mirror of
https://github.com/torvalds/linux.git
synced 2024-11-12 07:01:57 +00:00
146 lines
2.5 KiB
ArmAsm
146 lines
2.5 KiB
ArmAsm
|
/*
|
||
|
|
* arch/alpha/lib/copy_user.S
|
||
|
|
*
|
||
|
|
* Copy to/from user space, handling exceptions as we go.. This
|
||
|
|
* isn't exactly pretty.
|
||
|
|
*
|
||
|
|
* This is essentially the same as "memcpy()", but with a few twists.
|
||
|
|
* Notably, we have to make sure that $0 is always up-to-date and
|
||
|
|
* contains the right "bytes left to copy" value (and that it is updated
|
||
|
|
* only _after_ a successful copy). There is also some rather minor
|
||
|
|
* exception setup stuff..
|
||
|
|
*
|
||
|
|
* NOTE! This is not directly C-callable, because the calling semantics are
|
||
|
|
* different:
|
||
|
|
*
|
||
|
|
* Inputs:
|
||
|
|
* length in $0
|
||
|
|
* destination address in $6
|
||
|
|
* source address in $7
|
||
|
|
* return address in $28
|
||
|
|
*
|
||
|
|
* Outputs:
|
||
|
|
* bytes left to copy in $0
|
||
|
|
*
|
||
|
|
* Clobbers:
|
||
|
|
* $1,$2,$3,$4,$5,$6,$7
|
||
|
|
*/
|
||
|
|
|
||
|
|
/* Allow an exception for an insn; exit if we get one. */
|
||
|
|
#define EXI(x,y...) \
|
||
|
|
99: x,##y; \
|
||
|
|
.section __ex_table,"a"; \
|
||
|
|
.long 99b - .; \
|
||
|
|
lda $31, $exitin-99b($31); \
|
||
|
|
.previous
|
||
|
|
|
||
|
|
#define EXO(x,y...) \
|
||
|
|
99: x,##y; \
|
||
|
|
.section __ex_table,"a"; \
|
||
|
|
.long 99b - .; \
|
||
|
|
lda $31, $exitout-99b($31); \
|
||
|
|
.previous
|
||
|
|
|
||
|
|
.set noat
|
||
|
|
.align 4
|
||
|
|
.globl __copy_user
|
||
|
|
.ent __copy_user
|
||
|
|
__copy_user:
|
||
|
|
.prologue 0
|
||
|
|
and $6,7,$3
|
||
|
|
beq $0,$35
|
||
|
|
beq $3,$36
|
||
|
|
subq $3,8,$3
|
||
|
|
.align 4
|
||
|
|
$37:
|
||
|
|
EXI( ldq_u $1,0($7) )
|
||
|
|
EXO( ldq_u $2,0($6) )
|
||
|
|
extbl $1,$7,$1
|
||
|
|
mskbl $2,$6,$2
|
||
|
|
insbl $1,$6,$1
|
||
|
|
addq $3,1,$3
|
||
|
|
bis $1,$2,$1
|
||
|
|
EXO( stq_u $1,0($6) )
|
||
|
|
subq $0,1,$0
|
||
|
|
addq $6,1,$6
|
||
|
|
addq $7,1,$7
|
||
|
|
beq $0,$41
|
||
|
|
bne $3,$37
|
||
|
|
$36:
|
||
|
|
and $7,7,$1
|
||
|
|
bic $0,7,$4
|
||
|
|
beq $1,$43
|
||
|
|
beq $4,$48
|
||
|
|
EXI( ldq_u $3,0($7) )
|
||
|
|
.align 4
|
||
|
|
$50:
|
||
|
|
EXI( ldq_u $2,8($7) )
|
||
|
|
subq $4,8,$4
|
||
|
|
extql $3,$7,$3
|
||
|
|
extqh $2,$7,$1
|
||
|
|
bis $3,$1,$1
|
||
|
|
EXO( stq $1,0($6) )
|
||
|
|
addq $7,8,$7
|
||
|
|
subq $0,8,$0
|
||
|
|
addq $6,8,$6
|
||
|
|
bis $2,$2,$3
|
||
|
|
bne $4,$50
|
||
|
|
$48:
|
||
|
|
beq $0,$41
|
||
|
|
.align 4
|
||
|
|
$57:
|
||
|
|
EXI( ldq_u $1,0($7) )
|
||
|
|
EXO( ldq_u $2,0($6) )
|
||
|
|
extbl $1,$7,$1
|
||
|
|
mskbl $2,$6,$2
|
||
|
|
insbl $1,$6,$1
|
||
|
|
bis $1,$2,$1
|
||
|
|
EXO( stq_u $1,0($6) )
|
||
|
|
subq $0,1,$0
|
||
|
|
addq $6,1,$6
|
||
|
|
addq $7,1,$7
|
||
|
|
bne $0,$57
|
||
|
|
br $31,$41
|
||
|
|
.align 4
|
||
|
|
$43:
|
||
|
|
beq $4,$65
|
||
|
|
.align 4
|
||
|
|
$66:
|
||
|
|
EXI( ldq $1,0($7) )
|
||
|
|
subq $4,8,$4
|
||
|
|
EXO( stq $1,0($6) )
|
||
|
|
addq $7,8,$7
|
||
|
|
subq $0,8,$0
|
||
|
|
addq $6,8,$6
|
||
|
|
bne $4,$66
|
||
|
|
$65:
|
||
|
|
beq $0,$41
|
||
|
|
EXI( ldq $2,0($7) )
|
||
|
|
EXO( ldq $1,0($6) )
|
||
|
|
mskql $2,$0,$2
|
||
|
|
mskqh $1,$0,$1
|
||
|
|
bis $2,$1,$2
|
||
|
|
EXO( stq $2,0($6) )
|
||
|
|
bis $31,$31,$0
|
||
|
|
$41:
|
||
|
|
$35:
|
||
|
|
$exitout:
|
||
|
|
ret $31,($28),1
|
||
|
|
|
||
|
|
$exitin:
|
||
|
|
/* A stupid byte-by-byte zeroing of the rest of the output
|
||
|
|
buffer. This cures security holes by never leaving
|
||
|
|
random kernel data around to be copied elsewhere. */
|
||
|
|
|
||
|
|
mov $0,$1
|
||
|
|
$101:
|
||
|
|
EXO ( ldq_u $2,0($6) )
|
||
|
|
subq $1,1,$1
|
||
|
|
mskbl $2,$6,$2
|
||
|
|
EXO ( stq_u $2,0($6) )
|
||
|
|
addq $6,1,$6
|
||
|
|
bgt $1,$101
|
||
|
|
ret $31,($28),1
|
||
|
|
|
||
|
|
.end __copy_user
|