]>
Commit | Line | Data |
---|---|---|
4552d5dc JB |
1 | /* |
2 | * Copyright (C) 2002-2006 Novell, Inc. | |
3 | * Jan Beulich <jbeulich@novell.com> | |
4 | * This code is released under version 2 of the GNU GPL. | |
5 | * | |
6 | * A simple API for unwinding kernel stacks. This is used for | |
7 | * debugging and error reporting purposes. The kernel doesn't need | |
8 | * full-blown stack unwinding with all the bells and whistles, so there | |
9 | * is not much point in implementing the full Dwarf2 unwind API. | |
10 | */ | |
11 | ||
12 | #include <linux/unwind.h> | |
13 | #include <linux/module.h> | |
690a973f JB |
14 | #include <linux/bootmem.h> |
15 | #include <linux/sort.h> | |
4552d5dc JB |
16 | #include <linux/stop_machine.h> |
17 | #include <asm/sections.h> | |
18 | #include <asm/uaccess.h> | |
19 | #include <asm/unaligned.h> | |
20 | ||
21 | extern char __start_unwind[], __end_unwind[]; | |
690a973f | 22 | extern const u8 __start_unwind_hdr[], __end_unwind_hdr[]; |
4552d5dc JB |
23 | |
24 | #define MAX_STACK_DEPTH 8 | |
25 | ||
26 | #define EXTRA_INFO(f) { \ | |
27 | BUILD_BUG_ON_ZERO(offsetof(struct unwind_frame_info, f) \ | |
28 | % FIELD_SIZEOF(struct unwind_frame_info, f)) \ | |
29 | + offsetof(struct unwind_frame_info, f) \ | |
30 | / FIELD_SIZEOF(struct unwind_frame_info, f), \ | |
31 | FIELD_SIZEOF(struct unwind_frame_info, f) \ | |
32 | } | |
33 | #define PTREGS_INFO(f) EXTRA_INFO(regs.f) | |
34 | ||
35 | static const struct { | |
36 | unsigned offs:BITS_PER_LONG / 2; | |
37 | unsigned width:BITS_PER_LONG / 2; | |
38 | } reg_info[] = { | |
39 | UNW_REGISTER_INFO | |
40 | }; | |
41 | ||
42 | #undef PTREGS_INFO | |
43 | #undef EXTRA_INFO | |
44 | ||
45 | #ifndef REG_INVALID | |
46 | #define REG_INVALID(r) (reg_info[r].width == 0) | |
47 | #endif | |
48 | ||
49 | #define DW_CFA_nop 0x00 | |
50 | #define DW_CFA_set_loc 0x01 | |
51 | #define DW_CFA_advance_loc1 0x02 | |
52 | #define DW_CFA_advance_loc2 0x03 | |
53 | #define DW_CFA_advance_loc4 0x04 | |
54 | #define DW_CFA_offset_extended 0x05 | |
55 | #define DW_CFA_restore_extended 0x06 | |
56 | #define DW_CFA_undefined 0x07 | |
57 | #define DW_CFA_same_value 0x08 | |
58 | #define DW_CFA_register 0x09 | |
59 | #define DW_CFA_remember_state 0x0a | |
60 | #define DW_CFA_restore_state 0x0b | |
61 | #define DW_CFA_def_cfa 0x0c | |
62 | #define DW_CFA_def_cfa_register 0x0d | |
63 | #define DW_CFA_def_cfa_offset 0x0e | |
64 | #define DW_CFA_def_cfa_expression 0x0f | |
65 | #define DW_CFA_expression 0x10 | |
66 | #define DW_CFA_offset_extended_sf 0x11 | |
67 | #define DW_CFA_def_cfa_sf 0x12 | |
68 | #define DW_CFA_def_cfa_offset_sf 0x13 | |
69 | #define DW_CFA_val_offset 0x14 | |
70 | #define DW_CFA_val_offset_sf 0x15 | |
71 | #define DW_CFA_val_expression 0x16 | |
72 | #define DW_CFA_lo_user 0x1c | |
73 | #define DW_CFA_GNU_window_save 0x2d | |
74 | #define DW_CFA_GNU_args_size 0x2e | |
75 | #define DW_CFA_GNU_negative_offset_extended 0x2f | |
76 | #define DW_CFA_hi_user 0x3f | |
77 | ||
78 | #define DW_EH_PE_FORM 0x07 | |
79 | #define DW_EH_PE_native 0x00 | |
80 | #define DW_EH_PE_leb128 0x01 | |
81 | #define DW_EH_PE_data2 0x02 | |
82 | #define DW_EH_PE_data4 0x03 | |
83 | #define DW_EH_PE_data8 0x04 | |
84 | #define DW_EH_PE_signed 0x08 | |
85 | #define DW_EH_PE_ADJUST 0x70 | |
86 | #define DW_EH_PE_abs 0x00 | |
87 | #define DW_EH_PE_pcrel 0x10 | |
88 | #define DW_EH_PE_textrel 0x20 | |
89 | #define DW_EH_PE_datarel 0x30 | |
90 | #define DW_EH_PE_funcrel 0x40 | |
91 | #define DW_EH_PE_aligned 0x50 | |
92 | #define DW_EH_PE_indirect 0x80 | |
93 | #define DW_EH_PE_omit 0xff | |
94 | ||
95 | typedef unsigned long uleb128_t; | |
96 | typedef signed long sleb128_t; | |
97 | ||
98 | static struct unwind_table { | |
99 | struct { | |
100 | unsigned long pc; | |
101 | unsigned long range; | |
102 | } core, init; | |
103 | const void *address; | |
104 | unsigned long size; | |
690a973f JB |
105 | const unsigned char *header; |
106 | unsigned long hdrsz; | |
4552d5dc JB |
107 | struct unwind_table *link; |
108 | const char *name; | |
e6cab99b | 109 | } root_table; |
4552d5dc JB |
110 | |
111 | struct unwind_item { | |
112 | enum item_location { | |
113 | Nowhere, | |
114 | Memory, | |
115 | Register, | |
116 | Value | |
117 | } where; | |
118 | uleb128_t value; | |
119 | }; | |
120 | ||
121 | struct unwind_state { | |
122 | uleb128_t loc, org; | |
123 | const u8 *cieStart, *cieEnd; | |
124 | uleb128_t codeAlign; | |
125 | sleb128_t dataAlign; | |
126 | struct cfa { | |
127 | uleb128_t reg, offs; | |
128 | } cfa; | |
129 | struct unwind_item regs[ARRAY_SIZE(reg_info)]; | |
130 | unsigned stackDepth:8; | |
131 | unsigned version:8; | |
132 | const u8 *label; | |
133 | const u8 *stack[MAX_STACK_DEPTH]; | |
134 | }; | |
135 | ||
136 | static const struct cfa badCFA = { ARRAY_SIZE(reg_info), 1 }; | |
137 | ||
138 | static struct unwind_table *find_table(unsigned long pc) | |
139 | { | |
140 | struct unwind_table *table; | |
141 | ||
142 | for (table = &root_table; table; table = table->link) | |
143 | if ((pc >= table->core.pc | |
144 | && pc < table->core.pc + table->core.range) | |
145 | || (pc >= table->init.pc | |
146 | && pc < table->init.pc + table->init.range)) | |
147 | break; | |
148 | ||
149 | return table; | |
150 | } | |
151 | ||
690a973f JB |
152 | static unsigned long read_pointer(const u8 **pLoc, |
153 | const void *end, | |
154 | signed ptrType); | |
155 | ||
4552d5dc JB |
156 | static void init_unwind_table(struct unwind_table *table, |
157 | const char *name, | |
158 | const void *core_start, | |
159 | unsigned long core_size, | |
160 | const void *init_start, | |
161 | unsigned long init_size, | |
162 | const void *table_start, | |
690a973f JB |
163 | unsigned long table_size, |
164 | const u8 *header_start, | |
165 | unsigned long header_size) | |
4552d5dc | 166 | { |
690a973f JB |
167 | const u8 *ptr = header_start + 4; |
168 | const u8 *end = header_start + header_size; | |
169 | ||
4552d5dc JB |
170 | table->core.pc = (unsigned long)core_start; |
171 | table->core.range = core_size; | |
172 | table->init.pc = (unsigned long)init_start; | |
173 | table->init.range = init_size; | |
174 | table->address = table_start; | |
175 | table->size = table_size; | |
690a973f JB |
176 | /* See if the linker provided table looks valid. */ |
177 | if (header_size <= 4 | |
178 | || header_start[0] != 1 | |
179 | || (void *)read_pointer(&ptr, end, header_start[1]) != table_start | |
180 | || header_start[2] == DW_EH_PE_omit | |
181 | || read_pointer(&ptr, end, header_start[2]) <= 0 | |
182 | || header_start[3] == DW_EH_PE_omit) | |
183 | header_start = NULL; | |
184 | table->hdrsz = header_size; | |
185 | smp_wmb(); | |
186 | table->header = header_start; | |
4552d5dc JB |
187 | table->link = NULL; |
188 | table->name = name; | |
189 | } | |
190 | ||
191 | void __init unwind_init(void) | |
192 | { | |
193 | init_unwind_table(&root_table, "kernel", | |
194 | _text, _end - _text, | |
195 | NULL, 0, | |
690a973f JB |
196 | __start_unwind, __end_unwind - __start_unwind, |
197 | __start_unwind_hdr, __end_unwind_hdr - __start_unwind_hdr); | |
198 | } | |
199 | ||
200 | static const u32 bad_cie, not_fde; | |
201 | static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *); | |
202 | static signed fde_pointer_type(const u32 *cie); | |
203 | ||
204 | struct eh_frame_hdr_table_entry { | |
205 | unsigned long start, fde; | |
206 | }; | |
207 | ||
208 | static int cmp_eh_frame_hdr_table_entries(const void *p1, const void *p2) | |
209 | { | |
210 | const struct eh_frame_hdr_table_entry *e1 = p1; | |
211 | const struct eh_frame_hdr_table_entry *e2 = p2; | |
212 | ||
213 | return (e1->start > e2->start) - (e1->start < e2->start); | |
214 | } | |
215 | ||
216 | static void swap_eh_frame_hdr_table_entries(void *p1, void *p2, int size) | |
217 | { | |
218 | struct eh_frame_hdr_table_entry *e1 = p1; | |
219 | struct eh_frame_hdr_table_entry *e2 = p2; | |
220 | unsigned long v; | |
221 | ||
222 | v = e1->start; | |
223 | e1->start = e2->start; | |
224 | e2->start = v; | |
225 | v = e1->fde; | |
226 | e1->fde = e2->fde; | |
227 | e2->fde = v; | |
228 | } | |
229 | ||
230 | static void __init setup_unwind_table(struct unwind_table *table, | |
231 | void *(*alloc)(unsigned long)) | |
232 | { | |
233 | const u8 *ptr; | |
234 | unsigned long tableSize = table->size, hdrSize; | |
235 | unsigned n; | |
236 | const u32 *fde; | |
237 | struct { | |
238 | u8 version; | |
239 | u8 eh_frame_ptr_enc; | |
240 | u8 fde_count_enc; | |
241 | u8 table_enc; | |
242 | unsigned long eh_frame_ptr; | |
243 | unsigned int fde_count; | |
244 | struct eh_frame_hdr_table_entry table[]; | |
245 | } __attribute__((__packed__)) *header; | |
246 | ||
247 | if (table->header) | |
248 | return; | |
249 | ||
250 | if (table->hdrsz) | |
251 | printk(KERN_WARNING ".eh_frame_hdr for '%s' present but unusable\n", | |
252 | table->name); | |
253 | ||
254 | if (tableSize & (sizeof(*fde) - 1)) | |
255 | return; | |
256 | ||
257 | for (fde = table->address, n = 0; | |
258 | tableSize > sizeof(*fde) && tableSize - sizeof(*fde) >= *fde; | |
259 | tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { | |
260 | const u32 *cie = cie_for_fde(fde, table); | |
261 | signed ptrType; | |
262 | ||
263 | if (cie == ¬_fde) | |
264 | continue; | |
265 | if (cie == NULL | |
266 | || cie == &bad_cie | |
267 | || (ptrType = fde_pointer_type(cie)) < 0) | |
268 | return; | |
269 | ptr = (const u8 *)(fde + 2); | |
270 | if (!read_pointer(&ptr, | |
271 | (const u8 *)(fde + 1) + *fde, | |
272 | ptrType)) | |
273 | return; | |
274 | ++n; | |
275 | } | |
276 | ||
277 | if (tableSize || !n) | |
278 | return; | |
279 | ||
280 | hdrSize = 4 + sizeof(unsigned long) + sizeof(unsigned int) | |
281 | + 2 * n * sizeof(unsigned long); | |
282 | header = alloc(hdrSize); | |
283 | if (!header) | |
284 | return; | |
285 | header->version = 1; | |
286 | header->eh_frame_ptr_enc = DW_EH_PE_abs|DW_EH_PE_native; | |
287 | header->fde_count_enc = DW_EH_PE_abs|DW_EH_PE_data4; | |
288 | header->table_enc = DW_EH_PE_abs|DW_EH_PE_native; | |
289 | put_unaligned((unsigned long)table->address, &header->eh_frame_ptr); | |
290 | BUILD_BUG_ON(offsetof(typeof(*header), fde_count) | |
291 | % __alignof(typeof(header->fde_count))); | |
292 | header->fde_count = n; | |
293 | ||
294 | BUILD_BUG_ON(offsetof(typeof(*header), table) | |
295 | % __alignof(typeof(*header->table))); | |
296 | for (fde = table->address, tableSize = table->size, n = 0; | |
297 | tableSize; | |
298 | tableSize -= sizeof(*fde) + *fde, fde += 1 + *fde / sizeof(*fde)) { | |
299 | const u32 *cie = fde + 1 - fde[1] / sizeof(*fde); | |
300 | ||
301 | if (!fde[1]) | |
302 | continue; /* this is a CIE */ | |
303 | ptr = (const u8 *)(fde + 2); | |
304 | header->table[n].start = read_pointer(&ptr, | |
305 | (const u8 *)(fde + 1) + *fde, | |
306 | fde_pointer_type(cie)); | |
307 | header->table[n].fde = (unsigned long)fde; | |
308 | ++n; | |
309 | } | |
310 | WARN_ON(n != header->fde_count); | |
311 | ||
312 | sort(header->table, | |
313 | n, | |
314 | sizeof(*header->table), | |
315 | cmp_eh_frame_hdr_table_entries, | |
316 | swap_eh_frame_hdr_table_entries); | |
317 | ||
318 | table->hdrsz = hdrSize; | |
319 | smp_wmb(); | |
320 | table->header = (const void *)header; | |
321 | } | |
322 | ||
323 | static void *__init balloc(unsigned long sz) | |
324 | { | |
325 | return __alloc_bootmem_nopanic(sz, | |
326 | sizeof(unsigned int), | |
327 | __pa(MAX_DMA_ADDRESS)); | |
328 | } | |
329 | ||
330 | void __init unwind_setup(void) | |
331 | { | |
332 | setup_unwind_table(&root_table, balloc); | |
4552d5dc JB |
333 | } |
334 | ||
83f4fcce JB |
335 | #ifdef CONFIG_MODULES |
336 | ||
e6cab99b CE |
337 | static struct unwind_table *last_table; |
338 | ||
4552d5dc JB |
339 | /* Must be called with module_mutex held. */ |
340 | void *unwind_add_table(struct module *module, | |
341 | const void *table_start, | |
342 | unsigned long table_size) | |
343 | { | |
344 | struct unwind_table *table; | |
345 | ||
346 | if (table_size <= 0) | |
347 | return NULL; | |
348 | ||
349 | table = kmalloc(sizeof(*table), GFP_KERNEL); | |
350 | if (!table) | |
351 | return NULL; | |
352 | ||
353 | init_unwind_table(table, module->name, | |
354 | module->module_core, module->core_size, | |
355 | module->module_init, module->init_size, | |
690a973f JB |
356 | table_start, table_size, |
357 | NULL, 0); | |
4552d5dc JB |
358 | |
359 | if (last_table) | |
360 | last_table->link = table; | |
361 | else | |
362 | root_table.link = table; | |
363 | last_table = table; | |
364 | ||
365 | return table; | |
366 | } | |
367 | ||
368 | struct unlink_table_info | |
369 | { | |
370 | struct unwind_table *table; | |
371 | int init_only; | |
372 | }; | |
373 | ||
374 | static int unlink_table(void *arg) | |
375 | { | |
376 | struct unlink_table_info *info = arg; | |
377 | struct unwind_table *table = info->table, *prev; | |
378 | ||
379 | for (prev = &root_table; prev->link && prev->link != table; prev = prev->link) | |
380 | ; | |
381 | ||
382 | if (prev->link) { | |
383 | if (info->init_only) { | |
384 | table->init.pc = 0; | |
385 | table->init.range = 0; | |
386 | info->table = NULL; | |
387 | } else { | |
388 | prev->link = table->link; | |
389 | if (!prev->link) | |
390 | last_table = prev; | |
391 | } | |
392 | } else | |
393 | info->table = NULL; | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | /* Must be called with module_mutex held. */ | |
399 | void unwind_remove_table(void *handle, int init_only) | |
400 | { | |
401 | struct unwind_table *table = handle; | |
402 | struct unlink_table_info info; | |
403 | ||
404 | if (!table || table == &root_table) | |
405 | return; | |
406 | ||
407 | if (init_only && table == last_table) { | |
408 | table->init.pc = 0; | |
409 | table->init.range = 0; | |
410 | return; | |
411 | } | |
412 | ||
413 | info.table = table; | |
414 | info.init_only = init_only; | |
415 | stop_machine_run(unlink_table, &info, NR_CPUS); | |
416 | ||
417 | if (info.table) | |
418 | kfree(table); | |
419 | } | |
420 | ||
83f4fcce JB |
421 | #endif /* CONFIG_MODULES */ |
422 | ||
4552d5dc JB |
423 | static uleb128_t get_uleb128(const u8 **pcur, const u8 *end) |
424 | { | |
425 | const u8 *cur = *pcur; | |
426 | uleb128_t value; | |
427 | unsigned shift; | |
428 | ||
429 | for (shift = 0, value = 0; cur < end; shift += 7) { | |
430 | if (shift + 7 > 8 * sizeof(value) | |
431 | && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { | |
432 | cur = end + 1; | |
433 | break; | |
434 | } | |
435 | value |= (uleb128_t)(*cur & 0x7f) << shift; | |
436 | if (!(*cur++ & 0x80)) | |
437 | break; | |
438 | } | |
439 | *pcur = cur; | |
440 | ||
441 | return value; | |
442 | } | |
443 | ||
444 | static sleb128_t get_sleb128(const u8 **pcur, const u8 *end) | |
445 | { | |
446 | const u8 *cur = *pcur; | |
447 | sleb128_t value; | |
448 | unsigned shift; | |
449 | ||
450 | for (shift = 0, value = 0; cur < end; shift += 7) { | |
451 | if (shift + 7 > 8 * sizeof(value) | |
452 | && (*cur & 0x7fU) >= (1U << (8 * sizeof(value) - shift))) { | |
453 | cur = end + 1; | |
454 | break; | |
455 | } | |
456 | value |= (sleb128_t)(*cur & 0x7f) << shift; | |
457 | if (!(*cur & 0x80)) { | |
458 | value |= -(*cur++ & 0x40) << shift; | |
459 | break; | |
460 | } | |
461 | } | |
462 | *pcur = cur; | |
463 | ||
464 | return value; | |
465 | } | |
466 | ||
690a973f JB |
467 | static const u32 *cie_for_fde(const u32 *fde, const struct unwind_table *table) |
468 | { | |
469 | const u32 *cie; | |
470 | ||
471 | if (!*fde || (*fde & (sizeof(*fde) - 1))) | |
472 | return &bad_cie; | |
473 | if (!fde[1]) | |
474 | return ¬_fde; /* this is a CIE */ | |
475 | if ((fde[1] & (sizeof(*fde) - 1)) | |
476 | || fde[1] > (unsigned long)(fde + 1) - (unsigned long)table->address) | |
477 | return NULL; /* this is not a valid FDE */ | |
478 | cie = fde + 1 - fde[1] / sizeof(*fde); | |
479 | if (*cie <= sizeof(*cie) + 4 | |
480 | || *cie >= fde[1] - sizeof(*fde) | |
481 | || (*cie & (sizeof(*cie) - 1)) | |
482 | || cie[1]) | |
483 | return NULL; /* this is not a (valid) CIE */ | |
484 | return cie; | |
485 | } | |
486 | ||
4552d5dc JB |
487 | static unsigned long read_pointer(const u8 **pLoc, |
488 | const void *end, | |
489 | signed ptrType) | |
490 | { | |
491 | unsigned long value = 0; | |
492 | union { | |
493 | const u8 *p8; | |
494 | const u16 *p16u; | |
495 | const s16 *p16s; | |
496 | const u32 *p32u; | |
497 | const s32 *p32s; | |
498 | const unsigned long *pul; | |
499 | } ptr; | |
500 | ||
501 | if (ptrType < 0 || ptrType == DW_EH_PE_omit) | |
502 | return 0; | |
503 | ptr.p8 = *pLoc; | |
504 | switch(ptrType & DW_EH_PE_FORM) { | |
505 | case DW_EH_PE_data2: | |
506 | if (end < (const void *)(ptr.p16u + 1)) | |
507 | return 0; | |
508 | if(ptrType & DW_EH_PE_signed) | |
509 | value = get_unaligned(ptr.p16s++); | |
510 | else | |
511 | value = get_unaligned(ptr.p16u++); | |
512 | break; | |
513 | case DW_EH_PE_data4: | |
514 | #ifdef CONFIG_64BIT | |
515 | if (end < (const void *)(ptr.p32u + 1)) | |
516 | return 0; | |
517 | if(ptrType & DW_EH_PE_signed) | |
518 | value = get_unaligned(ptr.p32s++); | |
519 | else | |
520 | value = get_unaligned(ptr.p32u++); | |
521 | break; | |
522 | case DW_EH_PE_data8: | |
523 | BUILD_BUG_ON(sizeof(u64) != sizeof(value)); | |
524 | #else | |
525 | BUILD_BUG_ON(sizeof(u32) != sizeof(value)); | |
526 | #endif | |
527 | case DW_EH_PE_native: | |
528 | if (end < (const void *)(ptr.pul + 1)) | |
529 | return 0; | |
530 | value = get_unaligned(ptr.pul++); | |
531 | break; | |
532 | case DW_EH_PE_leb128: | |
533 | BUILD_BUG_ON(sizeof(uleb128_t) > sizeof(value)); | |
534 | value = ptrType & DW_EH_PE_signed | |
535 | ? get_sleb128(&ptr.p8, end) | |
536 | : get_uleb128(&ptr.p8, end); | |
537 | if ((const void *)ptr.p8 > end) | |
538 | return 0; | |
539 | break; | |
540 | default: | |
541 | return 0; | |
542 | } | |
543 | switch(ptrType & DW_EH_PE_ADJUST) { | |
544 | case DW_EH_PE_abs: | |
545 | break; | |
546 | case DW_EH_PE_pcrel: | |
547 | value += (unsigned long)*pLoc; | |
548 | break; | |
549 | default: | |
550 | return 0; | |
551 | } | |
552 | if ((ptrType & DW_EH_PE_indirect) | |
553 | && __get_user(value, (unsigned long *)value)) | |
554 | return 0; | |
555 | *pLoc = ptr.p8; | |
556 | ||
557 | return value; | |
558 | } | |
559 | ||
560 | static signed fde_pointer_type(const u32 *cie) | |
561 | { | |
562 | const u8 *ptr = (const u8 *)(cie + 2); | |
563 | unsigned version = *ptr; | |
564 | ||
565 | if (version != 1) | |
566 | return -1; /* unsupported */ | |
567 | if (*++ptr) { | |
568 | const char *aug; | |
569 | const u8 *end = (const u8 *)(cie + 1) + *cie; | |
570 | uleb128_t len; | |
571 | ||
572 | /* check if augmentation size is first (and thus present) */ | |
573 | if (*ptr != 'z') | |
574 | return -1; | |
575 | /* check if augmentation string is nul-terminated */ | |
576 | if ((ptr = memchr(aug = (const void *)ptr, 0, end - ptr)) == NULL) | |
577 | return -1; | |
578 | ++ptr; /* skip terminator */ | |
579 | get_uleb128(&ptr, end); /* skip code alignment */ | |
580 | get_sleb128(&ptr, end); /* skip data alignment */ | |
581 | /* skip return address column */ | |
582 | version <= 1 ? (void)++ptr : (void)get_uleb128(&ptr, end); | |
583 | len = get_uleb128(&ptr, end); /* augmentation length */ | |
584 | if (ptr + len < ptr || ptr + len > end) | |
585 | return -1; | |
586 | end = ptr + len; | |
587 | while (*++aug) { | |
588 | if (ptr >= end) | |
589 | return -1; | |
590 | switch(*aug) { | |
591 | case 'L': | |
592 | ++ptr; | |
593 | break; | |
594 | case 'P': { | |
595 | signed ptrType = *ptr++; | |
596 | ||
597 | if (!read_pointer(&ptr, end, ptrType) || ptr > end) | |
598 | return -1; | |
599 | } | |
600 | break; | |
601 | case 'R': | |
602 | return *ptr; | |
603 | default: | |
604 | return -1; | |
605 | } | |
606 | } | |
607 | } | |
608 | return DW_EH_PE_native|DW_EH_PE_abs; | |
609 | } | |
610 | ||
611 | static int advance_loc(unsigned long delta, struct unwind_state *state) | |
612 | { | |
613 | state->loc += delta * state->codeAlign; | |
614 | ||
615 | return delta > 0; | |
616 | } | |
617 | ||
618 | static void set_rule(uleb128_t reg, | |
619 | enum item_location where, | |
620 | uleb128_t value, | |
621 | struct unwind_state *state) | |
622 | { | |
623 | if (reg < ARRAY_SIZE(state->regs)) { | |
624 | state->regs[reg].where = where; | |
625 | state->regs[reg].value = value; | |
626 | } | |
627 | } | |
628 | ||
629 | static int processCFI(const u8 *start, | |
630 | const u8 *end, | |
631 | unsigned long targetLoc, | |
632 | signed ptrType, | |
633 | struct unwind_state *state) | |
634 | { | |
635 | union { | |
636 | const u8 *p8; | |
637 | const u16 *p16; | |
638 | const u32 *p32; | |
639 | } ptr; | |
640 | int result = 1; | |
641 | ||
642 | if (start != state->cieStart) { | |
643 | state->loc = state->org; | |
644 | result = processCFI(state->cieStart, state->cieEnd, 0, ptrType, state); | |
645 | if (targetLoc == 0 && state->label == NULL) | |
646 | return result; | |
647 | } | |
648 | for (ptr.p8 = start; result && ptr.p8 < end; ) { | |
649 | switch(*ptr.p8 >> 6) { | |
650 | uleb128_t value; | |
651 | ||
652 | case 0: | |
653 | switch(*ptr.p8++) { | |
654 | case DW_CFA_nop: | |
655 | break; | |
656 | case DW_CFA_set_loc: | |
657 | if ((state->loc = read_pointer(&ptr.p8, end, ptrType)) == 0) | |
658 | result = 0; | |
659 | break; | |
660 | case DW_CFA_advance_loc1: | |
661 | result = ptr.p8 < end && advance_loc(*ptr.p8++, state); | |
662 | break; | |
663 | case DW_CFA_advance_loc2: | |
664 | result = ptr.p8 <= end + 2 | |
665 | && advance_loc(*ptr.p16++, state); | |
666 | break; | |
667 | case DW_CFA_advance_loc4: | |
668 | result = ptr.p8 <= end + 4 | |
669 | && advance_loc(*ptr.p32++, state); | |
670 | break; | |
671 | case DW_CFA_offset_extended: | |
672 | value = get_uleb128(&ptr.p8, end); | |
673 | set_rule(value, Memory, get_uleb128(&ptr.p8, end), state); | |
674 | break; | |
675 | case DW_CFA_val_offset: | |
676 | value = get_uleb128(&ptr.p8, end); | |
677 | set_rule(value, Value, get_uleb128(&ptr.p8, end), state); | |
678 | break; | |
679 | case DW_CFA_offset_extended_sf: | |
680 | value = get_uleb128(&ptr.p8, end); | |
681 | set_rule(value, Memory, get_sleb128(&ptr.p8, end), state); | |
682 | break; | |
683 | case DW_CFA_val_offset_sf: | |
684 | value = get_uleb128(&ptr.p8, end); | |
685 | set_rule(value, Value, get_sleb128(&ptr.p8, end), state); | |
686 | break; | |
687 | case DW_CFA_restore_extended: | |
688 | case DW_CFA_undefined: | |
689 | case DW_CFA_same_value: | |
690 | set_rule(get_uleb128(&ptr.p8, end), Nowhere, 0, state); | |
691 | break; | |
692 | case DW_CFA_register: | |
693 | value = get_uleb128(&ptr.p8, end); | |
694 | set_rule(value, | |
695 | Register, | |
696 | get_uleb128(&ptr.p8, end), state); | |
697 | break; | |
698 | case DW_CFA_remember_state: | |
699 | if (ptr.p8 == state->label) { | |
700 | state->label = NULL; | |
701 | return 1; | |
702 | } | |
703 | if (state->stackDepth >= MAX_STACK_DEPTH) | |
704 | return 0; | |
705 | state->stack[state->stackDepth++] = ptr.p8; | |
706 | break; | |
707 | case DW_CFA_restore_state: | |
708 | if (state->stackDepth) { | |
709 | const uleb128_t loc = state->loc; | |
710 | const u8 *label = state->label; | |
711 | ||
712 | state->label = state->stack[state->stackDepth - 1]; | |
713 | memcpy(&state->cfa, &badCFA, sizeof(state->cfa)); | |
714 | memset(state->regs, 0, sizeof(state->regs)); | |
715 | state->stackDepth = 0; | |
716 | result = processCFI(start, end, 0, ptrType, state); | |
717 | state->loc = loc; | |
718 | state->label = label; | |
719 | } else | |
720 | return 0; | |
721 | break; | |
722 | case DW_CFA_def_cfa: | |
723 | state->cfa.reg = get_uleb128(&ptr.p8, end); | |
724 | /*nobreak*/ | |
725 | case DW_CFA_def_cfa_offset: | |
726 | state->cfa.offs = get_uleb128(&ptr.p8, end); | |
727 | break; | |
728 | case DW_CFA_def_cfa_sf: | |
729 | state->cfa.reg = get_uleb128(&ptr.p8, end); | |
730 | /*nobreak*/ | |
731 | case DW_CFA_def_cfa_offset_sf: | |
732 | state->cfa.offs = get_sleb128(&ptr.p8, end) | |
733 | * state->dataAlign; | |
734 | break; | |
735 | case DW_CFA_def_cfa_register: | |
736 | state->cfa.reg = get_uleb128(&ptr.p8, end); | |
737 | break; | |
738 | /*todo case DW_CFA_def_cfa_expression: */ | |
739 | /*todo case DW_CFA_expression: */ | |
740 | /*todo case DW_CFA_val_expression: */ | |
741 | case DW_CFA_GNU_args_size: | |
742 | get_uleb128(&ptr.p8, end); | |
743 | break; | |
744 | case DW_CFA_GNU_negative_offset_extended: | |
745 | value = get_uleb128(&ptr.p8, end); | |
746 | set_rule(value, | |
747 | Memory, | |
748 | (uleb128_t)0 - get_uleb128(&ptr.p8, end), state); | |
749 | break; | |
750 | case DW_CFA_GNU_window_save: | |
751 | default: | |
752 | result = 0; | |
753 | break; | |
754 | } | |
755 | break; | |
756 | case 1: | |
757 | result = advance_loc(*ptr.p8++ & 0x3f, state); | |
758 | break; | |
759 | case 2: | |
760 | value = *ptr.p8++ & 0x3f; | |
761 | set_rule(value, Memory, get_uleb128(&ptr.p8, end), state); | |
762 | break; | |
763 | case 3: | |
764 | set_rule(*ptr.p8++ & 0x3f, Nowhere, 0, state); | |
765 | break; | |
766 | } | |
767 | if (ptr.p8 > end) | |
768 | result = 0; | |
769 | if (result && targetLoc != 0 && targetLoc < state->loc) | |
770 | return 1; | |
771 | } | |
772 | ||
773 | return result | |
774 | && ptr.p8 == end | |
775 | && (targetLoc == 0 | |
776 | || (/*todo While in theory this should apply, gcc in practice omits | |
777 | everything past the function prolog, and hence the location | |
778 | never reaches the end of the function. | |
779 | targetLoc < state->loc &&*/ state->label == NULL)); | |
780 | } | |
781 | ||
782 | /* Unwind to previous to frame. Returns 0 if successful, negative | |
783 | * number in case of an error. */ | |
784 | int unwind(struct unwind_frame_info *frame) | |
785 | { | |
786 | #define FRAME_REG(r, t) (((t *)frame)[reg_info[r].offs]) | |
787 | const u32 *fde = NULL, *cie = NULL; | |
788 | const u8 *ptr = NULL, *end = NULL; | |
adf14236 | 789 | unsigned long pc = UNW_PC(frame) - frame->call_frame; |
4552d5dc JB |
790 | unsigned long startLoc = 0, endLoc = 0, cfa; |
791 | unsigned i; | |
792 | signed ptrType = -1; | |
793 | uleb128_t retAddrReg = 0; | |
690a973f | 794 | const struct unwind_table *table; |
4552d5dc JB |
795 | struct unwind_state state; |
796 | ||
797 | if (UNW_PC(frame) == 0) | |
798 | return -EINVAL; | |
adf14236 | 799 | if ((table = find_table(pc)) != NULL |
4552d5dc | 800 | && !(table->size & (sizeof(*fde) - 1))) { |
690a973f JB |
801 | const u8 *hdr = table->header; |
802 | unsigned long tableSize; | |
803 | ||
804 | smp_rmb(); | |
805 | if (hdr && hdr[0] == 1) { | |
806 | switch(hdr[3] & DW_EH_PE_FORM) { | |
807 | case DW_EH_PE_native: tableSize = sizeof(unsigned long); break; | |
808 | case DW_EH_PE_data2: tableSize = 2; break; | |
809 | case DW_EH_PE_data4: tableSize = 4; break; | |
810 | case DW_EH_PE_data8: tableSize = 8; break; | |
811 | default: tableSize = 0; break; | |
812 | } | |
813 | ptr = hdr + 4; | |
814 | end = hdr + table->hdrsz; | |
815 | if (tableSize | |
816 | && read_pointer(&ptr, end, hdr[1]) | |
817 | == (unsigned long)table->address | |
818 | && (i = read_pointer(&ptr, end, hdr[2])) > 0 | |
819 | && i == (end - ptr) / (2 * tableSize) | |
820 | && !((end - ptr) % (2 * tableSize))) { | |
821 | do { | |
822 | const u8 *cur = ptr + (i / 2) * (2 * tableSize); | |
823 | ||
824 | startLoc = read_pointer(&cur, | |
825 | cur + tableSize, | |
826 | hdr[3]); | |
827 | if (pc < startLoc) | |
828 | i /= 2; | |
829 | else { | |
830 | ptr = cur - tableSize; | |
831 | i = (i + 1) / 2; | |
832 | } | |
833 | } while (startLoc && i > 1); | |
834 | if (i == 1 | |
835 | && (startLoc = read_pointer(&ptr, | |
836 | ptr + tableSize, | |
837 | hdr[3])) != 0 | |
838 | && pc >= startLoc) | |
839 | fde = (void *)read_pointer(&ptr, | |
840 | ptr + tableSize, | |
841 | hdr[3]); | |
4552d5dc | 842 | } |
690a973f JB |
843 | } |
844 | ||
845 | if (fde != NULL) { | |
846 | cie = cie_for_fde(fde, table); | |
4552d5dc | 847 | ptr = (const u8 *)(fde + 2); |
690a973f JB |
848 | if(cie != NULL |
849 | && cie != &bad_cie | |
850 | && cie != ¬_fde | |
851 | && (ptrType = fde_pointer_type(cie)) >= 0 | |
852 | && read_pointer(&ptr, | |
853 | (const u8 *)(fde + 1) + *fde, | |
854 | ptrType) == startLoc) { | |
855 | if (!(ptrType & DW_EH_PE_indirect)) | |
856 | ptrType &= DW_EH_PE_FORM|DW_EH_PE_signed; | |
857 | endLoc = startLoc | |
858 | + read_pointer(&ptr, | |
859 | (const u8 *)(fde + 1) + *fde, | |
860 | ptrType); | |
861 | if(pc >= endLoc) | |
862 | fde = NULL; | |
863 | } else | |
864 | fde = NULL; | |
865 | } | |
866 | if (fde == NULL) { | |
867 | for (fde = table->address, tableSize = table->size; | |
868 | cie = NULL, tableSize > sizeof(*fde) | |
869 | && tableSize - sizeof(*fde) >= *fde; | |
870 | tableSize -= sizeof(*fde) + *fde, | |
871 | fde += 1 + *fde / sizeof(*fde)) { | |
872 | cie = cie_for_fde(fde, table); | |
873 | if (cie == &bad_cie) { | |
874 | cie = NULL; | |
875 | break; | |
876 | } | |
877 | if (cie == NULL | |
878 | || cie == ¬_fde | |
879 | || (ptrType = fde_pointer_type(cie)) < 0) | |
880 | continue; | |
881 | ptr = (const u8 *)(fde + 2); | |
882 | startLoc = read_pointer(&ptr, | |
883 | (const u8 *)(fde + 1) + *fde, | |
884 | ptrType); | |
885 | if (!startLoc) | |
886 | continue; | |
887 | if (!(ptrType & DW_EH_PE_indirect)) | |
888 | ptrType &= DW_EH_PE_FORM|DW_EH_PE_signed; | |
889 | endLoc = startLoc | |
890 | + read_pointer(&ptr, | |
891 | (const u8 *)(fde + 1) + *fde, | |
892 | ptrType); | |
893 | if (pc >= startLoc && pc < endLoc) | |
894 | break; | |
895 | } | |
4552d5dc JB |
896 | } |
897 | } | |
898 | if (cie != NULL) { | |
899 | memset(&state, 0, sizeof(state)); | |
900 | state.cieEnd = ptr; /* keep here temporarily */ | |
901 | ptr = (const u8 *)(cie + 2); | |
902 | end = (const u8 *)(cie + 1) + *cie; | |
adf14236 | 903 | frame->call_frame = 1; |
4552d5dc JB |
904 | if ((state.version = *ptr) != 1) |
905 | cie = NULL; /* unsupported version */ | |
906 | else if (*++ptr) { | |
907 | /* check if augmentation size is first (and thus present) */ | |
908 | if (*ptr == 'z') { | |
adf14236 JB |
909 | while (++ptr < end && *ptr) { |
910 | switch(*ptr) { | |
911 | /* check for ignorable (or already handled) | |
912 | * nul-terminated augmentation string */ | |
913 | case 'L': | |
914 | case 'P': | |
915 | case 'R': | |
916 | continue; | |
917 | case 'S': | |
918 | frame->call_frame = 0; | |
919 | continue; | |
920 | default: | |
4552d5dc | 921 | break; |
adf14236 JB |
922 | } |
923 | break; | |
924 | } | |
4552d5dc JB |
925 | } |
926 | if (ptr >= end || *ptr) | |
927 | cie = NULL; | |
928 | } | |
929 | ++ptr; | |
930 | } | |
931 | if (cie != NULL) { | |
932 | /* get code aligment factor */ | |
933 | state.codeAlign = get_uleb128(&ptr, end); | |
934 | /* get data aligment factor */ | |
935 | state.dataAlign = get_sleb128(&ptr, end); | |
936 | if (state.codeAlign == 0 || state.dataAlign == 0 || ptr >= end) | |
937 | cie = NULL; | |
938 | else { | |
939 | retAddrReg = state.version <= 1 ? *ptr++ : get_uleb128(&ptr, end); | |
940 | /* skip augmentation */ | |
941 | if (((const char *)(cie + 2))[1] == 'z') | |
942 | ptr += get_uleb128(&ptr, end); | |
943 | if (ptr > end | |
944 | || retAddrReg >= ARRAY_SIZE(reg_info) | |
945 | || REG_INVALID(retAddrReg) | |
946 | || reg_info[retAddrReg].width != sizeof(unsigned long)) | |
947 | cie = NULL; | |
948 | } | |
949 | } | |
950 | if (cie != NULL) { | |
951 | state.cieStart = ptr; | |
952 | ptr = state.cieEnd; | |
953 | state.cieEnd = end; | |
954 | end = (const u8 *)(fde + 1) + *fde; | |
955 | /* skip augmentation */ | |
956 | if (((const char *)(cie + 2))[1] == 'z') { | |
957 | uleb128_t augSize = get_uleb128(&ptr, end); | |
958 | ||
959 | if ((ptr += augSize) > end) | |
960 | fde = NULL; | |
961 | } | |
962 | } | |
963 | if (cie == NULL || fde == NULL) { | |
964 | #ifdef CONFIG_FRAME_POINTER | |
965 | unsigned long top, bottom; | |
966 | #endif | |
967 | ||
968 | #ifdef CONFIG_FRAME_POINTER | |
969 | top = STACK_TOP(frame->task); | |
970 | bottom = STACK_BOTTOM(frame->task); | |
971 | # if FRAME_RETADDR_OFFSET < 0 | |
972 | if (UNW_SP(frame) < top | |
973 | && UNW_FP(frame) <= UNW_SP(frame) | |
974 | && bottom < UNW_FP(frame) | |
975 | # else | |
976 | if (UNW_SP(frame) > top | |
977 | && UNW_FP(frame) >= UNW_SP(frame) | |
978 | && bottom > UNW_FP(frame) | |
979 | # endif | |
980 | && !((UNW_SP(frame) | UNW_FP(frame)) | |
981 | & (sizeof(unsigned long) - 1))) { | |
982 | unsigned long link; | |
983 | ||
984 | if (!__get_user(link, | |
985 | (unsigned long *)(UNW_FP(frame) | |
986 | + FRAME_LINK_OFFSET)) | |
987 | # if FRAME_RETADDR_OFFSET < 0 | |
988 | && link > bottom && link < UNW_FP(frame) | |
989 | # else | |
990 | && link > UNW_FP(frame) && link < bottom | |
991 | # endif | |
992 | && !(link & (sizeof(link) - 1)) | |
993 | && !__get_user(UNW_PC(frame), | |
994 | (unsigned long *)(UNW_FP(frame) | |
995 | + FRAME_RETADDR_OFFSET))) { | |
996 | UNW_SP(frame) = UNW_FP(frame) + FRAME_RETADDR_OFFSET | |
997 | # if FRAME_RETADDR_OFFSET < 0 | |
998 | - | |
999 | # else | |
1000 | + | |
1001 | # endif | |
1002 | sizeof(UNW_PC(frame)); | |
1003 | UNW_FP(frame) = link; | |
1004 | return 0; | |
1005 | } | |
1006 | } | |
1007 | #endif | |
1008 | return -ENXIO; | |
1009 | } | |
1010 | state.org = startLoc; | |
1011 | memcpy(&state.cfa, &badCFA, sizeof(state.cfa)); | |
1012 | /* process instructions */ | |
adf14236 | 1013 | if (!processCFI(ptr, end, pc, ptrType, &state) |
4552d5dc JB |
1014 | || state.loc > endLoc |
1015 | || state.regs[retAddrReg].where == Nowhere | |
1016 | || state.cfa.reg >= ARRAY_SIZE(reg_info) | |
1017 | || reg_info[state.cfa.reg].width != sizeof(unsigned long) | |
1018 | || state.cfa.offs % sizeof(unsigned long)) | |
1019 | return -EIO; | |
1020 | /* update frame */ | |
adf14236 JB |
1021 | #ifndef CONFIG_AS_CFI_SIGNAL_FRAME |
1022 | if(frame->call_frame | |
1023 | && !UNW_DEFAULT_RA(state.regs[retAddrReg], state.dataAlign)) | |
1024 | frame->call_frame = 0; | |
1025 | #endif | |
4552d5dc JB |
1026 | cfa = FRAME_REG(state.cfa.reg, unsigned long) + state.cfa.offs; |
1027 | startLoc = min((unsigned long)UNW_SP(frame), cfa); | |
1028 | endLoc = max((unsigned long)UNW_SP(frame), cfa); | |
1029 | if (STACK_LIMIT(startLoc) != STACK_LIMIT(endLoc)) { | |
1030 | startLoc = min(STACK_LIMIT(cfa), cfa); | |
1031 | endLoc = max(STACK_LIMIT(cfa), cfa); | |
1032 | } | |
1033 | #ifndef CONFIG_64BIT | |
1034 | # define CASES CASE(8); CASE(16); CASE(32) | |
1035 | #else | |
1036 | # define CASES CASE(8); CASE(16); CASE(32); CASE(64) | |
1037 | #endif | |
1038 | for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { | |
1039 | if (REG_INVALID(i)) { | |
1040 | if (state.regs[i].where == Nowhere) | |
1041 | continue; | |
1042 | return -EIO; | |
1043 | } | |
1044 | switch(state.regs[i].where) { | |
1045 | default: | |
1046 | break; | |
1047 | case Register: | |
1048 | if (state.regs[i].value >= ARRAY_SIZE(reg_info) | |
1049 | || REG_INVALID(state.regs[i].value) | |
1050 | || reg_info[i].width > reg_info[state.regs[i].value].width) | |
1051 | return -EIO; | |
1052 | switch(reg_info[state.regs[i].value].width) { | |
1053 | #define CASE(n) \ | |
1054 | case sizeof(u##n): \ | |
1055 | state.regs[i].value = FRAME_REG(state.regs[i].value, \ | |
1056 | const u##n); \ | |
1057 | break | |
1058 | CASES; | |
1059 | #undef CASE | |
1060 | default: | |
1061 | return -EIO; | |
1062 | } | |
1063 | break; | |
1064 | } | |
1065 | } | |
1066 | for (i = 0; i < ARRAY_SIZE(state.regs); ++i) { | |
1067 | if (REG_INVALID(i)) | |
1068 | continue; | |
1069 | switch(state.regs[i].where) { | |
1070 | case Nowhere: | |
1071 | if (reg_info[i].width != sizeof(UNW_SP(frame)) | |
1072 | || &FRAME_REG(i, __typeof__(UNW_SP(frame))) | |
1073 | != &UNW_SP(frame)) | |
1074 | continue; | |
1075 | UNW_SP(frame) = cfa; | |
1076 | break; | |
1077 | case Register: | |
1078 | switch(reg_info[i].width) { | |
1079 | #define CASE(n) case sizeof(u##n): \ | |
1080 | FRAME_REG(i, u##n) = state.regs[i].value; \ | |
1081 | break | |
1082 | CASES; | |
1083 | #undef CASE | |
1084 | default: | |
1085 | return -EIO; | |
1086 | } | |
1087 | break; | |
1088 | case Value: | |
1089 | if (reg_info[i].width != sizeof(unsigned long)) | |
1090 | return -EIO; | |
1091 | FRAME_REG(i, unsigned long) = cfa + state.regs[i].value | |
1092 | * state.dataAlign; | |
1093 | break; | |
1094 | case Memory: { | |
1095 | unsigned long addr = cfa + state.regs[i].value | |
1096 | * state.dataAlign; | |
1097 | ||
1098 | if ((state.regs[i].value * state.dataAlign) | |
1099 | % sizeof(unsigned long) | |
1100 | || addr < startLoc | |
1101 | || addr + sizeof(unsigned long) < addr | |
1102 | || addr + sizeof(unsigned long) > endLoc) | |
1103 | return -EIO; | |
1104 | switch(reg_info[i].width) { | |
1105 | #define CASE(n) case sizeof(u##n): \ | |
1106 | __get_user(FRAME_REG(i, u##n), (u##n *)addr); \ | |
1107 | break | |
1108 | CASES; | |
1109 | #undef CASE | |
1110 | default: | |
1111 | return -EIO; | |
1112 | } | |
1113 | } | |
1114 | break; | |
1115 | } | |
1116 | } | |
1117 | ||
1118 | return 0; | |
1119 | #undef CASES | |
1120 | #undef FRAME_REG | |
1121 | } | |
1122 | EXPORT_SYMBOL(unwind); | |
1123 | ||
1124 | int unwind_init_frame_info(struct unwind_frame_info *info, | |
1125 | struct task_struct *tsk, | |
1126 | /*const*/ struct pt_regs *regs) | |
1127 | { | |
1128 | info->task = tsk; | |
adf14236 | 1129 | info->call_frame = 0; |
4552d5dc JB |
1130 | arch_unw_init_frame_info(info, regs); |
1131 | ||
1132 | return 0; | |
1133 | } | |
1134 | EXPORT_SYMBOL(unwind_init_frame_info); | |
1135 | ||
1136 | /* | |
1137 | * Prepare to unwind a blocked task. | |
1138 | */ | |
1139 | int unwind_init_blocked(struct unwind_frame_info *info, | |
1140 | struct task_struct *tsk) | |
1141 | { | |
1142 | info->task = tsk; | |
adf14236 | 1143 | info->call_frame = 0; |
4552d5dc JB |
1144 | arch_unw_init_blocked(info); |
1145 | ||
1146 | return 0; | |
1147 | } | |
1148 | EXPORT_SYMBOL(unwind_init_blocked); | |
1149 | ||
1150 | /* | |
1151 | * Prepare to unwind the currently running thread. | |
1152 | */ | |
1153 | int unwind_init_running(struct unwind_frame_info *info, | |
c33bd9aa JB |
1154 | asmlinkage int (*callback)(struct unwind_frame_info *, |
1155 | void *arg), | |
4552d5dc JB |
1156 | void *arg) |
1157 | { | |
1158 | info->task = current; | |
adf14236 | 1159 | info->call_frame = 0; |
4552d5dc | 1160 | |
c33bd9aa | 1161 | return arch_unwind_init_running(info, callback, arg); |
4552d5dc JB |
1162 | } |
1163 | EXPORT_SYMBOL(unwind_init_running); | |
1164 | ||
1165 | /* | |
1166 | * Unwind until the return pointer is in user-land (or until an error | |
1167 | * occurs). Returns 0 if successful, negative number in case of | |
1168 | * error. | |
1169 | */ | |
1170 | int unwind_to_user(struct unwind_frame_info *info) | |
1171 | { | |
1172 | while (!arch_unw_user_mode(info)) { | |
1173 | int err = unwind(info); | |
1174 | ||
1175 | if (err < 0) | |
1176 | return err; | |
1177 | } | |
1178 | ||
1179 | return 0; | |
1180 | } | |
1181 | EXPORT_SYMBOL(unwind_to_user); |