Viewing file:  uaccess.h (20.95 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
#ifndef __M68K_UACCESS_H
#define __M68K_UACCESS_H
/*
* User space memory access functions
*/
#include <linux/sched.h>
#include <asm/segment.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
/* We let the MMU do all checking */
#define access_ok(type,addr,size) 1
extern inline int verify_area(int type, const void * addr, unsigned long size)
{
return access_ok(type,addr,size)?0:-EFAULT;
}
/*
* The exception table consists of pairs of addresses: the first is the
* address of an instruction that is allowed to fault, and the second is
* the address at which the program should continue. No registers are
* modified, so it is entirely up to the continuation code to figure out
* what to do.
*
* All the routines below use bits of fixup code that are out of line
* with the main instruction path. This means when everything is well,
* we don't even have to jump over them. Further, they do not intrude
* on our cache or tlb entries.
*/
struct exception_table_entry
{
unsigned long insn, fixup;
};
/* Returns 0 if exception not found and fixup otherwise. */
extern unsigned long search_exception_table(unsigned long);
/*
* These are the main single-value transfer routines. They automatically
* use the right size if we just have the right pointer type.
*/
#define put_user(x, ptr) \
({ \
int __pu_err; \
typeof(*(ptr)) __pu_val = (x); \
switch (sizeof (*(ptr))) { \
case 1: \
__put_user_asm(__pu_err, __pu_val, ptr, b); \
break; \
case 2: \
__put_user_asm(__pu_err, __pu_val, ptr, w); \
break; \
case 4: \
__put_user_asm(__pu_err, __pu_val, ptr, l); \
break; \
case 8: \
__pu_err = __constant_copy_to_user(ptr, &__pu_val, 8); \
break; \
default: \
__pu_err = __put_user_bad(); \
break; \
} \
__pu_err; \
})
#define __put_user(x, ptr) put_user(x, ptr)
extern int __put_user_bad(void);
/*
* Tell gcc we read from memory instead of writing: this is because
* we do not write to any memory gcc knows about, so there are no
* aliasing issues.
*/
#define __put_user_asm(err,x,ptr,bwl) \
__asm__ __volatile__ \
("21:moves" #bwl " %2,%1\n" \
"1:\n" \
".section .fixup,\"ax\"\n" \
" .even\n" \
"2: movel %3,%0\n" \
" jra 1b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 21b,2b\n" \
" .long 1b,2b\n" \
".previous" \
: "=d"(err) \
: "m"(*(ptr)), "r"(x), "i"(-EFAULT), "0"(0))
#define get_user(x, ptr) \
({ \
int __gu_err; \
typeof(*(ptr)) __gu_val; \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm(__gu_err, __gu_val, ptr, b, "=d"); \
break; \
case 2: \
__get_user_asm(__gu_err, __gu_val, ptr, w, "=r"); \
break; \
case 4: \
__get_user_asm(__gu_err, __gu_val, ptr, l, "=r"); \
break; \
case 8: \
__gu_err = __constant_copy_from_user(&__gu_val, ptr, 8); \
break; \
default: \
__gu_val = 0; \
__gu_err = __get_user_bad(); \
break; \
} \
(x) = __gu_val; \
__gu_err; \
})
#define __get_user(x, ptr) get_user(x, ptr)
extern int __get_user_bad(void);
#define __get_user_asm(err,x,ptr,bwl,reg) \
__asm__ __volatile__ \
("1: moves" #bwl " %2,%1\n" \
"2:\n" \
".section .fixup,\"ax\"\n" \
" .even\n" \
"3: movel %3,%0\n" \
" sub" #bwl " %1,%1\n" \
" jra 2b\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 1b,3b\n" \
".previous" \
: "=d"(err), reg(x) \
: "m"(*(ptr)), "i" (-EFAULT), "0"(0))
static inline unsigned long
__generic_copy_from_user(void *to, const void *from, unsigned long n)
{
unsigned long tmp;
__asm__ __volatile__
(" tstl %2\n"
" jeq 2f\n"
"1: movesl (%1)+,%3\n"
" movel %3,(%0)+\n"
" subql #1,%2\n"
" jne 1b\n"
"2: movel %4,%2\n"
" bclr #1,%2\n"
" jeq 4f\n"
"3: movesw (%1)+,%3\n"
" movew %3,(%0)+\n"
"4: bclr #0,%2\n"
" jeq 6f\n"
"5: movesb (%1)+,%3\n"
" moveb %3,(%0)+\n"
"6:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"7: movel %2,%%d0\n"
"71:clrl (%0)+\n"
" subql #1,%%d0\n"
" jne 71b\n"
" lsll #2,%2\n"
" addl %4,%2\n"
" btst #1,%4\n"
" jne 81f\n"
" btst #0,%4\n"
" jne 91f\n"
" jra 6b\n"
"8: addql #2,%2\n"
"81:clrw (%0)+\n"
" btst #0,%4\n"
" jne 91f\n"
" jra 6b\n"
"9: addql #1,%2\n"
"91:clrb (%0)+\n"
" jra 6b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,7b\n"
" .long 3b,8b\n"
" .long 5b,9b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n), "=&d"(tmp)
: "d"(n & 3), "0"(to), "1"(from), "2"(n/4)
: "d0", "memory");
return n;
}
static inline unsigned long
__generic_copy_to_user(void *to, const void *from, unsigned long n)
{
unsigned long tmp;
__asm__ __volatile__
(" tstl %2\n"
" jeq 3f\n"
"1: movel (%1)+,%3\n"
"22:movesl %3,(%0)+\n"
"2: subql #1,%2\n"
" jne 1b\n"
"3: movel %4,%2\n"
" bclr #1,%2\n"
" jeq 4f\n"
" movew (%1)+,%3\n"
"24:movesw %3,(%0)+\n"
"4: bclr #0,%2\n"
" jeq 5f\n"
" moveb (%1)+,%3\n"
"25:movesb %3,(%0)+\n"
"5:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"60:addql #1,%2\n"
"6: lsll #2,%2\n"
" addl %4,%2\n"
" jra 5b\n"
"7: addql #2,%2\n"
" jra 5b\n"
"8: addql #1,%2\n"
" jra 5b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,60b\n"
" .long 22b,6b\n"
" .long 2b,6b\n"
" .long 24b,7b\n"
" .long 3b,60b\n"
" .long 4b,7b\n"
" .long 25b,8b\n"
" .long 5b,8b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n), "=&d"(tmp)
: "r"(n & 3), "0"(to), "1"(from), "2"(n / 4)
: "memory");
return n;
}
#define __copy_from_user_big(to, from, n, fixup, copy) \
__asm__ __volatile__ \
("10: movesl (%1)+,%%d0\n" \
" movel %%d0,(%0)+\n" \
" subql #1,%2\n" \
" jne 10b\n" \
".section .fixup,\"ax\"\n" \
" .even\n" \
"11: movel %2,%%d0\n" \
"13: clrl (%0)+\n" \
" subql #1,%%d0\n" \
" jne 13b\n" \
" lsll #2,%2\n" \
fixup "\n" \
" jra 12f\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 10b,11b\n" \
".previous\n" \
copy "\n" \
"12:" \
: "=a"(to), "=a"(from), "=d"(n) \
: "0"(to), "1"(from), "2"(n/4) \
: "d0", "memory")
static inline unsigned long
__constant_copy_from_user(void *to, const void *from, unsigned long n)
{
switch (n) {
case 0:
break;
case 1:
__asm__ __volatile__
("1: movesb (%1)+,%%d0\n"
" moveb %%d0,(%0)+\n"
"2:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"3: addql #1,%2\n"
" clrb (%0)+\n"
" jra 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,3b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 2:
__asm__ __volatile__
("1: movesw (%1)+,%%d0\n"
" movew %%d0,(%0)+\n"
"2:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"3: addql #2,%2\n"
" clrw (%0)+\n"
" jra 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,3b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 3:
__asm__ __volatile__
("1: movesw (%1)+,%%d0\n"
" movew %%d0,(%0)+\n"
"2: movesb (%1)+,%%d0\n"
" moveb %%d0,(%0)+\n"
"3:"
".section .fixup,\"ax\"\n"
" .even\n"
"4: addql #2,%2\n"
" clrw (%0)+\n"
"5: addql #1,%2\n"
" clrb (%0)+\n"
" jra 3b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,4b\n"
" .long 2b,5b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 4:
__asm__ __volatile__
("1: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"2:"
".section .fixup,\"ax\"\n"
" .even\n"
"3: addql #4,%2\n"
" clrl (%0)+\n"
" jra 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,3b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 8:
__asm__ __volatile__
("1: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"2: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"3:"
".section .fixup,\"ax\"\n"
" .even\n"
"4: addql #4,%2\n"
" clrl (%0)+\n"
"5: addql #4,%2\n"
" clrl (%0)+\n"
" jra 3b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,4b\n"
" .long 2b,5b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 12:
__asm__ __volatile__
("1: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"2: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"3: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"4:"
".section .fixup,\"ax\"\n"
" .even\n"
"5: addql #4,%2\n"
" clrl (%0)+\n"
"6: addql #4,%2\n"
" clrl (%0)+\n"
"7: addql #4,%2\n"
" clrl (%0)+\n"
" jra 4b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,5b\n"
" .long 2b,6b\n"
" .long 3b,7b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 16:
__asm__ __volatile__
("1: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"2: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"3: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"4: movesl (%1)+,%%d0\n"
" movel %%d0,(%0)+\n"
"5:"
".section .fixup,\"ax\"\n"
" .even\n"
"6: addql #4,%2\n"
" clrl (%0)+\n"
"7: addql #4,%2\n"
" clrl (%0)+\n"
"8: addql #4,%2\n"
" clrl (%0)+\n"
"9: addql #4,%2\n"
" clrl (%0)+\n"
" jra 5b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,6b\n"
" .long 2b,7b\n"
" .long 3b,8b\n"
" .long 4b,9b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
default:
switch (n & 3) {
case 0:
__copy_from_user_big(to, from, n, "", "");
break;
case 1:
__copy_from_user_big(to, from, n,
/* fixup */
"1: addql #1,%2\n"
" clrb (%0)+",
/* copy */
"2: movesb (%1)+,%%d0\n"
" moveb %%d0,(%0)+\n"
".section __ex_table,\"a\"\n"
" .long 2b,1b\n"
".previous");
break;
case 2:
__copy_from_user_big(to, from, n,
/* fixup */
"1: addql #2,%2\n"
" clrw (%0)+",
/* copy */
"2: movesw (%1)+,%%d0\n"
" movew %%d0,(%0)+\n"
".section __ex_table,\"a\"\n"
" .long 2b,1b\n"
".previous");
break;
case 3:
__copy_from_user_big(to, from, n,
/* fixup */
"1: addql #2,%2\n"
" clrw (%0)+\n"
"2: addql #1,%2\n"
" clrb (%0)+",
/* copy */
"3: movesw (%1)+,%%d0\n"
" movew %%d0,(%0)+\n"
"4: movesb (%1)+,%%d0\n"
" moveb %%d0,(%0)+\n"
".section __ex_table,\"a\"\n"
" .long 3b,1b\n"
" .long 4b,2b\n"
".previous");
break;
}
break;
}
return n;
}
#define __copy_to_user_big(to, from, n, fixup, copy) \
__asm__ __volatile__ \
("10: movel (%1)+,%%d0\n" \
"31: movesl %%d0,(%0)+\n" \
"11: subql #1,%2\n" \
" jne 10b\n" \
"41:\n" \
".section .fixup,\"ax\"\n" \
" .even\n" \
"22: addql #1,%2\n" \
"12: lsll #2,%2\n" \
fixup "\n" \
" jra 13f\n" \
".previous\n" \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 10b,22b\n" \
" .long 31b,12b\n" \
" .long 11b,12b\n" \
" .long 41b,22b\n" \
".previous\n" \
copy "\n" \
"13:" \
: "=a"(to), "=a"(from), "=d"(n) \
: "0"(to), "1"(from), "2"(n/4) \
: "d0", "memory")
static inline unsigned long
__constant_copy_to_user(void *to, const void *from, unsigned long n)
{
switch (n) {
case 0:
break;
case 1:
__asm__ __volatile__
(" moveb (%1)+,%%d0\n"
"21:movesb %%d0,(%0)+\n"
"1:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"2: addql #1,%2\n"
" jra 1b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n "
" .long 21b,2b\n"
" .long 1b,2b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 2:
__asm__ __volatile__
(" movew (%1)+,%%d0\n"
"21:movesw %%d0,(%0)+\n"
"1:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"2: addql #2,%2\n"
" jra 1b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,2b\n"
" .long 1b,2b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 3:
__asm__ __volatile__
(" movew (%1)+,%%d0\n"
"21:movesw %%d0,(%0)+\n"
"1: moveb (%1)+,%%d0\n"
"22:movesb %%d0,(%0)+\n"
"2:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"3: addql #2,%2\n"
"4: addql #1,%2\n"
" jra 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,3b\n"
" .long 1b,3b\n"
" .long 22b,4b\n"
" .long 2b,4b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 4:
__asm__ __volatile__
(" movel (%1)+,%%d0\n"
"21:movesl %%d0,(%0)+\n"
"1:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"2: addql #4,%2\n"
" jra 1b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,2b\n"
" .long 1b,2b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 8:
__asm__ __volatile__
(" movel (%1)+,%%d0\n"
"21:movesl %%d0,(%0)+\n"
"1: movel (%1)+,%%d0\n"
"22:movesl %%d0,(%0)+\n"
"2:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"3: addql #4,%2\n"
"4: addql #4,%2\n"
" jra 2b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,3b\n"
" .long 1b,3b\n"
" .long 22b,4b\n"
" .long 2b,4b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 12:
__asm__ __volatile__
(" movel (%1)+,%%d0\n"
"21:movesl %%d0,(%0)+\n"
"1: movel (%1)+,%%d0\n"
"22:movesl %%d0,(%0)+\n"
"2: movel (%1)+,%%d0\n"
"23:movesl %%d0,(%0)+\n"
"3:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"4: addql #4,%2\n"
"5: addql #4,%2\n"
"6: addql #4,%2\n"
" jra 3b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,4b\n"
" .long 1b,4b\n"
" .long 22b,5b\n"
" .long 2b,5b\n"
" .long 23b,6b\n"
" .long 3b,6b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
case 16:
__asm__ __volatile__
(" movel (%1)+,%%d0\n"
"21:movesl %%d0,(%0)+\n"
"1: movel (%1)+,%%d0\n"
"22:movesl %%d0,(%0)+\n"
"2: movel (%1)+,%%d0\n"
"23:movesl %%d0,(%0)+\n"
"3: movel (%1)+,%%d0\n"
"24:movesl %%d0,(%0)+\n"
"4:"
".section .fixup,\"ax\"\n"
" .even\n"
"5: addql #4,%2\n"
"6: addql #4,%2\n"
"7: addql #4,%2\n"
"8: addql #4,%2\n"
" jra 4b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 21b,5b\n"
" .long 1b,5b\n"
" .long 22b,6b\n"
" .long 2b,6b\n"
" .long 23b,7b\n"
" .long 3b,7b\n"
" .long 24b,8b\n"
" .long 4b,8b\n"
".previous"
: "=a"(to), "=a"(from), "=d"(n)
: "0"(to), "1"(from), "2"(0)
: "d0", "memory");
break;
default:
switch (n & 3) {
case 0:
__copy_to_user_big(to, from, n, "", "");
break;
case 1:
__copy_to_user_big(to, from, n,
/* fixup */
"1: addql #1,%2",
/* copy */
" moveb (%1)+,%%d0\n"
"22:movesb %%d0,(%0)+\n"
"2:"
".section __ex_table,\"a\"\n"
" .long 22b,1b\n"
" .long 2b,1b\n"
".previous");
break;
case 2:
__copy_to_user_big(to, from, n,
/* fixup */
"1: addql #2,%2",
/* copy */
" movew (%1)+,%%d0\n"
"22:movesw %%d0,(%0)+\n"
"2:"
".section __ex_table,\"a\"\n"
" .long 22b,1b\n"
" .long 2b,1b\n"
".previous");
break;
case 3:
__copy_to_user_big(to, from, n,
/* fixup */
"1: addql #2,%2\n"
"2: addql #1,%2",
/* copy */
" movew (%1)+,%%d0\n"
"23:movesw %%d0,(%0)+\n"
"3: moveb (%1)+,%%d0\n"
"24:movesb %%d0,(%0)+\n"
"4:"
".section __ex_table,\"a\"\n"
" .long 23b,1b\n"
" .long 3b,1b\n"
" .long 24b,2b\n"
" .long 4b,2b\n"
".previous");
break;
}
break;
}
return n;
}
#define copy_from_user(to, from, n) \
(__builtin_constant_p(n) ? \
__constant_copy_from_user(to, from, n) : \
__generic_copy_from_user(to, from, n))
#define copy_to_user(to, from, n) \
(__builtin_constant_p(n) ? \
__constant_copy_to_user(to, from, n) : \
__generic_copy_to_user(to, from, n))
#define __copy_from_user(to, from, n) copy_from_user(to, from, n)
#define __copy_to_user(to, from, n) copy_to_user(to, from, n)
/*
* Copy a null terminated string from userspace.
*/
static inline long
strncpy_from_user(char *dst, const char *src, long count)
{
long res;
if (count == 0) return count;
__asm__ __volatile__
("1: movesb (%2)+,%%d0\n"
"12:moveb %%d0,(%1)+\n"
" jeq 2f\n"
" subql #1,%3\n"
" jne 1b\n"
"2: subl %3,%0\n"
"3:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"4: movel %4,%0\n"
" jra 3b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,4b\n"
" .long 12b,4b\n"
".previous"
: "=d"(res), "=a"(dst), "=a"(src), "=d"(count)
: "i"(-EFAULT), "0"(count), "1"(dst), "2"(src), "3"(count)
: "d0", "memory");
return res;
}
/*
* Return the size of a string (including the ending 0)
*
* Return 0 on exception, a value greater than N if too long
*/
static inline long strnlen_user(const char *src, long n)
{
long res;
res = -(long)src;
__asm__ __volatile__
("1:\n"
" tstl %2\n"
" jeq 3f\n"
"2: movesb (%1)+,%%d0\n"
"22:\n"
" subql #1,%2\n"
" tstb %%d0\n"
" jne 1b\n"
" jra 4f\n"
"3:\n"
" addql #1,%0\n"
"4:\n"
" addl %1,%0\n"
"5:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"6: moveq %3,%0\n"
" jra 5b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 2b,6b\n"
" .long 22b,6b\n"
".previous"
: "=d"(res), "=a"(src), "=d"(n)
: "i"(0), "0"(res), "1"(src), "2"(n)
: "d0");
return res;
}
#define strlen_user(str) strnlen_user(str, 32767)
/*
* Zero Userspace
*/
static inline unsigned long
clear_user(void *to, unsigned long n)
{
__asm__ __volatile__
(" tstl %1\n"
" jeq 3f\n"
"1: movesl %3,(%0)+\n"
"2: subql #1,%1\n"
" jne 1b\n"
"3: movel %2,%1\n"
" bclr #1,%1\n"
" jeq 4f\n"
"24:movesw %3,(%0)+\n"
"4: bclr #0,%1\n"
" jeq 5f\n"
"25:movesb %3,(%0)+\n"
"5:\n"
".section .fixup,\"ax\"\n"
" .even\n"
"61:addql #1,%1\n"
"6: lsll #2,%1\n"
" addl %2,%1\n"
" jra 5b\n"
"7: addql #2,%1\n"
" jra 5b\n"
"8: addql #1,%1\n"
" jra 5b\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 1b,61b\n"
" .long 2b,6b\n"
" .long 3b,61b\n"
" .long 24b,7b\n"
" .long 4b,7b\n"
" .long 25b,8b\n"
" .long 5b,8b\n"
".previous"
: "=a"(to), "=d"(n)
: "r"(n & 3), "r"(0), "0"(to), "1"(n/4));
return n;
}
#endif /* _M68K_UACCESS_H */
|