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