cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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copy_user.S (2116B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2/*
      3 * arch/alpha/lib/copy_user.S
      4 *
      5 * Copy to/from user space, handling exceptions as we go..  This
      6 * isn't exactly pretty.
      7 *
      8 * This is essentially the same as "memcpy()", but with a few twists.
      9 * Notably, we have to make sure that $0 is always up-to-date and
     10 * contains the right "bytes left to copy" value (and that it is updated
     11 * only _after_ a successful copy). There is also some rather minor
     12 * exception setup stuff..
     13 */
     14
     15#include <asm/export.h>
     16
     17/* Allow an exception for an insn; exit if we get one.  */
     18#define EXI(x,y...)			\
     19	99: x,##y;			\
     20	.section __ex_table,"a";	\
     21	.long 99b - .;			\
     22	lda $31, $exitin-99b($31);	\
     23	.previous
     24
     25#define EXO(x,y...)			\
     26	99: x,##y;			\
     27	.section __ex_table,"a";	\
     28	.long 99b - .;			\
     29	lda $31, $exitout-99b($31);	\
     30	.previous
     31
     32	.set noat
     33	.align 4
     34	.globl __copy_user
     35	.ent __copy_user
     36__copy_user:
     37	.prologue 0
     38	mov $18,$0
     39	and $16,7,$3
     40	beq $0,$35
     41	beq $3,$36
     42	subq $3,8,$3
     43	.align 4
     44$37:
     45	EXI( ldq_u $1,0($17) )
     46	EXO( ldq_u $2,0($16) )
     47	extbl $1,$17,$1
     48	mskbl $2,$16,$2
     49	insbl $1,$16,$1
     50	addq $3,1,$3
     51	bis $1,$2,$1
     52	EXO( stq_u $1,0($16) )
     53	subq $0,1,$0
     54	addq $16,1,$16
     55	addq $17,1,$17
     56	beq $0,$41
     57	bne $3,$37
     58$36:
     59	and $17,7,$1
     60	bic $0,7,$4
     61	beq $1,$43
     62	beq $4,$48
     63	EXI( ldq_u $3,0($17) )
     64	.align 4
     65$50:
     66	EXI( ldq_u $2,8($17) )
     67	subq $4,8,$4
     68	extql $3,$17,$3
     69	extqh $2,$17,$1
     70	bis $3,$1,$1
     71	EXO( stq $1,0($16) )
     72	addq $17,8,$17
     73	subq $0,8,$0
     74	addq $16,8,$16
     75	bis $2,$2,$3
     76	bne $4,$50
     77$48:
     78	beq $0,$41
     79	.align 4
     80$57:
     81	EXI( ldq_u $1,0($17) )
     82	EXO( ldq_u $2,0($16) )
     83	extbl $1,$17,$1
     84	mskbl $2,$16,$2
     85	insbl $1,$16,$1
     86	bis $1,$2,$1
     87	EXO( stq_u $1,0($16) )
     88	subq $0,1,$0
     89	addq $16,1,$16
     90	addq $17,1,$17
     91	bne $0,$57
     92	br $31,$41
     93	.align 4
     94$43:
     95	beq $4,$65
     96	.align 4
     97$66:
     98	EXI( ldq $1,0($17) )
     99	subq $4,8,$4
    100	EXO( stq $1,0($16) )
    101	addq $17,8,$17
    102	subq $0,8,$0
    103	addq $16,8,$16
    104	bne $4,$66
    105$65:
    106	beq $0,$41
    107	EXI( ldq $2,0($17) )
    108	EXO( ldq $1,0($16) )
    109	mskql $2,$0,$2
    110	mskqh $1,$0,$1
    111	bis $2,$1,$2
    112	EXO( stq $2,0($16) )
    113	bis $31,$31,$0
    114$41:
    115$35:
    116$exitin:
    117$exitout:
    118	ret $31,($26),1
    119
    120	.end __copy_user
    121EXPORT_SYMBOL(__copy_user)