & 3)
	154	goto badframe;
	155
	156	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	157	goto badframe;
	158	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	159	goto badframe;
	160
f3b5e822	161	set_current_blocked(&set);
a4858d4d	162
1da177e4 LT	163	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
	164	goto badframe;
	165
d970e428	166	if (restore_altstack(&frame->uc.uc_stack))
1da177e4 LT	167	goto badframe;
	168
	169	return regs->r10;
	170
	171	badframe:
	172	force_sig(SIGSEGV, current);
	173	return 0;
a4858d4d	174	}
1da177e4 LT	175
	176	/*
	177	* Set up a signal frame.
	178	*/
	179
a4858d4d JN	180	static int setup_sigcontext(struct sigcontext __user *sc,
a4858d4d JN	181	struct pt_regs *regs, unsigned long mask)
1da177e4 LT	182	{
	183	int err = 0;
	184	unsigned long usp = rdusp();
	185
	186	/* copy the regs. they are first in sc so we can use sc directly */
	187
	188	err \|= __copy_to_user(sc, regs, sizeof(struct pt_regs));
	189
	190	/* Set the frametype to CRIS_FRAME_NORMAL for the execution of
	191	the signal handler. The frametype will be restored to its previous
	192	value in restore_sigcontext. */
	193	regs->frametype = CRIS_FRAME_NORMAL;
	194
	195	/* then some other stuff */
	196
	197	err \|= __put_user(mask, &sc->oldmask);
	198
	199	err \|= __put_user(usp, &sc->usp);
	200
	201	return err;
	202	}
	203
a4858d4d JN	204	/* Figure out where we want to put the new signal frame
a4858d4d JN	205	* - usually on the stack. */
1da177e4 LT	206
1da177e4 LT	207	static inline void __user *
8215ade8	208	get_sigframe(struct ksignal *ksig, size_t frame_size)
1da177e4	209	{
8215ade8	210	unsigned long sp = sigsp(rdusp(), ksig);
1da177e4 LT	211
	212	/* make sure the frame is dword-aligned */
	213
	214	sp &= ~3;
	215
	216	return (void __user*)(sp - frame_size);
	217	}
	218
	219	/* grab and setup a signal frame.
a4858d4d	220	*
1da177e4 LT	221	* basically we stack a lot of state info, and arrange for the
	222	* user-mode program to return to the kernel using either a
	223	* trampoline which performs the syscall sigreturn, or a provided
	224	* user-mode trampoline.
	225	*/
	226
fa019772 RW	227	static int setup_frame(struct ksignal ksig, sigset_t set,
fa019772 RW	228	struct pt_regs *regs)
1da177e4 LT	229	{
	230	struct sigframe __user *frame;
	231	unsigned long return_ip;
	232	int err = 0;
	233
8215ade8	234	frame = get_sigframe(ksig, sizeof(*frame));
1da177e4 LT	235
1da177e4 LT	236	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
fa019772	237	return -EFAULT;
1da177e4 LT	238
	239	err \|= setup_sigcontext(&frame->sc, regs, set->sig[0]);
	240	if (err)
fa019772	241	return -EFAULT;
1da177e4 LT	242
	243	if (_NSIG_WORDS > 1) {
	244	err \|= __copy_to_user(frame->extramask, &set->sig[1],
	245	sizeof(frame->extramask));
	246	}
	247	if (err)
fa019772	248	return -EFAULT;
1da177e4 LT	249
	250	/* Set up to return from userspace. If provided, use a stub
	251	already in userspace. */
fa019772 RW	252	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
fa019772 RW	253	return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
1da177e4 LT	254	} else {
	255	/* trampoline - the desired return ip is the retcode itself */
	256	return_ip = (unsigned long)&frame->retcode;
	257	/* This is movu.w __NR_sigreturn, r9; break 13; */
	258	err \|= __put_user(0x9c5f, (short __user*)(frame->retcode+0));
	259	err \|= __put_user(__NR_sigreturn, (short __user*)(frame->retcode+2));
	260	err \|= __put_user(0xe93d, (short __user*)(frame->retcode+4));
	261	}
	262
	263	if (err)
fa019772	264	return -EFAULT;
1da177e4 LT	265
	266	/* Set up registers for signal handler */
	267
fa019772	268	regs->irp = (unsigned long) ksig->ka.sa.sa_handler; /* what we enter NOW */
1da177e4	269	regs->srp = return_ip; /* what we enter LATER */
fa019772	270	regs->r10 = ksig->sig; /* first argument is signo */
1da177e4 LT	271
	272	/* actually move the usp to reflect the stacked frame */
	273
	274	wrusp((unsigned long)frame);
	275
a4858d4d	276	return 0;
1da177e4 LT	277	}
1da177e4 LT	278
fa019772 RW	279	static int setup_rt_frame(struct ksignal ksig, sigset_t set,
fa019772 RW	280	struct pt_regs *regs)
1da177e4 LT	281	{
	282	struct rt_sigframe __user *frame;
	283	unsigned long return_ip;
	284	int err = 0;
	285
8215ade8	286	frame = get_sigframe(ksig, sizeof(*frame));
1da177e4 LT	287
1da177e4 LT	288	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
fa019772	289	return -EFAULT;
1da177e4 LT	290
	291	err \|= __put_user(&frame->info, &frame->pinfo);
	292	err \|= __put_user(&frame->uc, &frame->puc);
fa019772	293	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4	294	if (err)
fa019772	295	return -EFAULT;
1da177e4 LT	296
	297	/* Clear all the bits of the ucontext we don't use. */
	298	err \|= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
	299
	300	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	301
	302	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	303
9df794d9 AV	304	err \|= __save_altstack(&frame->uc.uc_stack, rdusp());
9df794d9 AV	305
1da177e4	306	if (err)
fa019772	307	return -EFAULT;
1da177e4 LT	308
	309	/* Set up to return from userspace. If provided, use a stub
	310	already in userspace. */
fa019772 RW	311	if (ksig->ka.sa.sa_flags & SA_RESTORER) {
fa019772 RW	312	return_ip = (unsigned long)ksig->ka.sa.sa_restorer;
1da177e4 LT	313	} else {
	314	/* trampoline - the desired return ip is the retcode itself */
	315	return_ip = (unsigned long)&frame->retcode;
	316	/* This is movu.w __NR_rt_sigreturn, r9; break 13; */
a4858d4d JN	317	err \|= __put_user(0x9c5f, (short __user *)(frame->retcode+0));
	318	err \|= __put_user(__NR_rt_sigreturn,
	319	(short __user *)(frame->retcode+2));
	320	err \|= __put_user(0xe93d, (short __user *)(frame->retcode+4));
1da177e4 LT	321	}
	322
	323	if (err)
fa019772	324	return -EFAULT;
1da177e4	325
1da177e4 LT	326	/* Set up registers for signal handler */
1da177e4 LT	327
a4858d4d	328	/* What we enter NOW */
fa019772	329	regs->irp = (unsigned long) ksig->ka.sa.sa_handler;
a4858d4d JN	330	/* What we enter LATER */
	331	regs->srp = return_ip;
	332	/* First argument is signo */
fa019772	333	regs->r10 = ksig->sig;
a4858d4d JN	334	/* Second argument is (siginfo_t ) /
	335	regs->r11 = (unsigned long)&frame->info;
	336	/* Third argument is unused */
	337	regs->r12 = 0;
	338
	339	/* Actually move the usp to reflect the stacked frame */
1da177e4 LT	340	wrusp((unsigned long)frame);
1da177e4 LT	341
a4858d4d	342	return 0;
1da177e4 LT	343	}
	344
	345	/*
	346	* OK, we're invoking a handler
a4858d4d	347	*/
1da177e4	348
fa019772 RW	349	static inline void handle_signal(int canrestart, struct ksignal *ksig,
fa019772 RW	350	struct pt_regs *regs)
1da177e4	351	{
b7f9a11a	352	sigset_t *oldset = sigmask_to_save();
a4858d4d JN	353	int ret;
a4858d4d JN	354
1da177e4 LT	355	/* Are we from a system call? */
	356	if (canrestart) {
	357	/* If so, check system call restarting.. */
	358	switch (regs->r10) {
a4858d4d JN	359	case -ERESTART_RESTARTBLOCK:
	360	case -ERESTARTNOHAND:
	361	/* ERESTARTNOHAND means that the syscall should
	362	* only be restarted if there was no handler for
	363	* the signal, and since we only get here if there
	364	* is a handler, we don't restart */
	365	regs->r10 = -EINTR;
	366	break;
	367	case -ERESTARTSYS:
	368	/* ERESTARTSYS means to restart the syscall if
	369	* there is no handler or the handler was
	370	* registered with SA_RESTART */
fa019772	371	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
1da177e4 LT	372	regs->r10 = -EINTR;
1da177e4 LT	373	break;
a4858d4d JN	374	}
	375	/* fallthrough */
	376	case -ERESTARTNOINTR:
	377	/* ERESTARTNOINTR means that the syscall should
	378	* be called again after the signal handler returns. */
	379	RESTART_CRIS_SYS(regs);
1da177e4 LT	380	}
	381	}
	382
	383	/* Set up the stack frame */
fa019772 RW	384	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
fa019772 RW	385	ret = setup_rt_frame(ksig, oldset, regs);
1da177e4	386	else
fa019772	387	ret = setup_frame(ksig, oldset, regs);
a4858d4d	388
fa019772	389	signal_setup_done(ret, ksig, 0);
1da177e4 LT	390	}
	391
	392	/*
	393	* Note that 'init' is a special process: it doesn't get signals it doesn't
	394	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	395	* mistake.
	396	*
	397	* Also note that the regs structure given here as an argument, is the latest
	398	* pushed pt_regs. It may or may not be the same as the first pushed registers
	399	* when the initial usermode->kernelmode transition took place. Therefore
	400	* we can use user_mode(regs) to see if we came directly from kernel or user
	401	* mode below.
	402	*/
	403
a4858d4d	404	void do_signal(int canrestart, struct pt_regs *regs)
1da177e4	405	{
fa019772	406	struct ksignal ksig;
1da177e4 LT	407
	408	/*
	409	* We want the common case to go fast, which
	410	* is why we may in certain cases get here from
	411	* kernel mode. Just return without doing anything
	412	* if so.
	413	*/
	414	if (!user_mode(regs))
a4858d4d	415	return;
1da177e4	416
fa019772	417	if (get_signal(&ksig)) {
1da177e4	418	/* Whee! Actually deliver the signal. */
fa019772	419	handle_signal(canrestart, &ksig, regs);
a4858d4d	420	return;
1da177e4 LT	421	}
	422
	423	/* Did we come from a system call? */
	424	if (canrestart) {
	425	/* Restart the system call - no handlers present */
	426	if (regs->r10 == -ERESTARTNOHAND \|\|
	427	regs->r10 == -ERESTARTSYS \|\|
	428	regs->r10 == -ERESTARTNOINTR) {
	429	RESTART_CRIS_SYS(regs);
	430	}
a4858d4d	431	if (regs->r10 == -ERESTART_RESTARTBLOCK) {
33dc0ad7	432	regs->r9 = __NR_restart_syscall;
1da177e4 LT	433	regs->irp -= 2;
	434	}
	435	}
a4858d4d JN	436
	437	/* if there's no signal to deliver, we just put the saved sigmask
	438	* back */
51a7b448	439	restore_saved_sigmask();
1da177e4	440	}