arch/x86/um/signal.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (C) 2003 PathScale, Inc.
  * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */


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

 #ifdef CONFIG_X86_32

 /*
  * 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;

 #endif

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

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

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

 #define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname

 #ifdef CONFIG_X86_32
 	GETREG(GS, gs);
 	GETREG(FS, fs);
 	GETREG(ES, es);
 	GETREG(DS, ds);
 #endif
 	GETREG(DI, di);
 	GETREG(SI, si);
 	GETREG(BP, bp);
 	GETREG(SP, sp);
 	GETREG(BX, bx);
 	GETREG(DX, dx);
 	GETREG(CX, cx);
 	GETREG(AX, ax);
 	GETREG(IP, ip);

 #ifdef CONFIG_X86_64
 	GETREG(R8, r8);
 	GETREG(R9, r9);
 	GETREG(R10, r10);
 	GETREG(R11, r11);
 	GETREG(R12, r12);
 	GETREG(R13, r13);
 	GETREG(R14, r14);
 	GETREG(R15, r15);
 #endif

 	GETREG(CS, cs);
 	GETREG(EFLAGS, flags);
 #ifdef CONFIG_X86_32
 	GETREG(SS, ss);
 #endif

 #undef GETREG

 	pid = userspace_pid[current_thread_info()->cpu];
 #ifdef CONFIG_X86_32
 	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
 #endif
 	{
 		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 mask)
 {
 	struct sigcontext sc;
 	struct faultinfo * fi = &current->thread.arch.faultinfo;
 	int err, pid;
 	memset(&sc, 0, sizeof(struct sigcontext));

 #define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]

 #ifdef CONFIG_X86_32
 	PUTREG(GS, gs);
 	PUTREG(FS, fs);
 	PUTREG(ES, es);
 	PUTREG(DS, ds);
 #endif
 	PUTREG(DI, di);
 	PUTREG(SI, si);
 	PUTREG(BP, bp);
 	PUTREG(SP, sp);
 	PUTREG(BX, bx);
 	PUTREG(DX, dx);
 	PUTREG(CX, cx);
 	PUTREG(AX, ax);
 #ifdef CONFIG_X86_64
 	PUTREG(R8, r8);
 	PUTREG(R9, r9);
 	PUTREG(R10, r10);
 	PUTREG(R11, r11);
 	PUTREG(R12, r12);
 	PUTREG(R13, r13);
 	PUTREG(R14, r14);
 	PUTREG(R15, r15);
 #endif

 	sc.cr2 = fi->cr2;
 	sc.err = fi->error_code;
 	sc.trapno = fi->trap_no;
 	PUTREG(IP, ip);
 	PUTREG(CS, cs);
 	PUTREG(EFLAGS, flags);
 #ifdef CONFIG_X86_32
 	PUTREG(SP, sp_at_signal);
 	PUTREG(SS, ss);
 #endif
 #undef PUTREG
 	sc.oldmask = mask;
 	sc.fpstate = to_fp;

 	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
 	if (err)
 		return 1;

 	pid = userspace_pid[current_thread_info()->cpu];

 #ifdef CONFIG_X86_32
 	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
 #endif
 	{
 		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 0;
 }

 #ifdef CONFIG_X86_32
 static int copy_ucontext_to_user(struct ucontext __user *uc,
 				 struct _fpstate __user *fp, sigset_t *set,
 				 unsigned long sp)
 {
 	int err = 0;

 	err |= __save_altstack(&uc->uc_stack, sp);
 	err |= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
 	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, struct ksignal *ksig,
 			  struct pt_regs *regs, sigset_t *mask)
 {
 	struct sigframe __user *frame;
 	void __user *restorer;
 	int err = 0, sig = ksig->sig;

 	/* 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 (ksig->ka.sa.sa_flags & SA_RESTORER)
 		restorer = ksig->ka.sa.sa_restorer;

 	err |= __put_user(restorer, &frame->pretcode);
 	err |= __put_user(sig, &frame->sig);
 	err |= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
 	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)
 		return err;

 	PT_REGS_SP(regs) = (unsigned long) frame;
 	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
 	PT_REGS_AX(regs) = (unsigned long) sig;
 	PT_REGS_DX(regs) = (unsigned long) 0;
 	PT_REGS_CX(regs) = (unsigned long) 0;
 	return 0;
 }

 int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
 			  struct pt_regs *regs, sigset_t *mask)
 {
 	struct rt_sigframe __user *frame;
 	void __user *restorer;
 	int err = 0, sig = ksig->sig;

 	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 (ksig->ka.sa.sa_flags & SA_RESTORER)
 		restorer = ksig->ka.sa.sa_restorer;

 	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, &ksig->info);
 	err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
 					PT_REGS_SP(regs));

 	/*
 	 * 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)
 		return err;

 	PT_REGS_SP(regs) = (unsigned long) frame;
 	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
 	PT_REGS_AX(regs) = (unsigned long) sig;
 	PT_REGS_DX(regs) = (unsigned long) &frame->info;
 	PT_REGS_CX(regs) = (unsigned long) &frame->uc;
 	return 0;
 }

 long sys_sigreturn(void)
 {
 	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;

 	set_current_blocked(&set);

 	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;
 }

 #else

 struct rt_sigframe
 {
 	char __user *pretcode;
 	struct ucontext uc;
 	struct siginfo info;
 	struct _fpstate fpstate;
 };

 int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
 			  struct pt_regs *regs, sigset_t *set)
 {
 	struct rt_sigframe __user *frame;
 	int err = 0, sig = ksig->sig;

 	frame = (struct rt_sigframe __user *)
 		round_down(stack_top - sizeof(struct rt_sigframe), 16);
 	/* Subtract 128 for a red zone and 8 for proper alignment */
 	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);

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

 	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
 		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 		if (err)
 			goto out;
 	}

 	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
 	err |= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
 	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
 			       set->sig[0]);
 	err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
 	if (sizeof(*set) == 16) {
 		err |= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 		err |= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 	}
 	else
 		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
 				      sizeof(*set));

 	/*
 	 * Set up to return from userspace.  If provided, use a stub
 	 * already in userspace.
 	 */
 	/* x86-64 should always use SA_RESTORER. */
 	if (ksig->ka.sa.sa_flags & SA_RESTORER)
 		err |= __put_user(ksig->ka.sa.sa_restorer, &frame->pretcode);
 	else
 		/* could use a vstub here */
 		return err;

 	if (err)
 		return err;

 	/* Set up registers for signal handler */
 	{
 		struct exec_domain *ed = current_thread_info()->exec_domain;
 		if (unlikely(ed && ed->signal_invmap && sig < 32))
 			sig = ed->signal_invmap[sig];
 	}

 	PT_REGS_SP(regs) = (unsigned long) frame;
 	PT_REGS_DI(regs) = sig;
 	/* In case the signal handler was declared without prototypes */
 	PT_REGS_AX(regs) = 0;

 	/*
 	 * This also works for non SA_SIGINFO handlers because they expect the
 	 * next argument after the signal number on the stack.
 	 */
 	PT_REGS_SI(regs) = (unsigned long) &frame->info;
 	PT_REGS_DX(regs) = (unsigned long) &frame->uc;
 	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
  out:
 	return err;
 }
 #endif

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

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

 	set_current_blocked(&set);

 	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;
 }
	/*
	* Copyright (C) 2003 PathScale, Inc.
	* Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
	* Licensed under the GPL
	*/


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

	#ifdef CONFIG_X86_32

	/*
	* 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;

	#endif

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

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

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

	#define GETREG(regno, regname) regs->regs.gp[HOST_##regno] = sc.regname

	#ifdef CONFIG_X86_32
	GETREG(GS, gs);
	GETREG(FS, fs);
	GETREG(ES, es);
	GETREG(DS, ds);
	#endif
	GETREG(DI, di);
	GETREG(SI, si);
	GETREG(BP, bp);
	GETREG(SP, sp);
	GETREG(BX, bx);
	GETREG(DX, dx);
	GETREG(CX, cx);
	GETREG(AX, ax);
	GETREG(IP, ip);

	#ifdef CONFIG_X86_64
	GETREG(R8, r8);
	GETREG(R9, r9);
	GETREG(R10, r10);
	GETREG(R11, r11);
	GETREG(R12, r12);
	GETREG(R13, r13);
	GETREG(R14, r14);
	GETREG(R15, r15);
	#endif

	GETREG(CS, cs);
	GETREG(EFLAGS, flags);
	#ifdef CONFIG_X86_32
	GETREG(SS, ss);
	#endif

	#undef GETREG

	pid = userspace_pid[current_thread_info()->cpu];
	#ifdef CONFIG_X86_32
	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
	#endif
	{
	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 mask)
	{
	struct sigcontext sc;
	struct faultinfo * fi = &current->thread.arch.faultinfo;
	int err, pid;
	memset(&sc, 0, sizeof(struct sigcontext));

	#define PUTREG(regno, regname) sc.regname = regs->regs.gp[HOST_##regno]

	#ifdef CONFIG_X86_32
	PUTREG(GS, gs);
	PUTREG(FS, fs);
	PUTREG(ES, es);
	PUTREG(DS, ds);
	#endif
	PUTREG(DI, di);
	PUTREG(SI, si);
	PUTREG(BP, bp);
	PUTREG(SP, sp);
	PUTREG(BX, bx);
	PUTREG(DX, dx);
	PUTREG(CX, cx);
	PUTREG(AX, ax);
	#ifdef CONFIG_X86_64
	PUTREG(R8, r8);
	PUTREG(R9, r9);
	PUTREG(R10, r10);
	PUTREG(R11, r11);
	PUTREG(R12, r12);
	PUTREG(R13, r13);
	PUTREG(R14, r14);
	PUTREG(R15, r15);
	#endif

	sc.cr2 = fi->cr2;
	sc.err = fi->error_code;
	sc.trapno = fi->trap_no;
	PUTREG(IP, ip);
	PUTREG(CS, cs);
	PUTREG(EFLAGS, flags);
	#ifdef CONFIG_X86_32
	PUTREG(SP, sp_at_signal);
	PUTREG(SS, ss);
	#endif
	#undef PUTREG
	sc.oldmask = mask;
	sc.fpstate = to_fp;

	err = copy_to_user(to, &sc, sizeof(struct sigcontext));
	if (err)
	return 1;

	pid = userspace_pid[current_thread_info()->cpu];

	#ifdef CONFIG_X86_32
	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
	#endif
	{
	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 0;
	}

	#ifdef CONFIG_X86_32
	static int copy_ucontext_to_user(struct ucontext __user *uc,
	struct _fpstate __user fp, sigset_t set,
	unsigned long sp)
	{
	int err = 0;

	err \|= __save_altstack(&uc->uc_stack, sp);
	err \|= copy_sc_to_user(&uc->uc_mcontext, fp, &current->thread.regs, 0);
	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, struct ksignal *ksig,
	struct pt_regs regs, sigset_t mask)
	{
	struct sigframe __user *frame;
	void __user *restorer;
	int err = 0, sig = ksig->sig;

	/* 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 (ksig->ka.sa.sa_flags & SA_RESTORER)
	restorer = ksig->ka.sa.sa_restorer;

	err \|= __put_user(restorer, &frame->pretcode);
	err \|= __put_user(sig, &frame->sig);
	err \|= copy_sc_to_user(&frame->sc, &frame->fpstate, regs, mask->sig[0]);
	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)
	return err;

	PT_REGS_SP(regs) = (unsigned long) frame;
	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
	PT_REGS_AX(regs) = (unsigned long) sig;
	PT_REGS_DX(regs) = (unsigned long) 0;
	PT_REGS_CX(regs) = (unsigned long) 0;
	return 0;
	}

	int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
	struct pt_regs regs, sigset_t mask)
	{
	struct rt_sigframe __user *frame;
	void __user *restorer;
	int err = 0, sig = ksig->sig;

	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 (ksig->ka.sa.sa_flags & SA_RESTORER)
	restorer = ksig->ka.sa.sa_restorer;

	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, &ksig->info);
	err \|= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask,
	PT_REGS_SP(regs));

	/*
	* 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)
	return err;

	PT_REGS_SP(regs) = (unsigned long) frame;
	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
	PT_REGS_AX(regs) = (unsigned long) sig;
	PT_REGS_DX(regs) = (unsigned long) &frame->info;
	PT_REGS_CX(regs) = (unsigned long) &frame->uc;
	return 0;
	}

	long sys_sigreturn(void)
	{
	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;

	set_current_blocked(&set);

	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;
	}

	#else

	struct rt_sigframe
	{
	char __user *pretcode;
	struct ucontext uc;
	struct siginfo info;
	struct _fpstate fpstate;
	};

	int setup_signal_stack_si(unsigned long stack_top, struct ksignal *ksig,
	struct pt_regs regs, sigset_t set)
	{
	struct rt_sigframe __user *frame;
	int err = 0, sig = ksig->sig;

	frame = (struct rt_sigframe __user *)
	round_down(stack_top - sizeof(struct rt_sigframe), 16);
	/* Subtract 128 for a red zone and 8 for proper alignment */
	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);

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

	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
	if (err)
	goto out;
	}

	/* Create the ucontext. */
	err \|= __put_user(0, &frame->uc.uc_flags);
	err \|= __put_user(0, &frame->uc.uc_link);
	err \|= __save_altstack(&frame->uc.uc_stack, PT_REGS_SP(regs));
	err \|= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
	set->sig[0]);
	err \|= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
	if (sizeof(*set) == 16) {
	err \|= __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
	err \|= __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
	}
	else
	err \|= __copy_to_user(&frame->uc.uc_sigmask, set,
	sizeof(*set));

	/*
	* Set up to return from userspace. If provided, use a stub
	* already in userspace.
	*/
	/* x86-64 should always use SA_RESTORER. */
	if (ksig->ka.sa.sa_flags & SA_RESTORER)
	err \|= __put_user(ksig->ka.sa.sa_restorer, &frame->pretcode);
	else
	/* could use a vstub here */
	return err;

	if (err)
	return err;

	/* Set up registers for signal handler */
	{
	struct exec_domain *ed = current_thread_info()->exec_domain;
	if (unlikely(ed && ed->signal_invmap && sig < 32))
	sig = ed->signal_invmap[sig];
	}

	PT_REGS_SP(regs) = (unsigned long) frame;
	PT_REGS_DI(regs) = sig;
	/* In case the signal handler was declared without prototypes */
	PT_REGS_AX(regs) = 0;

	/*
	* This also works for non SA_SIGINFO handlers because they expect the
	* next argument after the signal number on the stack.
	*/
	PT_REGS_SI(regs) = (unsigned long) &frame->info;
	PT_REGS_DX(regs) = (unsigned long) &frame->uc;
	PT_REGS_IP(regs) = (unsigned long) ksig->ka.sa.sa_handler;
	out:
	return err;
	}
	#endif

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

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

	set_current_blocked(&set);

	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;
	}