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linux/arch/x86/math-emu/reg_ld_str.c
Linus Torvalds 96d4f267e4 Remove 'type' argument from access_ok() function 
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00

1221 lines
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// SPDX-License-Identifier: GPL-2.0
/*---------------------------------------------------------------------------+
| reg_ld_str.c |
| |
| All of the functions which transfer data between user memory and FPU_REGs.|
| |
| Copyright (C) 1992,1993,1994,1996,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
| E-mail billm@suburbia.net |
| |
| |
+---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------+
| Note: |
| The file contains code which accesses user memory. |
| Emulator static data may change when user memory is accessed, due to |
| other processes using the emulator while swapping is in progress. |
+---------------------------------------------------------------------------*/
#include "fpu_emu.h"
#include <linux/uaccess.h>
#include "fpu_system.h"
#include "exception.h"
#include "reg_constant.h"
#include "control_w.h"
#include "status_w.h"
#define DOUBLE_Emax 1023 /* largest valid exponent */
#define DOUBLE_Ebias 1023
#define DOUBLE_Emin (-1022) /* smallest valid exponent */
#define SINGLE_Emax 127 /* largest valid exponent */
#define SINGLE_Ebias 127
#define SINGLE_Emin (-126) /* smallest valid exponent */
static u_char normalize_no_excep(FPU_REG *r, int exp, int sign)
{
u_char tag;
setexponent16(r, exp);
tag = FPU_normalize_nuo(r);
stdexp(r);
if (sign)
setnegative(r);
return tag;
}
int FPU_tagof(FPU_REG *ptr)
{
int exp;
exp = exponent16(ptr) & 0x7fff;
if (exp == 0) {
if (!(ptr->sigh | ptr->sigl)) {
return TAG_Zero;
}
/* The number is a de-normal or pseudodenormal. */
return TAG_Special;
}
if (exp == 0x7fff) {
/* Is an Infinity, a NaN, or an unsupported data type. */
return TAG_Special;
}
if (!(ptr->sigh & 0x80000000)) {
/* Unsupported data type. */
/* Valid numbers have the ms bit set to 1. */
/* Unnormal. */
return TAG_Special;
}
return TAG_Valid;
}
/* Get a long double from user memory */
int FPU_load_extended(long double __user *s, int stnr)
{
FPU_REG *sti_ptr = &st(stnr);
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(s, 10);
__copy_from_user(sti_ptr, s, 10);
RE_ENTRANT_CHECK_ON;
return FPU_tagof(sti_ptr);
}
/* Get a double from user memory */
int FPU_load_double(double __user *dfloat, FPU_REG *loaded_data)
{
int exp, tag, negative;
unsigned m64, l64;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(dfloat, 8);
FPU_get_user(m64, 1 + (unsigned long __user *)dfloat);
FPU_get_user(l64, (unsigned long __user *)dfloat);
RE_ENTRANT_CHECK_ON;
negative = (m64 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
exp = ((m64 & 0x7ff00000) >> 20) - DOUBLE_Ebias + EXTENDED_Ebias;
m64 &= 0xfffff;
if (exp > DOUBLE_Emax + EXTENDED_Ebias) {
/* Infinity or NaN */
if ((m64 == 0) && (l64 == 0)) {
/* +- infinity */
loaded_data->sigh = 0x80000000;
loaded_data->sigl = 0x00000000;
exp = EXP_Infinity + EXTENDED_Ebias;
tag = TAG_Special;
} else {
/* Must be a signaling or quiet NaN */
exp = EXP_NaN + EXTENDED_Ebias;
loaded_data->sigh = (m64 << 11) | 0x80000000;
loaded_data->sigh |= l64 >> 21;
loaded_data->sigl = l64 << 11;
tag = TAG_Special; /* The calling function must look for NaNs */
}
} else if (exp < DOUBLE_Emin + EXTENDED_Ebias) {
/* Zero or de-normal */
if ((m64 == 0) && (l64 == 0)) {
/* Zero */
reg_copy(&CONST_Z, loaded_data);
exp = 0;
tag = TAG_Zero;
} else {
/* De-normal */
loaded_data->sigh = m64 << 11;
loaded_data->sigh |= l64 >> 21;
loaded_data->sigl = l64 << 11;
return normalize_no_excep(loaded_data, DOUBLE_Emin,
negative)
| (denormal_operand() < 0 ? FPU_Exception : 0);
}
} else {
loaded_data->sigh = (m64 << 11) | 0x80000000;
loaded_data->sigh |= l64 >> 21;
loaded_data->sigl = l64 << 11;
tag = TAG_Valid;
}
setexponent16(loaded_data, exp | negative);
return tag;
}
/* Get a float from user memory */
int FPU_load_single(float __user *single, FPU_REG *loaded_data)
{
unsigned m32;
int exp, tag, negative;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(single, 4);
FPU_get_user(m32, (unsigned long __user *)single);
RE_ENTRANT_CHECK_ON;
negative = (m32 & 0x80000000) ? SIGN_Negative : SIGN_Positive;
if (!(m32 & 0x7fffffff)) {
/* Zero */
reg_copy(&CONST_Z, loaded_data);
addexponent(loaded_data, negative);
return TAG_Zero;
}
exp = ((m32 & 0x7f800000) >> 23) - SINGLE_Ebias + EXTENDED_Ebias;
m32 = (m32 & 0x7fffff) << 8;
if (exp < SINGLE_Emin + EXTENDED_Ebias) {
/* De-normals */
loaded_data->sigh = m32;
loaded_data->sigl = 0;
return normalize_no_excep(loaded_data, SINGLE_Emin, negative)
| (denormal_operand() < 0 ? FPU_Exception : 0);
} else if (exp > SINGLE_Emax + EXTENDED_Ebias) {
/* Infinity or NaN */
if (m32 == 0) {
/* +- infinity */
loaded_data->sigh = 0x80000000;
loaded_data->sigl = 0x00000000;
exp = EXP_Infinity + EXTENDED_Ebias;
tag = TAG_Special;
} else {
/* Must be a signaling or quiet NaN */
exp = EXP_NaN + EXTENDED_Ebias;
loaded_data->sigh = m32 | 0x80000000;
loaded_data->sigl = 0;
tag = TAG_Special; /* The calling function must look for NaNs */
}
} else {
loaded_data->sigh = m32 | 0x80000000;
loaded_data->sigl = 0;
tag = TAG_Valid;
}
setexponent16(loaded_data, exp | negative); /* Set the sign. */
return tag;
}
/* Get a long long from user memory */
int FPU_load_int64(long long __user *_s)
{
long long s;
int sign;
FPU_REG *st0_ptr = &st(0);
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(_s, 8);
if (copy_from_user(&s, _s, 8))
FPU_abort;
RE_ENTRANT_CHECK_ON;
if (s == 0) {
reg_copy(&CONST_Z, st0_ptr);
return TAG_Zero;
}
if (s > 0)
sign = SIGN_Positive;
else {
s = -s;
sign = SIGN_Negative;
}
significand(st0_ptr) = s;
return normalize_no_excep(st0_ptr, 63, sign);
}
/* Get a long from user memory */
int FPU_load_int32(long __user *_s, FPU_REG *loaded_data)
{
long s;
int negative;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(_s, 4);
FPU_get_user(s, _s);
RE_ENTRANT_CHECK_ON;
if (s == 0) {
reg_copy(&CONST_Z, loaded_data);
return TAG_Zero;
}
if (s > 0)
negative = SIGN_Positive;
else {
s = -s;
negative = SIGN_Negative;
}
loaded_data->sigh = s;
loaded_data->sigl = 0;
return normalize_no_excep(loaded_data, 31, negative);
}
/* Get a short from user memory */
int FPU_load_int16(short __user *_s, FPU_REG *loaded_data)
{
int s, negative;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(_s, 2);
/* Cast as short to get the sign extended. */
FPU_get_user(s, _s);
RE_ENTRANT_CHECK_ON;
if (s == 0) {
reg_copy(&CONST_Z, loaded_data);
return TAG_Zero;
}
if (s > 0)
negative = SIGN_Positive;
else {
s = -s;
negative = SIGN_Negative;
}
loaded_data->sigh = s << 16;
loaded_data->sigl = 0;
return normalize_no_excep(loaded_data, 15, negative);
}
/* Get a packed bcd array from user memory */
int FPU_load_bcd(u_char __user *s)
{
FPU_REG *st0_ptr = &st(0);
int pos;
u_char bcd;
long long l = 0;
int sign;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(s, 10);
RE_ENTRANT_CHECK_ON;
for (pos = 8; pos >= 0; pos--) {
l *= 10;
RE_ENTRANT_CHECK_OFF;
FPU_get_user(bcd, s + pos);
RE_ENTRANT_CHECK_ON;
l += bcd >> 4;
l *= 10;
l += bcd & 0x0f;
}
RE_ENTRANT_CHECK_OFF;
FPU_get_user(sign, s + 9);
sign = sign & 0x80 ? SIGN_Negative : SIGN_Positive;
RE_ENTRANT_CHECK_ON;
if (l == 0) {
reg_copy(&CONST_Z, st0_ptr);
addexponent(st0_ptr, sign); /* Set the sign. */
return TAG_Zero;
} else {
significand(st0_ptr) = l;
return normalize_no_excep(st0_ptr, 63, sign);
}
}
/*===========================================================================*/
/* Put a long double into user memory */
int FPU_store_extended(FPU_REG *st0_ptr, u_char st0_tag,
long double __user * d)
{
/*
The only exception raised by an attempt to store to an
extended format is the Invalid Stack exception, i.e.
attempting to store from an empty register.
*/
if (st0_tag != TAG_Empty) {
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 10);
FPU_put_user(st0_ptr->sigl, (unsigned long __user *)d);
FPU_put_user(st0_ptr->sigh,
(unsigned long __user *)((u_char __user *) d + 4));
FPU_put_user(exponent16(st0_ptr),
(unsigned short __user *)((u_char __user *) d +
8));
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
if (control_word & CW_Invalid) {
/* The masked response */
/* Put out the QNaN indefinite */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 10);
FPU_put_user(0, (unsigned long __user *)d);
FPU_put_user(0xc0000000, 1 + (unsigned long __user *)d);
FPU_put_user(0xffff, 4 + (short __user *)d);
RE_ENTRANT_CHECK_ON;
return 1;
} else
return 0;
}
/* Put a double into user memory */
int FPU_store_double(FPU_REG *st0_ptr, u_char st0_tag, double __user *dfloat)
{
unsigned long l[2];
unsigned long increment = 0; /* avoid gcc warnings */
int precision_loss;
int exp;
FPU_REG tmp;
l[0] = 0;
l[1] = 0;
if (st0_tag == TAG_Valid) {
reg_copy(st0_ptr, &tmp);
exp = exponent(&tmp);
if (exp < DOUBLE_Emin) { /* It may be a denormal */
addexponent(&tmp, -DOUBLE_Emin + 52); /* largest exp to be 51 */
denormal_arg:
if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
/* Did it round to a non-denormal ? */
/* This behaviour might be regarded as peculiar, it appears
that the 80486 rounds to the dest precision, then
converts to decide underflow. */
if (!
((tmp.sigh == 0x00100000) && (tmp.sigl == 0)
&& (st0_ptr->sigl & 0x000007ff)))
#endif /* PECULIAR_486 */
{
EXCEPTION(EX_Underflow);
/* This is a special case: see sec 16.2.5.1 of
the 80486 book */
if (!(control_word & CW_Underflow))
return 0;
}
EXCEPTION(precision_loss);
if (!(control_word & CW_Precision))
return 0;
}
l[0] = tmp.sigl;
l[1] = tmp.sigh;
} else {
if (tmp.sigl & 0x000007ff) {
precision_loss = 1;
switch (control_word & CW_RC) {
case RC_RND:
/* Rounding can get a little messy.. */
increment = ((tmp.sigl & 0x7ff) > 0x400) | /* nearest */
((tmp.sigl & 0xc00) == 0xc00); /* odd -> even */
break;
case RC_DOWN: /* towards -infinity */
increment =
signpositive(&tmp) ? 0 : tmp.
sigl & 0x7ff;
break;
case RC_UP: /* towards +infinity */
increment =
signpositive(&tmp) ? tmp.
sigl & 0x7ff : 0;
break;
case RC_CHOP:
increment = 0;
break;
}
/* Truncate the mantissa */
tmp.sigl &= 0xfffff800;
if (increment) {
if (tmp.sigl >= 0xfffff800) {
/* the sigl part overflows */
if (tmp.sigh == 0xffffffff) {
/* The sigh part overflows */
tmp.sigh = 0x80000000;
exp++;
if (exp >= EXP_OVER)
goto overflow;
} else {
tmp.sigh++;
}
tmp.sigl = 0x00000000;
} else {
/* We only need to increment sigl */
tmp.sigl += 0x00000800;
}
}
} else
precision_loss = 0;
l[0] = (tmp.sigl >> 11) | (tmp.sigh << 21);
l[1] = ((tmp.sigh >> 11) & 0xfffff);
if (exp > DOUBLE_Emax) {
overflow:
EXCEPTION(EX_Overflow);
if (!(control_word & CW_Overflow))
return 0;
set_precision_flag_up();
if (!(control_word & CW_Precision))
return 0;
/* This is a special case: see sec 16.2.5.1 of the 80486 book */
/* Overflow to infinity */
l[1] = 0x7ff00000; /* Set to + INF */
} else {
if (precision_loss) {
if (increment)
set_precision_flag_up();
else
set_precision_flag_down();
}
/* Add the exponent */
l[1] |= (((exp + DOUBLE_Ebias) & 0x7ff) << 20);
}
}
} else if (st0_tag == TAG_Zero) {
/* Number is zero */
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if (st0_tag == TW_Denormal) {
/* A denormal will always underflow. */
#ifndef PECULIAR_486
/* An 80486 is supposed to be able to generate
a denormal exception here, but... */
/* Underflow has priority. */
if (control_word & CW_Underflow)
denormal_operand();
#endif /* PECULIAR_486 */
reg_copy(st0_ptr, &tmp);
goto denormal_arg;
} else if (st0_tag == TW_Infinity) {
l[1] = 0x7ff00000;
} else if (st0_tag == TW_NaN) {
/* Is it really a NaN ? */
if ((exponent(st0_ptr) == EXP_OVER)
&& (st0_ptr->sigh & 0x80000000)) {
/* See if we can get a valid NaN from the FPU_REG */
l[0] =
(st0_ptr->sigl >> 11) | (st0_ptr->
sigh << 21);
l[1] = ((st0_ptr->sigh >> 11) & 0xfffff);
if (!(st0_ptr->sigh & 0x40000000)) {
/* It is a signalling NaN */
EXCEPTION(EX_Invalid);
if (!(control_word & CW_Invalid))
return 0;
l[1] |= (0x40000000 >> 11);
}
l[1] |= 0x7ff00000;
} else {
/* It is an unsupported data type */
EXCEPTION(EX_Invalid);
if (!(control_word & CW_Invalid))
return 0;
l[1] = 0xfff80000;
}
}
} else if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
if (control_word & CW_Invalid) {
/* The masked response */
/* Put out the QNaN indefinite */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(dfloat, 8);
FPU_put_user(0, (unsigned long __user *)dfloat);
FPU_put_user(0xfff80000,
1 + (unsigned long __user *)dfloat);
RE_ENTRANT_CHECK_ON;
return 1;
} else
return 0;
}
if (getsign(st0_ptr))
l[1] |= 0x80000000;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(dfloat, 8);
FPU_put_user(l[0], (unsigned long __user *)dfloat);
FPU_put_user(l[1], 1 + (unsigned long __user *)dfloat);
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Put a float into user memory */
int FPU_store_single(FPU_REG *st0_ptr, u_char st0_tag, float __user *single)
{
long templ = 0;
unsigned long increment = 0; /* avoid gcc warnings */
int precision_loss;
int exp;
FPU_REG tmp;
if (st0_tag == TAG_Valid) {
reg_copy(st0_ptr, &tmp);
exp = exponent(&tmp);
if (exp < SINGLE_Emin) {
addexponent(&tmp, -SINGLE_Emin + 23); /* largest exp to be 22 */
denormal_arg:
if ((precision_loss = FPU_round_to_int(&tmp, st0_tag))) {
#ifdef PECULIAR_486
/* Did it round to a non-denormal ? */
/* This behaviour might be regarded as peculiar, it appears
that the 80486 rounds to the dest precision, then
converts to decide underflow. */
if (!((tmp.sigl == 0x00800000) &&
((st0_ptr->sigh & 0x000000ff)
|| st0_ptr->sigl)))
#endif /* PECULIAR_486 */
{
EXCEPTION(EX_Underflow);
/* This is a special case: see sec 16.2.5.1 of
the 80486 book */
if (!(control_word & CW_Underflow))
return 0;
}
EXCEPTION(precision_loss);
if (!(control_word & CW_Precision))
return 0;
}
templ = tmp.sigl;
} else {
if (tmp.sigl | (tmp.sigh & 0x000000ff)) {
unsigned long sigh = tmp.sigh;
unsigned long sigl = tmp.sigl;
precision_loss = 1;
switch (control_word & CW_RC) {
case RC_RND:
increment = ((sigh & 0xff) > 0x80) /* more than half */
||(((sigh & 0xff) == 0x80) && sigl) /* more than half */
||((sigh & 0x180) == 0x180); /* round to even */
break;
case RC_DOWN: /* towards -infinity */
increment = signpositive(&tmp)
? 0 : (sigl | (sigh & 0xff));
break;
case RC_UP: /* towards +infinity */
increment = signpositive(&tmp)
? (sigl | (sigh & 0xff)) : 0;
break;
case RC_CHOP:
increment = 0;
break;
}
/* Truncate part of the mantissa */
tmp.sigl = 0;
if (increment) {
if (sigh >= 0xffffff00) {
/* The sigh part overflows */
tmp.sigh = 0x80000000;
exp++;
if (exp >= EXP_OVER)
goto overflow;
} else {
tmp.sigh &= 0xffffff00;
tmp.sigh += 0x100;
}
} else {
tmp.sigh &= 0xffffff00; /* Finish the truncation */
}
} else
precision_loss = 0;
templ = (tmp.sigh >> 8) & 0x007fffff;
if (exp > SINGLE_Emax) {
overflow:
EXCEPTION(EX_Overflow);
if (!(control_word & CW_Overflow))
return 0;
set_precision_flag_up();
if (!(control_word & CW_Precision))
return 0;
/* This is a special case: see sec 16.2.5.1 of the 80486 book. */
/* Masked response is overflow to infinity. */
templ = 0x7f800000;
} else {
if (precision_loss) {
if (increment)
set_precision_flag_up();
else
set_precision_flag_down();
}
/* Add the exponent */
templ |= ((exp + SINGLE_Ebias) & 0xff) << 23;
}
}
} else if (st0_tag == TAG_Zero) {
templ = 0;
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if (st0_tag == TW_Denormal) {
reg_copy(st0_ptr, &tmp);
/* A denormal will always underflow. */
#ifndef PECULIAR_486
/* An 80486 is supposed to be able to generate
a denormal exception here, but... */
/* Underflow has priority. */
if (control_word & CW_Underflow)
denormal_operand();
#endif /* PECULIAR_486 */
goto denormal_arg;
} else if (st0_tag == TW_Infinity) {
templ = 0x7f800000;
} else if (st0_tag == TW_NaN) {
/* Is it really a NaN ? */
if ((exponent(st0_ptr) == EXP_OVER)
&& (st0_ptr->sigh & 0x80000000)) {
/* See if we can get a valid NaN from the FPU_REG */
templ = st0_ptr->sigh >> 8;
if (!(st0_ptr->sigh & 0x40000000)) {
/* It is a signalling NaN */
EXCEPTION(EX_Invalid);
if (!(control_word & CW_Invalid))
return 0;
templ |= (0x40000000 >> 8);
}
templ |= 0x7f800000;
} else {
/* It is an unsupported data type */
EXCEPTION(EX_Invalid);
if (!(control_word & CW_Invalid))
return 0;
templ = 0xffc00000;
}
}
#ifdef PARANOID
else {
EXCEPTION(EX_INTERNAL | 0x164);
return 0;
}
#endif
} else if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
if (control_word & EX_Invalid) {
/* The masked response */
/* Put out the QNaN indefinite */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(single, 4);
FPU_put_user(0xffc00000,
(unsigned long __user *)single);
RE_ENTRANT_CHECK_ON;
return 1;
} else
return 0;
}
#ifdef PARANOID
else {
EXCEPTION(EX_INTERNAL | 0x163);
return 0;
}
#endif
if (getsign(st0_ptr))
templ |= 0x80000000;
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(single, 4);
FPU_put_user(templ, (unsigned long __user *)single);
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Put a long long into user memory */
int FPU_store_int64(FPU_REG *st0_ptr, u_char st0_tag, long long __user *d)
{
FPU_REG t;
long long tll;
int precision_loss;
if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
goto invalid_operand;
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
EXCEPTION(EX_Invalid);
goto invalid_operand;
}
}
reg_copy(st0_ptr, &t);
precision_loss = FPU_round_to_int(&t, st0_tag);
((long *)&tll)[0] = t.sigl;
((long *)&tll)[1] = t.sigh;
if ((precision_loss == 1) ||
((t.sigh & 0x80000000) &&
!((t.sigh == 0x80000000) && (t.sigl == 0) && signnegative(&t)))) {
EXCEPTION(EX_Invalid);
/* This is a special case: see sec 16.2.5.1 of the 80486 book */
invalid_operand:
if (control_word & EX_Invalid) {
/* Produce something like QNaN "indefinite" */
tll = 0x8000000000000000LL;
} else
return 0;
} else {
if (precision_loss)
set_precision_flag(precision_loss);
if (signnegative(&t))
tll = -tll;
}
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 8);
if (copy_to_user(d, &tll, 8))
FPU_abort;
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Put a long into user memory */
int FPU_store_int32(FPU_REG *st0_ptr, u_char st0_tag, long __user *d)
{
FPU_REG t;
int precision_loss;
if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
goto invalid_operand;
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
EXCEPTION(EX_Invalid);
goto invalid_operand;
}
}
reg_copy(st0_ptr, &t);
precision_loss = FPU_round_to_int(&t, st0_tag);
if (t.sigh ||
((t.sigl & 0x80000000) &&
!((t.sigl == 0x80000000) && signnegative(&t)))) {
EXCEPTION(EX_Invalid);
/* This is a special case: see sec 16.2.5.1 of the 80486 book */
invalid_operand:
if (control_word & EX_Invalid) {
/* Produce something like QNaN "indefinite" */
t.sigl = 0x80000000;
} else
return 0;
} else {
if (precision_loss)
set_precision_flag(precision_loss);
if (signnegative(&t))
t.sigl = -(long)t.sigl;
}
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 4);
FPU_put_user(t.sigl, (unsigned long __user *)d);
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Put a short into user memory */
int FPU_store_int16(FPU_REG *st0_ptr, u_char st0_tag, short __user *d)
{
FPU_REG t;
int precision_loss;
if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
goto invalid_operand;
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
EXCEPTION(EX_Invalid);
goto invalid_operand;
}
}
reg_copy(st0_ptr, &t);
precision_loss = FPU_round_to_int(&t, st0_tag);
if (t.sigh ||
((t.sigl & 0xffff8000) &&
!((t.sigl == 0x8000) && signnegative(&t)))) {
EXCEPTION(EX_Invalid);
/* This is a special case: see sec 16.2.5.1 of the 80486 book */
invalid_operand:
if (control_word & EX_Invalid) {
/* Produce something like QNaN "indefinite" */
t.sigl = 0x8000;
} else
return 0;
} else {
if (precision_loss)
set_precision_flag(precision_loss);
if (signnegative(&t))
t.sigl = -t.sigl;
}
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 2);
FPU_put_user((short)t.sigl, d);
RE_ENTRANT_CHECK_ON;
return 1;
}
/* Put a packed bcd array into user memory */
int FPU_store_bcd(FPU_REG *st0_ptr, u_char st0_tag, u_char __user *d)
{
FPU_REG t;
unsigned long long ll;
u_char b;
int i, precision_loss;
u_char sign = (getsign(st0_ptr) == SIGN_NEG) ? 0x80 : 0;
if (st0_tag == TAG_Empty) {
/* Empty register (stack underflow) */
EXCEPTION(EX_StackUnder);
goto invalid_operand;
} else if (st0_tag == TAG_Special) {
st0_tag = FPU_Special(st0_ptr);
if ((st0_tag == TW_Infinity) || (st0_tag == TW_NaN)) {
EXCEPTION(EX_Invalid);
goto invalid_operand;
}
}
reg_copy(st0_ptr, &t);
precision_loss = FPU_round_to_int(&t, st0_tag);
ll = significand(&t);
/* Check for overflow, by comparing with 999999999999999999 decimal. */
if ((t.sigh > 0x0de0b6b3) ||
((t.sigh == 0x0de0b6b3) && (t.sigl > 0xa763ffff))) {
EXCEPTION(EX_Invalid);
/* This is a special case: see sec 16.2.5.1 of the 80486 book */
invalid_operand:
if (control_word & CW_Invalid) {
/* Produce the QNaN "indefinite" */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 10);
for (i = 0; i < 7; i++)
FPU_put_user(0, d + i); /* These bytes "undefined" */
FPU_put_user(0xc0, d + 7); /* This byte "undefined" */
FPU_put_user(0xff, d + 8);
FPU_put_user(0xff, d + 9);
RE_ENTRANT_CHECK_ON;
return 1;
} else
return 0;
} else if (precision_loss) {
/* Precision loss doesn't stop the data transfer */
set_precision_flag(precision_loss);
}
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 10);
RE_ENTRANT_CHECK_ON;
for (i = 0; i < 9; i++) {
b = FPU_div_small(&ll, 10);
b |= (FPU_div_small(&ll, 10)) << 4;
RE_ENTRANT_CHECK_OFF;
FPU_put_user(b, d + i);
RE_ENTRANT_CHECK_ON;
}
RE_ENTRANT_CHECK_OFF;
FPU_put_user(sign, d + 9);
RE_ENTRANT_CHECK_ON;
return 1;
}
/*===========================================================================*/
/* r gets mangled such that sig is int, sign:
it is NOT normalized */
/* The return value (in eax) is zero if the result is exact,
if bits are changed due to rounding, truncation, etc, then
a non-zero value is returned */
/* Overflow is signalled by a non-zero return value (in eax).
In the case of overflow, the returned significand always has the
largest possible value */
int FPU_round_to_int(FPU_REG *r, u_char tag)
{
u_char very_big;
unsigned eax;
if (tag == TAG_Zero) {
/* Make sure that zero is returned */
significand(r) = 0;
return 0; /* o.k. */
}
if (exponent(r) > 63) {
r->sigl = r->sigh = ~0; /* The largest representable number */
return 1; /* overflow */
}
eax = FPU_shrxs(&r->sigl, 63 - exponent(r));
very_big = !(~(r->sigh) | ~(r->sigl)); /* test for 0xfff...fff */
#define half_or_more (eax & 0x80000000)
#define frac_part (eax)
#define more_than_half ((eax & 0x80000001) == 0x80000001)
switch (control_word & CW_RC) {
case RC_RND:
if (more_than_half /* nearest */
|| (half_or_more && (r->sigl & 1))) { /* odd -> even */
if (very_big)
return 1; /* overflow */
significand(r)++;
return PRECISION_LOST_UP;
}
break;
case RC_DOWN:
if (frac_part && getsign(r)) {
if (very_big)
return 1; /* overflow */
significand(r)++;
return PRECISION_LOST_UP;
}
break;
case RC_UP:
if (frac_part && !getsign(r)) {
if (very_big)
return 1; /* overflow */
significand(r)++;
return PRECISION_LOST_UP;
}
break;
case RC_CHOP:
break;
}
return eax ? PRECISION_LOST_DOWN : 0;
}
/*===========================================================================*/
u_char __user *fldenv(fpu_addr_modes addr_modes, u_char __user *s)
{
unsigned short tag_word = 0;
u_char tag;
int i;
if ((addr_modes.default_mode == VM86) ||
((addr_modes.default_mode == PM16)
^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(s, 0x0e);
FPU_get_user(control_word, (unsigned short __user *)s);
FPU_get_user(partial_status, (unsigned short __user *)(s + 2));
FPU_get_user(tag_word, (unsigned short __user *)(s + 4));
FPU_get_user(instruction_address.offset,
(unsigned short __user *)(s + 6));
FPU_get_user(instruction_address.selector,
(unsigned short __user *)(s + 8));
FPU_get_user(operand_address.offset,
(unsigned short __user *)(s + 0x0a));
FPU_get_user(operand_address.selector,
(unsigned short __user *)(s + 0x0c));
RE_ENTRANT_CHECK_ON;
s += 0x0e;
if (addr_modes.default_mode == VM86) {
instruction_address.offset
+= (instruction_address.selector & 0xf000) << 4;
operand_address.offset +=
(operand_address.selector & 0xf000) << 4;
}
} else {
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(s, 0x1c);
FPU_get_user(control_word, (unsigned short __user *)s);
FPU_get_user(partial_status, (unsigned short __user *)(s + 4));
FPU_get_user(tag_word, (unsigned short __user *)(s + 8));
FPU_get_user(instruction_address.offset,
(unsigned long __user *)(s + 0x0c));
FPU_get_user(instruction_address.selector,
(unsigned short __user *)(s + 0x10));
FPU_get_user(instruction_address.opcode,
(unsigned short __user *)(s + 0x12));
FPU_get_user(operand_address.offset,
(unsigned long __user *)(s + 0x14));
FPU_get_user(operand_address.selector,
(unsigned long __user *)(s + 0x18));
RE_ENTRANT_CHECK_ON;
s += 0x1c;
}
#ifdef PECULIAR_486
control_word &= ~0xe080;
#endif /* PECULIAR_486 */
top = (partial_status >> SW_Top_Shift) & 7;
if (partial_status & ~control_word & CW_Exceptions)
partial_status |= (SW_Summary | SW_Backward);
else
partial_status &= ~(SW_Summary | SW_Backward);
for (i = 0; i < 8; i++) {
tag = tag_word & 3;
tag_word >>= 2;
if (tag == TAG_Empty)
/* New tag is empty. Accept it */
FPU_settag(i, TAG_Empty);
else if (FPU_gettag(i) == TAG_Empty) {
/* Old tag is empty and new tag is not empty. New tag is determined
by old reg contents */
if (exponent(&fpu_register(i)) == -EXTENDED_Ebias) {
if (!
(fpu_register(i).sigl | fpu_register(i).
sigh))
FPU_settag(i, TAG_Zero);
else
FPU_settag(i, TAG_Special);
} else if (exponent(&fpu_register(i)) ==
0x7fff - EXTENDED_Ebias) {
FPU_settag(i, TAG_Special);
} else if (fpu_register(i).sigh & 0x80000000)
FPU_settag(i, TAG_Valid);
else
FPU_settag(i, TAG_Special); /* An Un-normal */
}
/* Else old tag is not empty and new tag is not empty. Old tag
remains correct */
}
return s;
}
void frstor(fpu_addr_modes addr_modes, u_char __user *data_address)
{
int i, regnr;
u_char __user *s = fldenv(addr_modes, data_address);
int offset = (top & 7) * 10, other = 80 - offset;
/* Copy all registers in stack order. */
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(s, 80);
__copy_from_user(register_base + offset, s, other);
if (offset)
__copy_from_user(register_base, s + other, offset);
RE_ENTRANT_CHECK_ON;
for (i = 0; i < 8; i++) {
regnr = (i + top) & 7;
if (FPU_gettag(regnr) != TAG_Empty)
/* The loaded data over-rides all other cases. */
FPU_settag(regnr, FPU_tagof(&st(i)));
}
}
u_char __user *fstenv(fpu_addr_modes addr_modes, u_char __user *d)
{
if ((addr_modes.default_mode == VM86) ||
((addr_modes.default_mode == PM16)
^ (addr_modes.override.operand_size == OP_SIZE_PREFIX))) {
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 14);
#ifdef PECULIAR_486
FPU_put_user(control_word & ~0xe080, (unsigned long __user *)d);
#else
FPU_put_user(control_word, (unsigned short __user *)d);
#endif /* PECULIAR_486 */
FPU_put_user(status_word(), (unsigned short __user *)(d + 2));
FPU_put_user(fpu_tag_word, (unsigned short __user *)(d + 4));
FPU_put_user(instruction_address.offset,
(unsigned short __user *)(d + 6));
FPU_put_user(operand_address.offset,
(unsigned short __user *)(d + 0x0a));
if (addr_modes.default_mode == VM86) {
FPU_put_user((instruction_address.
offset & 0xf0000) >> 4,
(unsigned short __user *)(d + 8));
FPU_put_user((operand_address.offset & 0xf0000) >> 4,
(unsigned short __user *)(d + 0x0c));
} else {
FPU_put_user(instruction_address.selector,
(unsigned short __user *)(d + 8));
FPU_put_user(operand_address.selector,
(unsigned short __user *)(d + 0x0c));
}
RE_ENTRANT_CHECK_ON;
d += 0x0e;
} else {
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 7 * 4);
#ifdef PECULIAR_486
control_word &= ~0xe080;
/* An 80486 sets nearly all of the reserved bits to 1. */
control_word |= 0xffff0040;
partial_status = status_word() | 0xffff0000;
fpu_tag_word |= 0xffff0000;
I387->soft.fcs &= ~0xf8000000;
I387->soft.fos |= 0xffff0000;
#endif /* PECULIAR_486 */
if (__copy_to_user(d, &control_word, 7 * 4))
FPU_abort;
RE_ENTRANT_CHECK_ON;
d += 0x1c;
}
control_word |= CW_Exceptions;
partial_status &= ~(SW_Summary | SW_Backward);
return d;
}
void fsave(fpu_addr_modes addr_modes, u_char __user *data_address)
{
u_char __user *d;
int offset = (top & 7) * 10, other = 80 - offset;
d = fstenv(addr_modes, data_address);
RE_ENTRANT_CHECK_OFF;
FPU_access_ok(d, 80);
/* Copy all registers in stack order. */
if (__copy_to_user(d, register_base + offset, other))
FPU_abort;
if (offset)
if (__copy_to_user(d + other, register_base, offset))
FPU_abort;
RE_ENTRANT_CHECK_ON;
finit();
}
/*===========================================================================*/
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