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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 * Copyright (C) 2002-2006 Novell, Inc.
5 * Jan Beulich <jbeulich@novell.com>
6 *
7 * A simple API for unwinding kernel stacks. This is used for
8 * debugging and error reporting purposes. The kernel doesn't need
9 * full-blown stack unwinding with all the bells and whistles, so there
10 * is not much point in implementing the full Dwarf2 unwind API.
11 */
12
13#include <linux/sched.h>
14#include <linux/module.h>
15#include <linux/memblock.h>
16#include <linux/sort.h>
17#include <linux/slab.h>
18#include <linux/stop_machine.h>
19#include <linux/uaccess.h>
20#include <linux/ptrace.h>
21#include <asm/sections.h>
22#include <asm/unaligned.h>
23#include <asm/unwind.h>
24
25extern char __start_unwind[], __end_unwind[];
26/* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/
27
28/* #define UNWIND_DEBUG */
29
30#ifdef UNWIND_DEBUG
31int dbg_unw;
32#define unw_debug(fmt, ...) \
33do { \
34 if (dbg_unw) \
35 pr_info(fmt, ##__VA_ARGS__); \
36} while (0);
37#else
38#define unw_debug(fmt, ...)
39#endif
40
41#define MAX_STACK_DEPTH 8
42
43#define EXTRA_INFO(f) { \
44 BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
45 % sizeof_field(struct unwind_frame_info, f)) \
46 + offsetof(struct unwind_frame_info, f) \
47 / sizeof_field(struct unwind_frame_info, f), \
48 sizeof_field(struct unwind_frame_info, f) \
49 }
50#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
51
52static const struct {
53 unsigned offs:BITS_PER_LONG / 2;
54 unsigned width:BITS_PER_LONG / 2;
55} reg_info[] = {
56UNW_REGISTER_INFO};
57
58#undef PTREGS_INFO
59#undef EXTRA_INFO
60
61#ifndef REG_INVALID
62#define REG_INVALID(r) (reg_info[r].width == 0)
63#endif
64
65#define DW_CFA_nop 0x00
66#define DW_CFA_set_loc 0x01
67#define DW_CFA_advance_loc1 0x02
68#define DW_CFA_advance_loc2 0x03
69#define DW_CFA_advance_loc4 0x04
70#define DW_CFA_offset_extended 0x05
71#define DW_CFA_restore_extended 0x06
72#define DW_CFA_undefined 0x07
73#define DW_CFA_same_value 0x08
74#define DW_CFA_register 0x09
75#define DW_CFA_remember_state 0x0a
76#define DW_CFA_restore_state 0x0b
77#define DW_CFA_def_cfa 0x0c
78#define DW_CFA_def_cfa_register 0x0d
79#define DW_CFA_def_cfa_offset 0x0e
80#define DW_CFA_def_cfa_expression 0x0f
81#define DW_CFA_expression 0x10
82#define DW_CFA_offset_extended_sf 0x11
83#define DW_CFA_def_cfa_sf 0x12
84#define DW_CFA_def_cfa_offset_sf 0x13
85#define DW_CFA_val_offset 0x14
86#define DW_CFA_val_offset_sf 0x15
87#define DW_CFA_val_expression 0x16
88#define DW_CFA_lo_user 0x1c
89#define DW_CFA_GNU_window_save 0x2d
90#define DW_CFA_GNU_args_size 0x2e
91#define DW_CFA_GNU_negative_offset_extended 0x2f
92#define DW_CFA_hi_user 0x3f
93
94#define DW_EH_PE_FORM 0x07
95#define DW_EH_PE_native 0x00
96#define DW_EH_PE_leb128 0x01
97#define DW_EH_PE_data2 0x02
98#define DW_EH_PE_data4 0x03
99#define DW_EH_PE_data8 0x04
100#define DW_EH_PE_signed 0x08
101#define DW_EH_PE_ADJUST 0x70
102#define DW_EH_PE_abs 0x00
103#define DW_EH_PE_pcrel 0x10
104#define DW_EH_PE_textrel 0x20
105#define DW_EH_PE_datarel 0x30
106#define DW_EH_PE_funcrel 0x40
107#define DW_EH_PE_aligned 0x50
108#define DW_EH_PE_indirect 0x80
109#define DW_EH_PE_omit 0xff
110
111#define CIE_ID 0
112
113typedef unsigned long uleb128_t;
114typedef signed long sleb128_t;
115
116static struct unwind_table {
117 struct {
118 unsigned long pc;
119 unsigned long range;
120 } core, init;
121 const void *address;
122 unsigned long size;
123 const unsigned char *header;
124 unsigned long hdrsz;
125 struct unwind_table *link;
126 const char *name;
127} root_table;
128
129struct unwind_item {
130 enum item_location {
131 Nowhere,
132 Memory,
133 Register,
134 Value
135 } where;
136 uleb128_t value;
137};
138
139struct unwind_state {
140 uleb128_t loc, org;
141 const u8 *cieStart, *cieEnd;
142 uleb128_t codeAlign;
143 sleb128_t dataAlign;
144 struct cfa {
145 uleb128_t reg, offs;
146 } cfa;
147 struct unwind_item regs[ARRAY_SIZE(reg_info)];
148 unsigned stackDepth:8;
149 unsigned version:8;
150 const u8 *label;
151 const u8 *stack[MAX_STACK_DEPTH];
152};
153
154static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
155
156static struct unwind_table *find_table(unsigned long pc)
157{
158 struct unwind_table *table;
159
160 for (table = &root_table; table; table = table->link)
161 if ((pc >= table->core.pc
162 && pc < table->core.pc + table->core.range)
163 || (pc >= table->init.pc
164 && pc < table->init.pc + table->init.range))
165 break;
166
167 return table;
168}
169
170static unsigned long read_pointer(const u8 **pLoc,
171 const void *end, signed ptrType);
172static void init_unwind_hdr(struct unwind_table *table,
173 void *(*alloc) (unsigned long));
174
175/*
176 * wrappers for header alloc (vs. calling one vs. other at call site)
177 * to elide section mismatches warnings
178 */
179static void *__init unw_hdr_alloc_early(unsigned long sz)
180{
181 return memblock_alloc_from(sz, sizeof(unsigned int), MAX_DMA_ADDRESS);
182}
183
184static void init_unwind_table(struct unwind_table *table, const char *name,
185 const void *core_start, unsigned long core_size,
186 const void *init_start, unsigned long init_size,
187 const void *table_start, unsigned long table_size,
188 const u8 *header_start, unsigned long header_size)
189{
190 const u8 *ptr = header_start + 4;
191 const u8 *end = header_start + header_size;
192
193 table->core.pc = (unsigned long)core_start;
194 table->core.range = core_size;
195 table->init.pc = (unsigned long)init_start;
196 table->init.range = init_size;
197 table->address = table_start;
198 table->size = table_size;
199
200 /* See if the linker provided table looks valid. */
201 if (header_size <= 4
202 || header_start[0] != 1
203 || (void *)read_pointer(&ptr, end, header_start[1]) != table_start
204 || header_start[2] == DW_EH_PE_omit
205 || read_pointer(&ptr, end, header_start[2]) <= 0
206 || header_start[3] == DW_EH_PE_omit)
207 header_start = NULL;
208
209 table->hdrsz = header_size;
210 smp_wmb();
211 table->header = header_start;
212 table->link = NULL;
213 table->name = name;
214}
215
216void __init arc_unwind_init(void)
217{
218 init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0,
219 __start_unwind, __end_unwind - __start_unwind,
220 NULL, 0);
221 /*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/
222
223 init_unwind_hdr(&root_table, unw_hdr_alloc_early);
224}
225
226static const u32 bad_cie, not_fde;
227static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
228static const u32 *__cie_for_fde(const u32 *fde);
229static signed fde_pointer_type(const u32 *cie);
230
231struct eh_frame_hdr_table_entry {
232 unsigned long start, fde;
233};
234
235static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2)
236{
237 const struct eh_frame_hdr_table_entry *e1 = p1;
238 const struct eh_frame_hdr_table_entry *e2 = p2;
239
240 return (e1->start > e2->start) - (e1->start < e2->start);
241}
242
243static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
244{
245 struct eh_frame_hdr_table_entry *e1 = p1;
246 struct eh_frame_hdr_table_entry *e2 = p2;
247 unsigned long v;
248
249 v = e1->start;
250 e1->start = e2->start;
251 e2->start = v;
252 v = e1->fde;
253 e1->fde = e2->fde;
254 e2->fde = v;
255}
256
257static void init_unwind_hdr(struct unwind_table *table,
258 void *(*alloc) (unsigned long))
259{
260 const u8 *ptr;
261 unsigned long tableSize = table->size, hdrSize;
262 unsigned n;
263 const u32 *fde;
264 struct {
265 u8 version;
266 u8 eh_frame_ptr_enc;
267 u8 fde_count_enc;
268 u8 table_enc;
269 unsigned long eh_frame_ptr;
270 unsigned int fde_count;
271 struct eh_frame_hdr_table_entry table[];
272 } __attribute__ ((__packed__)) *header;
273
274 if (table->header)
275 return;
276
277 if (table->hdrsz)
278 pr_warn(".eh_frame_hdr for '%s' present but unusable\n",
279 table->name);
280
281 if (tableSize & (sizeof(*fde) - 1))
282 return;
283
284 for (fde = table->address, n = 0;
285 tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
286 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
287 const u32 *cie = cie_for_fde(fde, table);
288 signed ptrType;
289
290 if (cie == ¬_fde)
291 continue;
292 if (cie == NULL || cie == &bad_cie)
293 goto ret_err;
294 ptrType = fde_pointer_type(cie);
295 if (ptrType < 0)
296 goto ret_err;
297
298 ptr = (const u8 *)(fde + 2);
299 if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde,
300 ptrType)) {
301 /* FIXME_Rajesh We have 4 instances of null addresses
302 * instead of the initial loc addr
303 * return;
304 */
305 WARN(1, "unwinder: FDE->initial_location NULL %p\n",
306 (const u8 *)(fde + 1) + *fde);
307 }
308 ++n;
309 }
310
311 if (tableSize || !n)
312 goto ret_err;
313
314 hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
315 + 2 * n * sizeof(unsigned long);
316
317 header = alloc(hdrSize);
318 if (!header)
319 goto ret_err;
320
321 header->version = 1;
322 header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native;
323 header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4;
324 header->table_enc = DW_EH_PE_abs | DW_EH_PE_native;
325 put_unaligned((unsigned long)table->address, &header->eh_frame_ptr);
326 BUILD_BUG_ON(offsetof(typeof(*header), fde_count)
327 % __alignof(typeof(header->fde_count)));
328 header->fde_count = n;
329
330 BUILD_BUG_ON(offsetof(typeof(*header), table)
331 % __alignof(typeof(*header->table)));
332 for (fde = table->address, tableSize = table->size, n = 0;
333 tableSize;
334 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
335 const u32 *cie = __cie_for_fde(fde);
336
337 if (fde[1] == CIE_ID)
338 continue; /* this is a CIE */
339 ptr = (const u8 *)(fde + 2);
340 header->table[n].start = read_pointer(&ptr,
341 (const u8 *)(fde + 1) +
342 *fde,
343 fde_pointer_type(cie));
344 header->table[n].fde = (unsigned long)fde;
345 ++n;
346 }
347 WARN_ON(n != header->fde_count);
348
349 sort(header->table,
350 n,
351 sizeof(*header->table),
352 cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries);
353
354 table->hdrsz = hdrSize;
355 smp_wmb();
356 table->header = (const void *)header;
357 return;
358
359ret_err:
360 panic("Attention !!! Dwarf FDE parsing errors\n");
361}
362
363#ifdef CONFIG_MODULES
364static void *unw_hdr_alloc(unsigned long sz)
365{
366 return kmalloc(sz, GFP_KERNEL);
367}
368
369static struct unwind_table *last_table;
370
371/* Must be called with module_mutex held. */
372void *unwind_add_table(struct module *module, const void *table_start,
373 unsigned long table_size)
374{
375 struct unwind_table *table;
376
377 if (table_size <= 0)
378 return NULL;
379
380 table = kmalloc(sizeof(*table), GFP_KERNEL);
381 if (!table)
382 return NULL;
383
384 init_unwind_table(table, module->name,
385 module->core_layout.base, module->core_layout.size,
386 module->init_layout.base, module->init_layout.size,
387 table_start, table_size,
388 NULL, 0);
389
390 init_unwind_hdr(table, unw_hdr_alloc);
391
392#ifdef UNWIND_DEBUG
393 unw_debug("Table added for [%s] %lx %lx\n",
394 module->name, table->core.pc, table->core.range);
395#endif
396 if (last_table)
397 last_table->link = table;
398 else
399 root_table.link = table;
400 last_table = table;
401
402 return table;
403}
404
405struct unlink_table_info {
406 struct unwind_table *table;
407 int init_only;
408};
409
410static int unlink_table(void *arg)
411{
412 struct unlink_table_info *info = arg;
413 struct unwind_table *table = info->table, *prev;
414
415 for (prev = &root_table; prev->link && prev->link != table;
416 prev = prev->link)
417 ;
418
419 if (prev->link) {
420 if (info->init_only) {
421 table->init.pc = 0;
422 table->init.range = 0;
423 info->table = NULL;
424 } else {
425 prev->link = table->link;
426 if (!prev->link)
427 last_table = prev;
428 }
429 } else
430 info->table = NULL;
431
432 return 0;
433}
434
435/* Must be called with module_mutex held. */
436void unwind_remove_table(void *handle, int init_only)
437{
438 struct unwind_table *table = handle;
439 struct unlink_table_info info;
440
441 if (!table || table == &root_table)
442 return;
443
444 if (init_only && table == last_table) {
445 table->init.pc = 0;
446 table->init.range = 0;
447 return;
448 }
449
450 info.table = table;
451 info.init_only = init_only;
452
453 unlink_table(&info); /* XXX: SMP */
454 kfree(table->header);
455 kfree(table);
456}
457
458#endif /* CONFIG_MODULES */
459
460static uleb128_t get_uleb128(const u8 **pcur, const u8 *end)
461{
462 const u8 *cur = *pcur;
463 uleb128_t value;
464 unsigned shift;
465
466 for (shift = 0, value = 0; cur < end; shift += 7) {
467 if (shift + 7 > 8 * sizeof(value)
468 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
469 cur = end + 1;
470 break;
471 }
472 value |= (uleb128_t) (*cur & 0x7f) << shift;
473 if (!(*cur++ & 0x80))
474 break;
475 }
476 *pcur = cur;
477
478 return value;
479}
480
481static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
482{
483 const u8 *cur = *pcur;
484 sleb128_t value;
485 unsigned shift;
486
487 for (shift = 0, value = 0; cur < end; shift += 7) {
488 if (shift + 7 > 8 * sizeof(value)
489 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
490 cur = end + 1;
491 break;
492 }
493 value |= (sleb128_t) (*cur & 0x7f) << shift;
494 if (!(*cur & 0x80)) {
495 value |= -(*cur++ & 0x40) << shift;
496 break;
497 }
498 }
499 *pcur = cur;
500
501 return value;
502}
503
504static const u32 *__cie_for_fde(const u32 *fde)
505{
506 const u32 *cie;
507
508 cie = fde + 1 - fde[1] / sizeof(*fde);
509
510 return cie;
511}
512
513static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
514{
515 const u32 *cie;
516
517 if (!*fde || (*fde & (sizeof(*fde) - 1)))
518 return &bad_cie;
519
520 if (fde[1] == CIE_ID)
521 return ¬_fde; /* this is a CIE */
522
523 if ((fde[1] & (sizeof(*fde) - 1)))
524/* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */
525 return NULL; /* this is not a valid FDE */
526
527 cie = __cie_for_fde(fde);
528
529 if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
530 || (*cie & (sizeof(*cie) - 1))
531 || (cie[1] != CIE_ID))
532 return NULL; /* this is not a (valid) CIE */
533 return cie;
534}
535
536static unsigned long read_pointer(const u8 **pLoc, const void *end,
537 signed ptrType)
538{
539 unsigned long value = 0;
540 union {
541 const u8 *p8;
542 const u16 *p16u;
543 const s16 *p16s;
544 const u32 *p32u;
545 const s32 *p32s;
546 const unsigned long *pul;
547 } ptr;
548
549 if (ptrType < 0 || ptrType == DW_EH_PE_omit)
550 return 0;
551 ptr.p8 = *pLoc;
552 switch (ptrType & DW_EH_PE_FORM) {
553 case DW_EH_PE_data2:
554 if (end < (const void *)(ptr.p16u + 1))
555 return 0;
556 if (ptrType & DW_EH_PE_signed)
557 value = get_unaligned((u16 *) ptr.p16s++);
558 else
559 value = get_unaligned((u16 *) ptr.p16u++);
560 break;
561 case DW_EH_PE_data4:
562#ifdef CONFIG_64BIT
563 if (end < (const void *)(ptr.p32u + 1))
564 return 0;
565 if (ptrType & DW_EH_PE_signed)
566 value = get_unaligned(ptr.p32s++);
567 else
568 value = get_unaligned(ptr.p32u++);
569 break;
570 case DW_EH_PE_data8:
571 BUILD_BUG_ON(sizeof(u64) != sizeof(value));
572#else
573 BUILD_BUG_ON(sizeof(u32) != sizeof(value));
574#endif
575 fallthrough;
576 case DW_EH_PE_native:
577 if (end < (const void *)(ptr.pul + 1))
578 return 0;
579 value = get_unaligned((unsigned long *)ptr.pul++);
580 break;
581 case DW_EH_PE_leb128:
582 BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value));
583 value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end)
584 : get_uleb128(&ptr.p8, end);
585 if ((const void *)ptr.p8 > end)
586 return 0;
587 break;
588 default:
589 return 0;
590 }
591 switch (ptrType & DW_EH_PE_ADJUST) {
592 case DW_EH_PE_abs:
593 break;
594 case DW_EH_PE_pcrel:
595 value += (unsigned long)*pLoc;
596 break;
597 default:
598 return 0;
599 }
600 if ((ptrType & DW_EH_PE_indirect)
601 && __get_user(value, (unsigned long __user *)value))
602 return 0;
603 *pLoc = ptr.p8;
604
605 return value;
606}
607
608static signed fde_pointer_type(const u32 *cie)
609{
610 const u8 *ptr = (const u8 *)(cie + 2);
611 unsigned version = *ptr;
612
613 if (*++ptr) {
614 const char *aug;
615 const u8 *end = (const u8 *)(cie + 1) + *cie;
616 uleb128_t len;
617
618 /* check if augmentation size is first (and thus present) */
619 if (*ptr != 'z')
620 return -1;
621
622 /* check if augmentation string is nul-terminated */
623 aug = (const void *)ptr;
624 ptr = memchr(aug, 0, end - ptr);
625 if (ptr == NULL)
626 return -1;
627
628 ++ptr; /* skip terminator */
629 get_uleb128(&ptr, end); /* skip code alignment */
630 get_sleb128(&ptr, end); /* skip data alignment */
631 /* skip return address column */
632 version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end);
633 len = get_uleb128(&ptr, end); /* augmentation length */
634
635 if (ptr + len < ptr || ptr + len > end)
636 return -1;
637
638 end = ptr + len;
639 while (*++aug) {
640 if (ptr >= end)
641 return -1;
642 switch (*aug) {
643 case 'L':
644 ++ptr;
645 break;
646 case 'P':{
647 signed ptrType = *ptr++;
648
649 if (!read_pointer(&ptr, end, ptrType)
650 || ptr > end)
651 return -1;
652 }
653 break;
654 case 'R':
655 return *ptr;
656 default:
657 return -1;
658 }
659 }
660 }
661 return DW_EH_PE_native | DW_EH_PE_abs;
662}
663
664static int advance_loc(unsigned long delta, struct unwind_state *state)
665{
666 state->loc += delta * state->codeAlign;
667
668 /* FIXME_Rajesh: Probably we are defining for the initial range as well;
669 return delta > 0;
670 */
671 unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc);
672 return 1;
673}
674
675static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value,
676 struct unwind_state *state)
677{
678 if (reg < ARRAY_SIZE(state->regs)) {
679 state->regs[reg].where = where;
680 state->regs[reg].value = value;
681
682#ifdef UNWIND_DEBUG
683 unw_debug("r%lu: ", reg);
684 switch (where) {
685 case Nowhere:
686 unw_debug("s ");
687 break;
688 case Memory:
689 unw_debug("c(%lu) ", value);
690 break;
691 case Register:
692 unw_debug("r(%lu) ", value);
693 break;
694 case Value:
695 unw_debug("v(%lu) ", value);
696 break;
697 default:
698 break;
699 }
700#endif
701 }
702}
703
704static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
705 signed ptrType, struct unwind_state *state)
706{
707 union {
708 const u8 *p8;
709 const u16 *p16;
710 const u32 *p32;
711 } ptr;
712 int result = 1;
713 u8 opcode;
714
715 if (start != state->cieStart) {
716 state->loc = state->org;
717 result =
718 processCFI(state->cieStart, state->cieEnd, 0, ptrType,
719 state);
720 if (targetLoc == 0 && state->label == NULL)
721 return result;
722 }
723 for (ptr.p8 = start; result && ptr.p8 < end;) {
724 switch (*ptr.p8 >> 6) {
725 uleb128_t value;
726
727 case 0:
728 opcode = *ptr.p8++;
729
730 switch (opcode) {
731 case DW_CFA_nop:
732 unw_debug("cfa nop ");
733 break;
734 case DW_CFA_set_loc:
735 state->loc = read_pointer(&ptr.p8, end,
736 ptrType);
737 if (state->loc == 0)
738 result = 0;
739 unw_debug("cfa_set_loc: 0x%lx ", state->loc);
740 break;
741 case DW_CFA_advance_loc1:
742 unw_debug("\ncfa advance loc1:");
743 result = ptr.p8 < end
744 && advance_loc(*ptr.p8++, state);
745 break;
746 case DW_CFA_advance_loc2:
747 value = *ptr.p8++;
748 value += *ptr.p8++ << 8;
749 unw_debug("\ncfa advance loc2:");
750 result = ptr.p8 <= end + 2
751 /* && advance_loc(*ptr.p16++, state); */
752 && advance_loc(value, state);
753 break;
754 case DW_CFA_advance_loc4:
755 unw_debug("\ncfa advance loc4:");
756 result = ptr.p8 <= end + 4
757 && advance_loc(*ptr.p32++, state);
758 break;
759 case DW_CFA_offset_extended:
760 value = get_uleb128(&ptr.p8, end);
761 unw_debug("cfa_offset_extended: ");
762 set_rule(value, Memory,
763 get_uleb128(&ptr.p8, end), state);
764 break;
765 case DW_CFA_val_offset:
766 value = get_uleb128(&ptr.p8, end);
767 set_rule(value, Value,
768 get_uleb128(&ptr.p8, end), state);
769 break;
770 case DW_CFA_offset_extended_sf:
771 value = get_uleb128(&ptr.p8, end);
772 set_rule(value, Memory,
773 get_sleb128(&ptr.p8, end), state);
774 break;
775 case DW_CFA_val_offset_sf:
776 value = get_uleb128(&ptr.p8, end);
777 set_rule(value, Value,
778 get_sleb128(&ptr.p8, end), state);
779 break;
780 case DW_CFA_restore_extended:
781 unw_debug("cfa_restore_extended: ");
782 case DW_CFA_undefined:
783 unw_debug("cfa_undefined: ");
784 case DW_CFA_same_value:
785 unw_debug("cfa_same_value: ");
786 set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0,
787 state);
788 break;
789 case DW_CFA_register:
790 unw_debug("cfa_register: ");
791 value = get_uleb128(&ptr.p8, end);
792 set_rule(value,
793 Register,
794 get_uleb128(&ptr.p8, end), state);
795 break;
796 case DW_CFA_remember_state:
797 unw_debug("cfa_remember_state: ");
798 if (ptr.p8 == state->label) {
799 state->label = NULL;
800 return 1;
801 }
802 if (state->stackDepth >= MAX_STACK_DEPTH)
803 return 0;
804 state->stack[state->stackDepth++] = ptr.p8;
805 break;
806 case DW_CFA_restore_state:
807 unw_debug("cfa_restore_state: ");
808 if (state->stackDepth) {
809 const uleb128_t loc = state->loc;
810 const u8 *label = state->label;
811
812 state->label =
813 state->stack[state->stackDepth - 1];
814 memcpy(&state->cfa, &badCFA,
815 sizeof(state->cfa));
816 memset(state->regs, 0,
817 sizeof(state->regs));
818 state->stackDepth = 0;
819 result =
820 processCFI(start, end, 0, ptrType,
821 state);
822 state->loc = loc;
823 state->label = label;
824 } else
825 return 0;
826 break;
827 case DW_CFA_def_cfa:
828 state->cfa.reg = get_uleb128(&ptr.p8, end);
829 unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg);
830 fallthrough;
831 case DW_CFA_def_cfa_offset:
832 state->cfa.offs = get_uleb128(&ptr.p8, end);
833 unw_debug("cfa_def_cfa_offset: 0x%lx ",
834 state->cfa.offs);
835 break;
836 case DW_CFA_def_cfa_sf:
837 state->cfa.reg = get_uleb128(&ptr.p8, end);
838 fallthrough;
839 case DW_CFA_def_cfa_offset_sf:
840 state->cfa.offs = get_sleb128(&ptr.p8, end)
841 * state->dataAlign;
842 break;
843 case DW_CFA_def_cfa_register:
844 unw_debug("cfa_def_cfa_register: ");
845 state->cfa.reg = get_uleb128(&ptr.p8, end);
846 break;
847 /*todo case DW_CFA_def_cfa_expression: */
848 /*todo case DW_CFA_expression: */
849 /*todo case DW_CFA_val_expression: */
850 case DW_CFA_GNU_args_size:
851 get_uleb128(&ptr.p8, end);
852 break;
853 case DW_CFA_GNU_negative_offset_extended:
854 value = get_uleb128(&ptr.p8, end);
855 set_rule(value,
856 Memory,
857 (uleb128_t) 0 - get_uleb128(&ptr.p8,
858 end),
859 state);
860 break;
861 case DW_CFA_GNU_window_save:
862 default:
863 unw_debug("UNKNOWN OPCODE 0x%x\n", opcode);
864 result = 0;
865 break;
866 }
867 break;
868 case 1:
869 unw_debug("\ncfa_adv_loc: ");
870 result = advance_loc(*ptr.p8++ & 0x3f, state);
871 break;
872 case 2:
873 unw_debug("cfa_offset: ");
874 value = *ptr.p8++ & 0x3f;
875 set_rule(value, Memory, get_uleb128(&ptr.p8, end),
876 state);
877 break;
878 case 3:
879 unw_debug("cfa_restore: ");
880 set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
881 break;
882 }
883
884 if (ptr.p8 > end)
885 result = 0;
886 if (result && targetLoc != 0 && targetLoc < state->loc)
887 return 1;
888 }
889
890 return result && ptr.p8 == end && (targetLoc == 0 || (
891 /*todo While in theory this should apply, gcc in practice omits
892 everything past the function prolog, and hence the location
893 never reaches the end of the function.
894 targetLoc < state->loc && */ state->label == NULL));
895}
896
897/* Unwind to previous to frame. Returns 0 if successful, negative
898 * number in case of an error. */
899int arc_unwind(struct unwind_frame_info *frame)
900{
901#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
902 const u32 *fde = NULL, *cie = NULL;
903 const u8 *ptr = NULL, *end = NULL;
904 unsigned long pc = UNW_PC(frame) - frame->call_frame;
905 unsigned long startLoc = 0, endLoc = 0, cfa;
906 unsigned i;
907 signed ptrType = -1;
908 uleb128_t retAddrReg = 0;
909 const struct unwind_table *table;
910 struct unwind_state state;
911 unsigned long *fptr;
912 unsigned long addr;
913
914 unw_debug("\n\nUNWIND FRAME:\n");
915 unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n",
916 UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame),
917 UNW_FP(frame));
918
919 if (UNW_PC(frame) == 0)
920 return -EINVAL;
921
922#ifdef UNWIND_DEBUG
923 {
924 unsigned long *sptr = (unsigned long *)UNW_SP(frame);
925 unw_debug("\nStack Dump:\n");
926 for (i = 0; i < 20; i++, sptr++)
927 unw_debug("0x%p: 0x%lx\n", sptr, *sptr);
928 unw_debug("\n");
929 }
930#endif
931
932 table = find_table(pc);
933 if (table != NULL
934 && !(table->size & (sizeof(*fde) - 1))) {
935 const u8 *hdr = table->header;
936 unsigned long tableSize;
937
938 smp_rmb();
939 if (hdr && hdr[0] == 1) {
940 switch (hdr[3] & DW_EH_PE_FORM) {
941 case DW_EH_PE_native:
942 tableSize = sizeof(unsigned long);
943 break;
944 case DW_EH_PE_data2:
945 tableSize = 2;
946 break;
947 case DW_EH_PE_data4:
948 tableSize = 4;
949 break;
950 case DW_EH_PE_data8:
951 tableSize = 8;
952 break;
953 default:
954 tableSize = 0;
955 break;
956 }
957 ptr = hdr + 4;
958 end = hdr + table->hdrsz;
959 if (tableSize && read_pointer(&ptr, end, hdr[1])
960 == (unsigned long)table->address
961 && (i = read_pointer(&ptr, end, hdr[2])) > 0
962 && i == (end - ptr) / (2 * tableSize)
963 && !((end - ptr) % (2 * tableSize))) {
964 do {
965 const u8 *cur =
966 ptr + (i / 2) * (2 * tableSize);
967
968 startLoc = read_pointer(&cur,
969 cur + tableSize,
970 hdr[3]);
971 if (pc < startLoc)
972 i /= 2;
973 else {
974 ptr = cur - tableSize;
975 i = (i + 1) / 2;
976 }
977 } while (startLoc && i > 1);
978 if (i == 1
979 && (startLoc = read_pointer(&ptr,
980 ptr + tableSize,
981 hdr[3])) != 0
982 && pc >= startLoc)
983 fde = (void *)read_pointer(&ptr,
984 ptr +
985 tableSize,
986 hdr[3]);
987 }
988 }
989
990 if (fde != NULL) {
991 cie = cie_for_fde(fde, table);
992 ptr = (const u8 *)(fde + 2);
993 if (cie != NULL
994 && cie != &bad_cie
995 && cie != ¬_fde
996 && (ptrType = fde_pointer_type(cie)) >= 0
997 && read_pointer(&ptr,
998 (const u8 *)(fde + 1) + *fde,
999 ptrType) == startLoc) {
1000 if (!(ptrType & DW_EH_PE_indirect))
1001 ptrType &=
1002 DW_EH_PE_FORM | DW_EH_PE_signed;
1003 endLoc =
1004 startLoc + read_pointer(&ptr,
1005 (const u8 *)(fde +
1006 1) +
1007 *fde, ptrType);
1008 if (pc >= endLoc) {
1009 fde = NULL;
1010 cie = NULL;
1011 }
1012 } else {
1013 fde = NULL;
1014 cie = NULL;
1015 }
1016 }
1017 }
1018 if (cie != NULL) {
1019 memset(&state, 0, sizeof(state));
1020 state.cieEnd = ptr; /* keep here temporarily */
1021 ptr = (const u8 *)(cie + 2);
1022 end = (const u8 *)(cie + 1) + *cie;
1023 frame->call_frame = 1;
1024 if (*++ptr) {
1025 /* check if augmentation size is first (thus present) */
1026 if (*ptr == 'z') {
1027 while (++ptr < end && *ptr) {
1028 switch (*ptr) {
1029 /* chk for ignorable or already handled
1030 * nul-terminated augmentation string */
1031 case 'L':
1032 case 'P':
1033 case 'R':
1034 continue;
1035 case 'S':
1036 frame->call_frame = 0;
1037 continue;
1038 default:
1039 break;
1040 }
1041 break;
1042 }
1043 }
1044 if (ptr >= end || *ptr)
1045 cie = NULL;
1046 }
1047 ++ptr;
1048 }
1049 if (cie != NULL) {
1050 /* get code alignment factor */
1051 state.codeAlign = get_uleb128(&ptr, end);
1052 /* get data alignment factor */
1053 state.dataAlign = get_sleb128(&ptr, end);
1054 if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
1055 cie = NULL;
1056 else {
1057 retAddrReg =
1058 state.version <= 1 ? *ptr++ : get_uleb128(&ptr,
1059 end);
1060 unw_debug("CIE Frame Info:\n");
1061 unw_debug("return Address register 0x%lx\n",
1062 retAddrReg);
1063 unw_debug("data Align: %ld\n", state.dataAlign);
1064 unw_debug("code Align: %lu\n", state.codeAlign);
1065 /* skip augmentation */
1066 if (((const char *)(cie + 2))[1] == 'z') {
1067 uleb128_t augSize = get_uleb128(&ptr, end);
1068
1069 ptr += augSize;
1070 }
1071 if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info)
1072 || REG_INVALID(retAddrReg)
1073 || reg_info[retAddrReg].width !=
1074 sizeof(unsigned long))
1075 cie = NULL;
1076 }
1077 }
1078 if (cie != NULL) {
1079 state.cieStart = ptr;
1080 ptr = state.cieEnd;
1081 state.cieEnd = end;
1082 end = (const u8 *)(fde + 1) + *fde;
1083 /* skip augmentation */
1084 if (((const char *)(cie + 2))[1] == 'z') {
1085 uleb128_t augSize = get_uleb128(&ptr, end);
1086
1087 if ((ptr += augSize) > end)
1088 fde = NULL;
1089 }
1090 }
1091 if (cie == NULL || fde == NULL) {
1092#ifdef CONFIG_FRAME_POINTER
1093 unsigned long top, bottom;
1094
1095 top = STACK_TOP_UNW(frame->task);
1096 bottom = STACK_BOTTOM_UNW(frame->task);
1097#if FRAME_RETADDR_OFFSET < 0
1098 if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame)
1099 && bottom < UNW_FP(frame)
1100#else
1101 if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame)
1102 && bottom > UNW_FP(frame)
1103#endif
1104 && !((UNW_SP(frame) | UNW_FP(frame))
1105 & (sizeof(unsigned long) - 1))) {
1106 unsigned long link;
1107
1108 if (!__get_user(link, (unsigned long *)
1109 (UNW_FP(frame) + FRAME_LINK_OFFSET))
1110#if FRAME_RETADDR_OFFSET < 0
1111 && link > bottom && link < UNW_FP(frame)
1112#else
1113 && link > UNW_FP(frame) && link < bottom
1114#endif
1115 && !(link & (sizeof(link) - 1))
1116 && !__get_user(UNW_PC(frame),
1117 (unsigned long *)(UNW_FP(frame)
1118 + FRAME_RETADDR_OFFSET)))
1119 {
1120 UNW_SP(frame) =
1121 UNW_FP(frame) + FRAME_RETADDR_OFFSET
1122#if FRAME_RETADDR_OFFSET < 0
1123 -
1124#else
1125 +
1126#endif
1127 sizeof(UNW_PC(frame));
1128 UNW_FP(frame) = link;
1129 return 0;
1130 }
1131 }
1132#endif
1133 return -ENXIO;
1134 }
1135 state.org = startLoc;
1136 memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
1137
1138 unw_debug("\nProcess instructions\n");
1139
1140 /* process instructions
1141 * For ARC, we optimize by having blink(retAddrReg) with
1142 * the sameValue in the leaf function, so we should not check
1143 * state.regs[retAddrReg].where == Nowhere
1144 */
1145 if (!processCFI(ptr, end, pc, ptrType, &state)
1146 || state.loc > endLoc
1147/* || state.regs[retAddrReg].where == Nowhere */
1148 || state.cfa.reg >= ARRAY_SIZE(reg_info)
1149 || reg_info[state.cfa.reg].width != sizeof(unsigned long)
1150 || state.cfa.offs % sizeof(unsigned long))
1151 return -EIO;
1152
1153#ifdef UNWIND_DEBUG
1154 unw_debug("\n");
1155
1156 unw_debug("\nRegister State Based on the rules parsed from FDE:\n");
1157 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1158
1159 if (REG_INVALID(i))
1160 continue;
1161
1162 switch (state.regs[i].where) {
1163 case Nowhere:
1164 break;
1165 case Memory:
1166 unw_debug(" r%d: c(%lu),", i, state.regs[i].value);
1167 break;
1168 case Register:
1169 unw_debug(" r%d: r(%lu),", i, state.regs[i].value);
1170 break;
1171 case Value:
1172 unw_debug(" r%d: v(%lu),", i, state.regs[i].value);
1173 break;
1174 }
1175 }
1176
1177 unw_debug("\n");
1178#endif
1179
1180 /* update frame */
1181 if (frame->call_frame
1182 && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
1183 frame->call_frame = 0;
1184 cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
1185 startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
1186 endLoc = max_t(unsigned long, UNW_SP(frame), cfa);
1187 if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) {
1188 startLoc = min(STACK_LIMIT(cfa), cfa);
1189 endLoc = max(STACK_LIMIT(cfa), cfa);
1190 }
1191
1192 unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n",
1193 state.cfa.reg, state.cfa.offs, cfa);
1194
1195 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1196 if (REG_INVALID(i)) {
1197 if (state.regs[i].where == Nowhere)
1198 continue;
1199 return -EIO;
1200 }
1201 switch (state.regs[i].where) {
1202 default:
1203 break;
1204 case Register:
1205 if (state.regs[i].value >= ARRAY_SIZE(reg_info)
1206 || REG_INVALID(state.regs[i].value)
1207 || reg_info[i].width >
1208 reg_info[state.regs[i].value].width)
1209 return -EIO;
1210 switch (reg_info[state.regs[i].value].width) {
1211 case sizeof(u8):
1212 state.regs[i].value =
1213 FRAME_REG(state.regs[i].value, const u8);
1214 break;
1215 case sizeof(u16):
1216 state.regs[i].value =
1217 FRAME_REG(state.regs[i].value, const u16);
1218 break;
1219 case sizeof(u32):
1220 state.regs[i].value =
1221 FRAME_REG(state.regs[i].value, const u32);
1222 break;
1223#ifdef CONFIG_64BIT
1224 case sizeof(u64):
1225 state.regs[i].value =
1226 FRAME_REG(state.regs[i].value, const u64);
1227 break;
1228#endif
1229 default:
1230 return -EIO;
1231 }
1232 break;
1233 }
1234 }
1235
1236 unw_debug("\nRegister state after evaluation with realtime Stack:\n");
1237 fptr = (unsigned long *)(&frame->regs);
1238 for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) {
1239
1240 if (REG_INVALID(i))
1241 continue;
1242 switch (state.regs[i].where) {
1243 case Nowhere:
1244 if (reg_info[i].width != sizeof(UNW_SP(frame))
1245 || &FRAME_REG(i, __typeof__(UNW_SP(frame)))
1246 != &UNW_SP(frame))
1247 continue;
1248 UNW_SP(frame) = cfa;
1249 break;
1250 case Register:
1251 switch (reg_info[i].width) {
1252 case sizeof(u8):
1253 FRAME_REG(i, u8) = state.regs[i].value;
1254 break;
1255 case sizeof(u16):
1256 FRAME_REG(i, u16) = state.regs[i].value;
1257 break;
1258 case sizeof(u32):
1259 FRAME_REG(i, u32) = state.regs[i].value;
1260 break;
1261#ifdef CONFIG_64BIT
1262 case sizeof(u64):
1263 FRAME_REG(i, u64) = state.regs[i].value;
1264 break;
1265#endif
1266 default:
1267 return -EIO;
1268 }
1269 break;
1270 case Value:
1271 if (reg_info[i].width != sizeof(unsigned long))
1272 return -EIO;
1273 FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
1274 * state.dataAlign;
1275 break;
1276 case Memory:
1277 addr = cfa + state.regs[i].value * state.dataAlign;
1278
1279 if ((state.regs[i].value * state.dataAlign)
1280 % sizeof(unsigned long)
1281 || addr < startLoc
1282 || addr + sizeof(unsigned long) < addr
1283 || addr + sizeof(unsigned long) > endLoc)
1284 return -EIO;
1285
1286 switch (reg_info[i].width) {
1287 case sizeof(u8):
1288 __get_user(FRAME_REG(i, u8),
1289 (u8 __user *)addr);
1290 break;
1291 case sizeof(u16):
1292 __get_user(FRAME_REG(i, u16),
1293 (u16 __user *)addr);
1294 break;
1295 case sizeof(u32):
1296 __get_user(FRAME_REG(i, u32),
1297 (u32 __user *)addr);
1298 break;
1299#ifdef CONFIG_64BIT
1300 case sizeof(u64):
1301 __get_user(FRAME_REG(i, u64),
1302 (u64 __user *)addr);
1303 break;
1304#endif
1305 default:
1306 return -EIO;
1307 }
1308
1309 break;
1310 }
1311 unw_debug("r%d: 0x%lx ", i, *fptr);
1312 }
1313
1314 return 0;
1315#undef FRAME_REG
1316}
1317EXPORT_SYMBOL(arc_unwind);
1/*
2 * Copyright (C) 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3 * Copyright (C) 2002-2006 Novell, Inc.
4 * Jan Beulich <jbeulich@novell.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * A simple API for unwinding kernel stacks. This is used for
11 * debugging and error reporting purposes. The kernel doesn't need
12 * full-blown stack unwinding with all the bells and whistles, so there
13 * is not much point in implementing the full Dwarf2 unwind API.
14 */
15
16#include <linux/sched.h>
17#include <linux/module.h>
18#include <linux/bootmem.h>
19#include <linux/sort.h>
20#include <linux/slab.h>
21#include <linux/stop_machine.h>
22#include <linux/uaccess.h>
23#include <linux/ptrace.h>
24#include <asm/sections.h>
25#include <asm/unaligned.h>
26#include <asm/unwind.h>
27
28extern char __start_unwind[], __end_unwind[];
29/* extern const u8 __start_unwind_hdr[], __end_unwind_hdr[];*/
30
31/* #define UNWIND_DEBUG */
32
33#ifdef UNWIND_DEBUG
34int dbg_unw;
35#define unw_debug(fmt, ...) \
36do { \
37 if (dbg_unw) \
38 pr_info(fmt, ##__VA_ARGS__); \
39} while (0);
40#else
41#define unw_debug(fmt, ...)
42#endif
43
44#define MAX_STACK_DEPTH 8
45
46#define EXTRA_INFO(f) { \
47 BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \
48 % FIELD_SIZEOF(struct unwind_frame_info, f)) \
49 + offsetof(struct unwind_frame_info, f) \
50 / FIELD_SIZEOF(struct unwind_frame_info, f), \
51 FIELD_SIZEOF(struct unwind_frame_info, f) \
52 }
53#define PTREGS_INFO(f) EXTRA_INFO(regs.f)
54
55static const struct {
56 unsigned offs:BITS_PER_LONG / 2;
57 unsigned width:BITS_PER_LONG / 2;
58} reg_info[] = {
59UNW_REGISTER_INFO};
60
61#undef PTREGS_INFO
62#undef EXTRA_INFO
63
64#ifndef REG_INVALID
65#define REG_INVALID(r) (reg_info[r].width == 0)
66#endif
67
68#define DW_CFA_nop 0x00
69#define DW_CFA_set_loc 0x01
70#define DW_CFA_advance_loc1 0x02
71#define DW_CFA_advance_loc2 0x03
72#define DW_CFA_advance_loc4 0x04
73#define DW_CFA_offset_extended 0x05
74#define DW_CFA_restore_extended 0x06
75#define DW_CFA_undefined 0x07
76#define DW_CFA_same_value 0x08
77#define DW_CFA_register 0x09
78#define DW_CFA_remember_state 0x0a
79#define DW_CFA_restore_state 0x0b
80#define DW_CFA_def_cfa 0x0c
81#define DW_CFA_def_cfa_register 0x0d
82#define DW_CFA_def_cfa_offset 0x0e
83#define DW_CFA_def_cfa_expression 0x0f
84#define DW_CFA_expression 0x10
85#define DW_CFA_offset_extended_sf 0x11
86#define DW_CFA_def_cfa_sf 0x12
87#define DW_CFA_def_cfa_offset_sf 0x13
88#define DW_CFA_val_offset 0x14
89#define DW_CFA_val_offset_sf 0x15
90#define DW_CFA_val_expression 0x16
91#define DW_CFA_lo_user 0x1c
92#define DW_CFA_GNU_window_save 0x2d
93#define DW_CFA_GNU_args_size 0x2e
94#define DW_CFA_GNU_negative_offset_extended 0x2f
95#define DW_CFA_hi_user 0x3f
96
97#define DW_EH_PE_FORM 0x07
98#define DW_EH_PE_native 0x00
99#define DW_EH_PE_leb128 0x01
100#define DW_EH_PE_data2 0x02
101#define DW_EH_PE_data4 0x03
102#define DW_EH_PE_data8 0x04
103#define DW_EH_PE_signed 0x08
104#define DW_EH_PE_ADJUST 0x70
105#define DW_EH_PE_abs 0x00
106#define DW_EH_PE_pcrel 0x10
107#define DW_EH_PE_textrel 0x20
108#define DW_EH_PE_datarel 0x30
109#define DW_EH_PE_funcrel 0x40
110#define DW_EH_PE_aligned 0x50
111#define DW_EH_PE_indirect 0x80
112#define DW_EH_PE_omit 0xff
113
114typedef unsigned long uleb128_t;
115typedef signed long sleb128_t;
116
117static struct unwind_table {
118 struct {
119 unsigned long pc;
120 unsigned long range;
121 } core, init;
122 const void *address;
123 unsigned long size;
124 const unsigned char *header;
125 unsigned long hdrsz;
126 struct unwind_table *link;
127 const char *name;
128} root_table;
129
130struct unwind_item {
131 enum item_location {
132 Nowhere,
133 Memory,
134 Register,
135 Value
136 } where;
137 uleb128_t value;
138};
139
140struct unwind_state {
141 uleb128_t loc, org;
142 const u8 *cieStart, *cieEnd;
143 uleb128_t codeAlign;
144 sleb128_t dataAlign;
145 struct cfa {
146 uleb128_t reg, offs;
147 } cfa;
148 struct unwind_item regs[ARRAY_SIZE(reg_info)];
149 unsigned stackDepth:8;
150 unsigned version:8;
151 const u8 *label;
152 const u8 *stack[MAX_STACK_DEPTH];
153};
154
155static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 };
156
157static struct unwind_table *find_table(unsigned long pc)
158{
159 struct unwind_table *table;
160
161 for (table = &root_table; table; table = table->link)
162 if ((pc >= table->core.pc
163 && pc < table->core.pc + table->core.range)
164 || (pc >= table->init.pc
165 && pc < table->init.pc + table->init.range))
166 break;
167
168 return table;
169}
170
171static unsigned long read_pointer(const u8 **pLoc,
172 const void *end, signed ptrType);
173
174static void init_unwind_table(struct unwind_table *table, const char *name,
175 const void *core_start, unsigned long core_size,
176 const void *init_start, unsigned long init_size,
177 const void *table_start, unsigned long table_size,
178 const u8 *header_start, unsigned long header_size)
179{
180 const u8 *ptr = header_start + 4;
181 const u8 *end = header_start + header_size;
182
183 table->core.pc = (unsigned long)core_start;
184 table->core.range = core_size;
185 table->init.pc = (unsigned long)init_start;
186 table->init.range = init_size;
187 table->address = table_start;
188 table->size = table_size;
189
190 /* See if the linker provided table looks valid. */
191 if (header_size <= 4
192 || header_start[0] != 1
193 || (void *)read_pointer(&ptr, end, header_start[1]) != table_start
194 || header_start[2] == DW_EH_PE_omit
195 || read_pointer(&ptr, end, header_start[2]) <= 0
196 || header_start[3] == DW_EH_PE_omit)
197 header_start = NULL;
198
199 table->hdrsz = header_size;
200 smp_wmb();
201 table->header = header_start;
202 table->link = NULL;
203 table->name = name;
204}
205
206void __init arc_unwind_init(void)
207{
208 init_unwind_table(&root_table, "kernel", _text, _end - _text, NULL, 0,
209 __start_unwind, __end_unwind - __start_unwind,
210 NULL, 0);
211 /*__start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr);*/
212}
213
214static const u32 bad_cie, not_fde;
215static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *);
216static signed fde_pointer_type(const u32 *cie);
217
218struct eh_frame_hdr_table_entry {
219 unsigned long start, fde;
220};
221
222static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2)
223{
224 const struct eh_frame_hdr_table_entry *e1 = p1;
225 const struct eh_frame_hdr_table_entry *e2 = p2;
226
227 return (e1->start > e2->start) - (e1->start < e2->start);
228}
229
230static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size)
231{
232 struct eh_frame_hdr_table_entry *e1 = p1;
233 struct eh_frame_hdr_table_entry *e2 = p2;
234 unsigned long v;
235
236 v = e1->start;
237 e1->start = e2->start;
238 e2->start = v;
239 v = e1->fde;
240 e1->fde = e2->fde;
241 e2->fde = v;
242}
243
244static void __init setup_unwind_table(struct unwind_table *table,
245 void *(*alloc) (unsigned long))
246{
247 const u8 *ptr;
248 unsigned long tableSize = table->size, hdrSize;
249 unsigned n;
250 const u32 *fde;
251 struct {
252 u8 version;
253 u8 eh_frame_ptr_enc;
254 u8 fde_count_enc;
255 u8 table_enc;
256 unsigned long eh_frame_ptr;
257 unsigned int fde_count;
258 struct eh_frame_hdr_table_entry table[];
259 } __attribute__ ((__packed__)) *header;
260
261 if (table->header)
262 return;
263
264 if (table->hdrsz)
265 pr_warn(".eh_frame_hdr for '%s' present but unusable\n",
266 table->name);
267
268 if (tableSize & (sizeof(*fde) - 1))
269 return;
270
271 for (fde = table->address, n = 0;
272 tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde;
273 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
274 const u32 *cie = cie_for_fde(fde, table);
275 signed ptrType;
276
277 if (cie == ¬_fde)
278 continue;
279 if (cie == NULL || cie == &bad_cie)
280 return;
281 ptrType = fde_pointer_type(cie);
282 if (ptrType < 0)
283 return;
284
285 ptr = (const u8 *)(fde + 2);
286 if (!read_pointer(&ptr, (const u8 *)(fde + 1) + *fde,
287 ptrType)) {
288 /* FIXME_Rajesh We have 4 instances of null addresses
289 * instead of the initial loc addr
290 * return;
291 */
292 WARN(1, "unwinder: FDE->initial_location NULL %p\n",
293 (const u8 *)(fde + 1) + *fde);
294 }
295 ++n;
296 }
297
298 if (tableSize || !n)
299 return;
300
301 hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int)
302 + 2 * n * sizeof(unsigned long);
303 header = alloc(hdrSize);
304 if (!header)
305 return;
306 header->version = 1;
307 header->eh_frame_ptr_enc = DW_EH_PE_abs | DW_EH_PE_native;
308 header->fde_count_enc = DW_EH_PE_abs | DW_EH_PE_data4;
309 header->table_enc = DW_EH_PE_abs | DW_EH_PE_native;
310 put_unaligned((unsigned long)table->address, &header->eh_frame_ptr);
311 BUILD_BUG_ON(offsetof(typeof(*header), fde_count)
312 % __alignof(typeof(header->fde_count)));
313 header->fde_count = n;
314
315 BUILD_BUG_ON(offsetof(typeof(*header), table)
316 % __alignof(typeof(*header->table)));
317 for (fde = table->address, tableSize = table->size, n = 0;
318 tableSize;
319 tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) {
320 /* const u32 *cie = fde + 1 - fde[1] / sizeof(*fde); */
321 const u32 *cie = (const u32 *)(fde[1]);
322
323 if (fde[1] == 0xffffffff)
324 continue; /* this is a CIE */
325 ptr = (const u8 *)(fde + 2);
326 header->table[n].start = read_pointer(&ptr,
327 (const u8 *)(fde + 1) +
328 *fde,
329 fde_pointer_type(cie));
330 header->table[n].fde = (unsigned long)fde;
331 ++n;
332 }
333 WARN_ON(n != header->fde_count);
334
335 sort(header->table,
336 n,
337 sizeof(*header->table),
338 cmp_eh_frame_hdr_table_entries, swap_eh_frame_hdr_table_entries);
339
340 table->hdrsz = hdrSize;
341 smp_wmb();
342 table->header = (const void *)header;
343}
344
345static void *__init balloc(unsigned long sz)
346{
347 return __alloc_bootmem_nopanic(sz,
348 sizeof(unsigned int),
349 __pa(MAX_DMA_ADDRESS));
350}
351
352void __init arc_unwind_setup(void)
353{
354 setup_unwind_table(&root_table, balloc);
355}
356
357#ifdef CONFIG_MODULES
358
359static struct unwind_table *last_table;
360
361/* Must be called with module_mutex held. */
362void *unwind_add_table(struct module *module, const void *table_start,
363 unsigned long table_size)
364{
365 struct unwind_table *table;
366
367 if (table_size <= 0)
368 return NULL;
369
370 table = kmalloc(sizeof(*table), GFP_KERNEL);
371 if (!table)
372 return NULL;
373
374 init_unwind_table(table, module->name,
375 module->module_core, module->core_size,
376 module->module_init, module->init_size,
377 table_start, table_size,
378 NULL, 0);
379
380#ifdef UNWIND_DEBUG
381 unw_debug("Table added for [%s] %lx %lx\n",
382 module->name, table->core.pc, table->core.range);
383#endif
384 if (last_table)
385 last_table->link = table;
386 else
387 root_table.link = table;
388 last_table = table;
389
390 return table;
391}
392
393struct unlink_table_info {
394 struct unwind_table *table;
395 int init_only;
396};
397
398static int unlink_table(void *arg)
399{
400 struct unlink_table_info *info = arg;
401 struct unwind_table *table = info->table, *prev;
402
403 for (prev = &root_table; prev->link && prev->link != table;
404 prev = prev->link)
405 ;
406
407 if (prev->link) {
408 if (info->init_only) {
409 table->init.pc = 0;
410 table->init.range = 0;
411 info->table = NULL;
412 } else {
413 prev->link = table->link;
414 if (!prev->link)
415 last_table = prev;
416 }
417 } else
418 info->table = NULL;
419
420 return 0;
421}
422
423/* Must be called with module_mutex held. */
424void unwind_remove_table(void *handle, int init_only)
425{
426 struct unwind_table *table = handle;
427 struct unlink_table_info info;
428
429 if (!table || table == &root_table)
430 return;
431
432 if (init_only && table == last_table) {
433 table->init.pc = 0;
434 table->init.range = 0;
435 return;
436 }
437
438 info.table = table;
439 info.init_only = init_only;
440
441 unlink_table(&info); /* XXX: SMP */
442 kfree(table);
443}
444
445#endif /* CONFIG_MODULES */
446
447static uleb128_t get_uleb128(const u8 **pcur, const u8 *end)
448{
449 const u8 *cur = *pcur;
450 uleb128_t value;
451 unsigned shift;
452
453 for (shift = 0, value = 0; cur < end; shift += 7) {
454 if (shift + 7 > 8 * sizeof(value)
455 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
456 cur = end + 1;
457 break;
458 }
459 value |= (uleb128_t) (*cur & 0x7f) << shift;
460 if (!(*cur++ & 0x80))
461 break;
462 }
463 *pcur = cur;
464
465 return value;
466}
467
468static sleb128_t get_sleb128(const u8 **pcur, const u8 *end)
469{
470 const u8 *cur = *pcur;
471 sleb128_t value;
472 unsigned shift;
473
474 for (shift = 0, value = 0; cur < end; shift += 7) {
475 if (shift + 7 > 8 * sizeof(value)
476 && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) {
477 cur = end + 1;
478 break;
479 }
480 value |= (sleb128_t) (*cur & 0x7f) << shift;
481 if (!(*cur & 0x80)) {
482 value |= -(*cur++ & 0x40) << shift;
483 break;
484 }
485 }
486 *pcur = cur;
487
488 return value;
489}
490
491static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table)
492{
493 const u32 *cie;
494
495 if (!*fde || (*fde & (sizeof(*fde) - 1)))
496 return &bad_cie;
497
498 if (fde[1] == 0xffffffff)
499 return ¬_fde; /* this is a CIE */
500
501 if ((fde[1] & (sizeof(*fde) - 1)))
502/* || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) */
503 return NULL; /* this is not a valid FDE */
504
505 /* cie = fde + 1 - fde[1] / sizeof(*fde); */
506 cie = (u32 *) fde[1];
507
508 if (*cie <= sizeof(*cie) + 4 || *cie >= fde[1] - sizeof(*fde)
509 || (*cie & (sizeof(*cie) - 1))
510 || (cie[1] != 0xffffffff))
511 return NULL; /* this is not a (valid) CIE */
512 return cie;
513}
514
515static unsigned long read_pointer(const u8 **pLoc, const void *end,
516 signed ptrType)
517{
518 unsigned long value = 0;
519 union {
520 const u8 *p8;
521 const u16 *p16u;
522 const s16 *p16s;
523 const u32 *p32u;
524 const s32 *p32s;
525 const unsigned long *pul;
526 } ptr;
527
528 if (ptrType < 0 || ptrType == DW_EH_PE_omit)
529 return 0;
530 ptr.p8 = *pLoc;
531 switch (ptrType & DW_EH_PE_FORM) {
532 case DW_EH_PE_data2:
533 if (end < (const void *)(ptr.p16u + 1))
534 return 0;
535 if (ptrType & DW_EH_PE_signed)
536 value = get_unaligned((u16 *) ptr.p16s++);
537 else
538 value = get_unaligned((u16 *) ptr.p16u++);
539 break;
540 case DW_EH_PE_data4:
541#ifdef CONFIG_64BIT
542 if (end < (const void *)(ptr.p32u + 1))
543 return 0;
544 if (ptrType & DW_EH_PE_signed)
545 value = get_unaligned(ptr.p32s++);
546 else
547 value = get_unaligned(ptr.p32u++);
548 break;
549 case DW_EH_PE_data8:
550 BUILD_BUG_ON(sizeof(u64) != sizeof(value));
551#else
552 BUILD_BUG_ON(sizeof(u32) != sizeof(value));
553#endif
554 case DW_EH_PE_native:
555 if (end < (const void *)(ptr.pul + 1))
556 return 0;
557 value = get_unaligned((unsigned long *)ptr.pul++);
558 break;
559 case DW_EH_PE_leb128:
560 BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value));
561 value = ptrType & DW_EH_PE_signed ? get_sleb128(&ptr.p8, end)
562 : get_uleb128(&ptr.p8, end);
563 if ((const void *)ptr.p8 > end)
564 return 0;
565 break;
566 default:
567 return 0;
568 }
569 switch (ptrType & DW_EH_PE_ADJUST) {
570 case DW_EH_PE_abs:
571 break;
572 case DW_EH_PE_pcrel:
573 value += (unsigned long)*pLoc;
574 break;
575 default:
576 return 0;
577 }
578 if ((ptrType & DW_EH_PE_indirect)
579 && __get_user(value, (unsigned long __user *)value))
580 return 0;
581 *pLoc = ptr.p8;
582
583 return value;
584}
585
586static signed fde_pointer_type(const u32 *cie)
587{
588 const u8 *ptr = (const u8 *)(cie + 2);
589 unsigned version = *ptr;
590
591 if (version != 1)
592 return -1; /* unsupported */
593
594 if (*++ptr) {
595 const char *aug;
596 const u8 *end = (const u8 *)(cie + 1) + *cie;
597 uleb128_t len;
598
599 /* check if augmentation size is first (and thus present) */
600 if (*ptr != 'z')
601 return -1;
602
603 /* check if augmentation string is nul-terminated */
604 aug = (const void *)ptr;
605 ptr = memchr(aug, 0, end - ptr);
606 if (ptr == NULL)
607 return -1;
608
609 ++ptr; /* skip terminator */
610 get_uleb128(&ptr, end); /* skip code alignment */
611 get_sleb128(&ptr, end); /* skip data alignment */
612 /* skip return address column */
613 version <= 1 ? (void) ++ptr : (void)get_uleb128(&ptr, end);
614 len = get_uleb128(&ptr, end); /* augmentation length */
615
616 if (ptr + len < ptr || ptr + len > end)
617 return -1;
618
619 end = ptr + len;
620 while (*++aug) {
621 if (ptr >= end)
622 return -1;
623 switch (*aug) {
624 case 'L':
625 ++ptr;
626 break;
627 case 'P':{
628 signed ptrType = *ptr++;
629
630 if (!read_pointer(&ptr, end, ptrType)
631 || ptr > end)
632 return -1;
633 }
634 break;
635 case 'R':
636 return *ptr;
637 default:
638 return -1;
639 }
640 }
641 }
642 return DW_EH_PE_native | DW_EH_PE_abs;
643}
644
645static int advance_loc(unsigned long delta, struct unwind_state *state)
646{
647 state->loc += delta * state->codeAlign;
648
649 /* FIXME_Rajesh: Probably we are defining for the initial range as well;
650 return delta > 0;
651 */
652 unw_debug("delta %3lu => loc 0x%lx: ", delta, state->loc);
653 return 1;
654}
655
656static void set_rule(uleb128_t reg, enum item_location where, uleb128_t value,
657 struct unwind_state *state)
658{
659 if (reg < ARRAY_SIZE(state->regs)) {
660 state->regs[reg].where = where;
661 state->regs[reg].value = value;
662
663#ifdef UNWIND_DEBUG
664 unw_debug("r%lu: ", reg);
665 switch (where) {
666 case Nowhere:
667 unw_debug("s ");
668 break;
669 case Memory:
670 unw_debug("c(%lu) ", value);
671 break;
672 case Register:
673 unw_debug("r(%lu) ", value);
674 break;
675 case Value:
676 unw_debug("v(%lu) ", value);
677 break;
678 default:
679 break;
680 }
681#endif
682 }
683}
684
685static int processCFI(const u8 *start, const u8 *end, unsigned long targetLoc,
686 signed ptrType, struct unwind_state *state)
687{
688 union {
689 const u8 *p8;
690 const u16 *p16;
691 const u32 *p32;
692 } ptr;
693 int result = 1;
694 u8 opcode;
695
696 if (start != state->cieStart) {
697 state->loc = state->org;
698 result =
699 processCFI(state->cieStart, state->cieEnd, 0, ptrType,
700 state);
701 if (targetLoc == 0 && state->label == NULL)
702 return result;
703 }
704 for (ptr.p8 = start; result && ptr.p8 < end;) {
705 switch (*ptr.p8 >> 6) {
706 uleb128_t value;
707
708 case 0:
709 opcode = *ptr.p8++;
710
711 switch (opcode) {
712 case DW_CFA_nop:
713 unw_debug("cfa nop ");
714 break;
715 case DW_CFA_set_loc:
716 state->loc = read_pointer(&ptr.p8, end,
717 ptrType);
718 if (state->loc == 0)
719 result = 0;
720 unw_debug("cfa_set_loc: 0x%lx ", state->loc);
721 break;
722 case DW_CFA_advance_loc1:
723 unw_debug("\ncfa advance loc1:");
724 result = ptr.p8 < end
725 && advance_loc(*ptr.p8++, state);
726 break;
727 case DW_CFA_advance_loc2:
728 value = *ptr.p8++;
729 value += *ptr.p8++ << 8;
730 unw_debug("\ncfa advance loc2:");
731 result = ptr.p8 <= end + 2
732 /* && advance_loc(*ptr.p16++, state); */
733 && advance_loc(value, state);
734 break;
735 case DW_CFA_advance_loc4:
736 unw_debug("\ncfa advance loc4:");
737 result = ptr.p8 <= end + 4
738 && advance_loc(*ptr.p32++, state);
739 break;
740 case DW_CFA_offset_extended:
741 value = get_uleb128(&ptr.p8, end);
742 unw_debug("cfa_offset_extended: ");
743 set_rule(value, Memory,
744 get_uleb128(&ptr.p8, end), state);
745 break;
746 case DW_CFA_val_offset:
747 value = get_uleb128(&ptr.p8, end);
748 set_rule(value, Value,
749 get_uleb128(&ptr.p8, end), state);
750 break;
751 case DW_CFA_offset_extended_sf:
752 value = get_uleb128(&ptr.p8, end);
753 set_rule(value, Memory,
754 get_sleb128(&ptr.p8, end), state);
755 break;
756 case DW_CFA_val_offset_sf:
757 value = get_uleb128(&ptr.p8, end);
758 set_rule(value, Value,
759 get_sleb128(&ptr.p8, end), state);
760 break;
761 case DW_CFA_restore_extended:
762 unw_debug("cfa_restore_extended: ");
763 case DW_CFA_undefined:
764 unw_debug("cfa_undefined: ");
765 case DW_CFA_same_value:
766 unw_debug("cfa_same_value: ");
767 set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0,
768 state);
769 break;
770 case DW_CFA_register:
771 unw_debug("cfa_register: ");
772 value = get_uleb128(&ptr.p8, end);
773 set_rule(value,
774 Register,
775 get_uleb128(&ptr.p8, end), state);
776 break;
777 case DW_CFA_remember_state:
778 unw_debug("cfa_remember_state: ");
779 if (ptr.p8 == state->label) {
780 state->label = NULL;
781 return 1;
782 }
783 if (state->stackDepth >= MAX_STACK_DEPTH)
784 return 0;
785 state->stack[state->stackDepth++] = ptr.p8;
786 break;
787 case DW_CFA_restore_state:
788 unw_debug("cfa_restore_state: ");
789 if (state->stackDepth) {
790 const uleb128_t loc = state->loc;
791 const u8 *label = state->label;
792
793 state->label =
794 state->stack[state->stackDepth - 1];
795 memcpy(&state->cfa, &badCFA,
796 sizeof(state->cfa));
797 memset(state->regs, 0,
798 sizeof(state->regs));
799 state->stackDepth = 0;
800 result =
801 processCFI(start, end, 0, ptrType,
802 state);
803 state->loc = loc;
804 state->label = label;
805 } else
806 return 0;
807 break;
808 case DW_CFA_def_cfa:
809 state->cfa.reg = get_uleb128(&ptr.p8, end);
810 unw_debug("cfa_def_cfa: r%lu ", state->cfa.reg);
811 /*nobreak*/
812 case DW_CFA_def_cfa_offset:
813 state->cfa.offs = get_uleb128(&ptr.p8, end);
814 unw_debug("cfa_def_cfa_offset: 0x%lx ",
815 state->cfa.offs);
816 break;
817 case DW_CFA_def_cfa_sf:
818 state->cfa.reg = get_uleb128(&ptr.p8, end);
819 /*nobreak */
820 case DW_CFA_def_cfa_offset_sf:
821 state->cfa.offs = get_sleb128(&ptr.p8, end)
822 * state->dataAlign;
823 break;
824 case DW_CFA_def_cfa_register:
825 unw_debug("cfa_def_cfa_regsiter: ");
826 state->cfa.reg = get_uleb128(&ptr.p8, end);
827 break;
828 /*todo case DW_CFA_def_cfa_expression: */
829 /*todo case DW_CFA_expression: */
830 /*todo case DW_CFA_val_expression: */
831 case DW_CFA_GNU_args_size:
832 get_uleb128(&ptr.p8, end);
833 break;
834 case DW_CFA_GNU_negative_offset_extended:
835 value = get_uleb128(&ptr.p8, end);
836 set_rule(value,
837 Memory,
838 (uleb128_t) 0 - get_uleb128(&ptr.p8,
839 end),
840 state);
841 break;
842 case DW_CFA_GNU_window_save:
843 default:
844 unw_debug("UNKNOW OPCODE 0x%x\n", opcode);
845 result = 0;
846 break;
847 }
848 break;
849 case 1:
850 unw_debug("\ncfa_adv_loc: ");
851 result = advance_loc(*ptr.p8++ & 0x3f, state);
852 break;
853 case 2:
854 unw_debug("cfa_offset: ");
855 value = *ptr.p8++ & 0x3f;
856 set_rule(value, Memory, get_uleb128(&ptr.p8, end),
857 state);
858 break;
859 case 3:
860 unw_debug("cfa_restore: ");
861 set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state);
862 break;
863 }
864
865 if (ptr.p8 > end)
866 result = 0;
867 if (result && targetLoc != 0 && targetLoc < state->loc)
868 return 1;
869 }
870
871 return result && ptr.p8 == end && (targetLoc == 0 || (
872 /*todo While in theory this should apply, gcc in practice omits
873 everything past the function prolog, and hence the location
874 never reaches the end of the function.
875 targetLoc < state->loc && */ state->label == NULL));
876}
877
878/* Unwind to previous to frame. Returns 0 if successful, negative
879 * number in case of an error. */
880int arc_unwind(struct unwind_frame_info *frame)
881{
882#define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs])
883 const u32 *fde = NULL, *cie = NULL;
884 const u8 *ptr = NULL, *end = NULL;
885 unsigned long pc = UNW_PC(frame) - frame->call_frame;
886 unsigned long startLoc = 0, endLoc = 0, cfa;
887 unsigned i;
888 signed ptrType = -1;
889 uleb128_t retAddrReg = 0;
890 const struct unwind_table *table;
891 struct unwind_state state;
892 unsigned long *fptr;
893 unsigned long addr;
894
895 unw_debug("\n\nUNWIND FRAME:\n");
896 unw_debug("PC: 0x%lx BLINK: 0x%lx, SP: 0x%lx, FP: 0x%x\n",
897 UNW_PC(frame), UNW_BLINK(frame), UNW_SP(frame),
898 UNW_FP(frame));
899
900 if (UNW_PC(frame) == 0)
901 return -EINVAL;
902
903#ifdef UNWIND_DEBUG
904 {
905 unsigned long *sptr = (unsigned long *)UNW_SP(frame);
906 unw_debug("\nStack Dump:\n");
907 for (i = 0; i < 20; i++, sptr++)
908 unw_debug("0x%p: 0x%lx\n", sptr, *sptr);
909 unw_debug("\n");
910 }
911#endif
912
913 table = find_table(pc);
914 if (table != NULL
915 && !(table->size & (sizeof(*fde) - 1))) {
916 const u8 *hdr = table->header;
917 unsigned long tableSize;
918
919 smp_rmb();
920 if (hdr && hdr[0] == 1) {
921 switch (hdr[3] & DW_EH_PE_FORM) {
922 case DW_EH_PE_native:
923 tableSize = sizeof(unsigned long);
924 break;
925 case DW_EH_PE_data2:
926 tableSize = 2;
927 break;
928 case DW_EH_PE_data4:
929 tableSize = 4;
930 break;
931 case DW_EH_PE_data8:
932 tableSize = 8;
933 break;
934 default:
935 tableSize = 0;
936 break;
937 }
938 ptr = hdr + 4;
939 end = hdr + table->hdrsz;
940 if (tableSize && read_pointer(&ptr, end, hdr[1])
941 == (unsigned long)table->address
942 && (i = read_pointer(&ptr, end, hdr[2])) > 0
943 && i == (end - ptr) / (2 * tableSize)
944 && !((end - ptr) % (2 * tableSize))) {
945 do {
946 const u8 *cur =
947 ptr + (i / 2) * (2 * tableSize);
948
949 startLoc = read_pointer(&cur,
950 cur + tableSize,
951 hdr[3]);
952 if (pc < startLoc)
953 i /= 2;
954 else {
955 ptr = cur - tableSize;
956 i = (i + 1) / 2;
957 }
958 } while (startLoc && i > 1);
959 if (i == 1
960 && (startLoc = read_pointer(&ptr,
961 ptr + tableSize,
962 hdr[3])) != 0
963 && pc >= startLoc)
964 fde = (void *)read_pointer(&ptr,
965 ptr +
966 tableSize,
967 hdr[3]);
968 }
969 }
970
971 if (fde != NULL) {
972 cie = cie_for_fde(fde, table);
973 ptr = (const u8 *)(fde + 2);
974 if (cie != NULL
975 && cie != &bad_cie
976 && cie != ¬_fde
977 && (ptrType = fde_pointer_type(cie)) >= 0
978 && read_pointer(&ptr,
979 (const u8 *)(fde + 1) + *fde,
980 ptrType) == startLoc) {
981 if (!(ptrType & DW_EH_PE_indirect))
982 ptrType &=
983 DW_EH_PE_FORM | DW_EH_PE_signed;
984 endLoc =
985 startLoc + read_pointer(&ptr,
986 (const u8 *)(fde +
987 1) +
988 *fde, ptrType);
989 if (pc >= endLoc)
990 fde = NULL;
991 } else
992 fde = NULL;
993 }
994 if (fde == NULL) {
995 for (fde = table->address, tableSize = table->size;
996 cie = NULL, tableSize > sizeof(*fde)
997 && tableSize - sizeof(*fde) >= *fde;
998 tableSize -= sizeof(*fde) + *fde,
999 fde += 1 + *fde / sizeof(*fde)) {
1000 cie = cie_for_fde(fde, table);
1001 if (cie == &bad_cie) {
1002 cie = NULL;
1003 break;
1004 }
1005 if (cie == NULL
1006 || cie == ¬_fde
1007 || (ptrType = fde_pointer_type(cie)) < 0)
1008 continue;
1009 ptr = (const u8 *)(fde + 2);
1010 startLoc = read_pointer(&ptr,
1011 (const u8 *)(fde + 1) +
1012 *fde, ptrType);
1013 if (!startLoc)
1014 continue;
1015 if (!(ptrType & DW_EH_PE_indirect))
1016 ptrType &=
1017 DW_EH_PE_FORM | DW_EH_PE_signed;
1018 endLoc =
1019 startLoc + read_pointer(&ptr,
1020 (const u8 *)(fde +
1021 1) +
1022 *fde, ptrType);
1023 if (pc >= startLoc && pc < endLoc)
1024 break;
1025 }
1026 }
1027 }
1028 if (cie != NULL) {
1029 memset(&state, 0, sizeof(state));
1030 state.cieEnd = ptr; /* keep here temporarily */
1031 ptr = (const u8 *)(cie + 2);
1032 end = (const u8 *)(cie + 1) + *cie;
1033 frame->call_frame = 1;
1034 if ((state.version = *ptr) != 1)
1035 cie = NULL; /* unsupported version */
1036 else if (*++ptr) {
1037 /* check if augmentation size is first (thus present) */
1038 if (*ptr == 'z') {
1039 while (++ptr < end && *ptr) {
1040 switch (*ptr) {
1041 /* chk for ignorable or already handled
1042 * nul-terminated augmentation string */
1043 case 'L':
1044 case 'P':
1045 case 'R':
1046 continue;
1047 case 'S':
1048 frame->call_frame = 0;
1049 continue;
1050 default:
1051 break;
1052 }
1053 break;
1054 }
1055 }
1056 if (ptr >= end || *ptr)
1057 cie = NULL;
1058 }
1059 ++ptr;
1060 }
1061 if (cie != NULL) {
1062 /* get code aligment factor */
1063 state.codeAlign = get_uleb128(&ptr, end);
1064 /* get data aligment factor */
1065 state.dataAlign = get_sleb128(&ptr, end);
1066 if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end)
1067 cie = NULL;
1068 else {
1069 retAddrReg =
1070 state.version <= 1 ? *ptr++ : get_uleb128(&ptr,
1071 end);
1072 unw_debug("CIE Frame Info:\n");
1073 unw_debug("return Address register 0x%lx\n",
1074 retAddrReg);
1075 unw_debug("data Align: %ld\n", state.dataAlign);
1076 unw_debug("code Align: %lu\n", state.codeAlign);
1077 /* skip augmentation */
1078 if (((const char *)(cie + 2))[1] == 'z') {
1079 uleb128_t augSize = get_uleb128(&ptr, end);
1080
1081 ptr += augSize;
1082 }
1083 if (ptr > end || retAddrReg >= ARRAY_SIZE(reg_info)
1084 || REG_INVALID(retAddrReg)
1085 || reg_info[retAddrReg].width !=
1086 sizeof(unsigned long))
1087 cie = NULL;
1088 }
1089 }
1090 if (cie != NULL) {
1091 state.cieStart = ptr;
1092 ptr = state.cieEnd;
1093 state.cieEnd = end;
1094 end = (const u8 *)(fde + 1) + *fde;
1095 /* skip augmentation */
1096 if (((const char *)(cie + 2))[1] == 'z') {
1097 uleb128_t augSize = get_uleb128(&ptr, end);
1098
1099 if ((ptr += augSize) > end)
1100 fde = NULL;
1101 }
1102 }
1103 if (cie == NULL || fde == NULL) {
1104#ifdef CONFIG_FRAME_POINTER
1105 unsigned long top, bottom;
1106
1107 top = STACK_TOP_UNW(frame->task);
1108 bottom = STACK_BOTTOM_UNW(frame->task);
1109#if FRAME_RETADDR_OFFSET < 0
1110 if (UNW_SP(frame) < top && UNW_FP(frame) <= UNW_SP(frame)
1111 && bottom < UNW_FP(frame)
1112#else
1113 if (UNW_SP(frame) > top && UNW_FP(frame) >= UNW_SP(frame)
1114 && bottom > UNW_FP(frame)
1115#endif
1116 && !((UNW_SP(frame) | UNW_FP(frame))
1117 & (sizeof(unsigned long) - 1))) {
1118 unsigned long link;
1119
1120 if (!__get_user(link, (unsigned long *)
1121 (UNW_FP(frame) + FRAME_LINK_OFFSET))
1122#if FRAME_RETADDR_OFFSET < 0
1123 && link > bottom && link < UNW_FP(frame)
1124#else
1125 && link > UNW_FP(frame) && link < bottom
1126#endif
1127 && !(link & (sizeof(link) - 1))
1128 && !__get_user(UNW_PC(frame),
1129 (unsigned long *)(UNW_FP(frame)
1130 + FRAME_RETADDR_OFFSET)))
1131 {
1132 UNW_SP(frame) =
1133 UNW_FP(frame) + FRAME_RETADDR_OFFSET
1134#if FRAME_RETADDR_OFFSET < 0
1135 -
1136#else
1137 +
1138#endif
1139 sizeof(UNW_PC(frame));
1140 UNW_FP(frame) = link;
1141 return 0;
1142 }
1143 }
1144#endif
1145 return -ENXIO;
1146 }
1147 state.org = startLoc;
1148 memcpy(&state.cfa, &badCFA, sizeof(state.cfa));
1149
1150 unw_debug("\nProcess instructions\n");
1151
1152 /* process instructions
1153 * For ARC, we optimize by having blink(retAddrReg) with
1154 * the sameValue in the leaf function, so we should not check
1155 * state.regs[retAddrReg].where == Nowhere
1156 */
1157 if (!processCFI(ptr, end, pc, ptrType, &state)
1158 || state.loc > endLoc
1159/* || state.regs[retAddrReg].where == Nowhere */
1160 || state.cfa.reg >= ARRAY_SIZE(reg_info)
1161 || reg_info[state.cfa.reg].width != sizeof(unsigned long)
1162 || state.cfa.offs % sizeof(unsigned long))
1163 return -EIO;
1164
1165#ifdef UNWIND_DEBUG
1166 unw_debug("\n");
1167
1168 unw_debug("\nRegister State Based on the rules parsed from FDE:\n");
1169 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1170
1171 if (REG_INVALID(i))
1172 continue;
1173
1174 switch (state.regs[i].where) {
1175 case Nowhere:
1176 break;
1177 case Memory:
1178 unw_debug(" r%d: c(%lu),", i, state.regs[i].value);
1179 break;
1180 case Register:
1181 unw_debug(" r%d: r(%lu),", i, state.regs[i].value);
1182 break;
1183 case Value:
1184 unw_debug(" r%d: v(%lu),", i, state.regs[i].value);
1185 break;
1186 }
1187 }
1188
1189 unw_debug("\n");
1190#endif
1191
1192 /* update frame */
1193#ifndef CONFIG_AS_CFI_SIGNAL_FRAME
1194 if (frame->call_frame
1195 && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign))
1196 frame->call_frame = 0;
1197#endif
1198 cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs;
1199 startLoc = min_t(unsigned long, UNW_SP(frame), cfa);
1200 endLoc = max_t(unsigned long, UNW_SP(frame), cfa);
1201 if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) {
1202 startLoc = min(STACK_LIMIT(cfa), cfa);
1203 endLoc = max(STACK_LIMIT(cfa), cfa);
1204 }
1205
1206 unw_debug("\nCFA reg: 0x%lx, offset: 0x%lx => 0x%lx\n",
1207 state.cfa.reg, state.cfa.offs, cfa);
1208
1209 for (i = 0; i < ARRAY_SIZE(state.regs); ++i) {
1210 if (REG_INVALID(i)) {
1211 if (state.regs[i].where == Nowhere)
1212 continue;
1213 return -EIO;
1214 }
1215 switch (state.regs[i].where) {
1216 default:
1217 break;
1218 case Register:
1219 if (state.regs[i].value >= ARRAY_SIZE(reg_info)
1220 || REG_INVALID(state.regs[i].value)
1221 || reg_info[i].width >
1222 reg_info[state.regs[i].value].width)
1223 return -EIO;
1224 switch (reg_info[state.regs[i].value].width) {
1225 case sizeof(u8):
1226 state.regs[i].value =
1227 FRAME_REG(state.regs[i].value, const u8);
1228 break;
1229 case sizeof(u16):
1230 state.regs[i].value =
1231 FRAME_REG(state.regs[i].value, const u16);
1232 break;
1233 case sizeof(u32):
1234 state.regs[i].value =
1235 FRAME_REG(state.regs[i].value, const u32);
1236 break;
1237#ifdef CONFIG_64BIT
1238 case sizeof(u64):
1239 state.regs[i].value =
1240 FRAME_REG(state.regs[i].value, const u64);
1241 break;
1242#endif
1243 default:
1244 return -EIO;
1245 }
1246 break;
1247 }
1248 }
1249
1250 unw_debug("\nRegister state after evaluation with realtime Stack:\n");
1251 fptr = (unsigned long *)(&frame->regs);
1252 for (i = 0; i < ARRAY_SIZE(state.regs); ++i, fptr++) {
1253
1254 if (REG_INVALID(i))
1255 continue;
1256 switch (state.regs[i].where) {
1257 case Nowhere:
1258 if (reg_info[i].width != sizeof(UNW_SP(frame))
1259 || &FRAME_REG(i, __typeof__(UNW_SP(frame)))
1260 != &UNW_SP(frame))
1261 continue;
1262 UNW_SP(frame) = cfa;
1263 break;
1264 case Register:
1265 switch (reg_info[i].width) {
1266 case sizeof(u8):
1267 FRAME_REG(i, u8) = state.regs[i].value;
1268 break;
1269 case sizeof(u16):
1270 FRAME_REG(i, u16) = state.regs[i].value;
1271 break;
1272 case sizeof(u32):
1273 FRAME_REG(i, u32) = state.regs[i].value;
1274 break;
1275#ifdef CONFIG_64BIT
1276 case sizeof(u64):
1277 FRAME_REG(i, u64) = state.regs[i].value;
1278 break;
1279#endif
1280 default:
1281 return -EIO;
1282 }
1283 break;
1284 case Value:
1285 if (reg_info[i].width != sizeof(unsigned long))
1286 return -EIO;
1287 FRAME_REG(i, unsigned long) = cfa + state.regs[i].value
1288 * state.dataAlign;
1289 break;
1290 case Memory:
1291 addr = cfa + state.regs[i].value * state.dataAlign;
1292
1293 if ((state.regs[i].value * state.dataAlign)
1294 % sizeof(unsigned long)
1295 || addr < startLoc
1296 || addr + sizeof(unsigned long) < addr
1297 || addr + sizeof(unsigned long) > endLoc)
1298 return -EIO;
1299
1300 switch (reg_info[i].width) {
1301 case sizeof(u8):
1302 __get_user(FRAME_REG(i, u8),
1303 (u8 __user *)addr);
1304 break;
1305 case sizeof(u16):
1306 __get_user(FRAME_REG(i, u16),
1307 (u16 __user *)addr);
1308 break;
1309 case sizeof(u32):
1310 __get_user(FRAME_REG(i, u32),
1311 (u32 __user *)addr);
1312 break;
1313#ifdef CONFIG_64BIT
1314 case sizeof(u64):
1315 __get_user(FRAME_REG(i, u64),
1316 (u64 __user *)addr);
1317 break;
1318#endif
1319 default:
1320 return -EIO;
1321 }
1322
1323 break;
1324 }
1325 unw_debug("r%d: 0x%lx ", i, *fptr);
1326 }
1327
1328 return 0;
1329#undef FRAME_REG
1330}
1331EXPORT_SYMBOL(arc_unwind);