1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
|
/*
* linux/arch/arm/lib/uaccess.S
*
* Copyright (C) 1995, 1996,1997,1998 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Routines to block copy data to/from user memory
* These are highly optimised both for the 4k page size
* and for various alignments.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/errno.h>
.text
#define PAGE_SHIFT 12
/* Prototype: int __copy_to_user(void *to, const char *from, size_t n)
* Purpose : copy a block to user memory from kernel memory
* Params : to - user memory
* : from - kernel memory
* : n - number of bytes to copy
* Returns : Number of bytes NOT copied.
*/
.Lc2u_dest_not_aligned:
rsb ip, ip, #4
cmp ip, #2
ldrb r3, [r1], #1
USER( strbt r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #1
USER( strgtbt r3, [r0], #1) @ May fault
sub r2, r2, ip
b .Lc2u_dest_aligned
ENTRY(__copy_to_user)
stmfd sp!, {r2, r4 - r7, lr}
cmp r2, #4
blt .Lc2u_not_enough
ands ip, r0, #3
bne .Lc2u_dest_not_aligned
.Lc2u_dest_aligned:
ands ip, r1, #3
bne .Lc2u_src_not_aligned
/*
* Seeing as there has to be at least 8 bytes to copy, we can
* copy one word, and force a user-mode page fault...
*/
.Lc2u_0fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lc2u_0nowords
ldr r3, [r1], #4
USER( strt r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lc2u_0fupi
/*
* ip = max no. of bytes to copy before needing another "strt" insn
*/
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #32
blt .Lc2u_0rem8lp
.Lc2u_0cpy8lp: ldmia r1!, {r3 - r6}
stmia r0!, {r3 - r6} @ Shouldnt fault
ldmia r1!, {r3 - r6}
subs ip, ip, #32
stmia r0!, {r3 - r6} @ Shouldnt fault
bpl .Lc2u_0cpy8lp
.Lc2u_0rem8lp: cmn ip, #16
ldmgeia r1!, {r3 - r6}
stmgeia r0!, {r3 - r6} @ Shouldnt fault
tst ip, #8
ldmneia r1!, {r3 - r4}
stmneia r0!, {r3 - r4} @ Shouldnt fault
tst ip, #4
ldrne r3, [r1], #4
strnet r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_0fupi
.Lc2u_0nowords: teq ip, #0
beq .Lc2u_finished
.Lc2u_nowords: cmp ip, #2
ldrb r3, [r1], #1
USER( strbt r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #1
USER( strgtbt r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_not_enough:
movs ip, r2
bne .Lc2u_nowords
.Lc2u_finished: mov r0, #0
ldmfd sp!, {r2, r4 - r7, pc}
.Lc2u_src_not_aligned:
bic r1, r1, #3
ldr r7, [r1], #4
cmp ip, #2
bgt .Lc2u_3fupi
beq .Lc2u_2fupi
.Lc2u_1fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lc2u_1nowords
mov r3, r7, pull #8
ldr r7, [r1], #4
orr r3, r3, r7, push #24
USER( strt r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lc2u_1fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lc2u_1rem8lp
.Lc2u_1cpy8lp: mov r3, r7, pull #8
ldmia r1!, {r4 - r7}
subs ip, ip, #16
orr r3, r3, r4, push #24
mov r4, r4, pull #8
orr r4, r4, r5, push #24
mov r5, r5, pull #8
orr r5, r5, r6, push #24
mov r6, r6, pull #8
orr r6, r6, r7, push #24
stmia r0!, {r3 - r6} @ Shouldnt fault
bpl .Lc2u_1cpy8lp
.Lc2u_1rem8lp: tst ip, #8
movne r3, r7, pull #8
ldmneia r1!, {r4, r7}
orrne r3, r3, r4, push #24
movne r4, r4, pull #8
orrne r4, r4, r7, push #24
stmneia r0!, {r3 - r4} @ Shouldnt fault
tst ip, #4
movne r3, r7, pull #8
ldrne r7, [r1], #4
orrne r3, r3, r7, push #24
strnet r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_1fupi
.Lc2u_1nowords: mov r3, r7, get_byte_1
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
movge r3, r7, get_byte_2
USER( strgebt r3, [r0], #1) @ May fault
movgt r3, r7, get_byte_3
USER( strgtbt r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_2fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lc2u_2nowords
mov r3, r7, pull #16
ldr r7, [r1], #4
orr r3, r3, r7, push #16
USER( strt r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lc2u_2fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lc2u_2rem8lp
.Lc2u_2cpy8lp: mov r3, r7, pull #16
ldmia r1!, {r4 - r7}
subs ip, ip, #16
orr r3, r3, r4, push #16
mov r4, r4, pull #16
orr r4, r4, r5, push #16
mov r5, r5, pull #16
orr r5, r5, r6, push #16
mov r6, r6, pull #16
orr r6, r6, r7, push #16
stmia r0!, {r3 - r6} @ Shouldnt fault
bpl .Lc2u_2cpy8lp
.Lc2u_2rem8lp: tst ip, #8
movne r3, r7, pull #16
ldmneia r1!, {r4, r7}
orrne r3, r3, r4, push #16
movne r4, r4, pull #16
orrne r4, r4, r7, push #16
stmneia r0!, {r3 - r4} @ Shouldnt fault
tst ip, #4
movne r3, r7, pull #16
ldrne r7, [r1], #4
orrne r3, r3, r7, push #16
strnet r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_2fupi
.Lc2u_2nowords: mov r3, r7, get_byte_2
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
movge r3, r7, get_byte_3
USER( strgebt r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #0
USER( strgtbt r3, [r0], #1) @ May fault
b .Lc2u_finished
.Lc2u_3fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lc2u_3nowords
mov r3, r7, pull #24
ldr r7, [r1], #4
orr r3, r3, r7, push #8
USER( strt r3, [r0], #4) @ May fault
mov ip, r0, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lc2u_3fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lc2u_3rem8lp
.Lc2u_3cpy8lp: mov r3, r7, pull #24
ldmia r1!, {r4 - r7}
subs ip, ip, #16
orr r3, r3, r4, push #8
mov r4, r4, pull #24
orr r4, r4, r5, push #8
mov r5, r5, pull #24
orr r5, r5, r6, push #8
mov r6, r6, pull #24
orr r6, r6, r7, push #8
stmia r0!, {r3 - r6} @ Shouldnt fault
bpl .Lc2u_3cpy8lp
.Lc2u_3rem8lp: tst ip, #8
movne r3, r7, pull #24
ldmneia r1!, {r4, r7}
orrne r3, r3, r4, push #8
movne r4, r4, pull #24
orrne r4, r4, r7, push #8
stmneia r0!, {r3 - r4} @ Shouldnt fault
tst ip, #4
movne r3, r7, pull #24
ldrne r7, [r1], #4
orrne r3, r3, r7, push #8
strnet r3, [r0], #4 @ Shouldnt fault
ands ip, ip, #3
beq .Lc2u_3fupi
.Lc2u_3nowords: mov r3, r7, get_byte_3
teq ip, #0
beq .Lc2u_finished
cmp ip, #2
USER( strbt r3, [r0], #1) @ May fault
ldrgeb r3, [r1], #1
USER( strgebt r3, [r0], #1) @ May fault
ldrgtb r3, [r1], #0
USER( strgtbt r3, [r0], #1) @ May fault
b .Lc2u_finished
ENDPROC(__copy_to_user)
.pushsection .fixup,"ax"
.align 0
9001: ldmfd sp!, {r0, r4 - r7, pc}
.popsection
/* Prototype: unsigned long __copy_from_user(void *to,const void *from,unsigned long n);
* Purpose : copy a block from user memory to kernel memory
* Params : to - kernel memory
* : from - user memory
* : n - number of bytes to copy
* Returns : Number of bytes NOT copied.
*/
.Lcfu_dest_not_aligned:
rsb ip, ip, #4
cmp ip, #2
USER( ldrbt r3, [r1], #1) @ May fault
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
sub r2, r2, ip
b .Lcfu_dest_aligned
ENTRY(__copy_from_user)
stmfd sp!, {r0, r2, r4 - r7, lr}
cmp r2, #4
blt .Lcfu_not_enough
ands ip, r0, #3
bne .Lcfu_dest_not_aligned
.Lcfu_dest_aligned:
ands ip, r1, #3
bne .Lcfu_src_not_aligned
/*
* Seeing as there has to be at least 8 bytes to copy, we can
* copy one word, and force a user-mode page fault...
*/
.Lcfu_0fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lcfu_0nowords
USER( ldrt r3, [r1], #4)
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT @ On each page, use a ld/st??t instruction
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lcfu_0fupi
/*
* ip = max no. of bytes to copy before needing another "strt" insn
*/
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #32
blt .Lcfu_0rem8lp
.Lcfu_0cpy8lp: ldmia r1!, {r3 - r6} @ Shouldnt fault
stmia r0!, {r3 - r6}
ldmia r1!, {r3 - r6} @ Shouldnt fault
subs ip, ip, #32
stmia r0!, {r3 - r6}
bpl .Lcfu_0cpy8lp
.Lcfu_0rem8lp: cmn ip, #16
ldmgeia r1!, {r3 - r6} @ Shouldnt fault
stmgeia r0!, {r3 - r6}
tst ip, #8
ldmneia r1!, {r3 - r4} @ Shouldnt fault
stmneia r0!, {r3 - r4}
tst ip, #4
ldrnet r3, [r1], #4 @ Shouldnt fault
strne r3, [r0], #4
ands ip, ip, #3
beq .Lcfu_0fupi
.Lcfu_0nowords: teq ip, #0
beq .Lcfu_finished
.Lcfu_nowords: cmp ip, #2
USER( ldrbt r3, [r1], #1) @ May fault
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
.Lcfu_not_enough:
movs ip, r2
bne .Lcfu_nowords
.Lcfu_finished: mov r0, #0
add sp, sp, #8
ldmfd sp!, {r4 - r7, pc}
.Lcfu_src_not_aligned:
bic r1, r1, #3
USER( ldrt r7, [r1], #4) @ May fault
cmp ip, #2
bgt .Lcfu_3fupi
beq .Lcfu_2fupi
.Lcfu_1fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lcfu_1nowords
mov r3, r7, pull #8
USER( ldrt r7, [r1], #4) @ May fault
orr r3, r3, r7, push #24
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lcfu_1fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lcfu_1rem8lp
.Lcfu_1cpy8lp: mov r3, r7, pull #8
ldmia r1!, {r4 - r7} @ Shouldnt fault
subs ip, ip, #16
orr r3, r3, r4, push #24
mov r4, r4, pull #8
orr r4, r4, r5, push #24
mov r5, r5, pull #8
orr r5, r5, r6, push #24
mov r6, r6, pull #8
orr r6, r6, r7, push #24
stmia r0!, {r3 - r6}
bpl .Lcfu_1cpy8lp
.Lcfu_1rem8lp: tst ip, #8
movne r3, r7, pull #8
ldmneia r1!, {r4, r7} @ Shouldnt fault
orrne r3, r3, r4, push #24
movne r4, r4, pull #8
orrne r4, r4, r7, push #24
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #8
USER( ldrnet r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #24
strne r3, [r0], #4
ands ip, ip, #3
beq .Lcfu_1fupi
.Lcfu_1nowords: mov r3, r7, get_byte_1
teq ip, #0
beq .Lcfu_finished
cmp ip, #2
strb r3, [r0], #1
movge r3, r7, get_byte_2
strgeb r3, [r0], #1
movgt r3, r7, get_byte_3
strgtb r3, [r0], #1
b .Lcfu_finished
.Lcfu_2fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lcfu_2nowords
mov r3, r7, pull #16
USER( ldrt r7, [r1], #4) @ May fault
orr r3, r3, r7, push #16
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lcfu_2fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lcfu_2rem8lp
.Lcfu_2cpy8lp: mov r3, r7, pull #16
ldmia r1!, {r4 - r7} @ Shouldnt fault
subs ip, ip, #16
orr r3, r3, r4, push #16
mov r4, r4, pull #16
orr r4, r4, r5, push #16
mov r5, r5, pull #16
orr r5, r5, r6, push #16
mov r6, r6, pull #16
orr r6, r6, r7, push #16
stmia r0!, {r3 - r6}
bpl .Lcfu_2cpy8lp
.Lcfu_2rem8lp: tst ip, #8
movne r3, r7, pull #16
ldmneia r1!, {r4, r7} @ Shouldnt fault
orrne r3, r3, r4, push #16
movne r4, r4, pull #16
orrne r4, r4, r7, push #16
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #16
USER( ldrnet r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #16
strne r3, [r0], #4
ands ip, ip, #3
beq .Lcfu_2fupi
.Lcfu_2nowords: mov r3, r7, get_byte_2
teq ip, #0
beq .Lcfu_finished
cmp ip, #2
strb r3, [r0], #1
movge r3, r7, get_byte_3
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #0) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
.Lcfu_3fupi: subs r2, r2, #4
addmi ip, r2, #4
bmi .Lcfu_3nowords
mov r3, r7, pull #24
USER( ldrt r7, [r1], #4) @ May fault
orr r3, r3, r7, push #8
str r3, [r0], #4
mov ip, r1, lsl #32 - PAGE_SHIFT
rsb ip, ip, #0
movs ip, ip, lsr #32 - PAGE_SHIFT
beq .Lcfu_3fupi
cmp r2, ip
movlt ip, r2
sub r2, r2, ip
subs ip, ip, #16
blt .Lcfu_3rem8lp
.Lcfu_3cpy8lp: mov r3, r7, pull #24
ldmia r1!, {r4 - r7} @ Shouldnt fault
orr r3, r3, r4, push #8
mov r4, r4, pull #24
orr r4, r4, r5, push #8
mov r5, r5, pull #24
orr r5, r5, r6, push #8
mov r6, r6, pull #24
orr r6, r6, r7, push #8
stmia r0!, {r3 - r6}
subs ip, ip, #16
bpl .Lcfu_3cpy8lp
.Lcfu_3rem8lp: tst ip, #8
movne r3, r7, pull #24
ldmneia r1!, {r4, r7} @ Shouldnt fault
orrne r3, r3, r4, push #8
movne r4, r4, pull #24
orrne r4, r4, r7, push #8
stmneia r0!, {r3 - r4}
tst ip, #4
movne r3, r7, pull #24
USER( ldrnet r7, [r1], #4) @ May fault
orrne r3, r3, r7, push #8
strne r3, [r0], #4
ands ip, ip, #3
beq .Lcfu_3fupi
.Lcfu_3nowords: mov r3, r7, get_byte_3
teq ip, #0
beq .Lcfu_finished
cmp ip, #2
strb r3, [r0], #1
USER( ldrgebt r3, [r1], #1) @ May fault
strgeb r3, [r0], #1
USER( ldrgtbt r3, [r1], #1) @ May fault
strgtb r3, [r0], #1
b .Lcfu_finished
ENDPROC(__copy_from_user)
.pushsection .fixup,"ax"
.align 0
/*
* We took an exception. r0 contains a pointer to
* the byte not copied.
*/
9001: ldr r2, [sp], #4 @ void *to
sub r2, r0, r2 @ bytes copied
ldr r1, [sp], #4 @ unsigned long count
subs r4, r1, r2 @ bytes left to copy
movne r1, r4
blne __memzero
mov r0, r4
ldmfd sp!, {r4 - r7, pc}
.popsection
|