2005-03-05 15:55:02

by Domen Puncer

Subject: [patch 10/12] arch/i386/math-emu/* - compile warning cleanup

compile warning cleanup - handle copy_to/from_user error
returns

Signed-off-by: Stephen Biggs <[email protected]>
Signed-off-by: Domen Puncer <[email protected]>
---


kj-domen/arch/i386/math-emu/fpu_entry.c | 3 +
kj-domen/arch/i386/math-emu/reg_ld_str.c | 52 +++++++++++++++++++++++++------
2 files changed, 44 insertions(+), 11 deletions(-)

diff -puN arch/i386/math-emu/fpu_entry.c~return_code-arch_i386_math-emu arch/i386/math-emu/fpu_entry.c
--- kj/arch/i386/math-emu/fpu_entry.c~return_code-arch_i386_math-emu 2005-03-05 16:13:04.000000000 +0100
+++ kj-domen/arch/i386/math-emu/fpu_entry.c 2005-03-05 16:13:04.000000000 +0100
@@ -742,7 +742,8 @@ int save_i387_soft(void *s387, struct _f
S387->fcs &= ~0xf8000000;
S387->fos |= 0xffff0000;
#endif /* PECULIAR_486 */
- __copy_to_user(d, &S387->cwd, 7*4);
+ if (__copy_to_user(d, &S387->cwd, 7*4))
+ return -1;
RE_ENTRANT_CHECK_ON;

d += 7*4;
diff -puN arch/i386/math-emu/reg_ld_str.c~return_code-arch_i386_math-emu arch/i386/math-emu/reg_ld_str.c
--- kj/arch/i386/math-emu/reg_ld_str.c~return_code-arch_i386_math-emu 2005-03-05 16:13:04.000000000 +0100
+++ kj-domen/arch/i386/math-emu/reg_ld_str.c 2005-03-05 16:13:04.000000000 +0100
@@ -89,12 +89,17 @@ int FPU_tagof(FPU_REG *ptr)
int FPU_load_extended(long double __user *s, int stnr)
{
FPU_REG *sti_ptr = &st(stnr);
+ int user_copy_err;

RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_READ, s, 10);
- __copy_from_user(sti_ptr, s, 10);
+ user_copy_err = __copy_from_user(sti_ptr, s, 10);
RE_ENTRANT_CHECK_ON;

+ if (user_copy_err) {
+ EXCEPTION(EX_INTERNAL);
+ return TAG_Special;
+ }
return FPU_tagof(sti_ptr);
}

@@ -240,13 +245,19 @@ int FPU_load_int64(long long __user *_s)
{
long long s;
int sign;
+ int user_copy_err;
FPU_REG *st0_ptr = &st(0);

RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_READ, _s, 8);
- copy_from_user(&s,_s,8);
+ user_copy_err = copy_from_user(&s,_s,8);
RE_ENTRANT_CHECK_ON;

+ if (user_copy_err) {
+ EXCEPTION(EX_INTERNAL);
+ return TAG_Special;
+ }
+
if (s == 0)
{
reg_copy(&CONST_Z, st0_ptr);
@@ -859,6 +870,7 @@ int FPU_store_int64(FPU_REG *st0_ptr, u_
FPU_REG t;
long long tll;
int precision_loss;
+ int user_copy_err;

if ( st0_tag == TAG_Empty )
{
@@ -907,9 +919,14 @@ int FPU_store_int64(FPU_REG *st0_ptr, u_

RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_WRITE,d,8);
- copy_to_user(d, &tll, 8);
+ user_copy_err = copy_to_user(d, &tll, 8);
RE_ENTRANT_CHECK_ON;

+ if (user_copy_err) {
+ EXCEPTION(EX_INTERNAL);
+ return 0;
+ }
+
return 1;
}

@@ -1271,15 +1288,21 @@ void frstor(fpu_addr_modes addr_modes, u
int i, regnr;
u_char __user *s = fldenv(addr_modes, data_address);
int offset = (top & 7) * 10, other = 80 - offset;
+ int user_copy_err;

/* Copy all registers in stack order. */
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_READ,s,80);
- __copy_from_user(register_base+offset, s, other);
- if ( offset )
- __copy_from_user(register_base, s+other, offset);
+ user_copy_err = __copy_from_user(register_base+offset, s, other);
+ if (!user_copy_err && offset)
+ user_copy_err = __copy_from_user(register_base, s+other, offset);
RE_ENTRANT_CHECK_ON;

+ if (user_copy_err) {
+ EXCEPTION(EX_INTERNAL);
+ return;
+ }
+
for ( i = 0; i < 8; i++ )
{
regnr = (i+top) & 7;
@@ -1325,6 +1348,7 @@ u_char __user *fstenv(fpu_addr_modes add
}
else
{
+ int user_copy_err;
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_WRITE, d, 7*4);
#ifdef PECULIAR_486
@@ -1336,8 +1360,12 @@ u_char __user *fstenv(fpu_addr_modes add
I387.soft.fcs &= ~0xf8000000;
I387.soft.fos |= 0xffff0000;
#endif /* PECULIAR_486 */
- __copy_to_user(d, &control_word, 7*4);
+ user_copy_err = __copy_to_user(d, &control_word, 7*4);
RE_ENTRANT_CHECK_ON;
+
+ if (user_copy_err)
+ EXCEPTION(EX_INTERNAL);
+
d += 0x1c;
}

@@ -1352,6 +1380,7 @@ void fsave(fpu_addr_modes addr_modes, u_
{
u_char __user *d;
int offset = (top & 7) * 10, other = 80 - offset;
+ int user_copy_err;

d = fstenv(addr_modes, data_address);

@@ -1359,11 +1388,14 @@ void fsave(fpu_addr_modes addr_modes, u_
FPU_verify_area(VERIFY_WRITE,d,80);

/* Copy all registers in stack order. */
- __copy_to_user(d, register_base+offset, other);
- if ( offset )
- __copy_to_user(d+other, register_base, offset);
+ user_copy_err = __copy_to_user(d, register_base+offset, other);
+ if (!user_copy_err && offset)
+ user_copy_err = __copy_to_user(d+other, register_base, offset);
RE_ENTRANT_CHECK_ON;

+ if (user_copy_err)
+ EXCEPTION(EX_INTERNAL);
+
finit();
}

_

2005-03-07 00:50:55

by Andrew Morton

Subject: Re: [patch 10/12] arch/i386/math-emu/* - compile warning cleanup

[email protected] wrote:
>
>
> compile warning cleanup - handle copy_to/from_user error
> returns
>

We made some changes like this in there a while back, and things broke
subtly. I'd prefer that someone who remembers how this code works take a
good look at this. But I don't think anyone remembers how this code works.



>
> diff -puN arch/i386/math-emu/fpu_entry.c~return_code-arch_i386_math-emu arch/i386/math-emu/fpu_entry.c
> --- kj/arch/i386/math-emu/fpu_entry.c~return_code-arch_i386_math-emu 2005-03-05 16:13:04.000000000 +0100
> +++ kj-domen/arch/i386/math-emu/fpu_entry.c 2005-03-05 16:13:04.000000000 +0100
> @@ -742,7 +742,8 @@ int save_i387_soft(void *s387, struct _f
> S387->fcs &= ~0xf8000000;
> S387->fos |= 0xffff0000;
> #endif /* PECULIAR_486 */
> - __copy_to_user(d, &S387->cwd, 7*4);
> + if (__copy_to_user(d, &S387->cwd, 7*4))
> + return -1;
> RE_ENTRANT_CHECK_ON;
>
> d += 7*4;
> diff -puN arch/i386/math-emu/reg_ld_str.c~return_code-arch_i386_math-emu arch/i386/math-emu/reg_ld_str.c
> --- kj/arch/i386/math-emu/reg_ld_str.c~return_code-arch_i386_math-emu 2005-03-05 16:13:04.000000000 +0100
> +++ kj-domen/arch/i386/math-emu/reg_ld_str.c 2005-03-05 16:13:04.000000000 +0100
> @@ -89,12 +89,17 @@ int FPU_tagof(FPU_REG *ptr)
> int FPU_load_extended(long double __user *s, int stnr)
> {
> FPU_REG *sti_ptr = &st(stnr);
> + int user_copy_err;
>
> RE_ENTRANT_CHECK_OFF;
> FPU_verify_area(VERIFY_READ, s, 10);
> - __copy_from_user(sti_ptr, s, 10);
> + user_copy_err = __copy_from_user(sti_ptr, s, 10);
> RE_ENTRANT_CHECK_ON;
>
> + if (user_copy_err) {
> + EXCEPTION(EX_INTERNAL);
> + return TAG_Special;
> + }
> return FPU_tagof(sti_ptr);
> }
>
> @@ -240,13 +245,19 @@ int FPU_load_int64(long long __user *_s)
> {
> long long s;
> int sign;
> + int user_copy_err;
> FPU_REG *st0_ptr = &st(0);
>
> RE_ENTRANT_CHECK_OFF;
> FPU_verify_area(VERIFY_READ, _s, 8);
> - copy_from_user(&s,_s,8);
> + user_copy_err = copy_from_user(&s,_s,8);
> RE_ENTRANT_CHECK_ON;
>
> + if (user_copy_err) {
> + EXCEPTION(EX_INTERNAL);
> + return TAG_Special;
> + }
> +
> if (s == 0)
> {
> reg_copy(&CONST_Z, st0_ptr);
> @@ -859,6 +870,7 @@ int FPU_store_int64(FPU_REG *st0_ptr, u_
> FPU_REG t;
> long long tll;
> int precision_loss;
> + int user_copy_err;
>
> if ( st0_tag == TAG_Empty )
> {
> @@ -907,9 +919,14 @@ int FPU_store_int64(FPU_REG *st0_ptr, u_
>
> RE_ENTRANT_CHECK_OFF;
> FPU_verify_area(VERIFY_WRITE,d,8);
> - copy_to_user(d, &tll, 8);
> + user_copy_err = copy_to_user(d, &tll, 8);
> RE_ENTRANT_CHECK_ON;
>
> + if (user_copy_err) {
> + EXCEPTION(EX_INTERNAL);
> + return 0;
> + }
> +
> return 1;
> }
>
> @@ -1271,15 +1288,21 @@ void frstor(fpu_addr_modes addr_modes, u
> int i, regnr;
> u_char __user *s = fldenv(addr_modes, data_address);
> int offset = (top & 7) * 10, other = 80 - offset;
> + int user_copy_err;
>
> /* Copy all registers in stack order. */
> RE_ENTRANT_CHECK_OFF;
> FPU_verify_area(VERIFY_READ,s,80);
> - __copy_from_user(register_base+offset, s, other);
> - if ( offset )
> - __copy_from_user(register_base, s+other, offset);
> + user_copy_err = __copy_from_user(register_base+offset, s, other);
> + if (!user_copy_err && offset)
> + user_copy_err = __copy_from_user(register_base, s+other, offset);
> RE_ENTRANT_CHECK_ON;
>
> + if (user_copy_err) {
> + EXCEPTION(EX_INTERNAL);
> + return;
> + }
> +
> for ( i = 0; i < 8; i++ )
> {
> regnr = (i+top) & 7;
> @@ -1325,6 +1348,7 @@ u_char __user *fstenv(fpu_addr_modes add
> }
> else
> {
> + int user_copy_err;
> RE_ENTRANT_CHECK_OFF;
> FPU_verify_area(VERIFY_WRITE, d, 7*4);
> #ifdef PECULIAR_486
> @@ -1336,8 +1360,12 @@ u_char __user *fstenv(fpu_addr_modes add
> I387.soft.fcs &= ~0xf8000000;
> I387.soft.fos |= 0xffff0000;
> #endif /* PECULIAR_486 */
> - __copy_to_user(d, &control_word, 7*4);
> + user_copy_err = __copy_to_user(d, &control_word, 7*4);
> RE_ENTRANT_CHECK_ON;
> +
> + if (user_copy_err)
> + EXCEPTION(EX_INTERNAL);
> +
> d += 0x1c;
> }
>
> @@ -1352,6 +1380,7 @@ void fsave(fpu_addr_modes addr_modes, u_
> {
> u_char __user *d;
> int offset = (top & 7) * 10, other = 80 - offset;
> + int user_copy_err;
>
> d = fstenv(addr_modes, data_address);
>
> @@ -1359,11 +1388,14 @@ void fsave(fpu_addr_modes addr_modes, u_
> FPU_verify_area(VERIFY_WRITE,d,80);
>
> /* Copy all registers in stack order. */
> - __copy_to_user(d, register_base+offset, other);
> - if ( offset )
> - __copy_to_user(d+other, register_base, offset);
> + user_copy_err = __copy_to_user(d, register_base+offset, other);
> + if (!user_copy_err && offset)
> + user_copy_err = __copy_to_user(d+other, register_base, offset);
> RE_ENTRANT_CHECK_ON;
>
> + if (user_copy_err)
> + EXCEPTION(EX_INTERNAL);
> +
> finit();
> }
>
> _