[linux-2.6-block.git] / arch / um / sys-i386 / signal.c

/*
 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <linux/ptrace.h>
#include <asm/unistd.h>
#include <asm/uaccess.h>
#include <asm/ucontext.h>
#include "frame_kern.h"
#include "skas.h"

void copy_sc(struct uml_pt_regs *regs, void *from)
{
	struct sigcontext *sc = from;

	REGS_GS(regs->gp) = sc->gs;
	REGS_FS(regs->gp) = sc->fs;
	REGS_ES(regs->gp) = sc->es;
	REGS_DS(regs->gp) = sc->ds;
	REGS_EDI(regs->gp) = sc->di;
	REGS_ESI(regs->gp) = sc->si;
	REGS_EBP(regs->gp) = sc->bp;
	REGS_SP(regs->gp) = sc->sp;
	REGS_EBX(regs->gp) = sc->bx;
	REGS_EDX(regs->gp) = sc->dx;
	REGS_ECX(regs->gp) = sc->cx;
	REGS_EAX(regs->gp) = sc->ax;
	REGS_IP(regs->gp) = sc->ip;
	REGS_CS(regs->gp) = sc->cs;
	REGS_EFLAGS(regs->gp) = sc->flags;
	REGS_SS(regs->gp) = sc->ss;
}

/*
 * FPU tag word conversions.
 */

static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
{
	unsigned int tmp; /* to avoid 16 bit prefixes in the code */

	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
	tmp = ~twd;
	tmp = (tmp | (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
	/* and move the valid bits to the lower byte. */
	tmp = (tmp | (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
	tmp = (tmp | (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
	tmp = (tmp | (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
	return tmp;
}

static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
{
	struct _fpxreg *st = NULL;
	unsigned long twd = (unsigned long) fxsave->twd;
	unsigned long tag;
	unsigned long ret = 0xffff0000;
	int i;

#define FPREG_ADDR(f, n)	((char *)&(f)->st_space + (n) * 16);

	for (i = 0; i < 8; i++) {
		if (twd & 0x1) {
			st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);

			switch (st->exponent & 0x7fff) {
			case 0x7fff:
				tag = 2;		/* Special */
				break;
			case 0x0000:
				if ( !st->significand[0] &&
				     !st->significand[1] &&
				     !st->significand[2] &&
				     !st->significand[3] ) {
					tag = 1;	/* Zero */
				} else {
					tag = 2;	/* Special */
				}
				break;
			default:
				if (st->significand[3] & 0x8000) {
					tag = 0;	/* Valid */
				} else {
					tag = 2;	/* Special */
				}
				break;
			}
		} else {
			tag = 3;			/* Empty */
		}
		ret |= (tag << (2 * i));
		twd = twd >> 1;
	}
	return ret;
}

static int convert_fxsr_to_user(struct _fpstate __user *buf,
				struct user_fxsr_struct *fxsave)
{
	unsigned long env[7];
	struct _fpreg __user *to;
	struct _fpxreg *from;
	int i;

	env[0] = (unsigned long)fxsave->cwd | 0xffff0000ul;
	env[1] = (unsigned long)fxsave->swd | 0xffff0000ul;
	env[2] = twd_fxsr_to_i387(fxsave);
	env[3] = fxsave->fip;
	env[4] = fxsave->fcs | ((unsigned long)fxsave->fop << 16);
	env[5] = fxsave->foo;
	env[6] = fxsave->fos;

	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
		return 1;

	to = &buf->_st[0];
	from = (struct _fpxreg *) &fxsave->st_space[0];
	for (i = 0; i < 8; i++, to++, from++) {
		unsigned long __user *t = (unsigned long __user *)to;
		unsigned long *f = (unsigned long *)from;

		if (__put_user(*f, t) ||
				__put_user(*(f + 1), t + 1) ||
				__put_user(from->exponent, &to->exponent))
			return 1;
	}
	return 0;
}

static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
				  struct _fpstate __user *buf)
{
	unsigned long env[7];
	struct _fpxreg *to;
	struct _fpreg __user *from;
	int i;

	if (copy_from_user( env, buf, 7 * sizeof(long)))
		return 1;

	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
	fxsave->swd = (unsigned short)(env[1] & 0xffff);
	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
	fxsave->fip = env[3];
	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
	fxsave->fcs = (env[4] & 0xffff);
	fxsave->foo = env[5];
	fxsave->fos = env[6];

	to = (struct _fpxreg *) &fxsave->st_space[0];
	from = &buf->_st[0];
	for (i = 0; i < 8; i++, to++, from++) {
		unsigned long *t = (unsigned long *)to;
		unsigned long __user *f = (unsigned long __user *)from;

		if (__get_user(*t, f) ||
		    __get_user(*(t + 1), f + 1) ||
		    __get_user(to->exponent, &from->exponent))
			return 1;
	}
	return 0;
}

extern int have_fpx_regs;

static int copy_sc_from_user(struct pt_regs *regs,
			     struct sigcontext __user *from)
{
	struct sigcontext sc;
	int err, pid;

	err = copy_from_user(&sc, from, sizeof(sc));
	if (err)
		return err;

	pid = userspace_pid[current_thread_info()->cpu];
	copy_sc(&regs->regs, &sc);
	if (have_fpx_regs) {
		struct user_fxsr_struct fpx;

		err = copy_from_user(&fpx,
			&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
				     sizeof(struct user_fxsr_struct));
		if (err)
			return 1;

		err = convert_fxsr_from_user(&fpx, sc.fpstate);
		if (err)
			return 1;

		err = restore_fpx_registers(pid, (unsigned long *) &fpx);
		if (err < 0) {
			printk(KERN_ERR "copy_sc_from_user - "
			       "restore_fpx_registers failed, errno = %d\n",
			       -err);
			return 1;
		}
	}
	else {
		struct user_i387_struct fp;

		err = copy_from_user(&fp, sc.fpstate,
				     sizeof(struct user_i387_struct));
		if (err)
			return 1;

		err = restore_fp_registers(pid, (unsigned long *) &fp);
		if (err < 0) {
			printk(KERN_ERR "copy_sc_from_user - "
			       "restore_fp_registers failed, errno = %d\n",
			       -err);
			return 1;
		}
	}

	return 0;
}

static int copy_sc_to_user(struct sigcontext __user *to,
			   struct _fpstate __user *to_fp, struct pt_regs *regs,
			   unsigned long sp)
{
	struct sigcontext sc;
	struct faultinfo * fi = &current->thread.arch.faultinfo;
	int err, pid;

	sc.gs = REGS_GS(regs->regs.gp);
	sc.fs = REGS_FS(regs->regs.gp);
	sc.es = REGS_ES(regs->regs.gp);
	sc.ds = REGS_DS(regs->regs.gp);
	sc.di = REGS_EDI(regs->regs.gp);
	sc.si = REGS_ESI(regs->regs.gp);
	sc.bp = REGS_EBP(regs->regs.gp);
	sc.sp = sp;
	sc.bx = REGS_EBX(regs->regs.gp);
	sc.dx = REGS_EDX(regs->regs.gp);
	sc.cx = REGS_ECX(regs->regs.gp);
	sc.ax = REGS_EAX(regs->regs.gp);
	sc.ip = REGS_IP(regs->regs.gp);
	sc.cs = REGS_CS(regs->regs.gp);
	sc.flags = REGS_EFLAGS(regs->regs.gp);
	sc.sp_at_signal = regs->regs.gp[UESP];
	sc.ss = regs->regs.gp[SS];
	sc.cr2 = fi->cr2;
	sc.err = fi->error_code;
	sc.trapno = fi->trap_no;

	to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
	sc.fpstate = to_fp;

	pid = userspace_pid[current_thread_info()->cpu];
	if (have_fpx_regs) {
		struct user_fxsr_struct fpx;

		err = save_fpx_registers(pid, (unsigned long *) &fpx);
		if (err < 0){
			printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
			       "failed, errno = %d\n", err);
			return 1;
		}

		err = convert_fxsr_to_user(to_fp, &fpx);
		if (err)
			return 1;

		err |= __put_user(fpx.swd, &to_fp->status);
		err |= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
		if (err)
			return 1;

		if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
				 sizeof(struct user_fxsr_struct)))
			return 1;
	}
	else {
		struct user_i387_struct fp;

		err = save_fp_registers(pid, (unsigned long *) &fp);
		if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
			return 1;
	}

	return copy_to_user(to, &sc, sizeof(sc));
}

static int copy_ucontext_to_user(struct ucontext __user *uc,
				 struct _fpstate __user *fp, sigset_t *set,
				 unsigned long sp)
{
	int err = 0;

	err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
	err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
	err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
	err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
	return err;
}

struct sigframe
{
	char __user *pretcode;
	int sig;
	struct sigcontext sc;
	struct _fpstate fpstate;
	unsigned long extramask[_NSIG_WORDS-1];
	char retcode[8];
};

struct rt_sigframe
{
	char __user *pretcode;
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	struct _fpstate fpstate;
	char retcode[8];
};

int setup_signal_stack_sc(unsigned long stack_top, int sig,
			  struct k_sigaction *ka, struct pt_regs *regs,
			  sigset_t *mask)
{
	struct sigframe __user *frame;
	void __user *restorer;
	unsigned long save_sp = PT_REGS_SP(regs);
	int err = 0;

	/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
	stack_top = ((stack_top + 4) & -16UL) - 4;
	frame = (struct sigframe __user *) stack_top - 1;
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return 1;

	restorer = frame->retcode;
	if (ka->sa.sa_flags & SA_RESTORER)
		restorer = ka->sa.sa_restorer;

	/* Update SP now because the page fault handler refuses to extend
	 * the stack if the faulting address is too far below the current
	 * SP, which frame now certainly is.  If there's an error, the original
	 * value is restored on the way out.
	 * When writing the sigcontext to the stack, we have to write the
	 * original value, so that's passed to copy_sc_to_user, which does
	 * the right thing with it.
	 */
	PT_REGS_SP(regs) = (unsigned long) frame;

	err |= __put_user(restorer, &frame->pretcode);
	err |= __put_user(sig, &frame->sig);
	err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
	err |= __put_user(mask->sig[0], &frame->sc.oldmask);
	if (_NSIG_WORDS > 1)
		err |= __copy_to_user(&frame->extramask, &mask->sig[1],
				      sizeof(frame->extramask));

	/*
	 * This is popl %eax ; movl $,%eax ; int $0x80
	 *
	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
	 * reasons and because gdb uses it as a signature to notice
	 * signal handler stack frames.
	 */
	err |= __put_user(0xb858, (short __user *)(frame->retcode+0));
	err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
	err |= __put_user(0x80cd, (short __user *)(frame->retcode+6));

	if (err)
		goto err;

	PT_REGS_SP(regs) = (unsigned long) frame;
	PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
	PT_REGS_EAX(regs) = (unsigned long) sig;
	PT_REGS_EDX(regs) = (unsigned long) 0;
	PT_REGS_ECX(regs) = (unsigned long) 0;

	if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
		ptrace_notify(SIGTRAP);
	return 0;

err:
	PT_REGS_SP(regs) = save_sp;
	return err;
}

int setup_signal_stack_si(unsigned long stack_top, int sig,
			  struct k_sigaction *ka, struct pt_regs *regs,
			  siginfo_t *info, sigset_t *mask)
{
	struct rt_sigframe __user *frame;
	void __user *restorer;
	unsigned long save_sp = PT_REGS_SP(regs);
	int err = 0;

	stack_top &= -8UL;
	frame = (struct rt_sigframe __user *) stack_top - 1;
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return 1;

	restorer = frame->retcode;
	if (ka->sa.sa_flags & SA_RESTORER)
		restorer = ka->sa.sa_restorer;

	/* See comment above about why this is here */
	PT_REGS_SP(regs) = (unsigned long) frame;

	err |= __put_user(restorer, &frame->pretcode);
	err |= __put_user(sig, &frame->sig);
	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
				     save_sp);

	/*
	 * This is movl $,%eax ; int $0x80
	 *
	 * WE DO NOT USE IT ANY MORE! It's only left here for historical
	 * reasons and because gdb uses it as a signature to notice
	 * signal handler stack frames.
	 */
	err |= __put_user(0xb8, (char __user *)(frame->retcode+0));
	err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
	err |= __put_user(0x80cd, (short __user *)(frame->retcode+5));

	if (err)
		goto err;

	PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
	PT_REGS_EAX(regs) = (unsigned long) sig;
	PT_REGS_EDX(regs) = (unsigned long) &frame->info;
	PT_REGS_ECX(regs) = (unsigned long) &frame->uc;

	if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
		ptrace_notify(SIGTRAP);
	return 0;

err:
	PT_REGS_SP(regs) = save_sp;
	return err;
}

long sys_sigreturn(struct pt_regs regs)
{
	unsigned long sp = PT_REGS_SP(&current->thread.regs);
	struct sigframe __user *frame = (struct sigframe __user *)(sp - 8);
	sigset_t set;
	struct sigcontext __user *sc = &frame->sc;
	unsigned long __user *oldmask = &sc->oldmask;
	unsigned long __user *extramask = frame->extramask;
	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);

	if (copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) ||
	    copy_from_user(&set.sig[1], extramask, sig_size))
		goto segfault;

	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	if (copy_sc_from_user(&current->thread.regs, sc))
		goto segfault;

	/* Avoid ERESTART handling */
	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
	return PT_REGS_SYSCALL_RET(&current->thread.regs);

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

long sys_rt_sigreturn(struct pt_regs regs)
{
	unsigned long sp = PT_REGS_SP(&current->thread.regs);
	struct rt_sigframe __user *frame =
		(struct rt_sigframe __user *) (sp - 4);
	sigset_t set;
	struct ucontext __user *uc = &frame->uc;
	int sig_size = _NSIG_WORDS * sizeof(unsigned long);

	if (copy_from_user(&set, &uc->uc_sigmask, sig_size))
		goto segfault;

	sigdelsetmask(&set, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
		goto segfault;

	/* Avoid ERESTART handling */
	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
	return PT_REGS_SYSCALL_RET(&current->thread.regs);

 segfault:
	force_sig(SIGSEGV, current);
	return 0;
}
Commit	Line	Data
1da177e4	1	/*
ba180fd4	2	* Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
1da177e4 LT	3	* Licensed under the GPL
	4	*/
	5
7796931f JD	6	#include <linux/ptrace.h>
	7	#include <asm/unistd.h>
	8	#include <asm/uaccess.h>
	9	#include <asm/ucontext.h>
1da177e4	10	#include "frame_kern.h"
1da177e4 LT	11	#include "skas.h"
1da177e4 LT	12
77bf4400	13	void copy_sc(struct uml_pt_regs regs, void from)
377fad3a JD	14	{
	15	struct sigcontext *sc = from;
	16
18baddda JD	17	REGS_GS(regs->gp) = sc->gs;
	18	REGS_FS(regs->gp) = sc->fs;
	19	REGS_ES(regs->gp) = sc->es;
	20	REGS_DS(regs->gp) = sc->ds;
7796931f JD	21	REGS_EDI(regs->gp) = sc->di;
	22	REGS_ESI(regs->gp) = sc->si;
	23	REGS_EBP(regs->gp) = sc->bp;
	24	REGS_SP(regs->gp) = sc->sp;
	25	REGS_EBX(regs->gp) = sc->bx;
	26	REGS_EDX(regs->gp) = sc->dx;
	27	REGS_ECX(regs->gp) = sc->cx;
	28	REGS_EAX(regs->gp) = sc->ax;
	29	REGS_IP(regs->gp) = sc->ip;
18baddda	30	REGS_CS(regs->gp) = sc->cs;
7796931f	31	REGS_EFLAGS(regs->gp) = sc->flags;
18baddda	32	REGS_SS(regs->gp) = sc->ss;
377fad3a JD	33	}
377fad3a JD	34
a5f6096c JD	35	/*
	36	* FPU tag word conversions.
	37	*/
	38
	39	static inline unsigned short twd_i387_to_fxsr(unsigned short twd)
	40	{
	41	unsigned int tmp; /* to avoid 16 bit prefixes in the code */
	42
	43	/* Transform each pair of bits into 01 (valid) or 00 (empty) */
	44	tmp = ~twd;
	45	tmp = (tmp \| (tmp>>1)) & 0x5555; /* 0V0V0V0V0V0V0V0V */
	46	/* and move the valid bits to the lower byte. */
	47	tmp = (tmp \| (tmp >> 1)) & 0x3333; /* 00VV00VV00VV00VV */
	48	tmp = (tmp \| (tmp >> 2)) & 0x0f0f; /* 0000VVVV0000VVVV */
	49	tmp = (tmp \| (tmp >> 4)) & 0x00ff; /* 00000000VVVVVVVV */
	50	return tmp;
	51	}
	52
	53	static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
	54	{
	55	struct _fpxreg *st = NULL;
	56	unsigned long twd = (unsigned long) fxsave->twd;
	57	unsigned long tag;
	58	unsigned long ret = 0xffff0000;
	59	int i;
	60
	61	#define FPREG_ADDR(f, n) ((char )&(f)->st_space + (n) 16);
	62
	63	for (i = 0; i < 8; i++) {
	64	if (twd & 0x1) {
	65	st = (struct _fpxreg *) FPREG_ADDR(fxsave, i);
	66
	67	switch (st->exponent & 0x7fff) {
	68	case 0x7fff:
	69	tag = 2; /* Special */
	70	break;
	71	case 0x0000:
	72	if ( !st->significand[0] &&
	73	!st->significand[1] &&
	74	!st->significand[2] &&
	75	!st->significand[3] ) {
	76	tag = 1; /* Zero */
	77	} else {
	78	tag = 2; /* Special */
	79	}
	80	break;
	81	default:
	82	if (st->significand[3] & 0x8000) {
	83	tag = 0; /* Valid */
	84	} else {
	85	tag = 2; /* Special */
	86	}
	87	break;
	88	}
	89	} else {
	90	tag = 3; /* Empty */
	91	}
	92	ret \|= (tag << (2 * i));
	93	twd = twd >> 1;
	94	}
	95	return ret;
	96	}
	97
	98	static int convert_fxsr_to_user(struct _fpstate __user *buf,
99	struct user_fxsr_struct *fxsave)
100	{
101	unsigned long env[7];
102	struct _fpreg __user *to;
103	struct _fpxreg *from;
104	int i;
105
106	env[0] = (unsigned long)fxsave->cwd \| 0xffff0000ul;
107	env[1] = (unsigned long)fxsave->swd \| 0xffff0000ul;
108	env[2] = twd_fxsr_to_i387(fxsave);
109	env[3] = fxsave->fip;
110	env[4] = fxsave->fcs \| ((unsigned long)fxsave->fop << 16);
111	env[5] = fxsave->foo;
112	env[6] = fxsave->fos;
113
114	if (__copy_to_user(buf, env, 7 * sizeof(unsigned long)))
115	return 1;
116
117	to = &buf->_st[0];
118	from = (struct _fpxreg *) &fxsave->st_space[0];
119	for (i = 0; i < 8; i++, to++, from++) {
120	unsigned long __user t = (unsigned long __user )to;
121	unsigned long f = (unsigned long )from;
122
123	if (__put_user(*f, t) \|\|
124	__put_user(*(f + 1), t + 1) \|\|
125	__put_user(from->exponent, &to->exponent))
126	return 1;
127	}
128	return 0;
129	}
130
131	static int convert_fxsr_from_user(struct user_fxsr_struct *fxsave,
132	struct _fpstate __user *buf)
133	{
134	unsigned long env[7];
135	struct _fpxreg *to;
136	struct _fpreg __user *from;
137	int i;
138
139	if (copy_from_user( env, buf, 7 * sizeof(long)))
140	return 1;
141
142	fxsave->cwd = (unsigned short)(env[0] & 0xffff);
143	fxsave->swd = (unsigned short)(env[1] & 0xffff);
144	fxsave->twd = twd_i387_to_fxsr((unsigned short)(env[2] & 0xffff));
145	fxsave->fip = env[3];
146	fxsave->fop = (unsigned short)((env[4] & 0xffff0000ul) >> 16);
147	fxsave->fcs = (env[4] & 0xffff);
148	fxsave->foo = env[5];
149	fxsave->fos = env[6];
150
151	to = (struct _fpxreg *) &fxsave->st_space[0];
152	from = &buf->_st[0];
153	for (i = 0; i < 8; i++, to++, from++) {
154	unsigned long t = (unsigned long )to;
155	unsigned long __user f = (unsigned long __user )from;
156
157	if (__get_user(*t, f) \|\|
158	__get_user(*(t + 1), f + 1) \|\|
159	__get_user(to->exponent, &from->exponent))
160	return 1;
161	}
162	return 0;
163	}
164
165	extern int have_fpx_regs;
166
77bf4400 JD	167	static int copy_sc_from_user(struct pt_regs *regs,
77bf4400 JD	168	struct sigcontext __user *from)
1da177e4	169	{
a5f6096c	170	struct sigcontext sc;
a5a678c8	171	int err, pid;
1da177e4 LT	172
1da177e4 LT	173	err = copy_from_user(&sc, from, sizeof(sc));
ba180fd4	174	if (err)
5d86456d	175	return err;
1da177e4	176
a5a678c8	177	pid = userspace_pid[current_thread_info()->cpu];
377fad3a	178	copy_sc(&regs->regs, &sc);
a5f6096c JD	179	if (have_fpx_regs) {
a5f6096c JD	180	struct user_fxsr_struct fpx;
1da177e4	181
966c8079 WC	182	err = copy_from_user(&fpx,
966c8079 WC	183	&((struct _fpstate __user *)sc.fpstate)->_fxsr_env[0],
a5f6096c JD	184	sizeof(struct user_fxsr_struct));
	185	if (err)
	186	return 1;
	187
	188	err = convert_fxsr_from_user(&fpx, sc.fpstate);
	189	if (err)
	190	return 1;
	191
a5a678c8	192	err = restore_fpx_registers(pid, (unsigned long *) &fpx);
a5f6096c JD	193	if (err < 0) {
	194	printk(KERN_ERR "copy_sc_from_user - "
	195	"restore_fpx_registers failed, errno = %d\n",
	196	-err);
	197	return 1;
	198	}
	199	}
	200	else {
	201	struct user_i387_struct fp;
	202
	203	err = copy_from_user(&fp, sc.fpstate,
	204	sizeof(struct user_i387_struct));
	205	if (err)
	206	return 1;
	207
a5a678c8	208	err = restore_fp_registers(pid, (unsigned long *) &fp);
a5f6096c JD	209	if (err < 0) {
	210	printk(KERN_ERR "copy_sc_from_user - "
	211	"restore_fp_registers failed, errno = %d\n",
	212	-err);
	213	return 1;
	214	}
1da177e4 LT	215	}
1da177e4 LT	216
5d86456d	217	return 0;
1da177e4 LT	218	}
1da177e4 LT	219
77bf4400 JD	220	static int copy_sc_to_user(struct sigcontext __user *to,
	221	struct _fpstate __user to_fp, struct pt_regs regs,
	222	unsigned long sp)
1da177e4	223	{
ba180fd4	224	struct sigcontext sc;
c578455a	225	struct faultinfo * fi = &current->thread.arch.faultinfo;
a5a678c8	226	int err, pid;
1da177e4	227
18baddda JD	228	sc.gs = REGS_GS(regs->regs.gp);
	229	sc.fs = REGS_FS(regs->regs.gp);
	230	sc.es = REGS_ES(regs->regs.gp);
	231	sc.ds = REGS_DS(regs->regs.gp);
7796931f JD	232	sc.di = REGS_EDI(regs->regs.gp);
	233	sc.si = REGS_ESI(regs->regs.gp);
	234	sc.bp = REGS_EBP(regs->regs.gp);
	235	sc.sp = sp;
	236	sc.bx = REGS_EBX(regs->regs.gp);
	237	sc.dx = REGS_EDX(regs->regs.gp);
	238	sc.cx = REGS_ECX(regs->regs.gp);
	239	sc.ax = REGS_EAX(regs->regs.gp);
	240	sc.ip = REGS_IP(regs->regs.gp);
18baddda	241	sc.cs = REGS_CS(regs->regs.gp);
7796931f JD	242	sc.flags = REGS_EFLAGS(regs->regs.gp);
7796931f JD	243	sc.sp_at_signal = regs->regs.gp[UESP];
18baddda	244	sc.ss = regs->regs.gp[SS];
ba180fd4 JD	245	sc.cr2 = fi->cr2;
	246	sc.err = fi->error_code;
	247	sc.trapno = fi->trap_no;
1da177e4	248
4d338e1a	249	to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1));
1da177e4 LT	250	sc.fpstate = to_fp;
1da177e4 LT	251
a5a678c8	252	pid = userspace_pid[current_thread_info()->cpu];
a5f6096c JD	253	if (have_fpx_regs) {
	254	struct user_fxsr_struct fpx;
	255
a5a678c8	256	err = save_fpx_registers(pid, (unsigned long *) &fpx);
a5f6096c JD	257	if (err < 0){
	258	printk(KERN_ERR "copy_sc_to_user - save_fpx_registers "
	259	"failed, errno = %d\n", err);
	260	return 1;
	261	}
	262
	263	err = convert_fxsr_to_user(to_fp, &fpx);
	264	if (err)
	265	return 1;
	266
	267	err \|= __put_user(fpx.swd, &to_fp->status);
	268	err \|= __put_user(X86_FXSR_MAGIC, &to_fp->magic);
	269	if (err)
	270	return 1;
	271
	272	if (copy_to_user(&to_fp->_fxsr_env[0], &fpx,
	273	sizeof(struct user_fxsr_struct)))
	274	return 1;
	275	}
	276	else {
	277	struct user_i387_struct fp;
	278
a5a678c8	279	err = save_fp_registers(pid, (unsigned long *) &fp);
a5f6096c JD	280	if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
	281	return 1;
	282	}
1da177e4	283
a5f6096c	284	return copy_to_user(to, &sc, sizeof(sc));
1da177e4	285	}
1da177e4	286
ba180fd4 JD	287	static int copy_ucontext_to_user(struct ucontext __user *uc,
	288	struct _fpstate __user fp, sigset_t set,
	289	unsigned long sp)
1da177e4 LT	290	{
	291	int err = 0;
	292
	293	err \|= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp);
	294	err \|= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags);
	295	err \|= put_user(current->sas_ss_size, &uc->uc_stack.ss_size);
98c18238	296	err \|= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, sp);
1da177e4	297	err \|= copy_to_user(&uc->uc_sigmask, set, sizeof(*set));
5d86456d	298	return err;
1da177e4 LT	299	}
	300
	301	struct sigframe
	302	{
4d338e1a	303	char __user *pretcode;
1da177e4 LT	304	int sig;
	305	struct sigcontext sc;
	306	struct _fpstate fpstate;
	307	unsigned long extramask[_NSIG_WORDS-1];
	308	char retcode[8];
	309	};
	310
	311	struct rt_sigframe
	312	{
4d338e1a	313	char __user *pretcode;
1da177e4	314	int sig;
4d338e1a AV	315	struct siginfo __user *pinfo;
4d338e1a AV	316	void __user *puc;
1da177e4 LT	317	struct siginfo info;
	318	struct ucontext uc;
	319	struct _fpstate fpstate;
	320	char retcode[8];
	321	};
	322
	323	int setup_signal_stack_sc(unsigned long stack_top, int sig,
	324	struct k_sigaction ka, struct pt_regs regs,
	325	sigset_t *mask)
	326	{
	327	struct sigframe __user *frame;
4d338e1a	328	void __user *restorer;
98c18238	329	unsigned long save_sp = PT_REGS_SP(regs);
1da177e4 LT	330	int err = 0;
1da177e4 LT	331
3896625d JD	332	/* This is the same calculation as i386 - ((sp + 4) & 15) == 0 */
3896625d JD	333	stack_top = ((stack_top + 4) & -16UL) - 4;
4d338e1a	334	frame = (struct sigframe __user *) stack_top - 1;
1da177e4 LT	335	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	336	return 1;
	337
4d338e1a	338	restorer = frame->retcode;
ba180fd4	339	if (ka->sa.sa_flags & SA_RESTORER)
1da177e4 LT	340	restorer = ka->sa.sa_restorer;
1da177e4 LT	341
98c18238 JD	342	/* Update SP now because the page fault handler refuses to extend
	343	* the stack if the faulting address is too far below the current
	344	* SP, which frame now certainly is. If there's an error, the original
	345	* value is restored on the way out.
	346	* When writing the sigcontext to the stack, we have to write the
	347	* original value, so that's passed to copy_sc_to_user, which does
	348	* the right thing with it.
	349	*/
	350	PT_REGS_SP(regs) = (unsigned long) frame;
	351
1da177e4 LT	352	err \|= __put_user(restorer, &frame->pretcode);
1da177e4 LT	353	err \|= __put_user(sig, &frame->sig);
98c18238	354	err \|= copy_sc_to_user(&frame->sc, NULL, regs, save_sp);
1da177e4 LT	355	err \|= __put_user(mask->sig[0], &frame->sc.oldmask);
	356	if (_NSIG_WORDS > 1)
	357	err \|= __copy_to_user(&frame->extramask, &mask->sig[1],
	358	sizeof(frame->extramask));
	359
	360	/*
	361	* This is popl %eax ; movl $,%eax ; int $0x80
	362	*
	363	* WE DO NOT USE IT ANY MORE! It's only left here for historical
	364	* reasons and because gdb uses it as a signature to notice
	365	* signal handler stack frames.
	366	*/
	367	err \|= __put_user(0xb858, (short __user *)(frame->retcode+0));
	368	err \|= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2));
	369	err \|= __put_user(0x80cd, (short __user *)(frame->retcode+6));
	370
ba180fd4	371	if (err)
98c18238	372	goto err;
1da177e4 LT	373
	374	PT_REGS_SP(regs) = (unsigned long) frame;
	375	PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
	376	PT_REGS_EAX(regs) = (unsigned long) sig;
	377	PT_REGS_EDX(regs) = (unsigned long) 0;
	378	PT_REGS_ECX(regs) = (unsigned long) 0;
	379
	380	if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
	381	ptrace_notify(SIGTRAP);
98c18238 JD	382	return 0;
	383
	384	err:
	385	PT_REGS_SP(regs) = save_sp;
	386	return err;
1da177e4 LT	387	}
	388
	389	int setup_signal_stack_si(unsigned long stack_top, int sig,
	390	struct k_sigaction ka, struct pt_regs regs,
	391	siginfo_t info, sigset_t mask)
	392	{
	393	struct rt_sigframe __user *frame;
4d338e1a	394	void __user *restorer;
98c18238	395	unsigned long save_sp = PT_REGS_SP(regs);
1da177e4 LT	396	int err = 0;
	397
	398	stack_top &= -8UL;
4d338e1a	399	frame = (struct rt_sigframe __user *) stack_top - 1;
1da177e4 LT	400	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	401	return 1;
	402
4d338e1a	403	restorer = frame->retcode;
ba180fd4	404	if (ka->sa.sa_flags & SA_RESTORER)
1da177e4 LT	405	restorer = ka->sa.sa_restorer;
1da177e4 LT	406
98c18238 JD	407	/* See comment above about why this is here */
	408	PT_REGS_SP(regs) = (unsigned long) frame;
	409
1da177e4 LT	410	err \|= __put_user(restorer, &frame->pretcode);
	411	err \|= __put_user(sig, &frame->sig);
	412	err \|= __put_user(&frame->info, &frame->pinfo);
	413	err \|= __put_user(&frame->uc, &frame->puc);
	414	err \|= copy_siginfo_to_user(&frame->info, info);
	415	err \|= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
98c18238	416	save_sp);
1da177e4 LT	417
	418	/*
	419	* This is movl $,%eax ; int $0x80
	420	*
	421	* WE DO NOT USE IT ANY MORE! It's only left here for historical
	422	* reasons and because gdb uses it as a signature to notice
	423	* signal handler stack frames.
	424	*/
	425	err \|= __put_user(0xb8, (char __user *)(frame->retcode+0));
	426	err \|= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1));
	427	err \|= __put_user(0x80cd, (short __user *)(frame->retcode+5));
	428
ba180fd4	429	if (err)
98c18238	430	goto err;
1da177e4	431
1da177e4 LT	432	PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler;
	433	PT_REGS_EAX(regs) = (unsigned long) sig;
	434	PT_REGS_EDX(regs) = (unsigned long) &frame->info;
	435	PT_REGS_ECX(regs) = (unsigned long) &frame->uc;
	436
	437	if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED))
	438	ptrace_notify(SIGTRAP);
98c18238 JD	439	return 0;
	440
	441	err:
	442	PT_REGS_SP(regs) = save_sp;
	443	return err;
1da177e4 LT	444	}
	445
	446	long sys_sigreturn(struct pt_regs regs)
	447	{
	448	unsigned long sp = PT_REGS_SP(&current->thread.regs);
4d338e1a	449	struct sigframe __user frame = (struct sigframe __user )(sp - 8);
1da177e4 LT	450	sigset_t set;
	451	struct sigcontext __user *sc = &frame->sc;
	452	unsigned long __user *oldmask = &sc->oldmask;
	453	unsigned long __user *extramask = frame->extramask;
	454	int sig_size = (_NSIG_WORDS - 1) * sizeof(unsigned long);
	455
ba180fd4 JD	456	if (copy_from_user(&set.sig[0], oldmask, sizeof(set.sig[0])) \|\|
ba180fd4 JD	457	copy_from_user(&set.sig[1], extramask, sig_size))
1da177e4 LT	458	goto segfault;
	459
	460	sigdelsetmask(&set, ~_BLOCKABLE);
	461
	462	spin_lock_irq(&current->sighand->siglock);
	463	current->blocked = set;
	464	recalc_sigpending();
	465	spin_unlock_irq(&current->sighand->siglock);
	466
ba180fd4	467	if (copy_sc_from_user(&current->thread.regs, sc))
1da177e4 LT	468	goto segfault;
	469
	470	/* Avoid ERESTART handling */
	471	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
5d86456d	472	return PT_REGS_SYSCALL_RET(&current->thread.regs);
1da177e4 LT	473
	474	segfault:
	475	force_sig(SIGSEGV, current);
	476	return 0;
	477	}
	478
	479	long sys_rt_sigreturn(struct pt_regs regs)
	480	{
4d338e1a	481	unsigned long sp = PT_REGS_SP(&current->thread.regs);
ba180fd4 JD	482	struct rt_sigframe __user *frame =
ba180fd4 JD	483	(struct rt_sigframe __user *) (sp - 4);
1da177e4 LT	484	sigset_t set;
	485	struct ucontext __user *uc = &frame->uc;
	486	int sig_size = _NSIG_WORDS * sizeof(unsigned long);
	487
ba180fd4	488	if (copy_from_user(&set, &uc->uc_sigmask, sig_size))
1da177e4 LT	489	goto segfault;
	490
	491	sigdelsetmask(&set, ~_BLOCKABLE);
	492
	493	spin_lock_irq(&current->sighand->siglock);
	494	current->blocked = set;
	495	recalc_sigpending();
	496	spin_unlock_irq(&current->sighand->siglock);
	497
ba180fd4	498	if (copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
1da177e4 LT	499	goto segfault;
	500
	501	/* Avoid ERESTART handling */
	502	PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
5d86456d	503	return PT_REGS_SYSCALL_RET(&current->thread.regs);
1da177e4 LT	504
	505	segfault:
	506	force_sig(SIGSEGV, current);
	507	return 0;
	508	}