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[SB #944] bug in mips32 gcc-3.0.1 doing copy_to_user in 2.4.17 linux affects ip_tables-1.2.5 firewall code update
- From: DJ Barrow <dj dot barrow at asitatech dot com>
- To: gcc-bugs at gcc dot gnu dot org,netfilter-devel at lists dot samba dot org,bcm1250-sw at broadcom dot com
- Cc: Jon Crowe <jon dot crowe at asitatech dot com>,"Brian O'Sullivan" <Brian dot OSullivan at asitatech dot com>,John Brosnan <John dot Brosnan at asitatech dot com>
- Date: Wed, 24 Apr 2002 16:32:42 +0100
- Subject: [SB #944] bug in mips32 gcc-3.0.1 doing copy_to_user in 2.4.17 linux affects ip_tables-1.2.5 firewall code update
- Organization: Asita Technologies
I did some more tests with ip_tables & it still crashed when
using other options with the fix I previously posted.
The bug I suspect doesn't happen in the 2.4.18 distro from
kernel.org as its uaccess.h is less aggressive.
gcc is buggy & the broadcom distro of uaccess.h register
usage macros highlight this bug.
Basically gcc has a bad hair day when you try to force
specific registers for parameters on assembly inlines if
under pressure & in danger of register spillage.
We had these problems in the s390 port also in uaccess macros.
I merged the uaccess.h of the generic 2.4.18
from kernel.org which doesn't do this
with the uaccess.h from a 2.4.17 from broadcom
& kept broadcom's fixes.
I suggest you broadcom guys use it in your next distro.
In short all you need is the uaccess.h patch below & the
the iptables problems appear to be fixed.
--- uaccess.orig.h Wed Apr 24 15:42:25 2002
+++ uaccess.h Wed Apr 24 15:45:08 2002
@@ -56,7 +56,7 @@
#define access_ok(type,addr,size) \
__access_ok(((unsigned long)(addr)),(size),__access_mask)
-static inline int verify_area(int type, const void * addr, unsigned long size)
+extern inline int verify_area(int type, const void * addr, unsigned long size)
{
return access_ok(type,addr,size) ? 0 : -EFAULT;
}
@@ -280,84 +280,102 @@
extern size_t __copy_user(void *__to, const void *__from, size_t __n);
#define __copy_to_user(to,from,n) ({ \
- register void *__cu_to __asm__ ("$4"); \
- register const void *__cu_from __asm__ ("$5"); \
- register long __cu_len __asm__ ("$6"); \
+ void *__cu_to; \
+ const void *__cu_from; \
+ long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__asm__ __volatile__( \
+ "move\t$4, %1\n\t" \
+ "move\t$5, %2\n\t" \
+ "move\t$6, %3\n\t" \
__MODULE_JAL(__copy_user) \
- : "+r" (__cu_to), "+r" (__cu_from), "+r" (__cu_len) \
- : \
- : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", "memory"); \
+ "move\t%0, $6" \
+ : "=r" (__cu_len) \
+ : "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
+ : "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", "$15", \
+ "$24", "$31","memory"); \
__cu_len; \
})
#define __copy_from_user(to,from,n) ({ \
- register void *__cu_to __asm__ ("$4"); \
- register const void *__cu_from __asm__ ("$5"); \
- register long __cu_len __asm__ ("$6"); \
+ void *__cu_to; \
+ const void *__cu_from; \
+ long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__asm__ __volatile__( \
+ "move\t$4, %1\n\t" \
+ "move\t$5, %2\n\t" \
+ "move\t$6, %3\n\t" \
".set\tnoreorder\n\t" \
__MODULE_JAL(__copy_user) \
".set\tnoat\n\t" \
- "addu\t$1, %1, %2\n\t" \
+ "addu\t$1, %2, %3\n\t" \
".set\tat\n\t" \
".set\treorder\n\t" \
- : "+r" (__cu_to), "+r" (__cu_from), "+r" (__cu_len) \
- : \
- : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", "memory"); \
+ "move\t%0, $6" \
+ : "=r" (__cu_len) \
+ : "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
+ : "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", "$15", \
+ "$24", "$31","memory"); \
__cu_len; \
})
#define copy_to_user(to,from,n) ({ \
- register void *__cu_to __asm__ ("$4"); \
- register const void *__cu_from __asm__ ("$5"); \
- register long __cu_len __asm__ ("$6"); \
+ void *__cu_to; \
+ const void *__cu_from; \
+ long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
__asm__ __volatile__( \
+ "move\t$4, %1\n\t" \
+ "move\t$5, %2\n\t" \
+ "move\t$6, %3\n\t" \
__MODULE_JAL(__copy_user) \
- : "+r" (__cu_to), "+r" (__cu_from), "+r" (__cu_len) \
- : \
- : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
- "memory"); \
+ "move\t%0, $6" \
+ : "=r" (__cu_len) \
+ : "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
+ : "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", \
+ "$15", "$24", "$31","memory"); \
__cu_len; \
})
#define copy_from_user(to,from,n) ({ \
- register void *__cu_to __asm__ ("$4"); \
- register const void *__cu_from __asm__ ("$5"); \
- register long __cu_len __asm__ ("$6"); \
+ void *__cu_to; \
+ const void *__cu_from; \
+ long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
__asm__ __volatile__( \
+ "move\t$4, %1\n\t" \
+ "move\t$5, %2\n\t" \
+ "move\t$6, %3\n\t" \
".set\tnoreorder\n\t" \
__MODULE_JAL(__copy_user) \
".set\tnoat\n\t" \
- "addu\t$1, %1, %2\n\t" \
+ "addu\t$1, %2, %3\n\t" \
".set\tat\n\t" \
".set\treorder\n\t" \
- : "+r" (__cu_to), "+r" (__cu_from), "+r" (__cu_len) \
- : \
- : "$8", "$9", "$10", "$11", "$12", "$15", "$24", "$31", \
- "memory"); \
+ "move\t%0, $6" \
+ : "=r" (__cu_len) \
+ : "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
+ : "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", \
+ "$15", "$24", "$31","memory"); \
__cu_len; \
})
-static inline __kernel_size_t
+extern inline __kernel_size_t
__clear_user(void *addr, __kernel_size_t size)
{
__kernel_size_t res;
@@ -386,7 +404,7 @@
* Returns: -EFAULT if exception before terminator, N if the entire
* buffer filled, else strlen.
*/
-static inline long
+extern inline long
__strncpy_from_user(char *__to, const char *__from, long __len)
{
long res;
@@ -404,7 +422,7 @@
return res;
}
-static inline long
+extern inline long
strncpy_from_user(char *__to, const char *__from, long __len)
{
long res;
@@ -423,7 +441,7 @@
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
-static inline long __strlen_user(const char *s)
+extern inline long __strlen_user(const char *s)
{
long res;
@@ -438,7 +456,7 @@
return res;
}
-static inline long strlen_user(const char *s)
+extern inline long strlen_user(const char *s)
{
long res;
@@ -454,7 +472,7 @@
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
-static inline long __strnlen_user(const char *s, long n)
+extern inline long __strnlen_user(const char *s, long n)
{
long res;
@@ -470,7 +488,7 @@
return res;
}
-static inline long strnlen_user(const char *s, long n)
+extern inline long strnlen_user(const char *s, long n)
{
long res;
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 1996, 1997, 1998, 1999, 2000 by Ralf Baechle
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
*/
#ifndef _ASM_UACCESS_H
#define _ASM_UACCESS_H
#include <linux/errno.h>
#include <linux/sched.h>
#define STR(x) __STR(x)
#define __STR(x) #x
/*
* The fs value determines whether argument validity checking should be
* performed or not. If get_fs() == USER_DS, checking is performed, with
* get_fs() == KERNEL_DS, checking is bypassed.
*
* For historical reasons, these macros are grossly misnamed.
*/
#define KERNEL_DS ((mm_segment_t) { (unsigned long) 0L })
#define USER_DS ((mm_segment_t) { (unsigned long) -1L })
#define VERIFY_READ 0
#define VERIFY_WRITE 1
#define get_fs() (current->thread.current_ds)
#define get_ds() (KERNEL_DS)
#define set_fs(x) (current->thread.current_ds=(x))
#define segment_eq(a,b) ((a).seg == (b).seg)
/*
* Is a address valid? This does a straighforward calculation rather
* than tests.
*
* Address valid if:
* - "addr" doesn't have any high-bits set
* - AND "size" doesn't have any high-bits set
* - AND "addr+size" doesn't have any high-bits set
* - OR we are in kernel mode.
*/
#define __ua_size(size) \
(__builtin_constant_p(size) && (signed long) (size) > 0 ? 0 : (size))
#define __access_ok(addr,size,mask) \
(((signed long)((mask)&(addr | (addr + size) | __ua_size(size)))) >= 0)
#define __access_mask ((long)(get_fs().seg))
#define access_ok(type,addr,size) \
__access_ok(((unsigned long)(addr)),(size),__access_mask)
extern inline int verify_area(int type, const void * addr, unsigned long size)
{
return access_ok(type,addr,size) ? 0 : -EFAULT;
}
/*
* Uh, these should become the main single-value transfer routines ...
* They automatically use the right size if we just have the right
* pointer type ...
*
* As MIPS uses the same address space for kernel and user data, we
* can just do these as direct assignments.
*
* Careful to not
* (a) re-use the arguments for side effects (sizeof is ok)
* (b) require any knowledge of processes at this stage
*/
#define put_user(x,ptr) \
__put_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define get_user(x,ptr) \
__get_user_check((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
/*
* The "__xxx" versions do not do address space checking, useful when
* doing multiple accesses to the same area (the user has to do the
* checks by hand with "access_ok()")
*/
#define __put_user(x,ptr) \
__put_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
#define __get_user(x,ptr) \
__get_user_nocheck((__typeof__(*(ptr)))(x),(ptr),sizeof(*(ptr)))
struct __large_struct { unsigned long buf[100]; };
#define __m(x) (*(struct __large_struct *)(x))
/*
* Yuck. We need two variants, one for 64bit operation and one
* for 32 bit mode and old iron.
*/
#ifdef __mips64
#define __GET_USER_DW __get_user_asm("ld")
#else
#define __GET_USER_DW __get_user_asm_ll32
#endif
#define __get_user_nocheck(x,ptr,size) ({ \
long __gu_err; \
__typeof(*(ptr)) __gu_val; \
long __gu_addr; \
__asm__("":"=r" (__gu_val)); \
__gu_addr = (long) (ptr); \
__asm__("":"=r" (__gu_err)); \
switch (size) { \
case 1: __get_user_asm("lb"); break; \
case 2: __get_user_asm("lh"); break; \
case 4: __get_user_asm("lw"); break; \
case 8: __GET_USER_DW; break; \
default: __get_user_unknown(); break; \
} x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
#define __get_user_check(x,ptr,size) ({ \
long __gu_err; \
__typeof__(*(ptr)) __gu_val; \
long __gu_addr; \
__asm__("":"=r" (__gu_val)); \
__gu_addr = (long) (ptr); \
__asm__("":"=r" (__gu_err)); \
if (__access_ok(__gu_addr,size,__access_mask)) { \
switch (size) { \
case 1: __get_user_asm("lb"); break; \
case 2: __get_user_asm("lh"); break; \
case 4: __get_user_asm("lw"); break; \
case 8: __GET_USER_DW; break; \
default: __get_user_unknown(); break; \
} } x = (__typeof__(*(ptr))) __gu_val; __gu_err; })
#define __get_user_asm(insn) \
({ \
__asm__ __volatile__( \
"1:\t" insn "\t%1,%2\n\t" \
"move\t%0,$0\n" \
"2:\n\t" \
".section\t.fixup,\"ax\"\n" \
"3:\tli\t%0,%3\n\t" \
"move\t%1,$0\n\t" \
"j\t2b\n\t" \
".previous\n\t" \
".section\t__ex_table,\"a\"\n\t" \
".word\t1b,3b\n\t" \
".previous" \
:"=r" (__gu_err), "=r" (__gu_val) \
:"o" (__m(__gu_addr)), "i" (-EFAULT)); })
/*
* Get a long long 64 using 32 bit registers.
*/
#define __get_user_asm_ll32 \
({ \
__asm__ __volatile__( \
"1:\tlw\t%1,%2\n" \
"2:\tlw\t%D1,%3\n\t" \
"move\t%0,$0\n" \
"3:\t.section\t.fixup,\"ax\"\n" \
"4:\tli\t%0,%4\n\t" \
"move\t%1,$0\n\t" \
"move\t%D1,$0\n\t" \
"j\t3b\n\t" \
".previous\n\t" \
".section\t__ex_table,\"a\"\n\t" \
".word\t1b,4b\n\t" \
".word\t2b,4b\n\t" \
".previous" \
:"=r" (__gu_err), "=&r" (__gu_val) \
:"o" (__m(__gu_addr)), "o" (__m(__gu_addr + 4)), \
"i" (-EFAULT)); })
extern void __get_user_unknown(void);
/*
* Yuck. We need two variants, one for 64bit operation and one
* for 32 bit mode and old iron.
*/
#ifdef __mips64
#define __PUT_USER_DW __put_user_asm("sd")
#else
#define __PUT_USER_DW __put_user_asm_ll32
#endif
#define __put_user_nocheck(x,ptr,size) ({ \
long __pu_err; \
__typeof__(*(ptr)) __pu_val; \
long __pu_addr; \
__pu_val = (x); \
__pu_addr = (long) (ptr); \
__asm__("":"=r" (__pu_err)); \
switch (size) { \
case 1: __put_user_asm("sb"); break; \
case 2: __put_user_asm("sh"); break; \
case 4: __put_user_asm("sw"); break; \
case 8: __PUT_USER_DW; break; \
default: __put_user_unknown(); break; \
} __pu_err; })
#define __put_user_check(x,ptr,size) ({ \
long __pu_err; \
__typeof__(*(ptr)) __pu_val; \
long __pu_addr; \
__pu_val = (x); \
__pu_addr = (long) (ptr); \
__asm__("":"=r" (__pu_err)); \
if (__access_ok(__pu_addr,size,__access_mask)) { \
switch (size) { \
case 1: __put_user_asm("sb"); break; \
case 2: __put_user_asm("sh"); break; \
case 4: __put_user_asm("sw"); break; \
case 8: __PUT_USER_DW; break; \
default: __put_user_unknown(); break; \
} } __pu_err; })
#ifdef CONFIG_SB1_PASS_1_WORKAROUNDS
#define ALIGN_JUMP ".align 3\n\t"
#else
#define ALIGN_JUMP ""
#endif
#define __put_user_asm(insn) \
({ \
__asm__ __volatile__( \
"1:\t" insn "\t%z1, %2\t\t\t# __put_user_asm\n\t" \
"move\t%0, $0\n" \
"2:\n\t" \
".section\t.fixup,\"ax\"\n" \
"3:\tli\t%0,%3\n\t" \
ALIGN_JUMP \
"j\t2b\n\t" \
".previous\n\t" \
".section\t__ex_table,\"a\"\n\t" \
".word\t1b,3b\n\t" \
".previous" \
:"=r" (__pu_err) \
:"Jr" (__pu_val), "o" (__m(__pu_addr)), "i" (-EFAULT)); })
#define __put_user_asm_ll32 \
({ \
__asm__ __volatile__( \
"1:\tsw\t%1, %2\t\t\t# __put_user_asm_ll32\n\t" \
"2:\tsw\t%D1, %3\n" \
"move\t%0, $0\n" \
"3:\n\t" \
".section\t.fixup,\"ax\"\n" \
"4:\tli\t%0,%4\n\t" \
ALIGN_JUMP \
"j\t3b\n\t" \
".previous\n\t" \
".section\t__ex_table,\"a\"\n\t" \
".word\t1b,4b\n\t" \
".word\t2b,4b\n\t" \
".previous" \
:"=r" (__pu_err) \
:"r" (__pu_val), "o" (__m(__pu_addr)), "o" (__m(__pu_addr + 4)), \
"i" (-EFAULT)); })
extern void __put_user_unknown(void);
/*
* We're generating jump to subroutines which will be outside the range of
* jump instructions
*/
#ifdef MODULE
#define __MODULE_JAL(destination) \
".set\tnoat\n\t" \
"la\t$1, " #destination "\n\t" \
ALIGN_JUMP \
"jalr\t$1\n\t" \
".set\tat\n\t"
#else
#define __MODULE_JAL(destination) \
ALIGN_JUMP \
"jal\t" #destination "\n\t"
#endif
extern size_t __copy_user(void *__to, const void *__from, size_t __n);
#define __copy_to_user(to,from,n) ({ \
void *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__asm__ __volatile__( \
"move\t$4, %1\n\t" \
"move\t$5, %2\n\t" \
"move\t$6, %3\n\t" \
__MODULE_JAL(__copy_user) \
"move\t%0, $6" \
: "=r" (__cu_len) \
: "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
: "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", "$15", \
"$24", "$31","memory"); \
__cu_len; \
})
#define __copy_from_user(to,from,n) ({ \
void *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
__asm__ __volatile__( \
"move\t$4, %1\n\t" \
"move\t$5, %2\n\t" \
"move\t$6, %3\n\t" \
".set\tnoreorder\n\t" \
__MODULE_JAL(__copy_user) \
".set\tnoat\n\t" \
"addu\t$1, %2, %3\n\t" \
".set\tat\n\t" \
".set\treorder\n\t" \
"move\t%0, $6" \
: "=r" (__cu_len) \
: "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
: "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", "$15", \
"$24", "$31","memory"); \
__cu_len; \
})
#define copy_to_user(to,from,n) ({ \
void *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_WRITE, __cu_to, __cu_len)) \
__asm__ __volatile__( \
"move\t$4, %1\n\t" \
"move\t$5, %2\n\t" \
"move\t$6, %3\n\t" \
__MODULE_JAL(__copy_user) \
"move\t%0, $6" \
: "=r" (__cu_len) \
: "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
: "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", \
"$15", "$24", "$31","memory"); \
__cu_len; \
})
#define copy_from_user(to,from,n) ({ \
void *__cu_to; \
const void *__cu_from; \
long __cu_len; \
\
__cu_to = (to); \
__cu_from = (from); \
__cu_len = (n); \
if (access_ok(VERIFY_READ, __cu_from, __cu_len)) \
__asm__ __volatile__( \
"move\t$4, %1\n\t" \
"move\t$5, %2\n\t" \
"move\t$6, %3\n\t" \
".set\tnoreorder\n\t" \
__MODULE_JAL(__copy_user) \
".set\tnoat\n\t" \
"addu\t$1, %2, %3\n\t" \
".set\tat\n\t" \
".set\treorder\n\t" \
"move\t%0, $6" \
: "=r" (__cu_len) \
: "r" (__cu_to), "r" (__cu_from), "r" (__cu_len) \
: "$4", "$5", "$6", "$8", "$9", "$10", "$11", "$12", \
"$15", "$24", "$31","memory"); \
__cu_len; \
})
extern inline __kernel_size_t
__clear_user(void *addr, __kernel_size_t size)
{
__kernel_size_t res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, $0\n\t"
"move\t$6, %2\n\t"
__MODULE_JAL(__bzero)
"move\t%0, $6"
: "=r" (res)
: "r" (addr), "r" (size)
: "$4", "$5", "$6", "$8", "$9", "$31");
return res;
}
#define clear_user(addr,n) ({ \
void * __cl_addr = (addr); \
unsigned long __cl_size = (n); \
if (__cl_size && access_ok(VERIFY_WRITE, ((unsigned long)(__cl_addr)), __cl_size)) \
__cl_size = __clear_user(__cl_addr, __cl_size); \
__cl_size; })
/*
* Returns: -EFAULT if exception before terminator, N if the entire
* buffer filled, else strlen.
*/
extern inline long
__strncpy_from_user(char *__to, const char *__from, long __len)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
"move\t$6, %3\n\t"
__MODULE_JAL(__strncpy_from_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (__to), "r" (__from), "r" (__len)
: "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");
return res;
}
extern inline long
strncpy_from_user(char *__to, const char *__from, long __len)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
"move\t$6, %3\n\t"
__MODULE_JAL(__strncpy_from_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (__to), "r" (__from), "r" (__len)
: "$2", "$3", "$4", "$5", "$6", "$8", "$31", "memory");
return res;
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
extern inline long __strlen_user(const char *s)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
__MODULE_JAL(__strlen_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s)
: "$2", "$4", "$8", "$31");
return res;
}
extern inline long strlen_user(const char *s)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
__MODULE_JAL(__strlen_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s)
: "$2", "$4", "$8", "$31");
return res;
}
/* Returns: 0 if bad, string length+1 (memory size) of string if ok */
extern inline long __strnlen_user(const char *s, long n)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
__MODULE_JAL(__strnlen_user_nocheck_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s), "r" (n)
: "$2", "$4", "$5", "$8", "$31");
return res;
}
extern inline long strnlen_user(const char *s, long n)
{
long res;
__asm__ __volatile__(
"move\t$4, %1\n\t"
"move\t$5, %2\n\t"
__MODULE_JAL(__strnlen_user_asm)
"move\t%0, $2"
: "=r" (res)
: "r" (s), "r" (n)
: "$2", "$4", "$5", "$8", "$31");
return res;
}
struct exception_table_entry
{
unsigned long insn;
unsigned long nextinsn;
};
/* Returns 0 if exception not found and fixup.unit otherwise. */
extern unsigned long search_exception_table(unsigned long addr);
/* Returns the new pc */
#define fixup_exception(map_reg, fixup_unit, pc) \
({ \
fixup_unit; \
})
#endif /* _ASM_UACCESS_H */