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14#include <linux/moduleparam.h>
15#include <linux/compiler.h>
16#include <linux/kernel.h>
17#include <linux/errno.h>
18#include <linux/string.h>
19#include <linux/proc_fs.h>
20#include <linux/seq_file.h>
21#include <linux/init.h>
22#include <linux/sched.h>
23#include <linux/uaccess.h>
24
25#include <asm/system.h>
26#include <asm/unaligned.h>
27
28#include "fault.h"
29
30
31
32
33
34
35
36
37
38
39
40#define CODING_BITS(i) (i & 0x0e000000)
41
42#define LDST_I_BIT(i) (i & (1 << 26))
43#define LDST_P_BIT(i) (i & (1 << 24))
44#define LDST_U_BIT(i) (i & (1 << 23))
45#define LDST_W_BIT(i) (i & (1 << 21))
46#define LDST_L_BIT(i) (i & (1 << 20))
47
48#define LDST_P_EQ_U(i) ((((i) ^ ((i) >> 1)) & (1 << 23)) == 0)
49
50#define LDSTHD_I_BIT(i) (i & (1 << 22))
51#define LDM_S_BIT(i) (i & (1 << 22))
52
53#define RN_BITS(i) ((i >> 16) & 15)
54#define RD_BITS(i) ((i >> 12) & 15)
55#define RM_BITS(i) (i & 15)
56
57#define REGMASK_BITS(i) (i & 0xffff)
58#define OFFSET_BITS(i) (i & 0x0fff)
59
60#define IS_SHIFT(i) (i & 0x0ff0)
61#define SHIFT_BITS(i) ((i >> 7) & 0x1f)
62#define SHIFT_TYPE(i) (i & 0x60)
63#define SHIFT_LSL 0x00
64#define SHIFT_LSR 0x20
65#define SHIFT_ASR 0x40
66#define SHIFT_RORRRX 0x60
67
68#define BAD_INSTR 0xdeadc0de
69
70
71#define IS_T32(hi16) \
72 (((hi16) & 0xe000) == 0xe000 && ((hi16) & 0x1800))
73
74static unsigned long ai_user;
75static unsigned long ai_sys;
76static unsigned long ai_skipped;
77static unsigned long ai_half;
78static unsigned long ai_word;
79static unsigned long ai_dword;
80static unsigned long ai_multi;
81static int ai_usermode;
82
83core_param(alignment, ai_usermode, int, 0600);
84
85#define UM_WARN (1 << 0)
86#define UM_FIXUP (1 << 1)
87#define UM_SIGNAL (1 << 2)
88
89#ifdef CONFIG_PROC_FS
90static const char *usermode_action[] = {
91 "ignored",
92 "warn",
93 "fixup",
94 "fixup+warn",
95 "signal",
96 "signal+warn"
97};
98
99
100static bool cpu_is_v6_unaligned(void)
101{
102 return cpu_architecture() >= CPU_ARCH_ARMv6 && (cr_alignment & CR_U);
103}
104
105static int safe_usermode(int new_usermode, bool warn)
106{
107
108
109
110
111
112
113
114
115
116 if (cpu_is_v6_unaligned() && !(new_usermode & (UM_FIXUP | UM_SIGNAL))) {
117 new_usermode |= UM_FIXUP;
118
119 if (warn)
120 printk(KERN_WARNING "alignment: ignoring faults is unsafe on this CPU. Defaulting to fixup mode.\n");
121 }
122
123 return new_usermode;
124}
125
126static int alignment_proc_show(struct seq_file *m, void *v)
127{
128 seq_printf(m, "User:\t\t%lu\n", ai_user);
129 seq_printf(m, "System:\t\t%lu\n", ai_sys);
130 seq_printf(m, "Skipped:\t%lu\n", ai_skipped);
131 seq_printf(m, "Half:\t\t%lu\n", ai_half);
132 seq_printf(m, "Word:\t\t%lu\n", ai_word);
133 if (cpu_architecture() >= CPU_ARCH_ARMv5TE)
134 seq_printf(m, "DWord:\t\t%lu\n", ai_dword);
135 seq_printf(m, "Multi:\t\t%lu\n", ai_multi);
136 seq_printf(m, "User faults:\t%i (%s)\n", ai_usermode,
137 usermode_action[ai_usermode]);
138
139 return 0;
140}
141
142static int alignment_proc_open(struct inode *inode, struct file *file)
143{
144 return single_open(file, alignment_proc_show, NULL);
145}
146
147static ssize_t alignment_proc_write(struct file *file, const char __user *buffer,
148 size_t count, loff_t *pos)
149{
150 char mode;
151
152 if (count > 0) {
153 if (get_user(mode, buffer))
154 return -EFAULT;
155 if (mode >= '0' && mode <= '5')
156 ai_usermode = safe_usermode(mode - '0', true);
157 }
158 return count;
159}
160
161static const struct file_operations alignment_proc_fops = {
162 .open = alignment_proc_open,
163 .read = seq_read,
164 .llseek = seq_lseek,
165 .release = single_release,
166 .write = alignment_proc_write,
167};
168#endif
169
170union offset_union {
171 unsigned long un;
172 signed long sn;
173};
174
175#define TYPE_ERROR 0
176#define TYPE_FAULT 1
177#define TYPE_LDST 2
178#define TYPE_DONE 3
179
180#ifdef __ARMEB__
181#define BE 1
182#define FIRST_BYTE_16 "mov %1, %1, ror #8\n"
183#define FIRST_BYTE_32 "mov %1, %1, ror #24\n"
184#define NEXT_BYTE "ror #24"
185#else
186#define BE 0
187#define FIRST_BYTE_16
188#define FIRST_BYTE_32
189#define NEXT_BYTE "lsr #8"
190#endif
191
192#define __get8_unaligned_check(ins,val,addr,err) \
193 __asm__( \
194 ARM( "1: "ins" %1, [%2], #1\n" ) \
195 THUMB( "1: "ins" %1, [%2]\n" ) \
196 THUMB( " add %2, %2, #1\n" ) \
197 "2:\n" \
198 " .pushsection .fixup,\"ax\"\n" \
199 " .align 2\n" \
200 "3: mov %0, #1\n" \
201 " b 2b\n" \
202 " .popsection\n" \
203 " .pushsection __ex_table,\"a\"\n" \
204 " .align 3\n" \
205 " .long 1b, 3b\n" \
206 " .popsection\n" \
207 : "=r" (err), "=&r" (val), "=r" (addr) \
208 : "0" (err), "2" (addr))
209
210#define __get16_unaligned_check(ins,val,addr) \
211 do { \
212 unsigned int err = 0, v, a = addr; \
213 __get8_unaligned_check(ins,v,a,err); \
214 val = v << ((BE) ? 8 : 0); \
215 __get8_unaligned_check(ins,v,a,err); \
216 val |= v << ((BE) ? 0 : 8); \
217 if (err) \
218 goto fault; \
219 } while (0)
220
221#define get16_unaligned_check(val,addr) \
222 __get16_unaligned_check("ldrb",val,addr)
223
224#define get16t_unaligned_check(val,addr) \
225 __get16_unaligned_check("ldrbt",val,addr)
226
227#define __get32_unaligned_check(ins,val,addr) \
228 do { \
229 unsigned int err = 0, v, a = addr; \
230 __get8_unaligned_check(ins,v,a,err); \
231 val = v << ((BE) ? 24 : 0); \
232 __get8_unaligned_check(ins,v,a,err); \
233 val |= v << ((BE) ? 16 : 8); \
234 __get8_unaligned_check(ins,v,a,err); \
235 val |= v << ((BE) ? 8 : 16); \
236 __get8_unaligned_check(ins,v,a,err); \
237 val |= v << ((BE) ? 0 : 24); \
238 if (err) \
239 goto fault; \
240 } while (0)
241
242#define get32_unaligned_check(val,addr) \
243 __get32_unaligned_check("ldrb",val,addr)
244
245#define get32t_unaligned_check(val,addr) \
246 __get32_unaligned_check("ldrbt",val,addr)
247
248#define __put16_unaligned_check(ins,val,addr) \
249 do { \
250 unsigned int err = 0, v = val, a = addr; \
251 __asm__( FIRST_BYTE_16 \
252 ARM( "1: "ins" %1, [%2], #1\n" ) \
253 THUMB( "1: "ins" %1, [%2]\n" ) \
254 THUMB( " add %2, %2, #1\n" ) \
255 " mov %1, %1, "NEXT_BYTE"\n" \
256 "2: "ins" %1, [%2]\n" \
257 "3:\n" \
258 " .pushsection .fixup,\"ax\"\n" \
259 " .align 2\n" \
260 "4: mov %0, #1\n" \
261 " b 3b\n" \
262 " .popsection\n" \
263 " .pushsection __ex_table,\"a\"\n" \
264 " .align 3\n" \
265 " .long 1b, 4b\n" \
266 " .long 2b, 4b\n" \
267 " .popsection\n" \
268 : "=r" (err), "=&r" (v), "=&r" (a) \
269 : "0" (err), "1" (v), "2" (a)); \
270 if (err) \
271 goto fault; \
272 } while (0)
273
274#define put16_unaligned_check(val,addr) \
275 __put16_unaligned_check("strb",val,addr)
276
277#define put16t_unaligned_check(val,addr) \
278 __put16_unaligned_check("strbt",val,addr)
279
280#define __put32_unaligned_check(ins,val,addr) \
281 do { \
282 unsigned int err = 0, v = val, a = addr; \
283 __asm__( FIRST_BYTE_32 \
284 ARM( "1: "ins" %1, [%2], #1\n" ) \
285 THUMB( "1: "ins" %1, [%2]\n" ) \
286 THUMB( " add %2, %2, #1\n" ) \
287 " mov %1, %1, "NEXT_BYTE"\n" \
288 ARM( "2: "ins" %1, [%2], #1\n" ) \
289 THUMB( "2: "ins" %1, [%2]\n" ) \
290 THUMB( " add %2, %2, #1\n" ) \
291 " mov %1, %1, "NEXT_BYTE"\n" \
292 ARM( "3: "ins" %1, [%2], #1\n" ) \
293 THUMB( "3: "ins" %1, [%2]\n" ) \
294 THUMB( " add %2, %2, #1\n" ) \
295 " mov %1, %1, "NEXT_BYTE"\n" \
296 "4: "ins" %1, [%2]\n" \
297 "5:\n" \
298 " .pushsection .fixup,\"ax\"\n" \
299 " .align 2\n" \
300 "6: mov %0, #1\n" \
301 " b 5b\n" \
302 " .popsection\n" \
303 " .pushsection __ex_table,\"a\"\n" \
304 " .align 3\n" \
305 " .long 1b, 6b\n" \
306 " .long 2b, 6b\n" \
307 " .long 3b, 6b\n" \
308 " .long 4b, 6b\n" \
309 " .popsection\n" \
310 : "=r" (err), "=&r" (v), "=&r" (a) \
311 : "0" (err), "1" (v), "2" (a)); \
312 if (err) \
313 goto fault; \
314 } while (0)
315
316#define put32_unaligned_check(val,addr) \
317 __put32_unaligned_check("strb", val, addr)
318
319#define put32t_unaligned_check(val,addr) \
320 __put32_unaligned_check("strbt", val, addr)
321
322static void
323do_alignment_finish_ldst(unsigned long addr, unsigned long instr, struct pt_regs *regs, union offset_union offset)
324{
325 if (!LDST_U_BIT(instr))
326 offset.un = -offset.un;
327
328 if (!LDST_P_BIT(instr))
329 addr += offset.un;
330
331 if (!LDST_P_BIT(instr) || LDST_W_BIT(instr))
332 regs->uregs[RN_BITS(instr)] = addr;
333}
334
335static int
336do_alignment_ldrhstrh(unsigned long addr, unsigned long instr, struct pt_regs *regs)
337{
338 unsigned int rd = RD_BITS(instr);
339
340 ai_half += 1;
341
342 if (user_mode(regs))
343 goto user;
344
345 if (LDST_L_BIT(instr)) {
346 unsigned long val;
347 get16_unaligned_check(val, addr);
348
349
350 if (instr & 0x40)
351 val = (signed long)((signed short) val);
352
353 regs->uregs[rd] = val;
354 } else
355 put16_unaligned_check(regs->uregs[rd], addr);
356
357 return TYPE_LDST;
358
359 user:
360 if (LDST_L_BIT(instr)) {
361 unsigned long val;
362 get16t_unaligned_check(val, addr);
363
364
365 if (instr & 0x40)
366 val = (signed long)((signed short) val);
367
368 regs->uregs[rd] = val;
369 } else
370 put16t_unaligned_check(regs->uregs[rd], addr);
371
372 return TYPE_LDST;
373
374 fault:
375 return TYPE_FAULT;
376}
377
378static int
379do_alignment_ldrdstrd(unsigned long addr, unsigned long instr,
380 struct pt_regs *regs)
381{
382 unsigned int rd = RD_BITS(instr);
383 unsigned int rd2;
384 int load;
385
386 if ((instr & 0xfe000000) == 0xe8000000) {
387
388 rd2 = (instr >> 8) & 0xf;
389 load = !!(LDST_L_BIT(instr));
390 } else if (((rd & 1) == 1) || (rd == 14))
391 goto bad;
392 else {
393 load = ((instr & 0xf0) == 0xd0);
394 rd2 = rd + 1;
395 }
396
397 ai_dword += 1;
398
399 if (user_mode(regs))
400 goto user;
401
402 if (load) {
403 unsigned long val;
404 get32_unaligned_check(val, addr);
405 regs->uregs[rd] = val;
406 get32_unaligned_check(val, addr + 4);
407 regs->uregs[rd2] = val;
408 } else {
409 put32_unaligned_check(regs->uregs[rd], addr);
410 put32_unaligned_check(regs->uregs[rd2], addr + 4);
411 }
412
413 return TYPE_LDST;
414
415 user:
416 if (load) {
417 unsigned long val;
418 get32t_unaligned_check(val, addr);
419 regs->uregs[rd] = val;
420 get32t_unaligned_check(val, addr + 4);
421 regs->uregs[rd2] = val;
422 } else {
423 put32t_unaligned_check(regs->uregs[rd], addr);
424 put32t_unaligned_check(regs->uregs[rd2], addr + 4);
425 }
426
427 return TYPE_LDST;
428 bad:
429 return TYPE_ERROR;
430 fault:
431 return TYPE_FAULT;
432}
433
434static int
435do_alignment_ldrstr(unsigned long addr, unsigned long instr, struct pt_regs *regs)
436{
437 unsigned int rd = RD_BITS(instr);
438
439 ai_word += 1;
440
441 if ((!LDST_P_BIT(instr) && LDST_W_BIT(instr)) || user_mode(regs))
442 goto trans;
443
444 if (LDST_L_BIT(instr)) {
445 unsigned int val;
446 get32_unaligned_check(val, addr);
447 regs->uregs[rd] = val;
448 } else
449 put32_unaligned_check(regs->uregs[rd], addr);
450 return TYPE_LDST;
451
452 trans:
453 if (LDST_L_BIT(instr)) {
454 unsigned int val;
455 get32t_unaligned_check(val, addr);
456 regs->uregs[rd] = val;
457 } else
458 put32t_unaligned_check(regs->uregs[rd], addr);
459 return TYPE_LDST;
460
461 fault:
462 return TYPE_FAULT;
463}
464
465
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468
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470
471
472
473
474
475
476
477
478static int
479do_alignment_ldmstm(unsigned long addr, unsigned long instr, struct pt_regs *regs)
480{
481 unsigned int rd, rn, correction, nr_regs, regbits;
482 unsigned long eaddr, newaddr;
483
484 if (LDM_S_BIT(instr))
485 goto bad;
486
487 correction = 4;
488 regs->ARM_pc += correction;
489
490 ai_multi += 1;
491
492
493 nr_regs = hweight16(REGMASK_BITS(instr)) * 4;
494
495 rn = RN_BITS(instr);
496 newaddr = eaddr = regs->uregs[rn];
497
498 if (!LDST_U_BIT(instr))
499 nr_regs = -nr_regs;
500 newaddr += nr_regs;
501 if (!LDST_U_BIT(instr))
502 eaddr = newaddr;
503
504 if (LDST_P_EQ_U(instr))
505 eaddr += 4;
506
507
508
509
510
511
512
513
514#if !(defined CONFIG_CPU_ARM922T) && !(defined CONFIG_CPU_ARM920T)
515
516
517
518
519 if (addr != eaddr) {
520 printk(KERN_ERR "LDMSTM: PC = %08lx, instr = %08lx, "
521 "addr = %08lx, eaddr = %08lx\n",
522 instruction_pointer(regs), instr, addr, eaddr);
523 show_regs(regs);
524 }
525#endif
526
527 if (user_mode(regs)) {
528 for (regbits = REGMASK_BITS(instr), rd = 0; regbits;
529 regbits >>= 1, rd += 1)
530 if (regbits & 1) {
531 if (LDST_L_BIT(instr)) {
532 unsigned int val;
533 get32t_unaligned_check(val, eaddr);
534 regs->uregs[rd] = val;
535 } else
536 put32t_unaligned_check(regs->uregs[rd], eaddr);
537 eaddr += 4;
538 }
539 } else {
540 for (regbits = REGMASK_BITS(instr), rd = 0; regbits;
541 regbits >>= 1, rd += 1)
542 if (regbits & 1) {
543 if (LDST_L_BIT(instr)) {
544 unsigned int val;
545 get32_unaligned_check(val, eaddr);
546 regs->uregs[rd] = val;
547 } else
548 put32_unaligned_check(regs->uregs[rd], eaddr);
549 eaddr += 4;
550 }
551 }
552
553 if (LDST_W_BIT(instr))
554 regs->uregs[rn] = newaddr;
555 if (!LDST_L_BIT(instr) || !(REGMASK_BITS(instr) & (1 << 15)))
556 regs->ARM_pc -= correction;
557 return TYPE_DONE;
558
559fault:
560 regs->ARM_pc -= correction;
561 return TYPE_FAULT;
562
563bad:
564 printk(KERN_ERR "Alignment trap: not handling ldm with s-bit set\n");
565 return TYPE_ERROR;
566}
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584static unsigned long
585thumb2arm(u16 tinstr)
586{
587 u32 L = (tinstr & (1<<11)) >> 11;
588
589 switch ((tinstr & 0xf800) >> 11) {
590
591 case 0x6000 >> 11:
592 case 0x6800 >> 11:
593 case 0x7000 >> 11:
594 case 0x7800 >> 11:
595 return 0xe5800000 |
596 ((tinstr & (1<<12)) << (22-12)) |
597 (L<<20) |
598 ((tinstr & (7<<0)) << (12-0)) |
599 ((tinstr & (7<<3)) << (16-3)) |
600 ((tinstr & (31<<6)) >>
601 (6 - ((tinstr & (1<<12)) ? 0 : 2)));
602 case 0x8000 >> 11:
603 case 0x8800 >> 11:
604 return 0xe1c000b0 |
605 (L<<20) |
606 ((tinstr & (7<<0)) << (12-0)) |
607 ((tinstr & (7<<3)) << (16-3)) |
608 ((tinstr & (7<<6)) >> (6-1)) |
609 ((tinstr & (3<<9)) >> (9-8));
610
611
612 case 0x5000 >> 11:
613 case 0x5800 >> 11:
614 {
615 static const u32 subset[8] = {
616 0xe7800000,
617 0xe18000b0,
618 0xe7c00000,
619 0xe19000d0,
620 0xe7900000,
621 0xe19000b0,
622 0xe7d00000,
623 0xe19000f0
624 };
625 return subset[(tinstr & (7<<9)) >> 9] |
626 ((tinstr & (7<<0)) << (12-0)) |
627 ((tinstr & (7<<3)) << (16-3)) |
628 ((tinstr & (7<<6)) >> (6-0));
629 }
630
631
632 case 0x4800 >> 11:
633
634
635
636
637
638 return 0xe59f0000 |
639 ((tinstr & (7<<8)) << (12-8)) |
640 ((tinstr & 255) << (2-0));
641
642
643 case 0x9000 >> 11:
644 case 0x9800 >> 11:
645 return 0xe58d0000 |
646 (L<<20) |
647 ((tinstr & (7<<8)) << (12-8)) |
648 ((tinstr & 255) << 2);
649
650
651 case 0xc000 >> 11:
652 case 0xc800 >> 11:
653 {
654 u32 Rn = (tinstr & (7<<8)) >> 8;
655 u32 W = ((L<<Rn) & (tinstr&255)) ? 0 : 1<<21;
656
657 return 0xe8800000 | W | (L<<20) | (Rn<<16) |
658 (tinstr&255);
659 }
660
661
662 case 0xb000 >> 11:
663 case 0xb800 >> 11:
664 if ((tinstr & (3 << 9)) == 0x0400) {
665 static const u32 subset[4] = {
666 0xe92d0000,
667 0xe92d4000,
668 0xe8bd0000,
669 0xe8bd8000
670 };
671 return subset[(L<<1) | ((tinstr & (1<<8)) >> 8)] |
672 (tinstr & 255);
673 }
674
675
676 default:
677 return BAD_INSTR;
678 }
679}
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694static void *
695do_alignment_t32_to_handler(unsigned long *pinstr, struct pt_regs *regs,
696 union offset_union *poffset)
697{
698 unsigned long instr = *pinstr;
699 u16 tinst1 = (instr >> 16) & 0xffff;
700 u16 tinst2 = instr & 0xffff;
701 poffset->un = 0;
702
703 switch (tinst1 & 0xffe0) {
704
705 case 0xe880:
706 case 0xe8a0:
707 case 0xe900:
708 case 0xe920:
709
710 return do_alignment_ldmstm;
711
712 case 0xf840:
713 if (RN_BITS(instr) == 13 && (tinst2 & 0x09ff) == 0x0904) {
714 u32 L = !!(LDST_L_BIT(instr));
715 const u32 subset[2] = {
716 0xe92d0000,
717 0xe8bd0000,
718 };
719 *pinstr = subset[L] | (1<<RD_BITS(instr));
720 return do_alignment_ldmstm;
721 }
722
723 break;
724
725
726 case 0xe860:
727 case 0xe960:
728 case 0xe8e0:
729 case 0xe9e0:
730 poffset->un = (tinst2 & 0xff) << 2;
731 case 0xe940:
732 case 0xe9c0:
733 return do_alignment_ldrdstrd;
734
735
736
737
738
739 default:
740 break;
741 }
742 return NULL;
743}
744
745static int
746do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs)
747{
748 union offset_union offset;
749 unsigned long instr = 0, instrptr;
750 int (*handler)(unsigned long addr, unsigned long instr, struct pt_regs *regs);
751 unsigned int type;
752 mm_segment_t fs;
753 unsigned int fault;
754 u16 tinstr = 0;
755 int isize = 4;
756 int thumb2_32b = 0;
757
758 if (interrupts_enabled(regs))
759 local_irq_enable();
760
761 instrptr = instruction_pointer(regs);
762
763 fs = get_fs();
764 set_fs(KERNEL_DS);
765 if (thumb_mode(regs)) {
766 fault = __get_user(tinstr, (u16 *)(instrptr & ~1));
767 if (!fault) {
768 if (cpu_architecture() >= CPU_ARCH_ARMv7 &&
769 IS_T32(tinstr)) {
770
771 u16 tinst2 = 0;
772 fault = __get_user(tinst2, (u16 *)(instrptr+2));
773 instr = (tinstr << 16) | tinst2;
774 thumb2_32b = 1;
775 } else {
776 isize = 2;
777 instr = thumb2arm(tinstr);
778 }
779 }
780 } else
781 fault = __get_user(instr, (u32 *)instrptr);
782 set_fs(fs);
783
784 if (fault) {
785 type = TYPE_FAULT;
786 goto bad_or_fault;
787 }
788
789 if (user_mode(regs))
790 goto user;
791
792 ai_sys += 1;
793
794 fixup:
795
796 regs->ARM_pc += isize;
797
798 switch (CODING_BITS(instr)) {
799 case 0x00000000:
800 if (LDSTHD_I_BIT(instr))
801 offset.un = (instr & 0xf00) >> 4 | (instr & 15);
802 else
803 offset.un = regs->uregs[RM_BITS(instr)];
804
805 if ((instr & 0x000000f0) == 0x000000b0 ||
806 (instr & 0x001000f0) == 0x001000f0)
807 handler = do_alignment_ldrhstrh;
808 else if ((instr & 0x001000f0) == 0x000000d0 ||
809 (instr & 0x001000f0) == 0x000000f0)
810 handler = do_alignment_ldrdstrd;
811 else if ((instr & 0x01f00ff0) == 0x01000090)
812 goto swp;
813 else
814 goto bad;
815 break;
816
817 case 0x04000000:
818 offset.un = OFFSET_BITS(instr);
819 handler = do_alignment_ldrstr;
820 break;
821
822 case 0x06000000:
823 offset.un = regs->uregs[RM_BITS(instr)];
824
825 if (IS_SHIFT(instr)) {
826 unsigned int shiftval = SHIFT_BITS(instr);
827
828 switch(SHIFT_TYPE(instr)) {
829 case SHIFT_LSL:
830 offset.un <<= shiftval;
831 break;
832
833 case SHIFT_LSR:
834 offset.un >>= shiftval;
835 break;
836
837 case SHIFT_ASR:
838 offset.sn >>= shiftval;
839 break;
840
841 case SHIFT_RORRRX:
842 if (shiftval == 0) {
843 offset.un >>= 1;
844 if (regs->ARM_cpsr & PSR_C_BIT)
845 offset.un |= 1 << 31;
846 } else
847 offset.un = offset.un >> shiftval |
848 offset.un << (32 - shiftval);
849 break;
850 }
851 }
852 handler = do_alignment_ldrstr;
853 break;
854
855 case 0x08000000:
856 if (thumb2_32b)
857 handler = do_alignment_t32_to_handler(&instr, regs, &offset);
858 else
859 handler = do_alignment_ldmstm;
860 break;
861
862 default:
863 goto bad;
864 }
865
866 if (!handler)
867 goto bad;
868 type = handler(addr, instr, regs);
869
870 if (type == TYPE_ERROR || type == TYPE_FAULT) {
871 regs->ARM_pc -= isize;
872 goto bad_or_fault;
873 }
874
875 if (type == TYPE_LDST)
876 do_alignment_finish_ldst(addr, instr, regs, offset);
877
878 return 0;
879
880 bad_or_fault:
881 if (type == TYPE_ERROR)
882 goto bad;
883
884
885
886 do_bad_area(addr, fsr, regs);
887 return 0;
888
889 swp:
890 printk(KERN_ERR "Alignment trap: not handling swp instruction\n");
891
892 bad:
893
894
895
896 printk(KERN_ERR "Alignment trap: not handling instruction "
897 "%0*lx at [<%08lx>]\n",
898 isize << 1,
899 isize == 2 ? tinstr : instr, instrptr);
900 ai_skipped += 1;
901 return 1;
902
903 user:
904 ai_user += 1;
905
906 if (ai_usermode & UM_WARN)
907 printk("Alignment trap: %s (%d) PC=0x%08lx Instr=0x%0*lx "
908 "Address=0x%08lx FSR 0x%03x\n", current->comm,
909 task_pid_nr(current), instrptr,
910 isize << 1,
911 isize == 2 ? tinstr : instr,
912 addr, fsr);
913
914 if (ai_usermode & UM_FIXUP)
915 goto fixup;
916
917 if (ai_usermode & UM_SIGNAL) {
918 siginfo_t si;
919
920 si.si_signo = SIGBUS;
921 si.si_errno = 0;
922 si.si_code = BUS_ADRALN;
923 si.si_addr = (void __user *)addr;
924
925 force_sig_info(si.si_signo, &si, current);
926 } else {
927
928
929
930
931
932
933
934
935
936
937
938
939 raw_local_irq_disable();
940 if (!(current_thread_info()->flags & _TIF_WORK_MASK))
941 set_cr(cr_no_alignment);
942 }
943
944 return 0;
945}
946
947
948
949
950
951
952
953static int __init alignment_init(void)
954{
955#ifdef CONFIG_PROC_FS
956 struct proc_dir_entry *res;
957
958 res = proc_create("cpu/alignment", S_IWUSR | S_IRUGO, NULL,
959 &alignment_proc_fops);
960 if (!res)
961 return -ENOMEM;
962#endif
963
964 if (cpu_is_v6_unaligned()) {
965 cr_alignment &= ~CR_A;
966 cr_no_alignment &= ~CR_A;
967 set_cr(cr_alignment);
968 ai_usermode = safe_usermode(ai_usermode, false);
969 }
970
971 hook_fault_code(1, do_alignment, SIGBUS, BUS_ADRALN,
972 "alignment exception");
973
974
975
976
977
978
979
980
981 if (cpu_architecture() <= CPU_ARCH_ARMv6) {
982 hook_fault_code(3, do_alignment, SIGBUS, BUS_ADRALN,
983 "alignment exception");
984 }
985
986 return 0;
987}
988
989fs_initcall(alignment_init);
990