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442f04c3 JP |
1 | /* |
2 | * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version 2 | |
7 | * of the License, or (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | /* | |
19 | * objtool check: | |
20 | * | |
21 | * This command analyzes every .o file and ensures the validity of its stack | |
22 | * trace metadata. It enforces a set of rules on asm code and C inline | |
23 | * assembly code so that stack traces can be reliable. | |
24 | * | |
25 | * For more information, see tools/objtool/Documentation/stack-validation.txt. | |
26 | */ | |
27 | ||
28 | #include <string.h> | |
d0761e37 | 29 | #include <stdlib.h> |
442f04c3 JP |
30 | #include <subcmd/parse-options.h> |
31 | ||
32 | #include "builtin.h" | |
33 | #include "elf.h" | |
34 | #include "special.h" | |
35 | #include "arch.h" | |
36 | #include "warn.h" | |
37 | ||
042ba73f JP |
38 | #include <linux/hashtable.h> |
39 | ||
442f04c3 JP |
40 | #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) |
41 | ||
42 | #define STATE_FP_SAVED 0x1 | |
43 | #define STATE_FP_SETUP 0x2 | |
44 | #define STATE_FENTRY 0x4 | |
45 | ||
46 | struct instruction { | |
47 | struct list_head list; | |
042ba73f | 48 | struct hlist_node hash; |
442f04c3 JP |
49 | struct section *sec; |
50 | unsigned long offset; | |
51 | unsigned int len, state; | |
52 | unsigned char type; | |
53 | unsigned long immediate; | |
54 | bool alt_group, visited; | |
55 | struct symbol *call_dest; | |
56 | struct instruction *jump_dest; | |
57 | struct list_head alts; | |
b1547d31 | 58 | struct symbol *func; |
442f04c3 JP |
59 | }; |
60 | ||
61 | struct alternative { | |
62 | struct list_head list; | |
63 | struct instruction *insn; | |
64 | }; | |
65 | ||
66 | struct objtool_file { | |
67 | struct elf *elf; | |
a196e171 | 68 | struct list_head insn_list; |
042ba73f JP |
69 | DECLARE_HASHTABLE(insn_hash, 16); |
70 | struct section *rodata, *whitelist; | |
b1547d31 | 71 | bool ignore_unreachables, c_file; |
442f04c3 JP |
72 | }; |
73 | ||
74 | const char *objname; | |
75 | static bool nofp; | |
76 | ||
74aec058 JP |
77 | static struct instruction *find_insn(struct objtool_file *file, |
78 | struct section *sec, unsigned long offset) | |
442f04c3 JP |
79 | { |
80 | struct instruction *insn; | |
81 | ||
042ba73f | 82 | hash_for_each_possible(file->insn_hash, insn, hash, offset) |
442f04c3 JP |
83 | if (insn->sec == sec && insn->offset == offset) |
84 | return insn; | |
85 | ||
86 | return NULL; | |
87 | } | |
88 | ||
74aec058 JP |
89 | static struct instruction *next_insn_same_sec(struct objtool_file *file, |
90 | struct instruction *insn) | |
91 | { | |
92 | struct instruction *next = list_next_entry(insn, list); | |
93 | ||
a196e171 | 94 | if (&next->list == &file->insn_list || next->sec != insn->sec) |
74aec058 JP |
95 | return NULL; |
96 | ||
97 | return next; | |
98 | } | |
99 | ||
100 | #define for_each_insn(file, insn) \ | |
a196e171 | 101 | list_for_each_entry(insn, &file->insn_list, list) |
74aec058 JP |
102 | |
103 | #define func_for_each_insn(file, func, insn) \ | |
104 | for (insn = find_insn(file, func->sec, func->offset); \ | |
a196e171 | 105 | insn && &insn->list != &file->insn_list && \ |
74aec058 JP |
106 | insn->sec == func->sec && \ |
107 | insn->offset < func->offset + func->len; \ | |
108 | insn = list_next_entry(insn, list)) | |
109 | ||
6d01f28b JP |
110 | #define func_for_each_insn_continue_reverse(file, func, insn) \ |
111 | for (insn = list_prev_entry(insn, list); \ | |
112 | &insn->list != &file->insn_list && \ | |
113 | insn->sec == func->sec && insn->offset >= func->offset; \ | |
114 | insn = list_prev_entry(insn, list)) | |
115 | ||
74aec058 JP |
116 | #define sec_for_each_insn_from(file, insn) \ |
117 | for (; insn; insn = next_insn_same_sec(file, insn)) | |
118 | ||
119 | ||
442f04c3 JP |
120 | /* |
121 | * Check if the function has been manually whitelisted with the | |
122 | * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted | |
123 | * due to its use of a context switching instruction. | |
124 | */ | |
125 | static bool ignore_func(struct objtool_file *file, struct symbol *func) | |
126 | { | |
442f04c3 JP |
127 | struct rela *rela; |
128 | struct instruction *insn; | |
129 | ||
130 | /* check for STACK_FRAME_NON_STANDARD */ | |
042ba73f | 131 | if (file->whitelist && file->whitelist->rela) |
0ea5ad86 JP |
132 | list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) { |
133 | if (rela->sym->type == STT_SECTION && | |
134 | rela->sym->sec == func->sec && | |
442f04c3 JP |
135 | rela->addend == func->offset) |
136 | return true; | |
0ea5ad86 JP |
137 | if (rela->sym->type == STT_FUNC && rela->sym == func) |
138 | return true; | |
139 | } | |
442f04c3 JP |
140 | |
141 | /* check if it has a context switching instruction */ | |
74aec058 | 142 | func_for_each_insn(file, func, insn) |
442f04c3 JP |
143 | if (insn->type == INSN_CONTEXT_SWITCH) |
144 | return true; | |
442f04c3 JP |
145 | |
146 | return false; | |
147 | } | |
148 | ||
149 | /* | |
150 | * This checks to see if the given function is a "noreturn" function. | |
151 | * | |
152 | * For global functions which are outside the scope of this object file, we | |
153 | * have to keep a manual list of them. | |
154 | * | |
155 | * For local functions, we have to detect them manually by simply looking for | |
156 | * the lack of a return instruction. | |
b1e03249 JP |
157 | * |
158 | * Returns: | |
159 | * -1: error | |
160 | * 0: no dead end | |
161 | * 1: dead end | |
442f04c3 | 162 | */ |
b1e03249 JP |
163 | static int __dead_end_function(struct objtool_file *file, struct symbol *func, |
164 | int recursion) | |
442f04c3 JP |
165 | { |
166 | int i; | |
74aec058 | 167 | struct instruction *insn; |
442f04c3 JP |
168 | bool empty = true; |
169 | ||
170 | /* | |
171 | * Unfortunately these have to be hard coded because the noreturn | |
172 | * attribute isn't provided in ELF data. | |
173 | */ | |
174 | static const char * const global_noreturns[] = { | |
175 | "__stack_chk_fail", | |
176 | "panic", | |
177 | "do_exit", | |
178 | "__module_put_and_exit", | |
179 | "complete_and_exit", | |
180 | "kvm_spurious_fault", | |
181 | "__reiserfs_panic", | |
182 | "lbug_with_loc" | |
183 | }; | |
184 | ||
185 | if (func->bind == STB_WEAK) | |
b1e03249 | 186 | return 0; |
442f04c3 JP |
187 | |
188 | if (func->bind == STB_GLOBAL) | |
189 | for (i = 0; i < ARRAY_SIZE(global_noreturns); i++) | |
190 | if (!strcmp(func->name, global_noreturns[i])) | |
b1e03249 | 191 | return 1; |
442f04c3 JP |
192 | |
193 | if (!func->sec) | |
b1e03249 | 194 | return 0; |
442f04c3 | 195 | |
74aec058 | 196 | func_for_each_insn(file, func, insn) { |
442f04c3 JP |
197 | empty = false; |
198 | ||
199 | if (insn->type == INSN_RETURN) | |
b1e03249 | 200 | return 0; |
81bfafca JP |
201 | } |
202 | ||
203 | if (empty) | |
b1e03249 | 204 | return 0; |
81bfafca JP |
205 | |
206 | /* | |
207 | * A function can have a sibling call instead of a return. In that | |
208 | * case, the function's dead-end status depends on whether the target | |
209 | * of the sibling call returns. | |
210 | */ | |
74aec058 | 211 | func_for_each_insn(file, func, insn) { |
81bfafca JP |
212 | if (insn->sec != func->sec || |
213 | insn->offset >= func->offset + func->len) | |
214 | break; | |
442f04c3 JP |
215 | |
216 | if (insn->type == INSN_JUMP_UNCONDITIONAL) { | |
217 | struct instruction *dest = insn->jump_dest; | |
218 | struct symbol *dest_func; | |
219 | ||
220 | if (!dest) | |
221 | /* sibling call to another file */ | |
b1e03249 | 222 | return 0; |
442f04c3 JP |
223 | |
224 | if (dest->sec != func->sec || | |
225 | dest->offset < func->offset || | |
226 | dest->offset >= func->offset + func->len) { | |
227 | /* local sibling call */ | |
228 | dest_func = find_symbol_by_offset(dest->sec, | |
229 | dest->offset); | |
230 | if (!dest_func) | |
231 | continue; | |
232 | ||
b1e03249 JP |
233 | if (recursion == 5) { |
234 | WARN_FUNC("infinite recursion (objtool bug!)", | |
235 | dest->sec, dest->offset); | |
236 | return -1; | |
237 | } | |
238 | ||
239 | return __dead_end_function(file, dest_func, | |
240 | recursion + 1); | |
442f04c3 JP |
241 | } |
242 | } | |
243 | ||
b1547d31 | 244 | if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts)) |
442f04c3 | 245 | /* sibling call */ |
b1e03249 | 246 | return 0; |
442f04c3 JP |
247 | } |
248 | ||
b1e03249 JP |
249 | return 1; |
250 | } | |
251 | ||
252 | static int dead_end_function(struct objtool_file *file, struct symbol *func) | |
253 | { | |
254 | return __dead_end_function(file, func, 0); | |
442f04c3 JP |
255 | } |
256 | ||
257 | /* | |
258 | * Call the arch-specific instruction decoder for all the instructions and add | |
a196e171 | 259 | * them to the global instruction list. |
442f04c3 JP |
260 | */ |
261 | static int decode_instructions(struct objtool_file *file) | |
262 | { | |
263 | struct section *sec; | |
b1547d31 | 264 | struct symbol *func; |
442f04c3 JP |
265 | unsigned long offset; |
266 | struct instruction *insn; | |
267 | int ret; | |
268 | ||
442f04c3 JP |
269 | list_for_each_entry(sec, &file->elf->sections, list) { |
270 | ||
271 | if (!(sec->sh.sh_flags & SHF_EXECINSTR)) | |
272 | continue; | |
273 | ||
274 | for (offset = 0; offset < sec->len; offset += insn->len) { | |
275 | insn = malloc(sizeof(*insn)); | |
276 | memset(insn, 0, sizeof(*insn)); | |
277 | ||
278 | INIT_LIST_HEAD(&insn->alts); | |
279 | insn->sec = sec; | |
280 | insn->offset = offset; | |
281 | ||
282 | ret = arch_decode_instruction(file->elf, sec, offset, | |
283 | sec->len - offset, | |
284 | &insn->len, &insn->type, | |
285 | &insn->immediate); | |
286 | if (ret) | |
287 | return ret; | |
288 | ||
289 | if (!insn->type || insn->type > INSN_LAST) { | |
290 | WARN_FUNC("invalid instruction type %d", | |
291 | insn->sec, insn->offset, insn->type); | |
292 | return -1; | |
293 | } | |
294 | ||
042ba73f | 295 | hash_add(file->insn_hash, &insn->hash, insn->offset); |
a196e171 | 296 | list_add_tail(&insn->list, &file->insn_list); |
442f04c3 | 297 | } |
b1547d31 JP |
298 | |
299 | list_for_each_entry(func, &sec->symbol_list, list) { | |
300 | if (func->type != STT_FUNC) | |
301 | continue; | |
302 | ||
303 | if (!find_insn(file, sec, func->offset)) { | |
304 | WARN("%s(): can't find starting instruction", | |
305 | func->name); | |
306 | return -1; | |
307 | } | |
308 | ||
309 | func_for_each_insn(file, func, insn) | |
310 | if (!insn->func) | |
311 | insn->func = func; | |
312 | } | |
442f04c3 JP |
313 | } |
314 | ||
315 | return 0; | |
316 | } | |
317 | ||
318 | /* | |
319 | * Warnings shouldn't be reported for ignored functions. | |
320 | */ | |
a196e171 | 321 | static void add_ignores(struct objtool_file *file) |
442f04c3 JP |
322 | { |
323 | struct instruction *insn; | |
324 | struct section *sec; | |
325 | struct symbol *func; | |
326 | ||
327 | list_for_each_entry(sec, &file->elf->sections, list) { | |
a196e171 | 328 | list_for_each_entry(func, &sec->symbol_list, list) { |
442f04c3 JP |
329 | if (func->type != STT_FUNC) |
330 | continue; | |
331 | ||
332 | if (!ignore_func(file, func)) | |
333 | continue; | |
334 | ||
74aec058 | 335 | func_for_each_insn(file, func, insn) |
442f04c3 | 336 | insn->visited = true; |
442f04c3 JP |
337 | } |
338 | } | |
339 | } | |
340 | ||
341 | /* | |
342 | * Find the destination instructions for all jumps. | |
343 | */ | |
a196e171 | 344 | static int add_jump_destinations(struct objtool_file *file) |
442f04c3 JP |
345 | { |
346 | struct instruction *insn; | |
347 | struct rela *rela; | |
348 | struct section *dest_sec; | |
349 | unsigned long dest_off; | |
350 | ||
74aec058 | 351 | for_each_insn(file, insn) { |
442f04c3 JP |
352 | if (insn->type != INSN_JUMP_CONDITIONAL && |
353 | insn->type != INSN_JUMP_UNCONDITIONAL) | |
354 | continue; | |
355 | ||
356 | /* skip ignores */ | |
357 | if (insn->visited) | |
358 | continue; | |
359 | ||
360 | rela = find_rela_by_dest_range(insn->sec, insn->offset, | |
361 | insn->len); | |
362 | if (!rela) { | |
363 | dest_sec = insn->sec; | |
364 | dest_off = insn->offset + insn->len + insn->immediate; | |
365 | } else if (rela->sym->type == STT_SECTION) { | |
366 | dest_sec = rela->sym->sec; | |
367 | dest_off = rela->addend + 4; | |
368 | } else if (rela->sym->sec->idx) { | |
369 | dest_sec = rela->sym->sec; | |
370 | dest_off = rela->sym->sym.st_value + rela->addend + 4; | |
371 | } else { | |
372 | /* sibling call */ | |
373 | insn->jump_dest = 0; | |
374 | continue; | |
375 | } | |
376 | ||
74aec058 | 377 | insn->jump_dest = find_insn(file, dest_sec, dest_off); |
442f04c3 JP |
378 | if (!insn->jump_dest) { |
379 | ||
380 | /* | |
381 | * This is a special case where an alt instruction | |
382 | * jumps past the end of the section. These are | |
383 | * handled later in handle_group_alt(). | |
384 | */ | |
385 | if (!strcmp(insn->sec->name, ".altinstr_replacement")) | |
386 | continue; | |
387 | ||
388 | WARN_FUNC("can't find jump dest instruction at %s+0x%lx", | |
389 | insn->sec, insn->offset, dest_sec->name, | |
390 | dest_off); | |
391 | return -1; | |
392 | } | |
393 | } | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Find the destination instructions for all calls. | |
400 | */ | |
a196e171 | 401 | static int add_call_destinations(struct objtool_file *file) |
442f04c3 JP |
402 | { |
403 | struct instruction *insn; | |
404 | unsigned long dest_off; | |
405 | struct rela *rela; | |
406 | ||
74aec058 | 407 | for_each_insn(file, insn) { |
442f04c3 JP |
408 | if (insn->type != INSN_CALL) |
409 | continue; | |
410 | ||
411 | rela = find_rela_by_dest_range(insn->sec, insn->offset, | |
412 | insn->len); | |
413 | if (!rela) { | |
414 | dest_off = insn->offset + insn->len + insn->immediate; | |
415 | insn->call_dest = find_symbol_by_offset(insn->sec, | |
416 | dest_off); | |
417 | if (!insn->call_dest) { | |
418 | WARN_FUNC("can't find call dest symbol at offset 0x%lx", | |
419 | insn->sec, insn->offset, dest_off); | |
420 | return -1; | |
421 | } | |
422 | } else if (rela->sym->type == STT_SECTION) { | |
423 | insn->call_dest = find_symbol_by_offset(rela->sym->sec, | |
424 | rela->addend+4); | |
425 | if (!insn->call_dest || | |
426 | insn->call_dest->type != STT_FUNC) { | |
427 | WARN_FUNC("can't find call dest symbol at %s+0x%x", | |
428 | insn->sec, insn->offset, | |
429 | rela->sym->sec->name, | |
430 | rela->addend + 4); | |
431 | return -1; | |
432 | } | |
433 | } else | |
434 | insn->call_dest = rela->sym; | |
435 | } | |
436 | ||
437 | return 0; | |
438 | } | |
439 | ||
440 | /* | |
441 | * The .alternatives section requires some extra special care, over and above | |
442 | * what other special sections require: | |
443 | * | |
444 | * 1. Because alternatives are patched in-place, we need to insert a fake jump | |
445 | * instruction at the end so that validate_branch() skips all the original | |
446 | * replaced instructions when validating the new instruction path. | |
447 | * | |
448 | * 2. An added wrinkle is that the new instruction length might be zero. In | |
449 | * that case the old instructions are replaced with noops. We simulate that | |
450 | * by creating a fake jump as the only new instruction. | |
451 | * | |
452 | * 3. In some cases, the alternative section includes an instruction which | |
453 | * conditionally jumps to the _end_ of the entry. We have to modify these | |
454 | * jumps' destinations to point back to .text rather than the end of the | |
455 | * entry in .altinstr_replacement. | |
456 | * | |
457 | * 4. It has been requested that we don't validate the !POPCNT feature path | |
458 | * which is a "very very small percentage of machines". | |
459 | */ | |
460 | static int handle_group_alt(struct objtool_file *file, | |
461 | struct special_alt *special_alt, | |
462 | struct instruction *orig_insn, | |
463 | struct instruction **new_insn) | |
464 | { | |
465 | struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump; | |
466 | unsigned long dest_off; | |
467 | ||
468 | last_orig_insn = NULL; | |
469 | insn = orig_insn; | |
74aec058 JP |
470 | sec_for_each_insn_from(file, insn) { |
471 | if (insn->offset >= special_alt->orig_off + special_alt->orig_len) | |
442f04c3 JP |
472 | break; |
473 | ||
474 | if (special_alt->skip_orig) | |
475 | insn->type = INSN_NOP; | |
476 | ||
477 | insn->alt_group = true; | |
478 | last_orig_insn = insn; | |
479 | } | |
480 | ||
74aec058 | 481 | if (!next_insn_same_sec(file, last_orig_insn)) { |
442f04c3 JP |
482 | WARN("%s: don't know how to handle alternatives at end of section", |
483 | special_alt->orig_sec->name); | |
484 | return -1; | |
485 | } | |
486 | ||
487 | fake_jump = malloc(sizeof(*fake_jump)); | |
488 | if (!fake_jump) { | |
489 | WARN("malloc failed"); | |
490 | return -1; | |
491 | } | |
492 | memset(fake_jump, 0, sizeof(*fake_jump)); | |
493 | INIT_LIST_HEAD(&fake_jump->alts); | |
494 | fake_jump->sec = special_alt->new_sec; | |
495 | fake_jump->offset = -1; | |
496 | fake_jump->type = INSN_JUMP_UNCONDITIONAL; | |
497 | fake_jump->jump_dest = list_next_entry(last_orig_insn, list); | |
498 | ||
499 | if (!special_alt->new_len) { | |
500 | *new_insn = fake_jump; | |
501 | return 0; | |
502 | } | |
503 | ||
504 | last_new_insn = NULL; | |
505 | insn = *new_insn; | |
74aec058 JP |
506 | sec_for_each_insn_from(file, insn) { |
507 | if (insn->offset >= special_alt->new_off + special_alt->new_len) | |
442f04c3 JP |
508 | break; |
509 | ||
510 | last_new_insn = insn; | |
511 | ||
512 | if (insn->type != INSN_JUMP_CONDITIONAL && | |
513 | insn->type != INSN_JUMP_UNCONDITIONAL) | |
514 | continue; | |
515 | ||
516 | if (!insn->immediate) | |
517 | continue; | |
518 | ||
519 | dest_off = insn->offset + insn->len + insn->immediate; | |
520 | if (dest_off == special_alt->new_off + special_alt->new_len) | |
521 | insn->jump_dest = fake_jump; | |
522 | ||
523 | if (!insn->jump_dest) { | |
524 | WARN_FUNC("can't find alternative jump destination", | |
525 | insn->sec, insn->offset); | |
526 | return -1; | |
527 | } | |
528 | } | |
529 | ||
530 | if (!last_new_insn) { | |
531 | WARN_FUNC("can't find last new alternative instruction", | |
532 | special_alt->new_sec, special_alt->new_off); | |
533 | return -1; | |
534 | } | |
535 | ||
536 | list_add(&fake_jump->list, &last_new_insn->list); | |
537 | ||
538 | return 0; | |
539 | } | |
540 | ||
541 | /* | |
542 | * A jump table entry can either convert a nop to a jump or a jump to a nop. | |
543 | * If the original instruction is a jump, make the alt entry an effective nop | |
544 | * by just skipping the original instruction. | |
545 | */ | |
546 | static int handle_jump_alt(struct objtool_file *file, | |
547 | struct special_alt *special_alt, | |
548 | struct instruction *orig_insn, | |
549 | struct instruction **new_insn) | |
550 | { | |
551 | if (orig_insn->type == INSN_NOP) | |
552 | return 0; | |
553 | ||
554 | if (orig_insn->type != INSN_JUMP_UNCONDITIONAL) { | |
555 | WARN_FUNC("unsupported instruction at jump label", | |
556 | orig_insn->sec, orig_insn->offset); | |
557 | return -1; | |
558 | } | |
559 | ||
560 | *new_insn = list_next_entry(orig_insn, list); | |
561 | return 0; | |
562 | } | |
563 | ||
564 | /* | |
565 | * Read all the special sections which have alternate instructions which can be | |
566 | * patched in or redirected to at runtime. Each instruction having alternate | |
567 | * instruction(s) has them added to its insn->alts list, which will be | |
568 | * traversed in validate_branch(). | |
569 | */ | |
a196e171 | 570 | static int add_special_section_alts(struct objtool_file *file) |
442f04c3 JP |
571 | { |
572 | struct list_head special_alts; | |
573 | struct instruction *orig_insn, *new_insn; | |
574 | struct special_alt *special_alt, *tmp; | |
575 | struct alternative *alt; | |
576 | int ret; | |
577 | ||
578 | ret = special_get_alts(file->elf, &special_alts); | |
579 | if (ret) | |
580 | return ret; | |
581 | ||
582 | list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { | |
583 | alt = malloc(sizeof(*alt)); | |
584 | if (!alt) { | |
585 | WARN("malloc failed"); | |
586 | ret = -1; | |
587 | goto out; | |
588 | } | |
589 | ||
74aec058 JP |
590 | orig_insn = find_insn(file, special_alt->orig_sec, |
591 | special_alt->orig_off); | |
442f04c3 JP |
592 | if (!orig_insn) { |
593 | WARN_FUNC("special: can't find orig instruction", | |
594 | special_alt->orig_sec, special_alt->orig_off); | |
595 | ret = -1; | |
596 | goto out; | |
597 | } | |
598 | ||
599 | new_insn = NULL; | |
600 | if (!special_alt->group || special_alt->new_len) { | |
74aec058 JP |
601 | new_insn = find_insn(file, special_alt->new_sec, |
602 | special_alt->new_off); | |
442f04c3 JP |
603 | if (!new_insn) { |
604 | WARN_FUNC("special: can't find new instruction", | |
605 | special_alt->new_sec, | |
606 | special_alt->new_off); | |
607 | ret = -1; | |
608 | goto out; | |
609 | } | |
610 | } | |
611 | ||
612 | if (special_alt->group) { | |
613 | ret = handle_group_alt(file, special_alt, orig_insn, | |
614 | &new_insn); | |
615 | if (ret) | |
616 | goto out; | |
617 | } else if (special_alt->jump_or_nop) { | |
618 | ret = handle_jump_alt(file, special_alt, orig_insn, | |
619 | &new_insn); | |
620 | if (ret) | |
621 | goto out; | |
622 | } | |
623 | ||
624 | alt->insn = new_insn; | |
625 | list_add_tail(&alt->list, &orig_insn->alts); | |
626 | ||
627 | list_del(&special_alt->list); | |
628 | free(special_alt); | |
629 | } | |
630 | ||
631 | out: | |
632 | return ret; | |
633 | } | |
634 | ||
8133fbb4 JP |
635 | static int add_switch_table(struct objtool_file *file, struct symbol *func, |
636 | struct instruction *insn, struct rela *table, | |
637 | struct rela *next_table) | |
442f04c3 | 638 | { |
8133fbb4 JP |
639 | struct rela *rela = table; |
640 | struct instruction *alt_insn; | |
442f04c3 JP |
641 | struct alternative *alt; |
642 | ||
8133fbb4 JP |
643 | list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) { |
644 | if (rela == next_table) | |
645 | break; | |
646 | ||
647 | if (rela->sym->sec != insn->sec || | |
648 | rela->addend <= func->offset || | |
649 | rela->addend >= func->offset + func->len) | |
650 | break; | |
651 | ||
652 | alt_insn = find_insn(file, insn->sec, rela->addend); | |
653 | if (!alt_insn) { | |
654 | WARN("%s: can't find instruction at %s+0x%x", | |
655 | file->rodata->rela->name, insn->sec->name, | |
656 | rela->addend); | |
657 | return -1; | |
658 | } | |
659 | ||
660 | alt = malloc(sizeof(*alt)); | |
661 | if (!alt) { | |
662 | WARN("malloc failed"); | |
663 | return -1; | |
664 | } | |
665 | ||
666 | alt->insn = alt_insn; | |
667 | list_add_tail(&alt->list, &insn->alts); | |
668 | } | |
669 | ||
670 | return 0; | |
671 | } | |
672 | ||
6d01f28b JP |
673 | /* |
674 | * find_switch_table() - Given a dynamic jump, find the switch jump table in | |
675 | * .rodata associated with it. | |
676 | * | |
677 | * There are 3 basic patterns: | |
678 | * | |
679 | * 1. jmpq *[rodata addr](,%reg,8) | |
680 | * | |
681 | * This is the most common case by far. It jumps to an address in a simple | |
682 | * jump table which is stored in .rodata. | |
683 | * | |
684 | * 2. jmpq *[rodata addr](%rip) | |
685 | * | |
686 | * This is caused by a rare GCC quirk, currently only seen in three driver | |
687 | * functions in the kernel, only with certain obscure non-distro configs. | |
688 | * | |
689 | * As part of an optimization, GCC makes a copy of an existing switch jump | |
690 | * table, modifies it, and then hard-codes the jump (albeit with an indirect | |
691 | * jump) to use a single entry in the table. The rest of the jump table and | |
692 | * some of its jump targets remain as dead code. | |
693 | * | |
694 | * In such a case we can just crudely ignore all unreachable instruction | |
695 | * warnings for the entire object file. Ideally we would just ignore them | |
696 | * for the function, but that would require redesigning the code quite a | |
697 | * bit. And honestly that's just not worth doing: unreachable instruction | |
698 | * warnings are of questionable value anyway, and this is such a rare issue. | |
699 | * | |
700 | * 3. mov [rodata addr],%reg1 | |
701 | * ... some instructions ... | |
702 | * jmpq *(%reg1,%reg2,8) | |
703 | * | |
704 | * This is a fairly uncommon pattern which is new for GCC 6. As of this | |
705 | * writing, there are 11 occurrences of it in the allmodconfig kernel. | |
706 | * | |
707 | * TODO: Once we have DWARF CFI and smarter instruction decoding logic, | |
708 | * ensure the same register is used in the mov and jump instructions. | |
709 | */ | |
710 | static struct rela *find_switch_table(struct objtool_file *file, | |
711 | struct symbol *func, | |
712 | struct instruction *insn) | |
8133fbb4 | 713 | { |
6d01f28b | 714 | struct rela *text_rela, *rodata_rela; |
8133fbb4 | 715 | |
6d01f28b JP |
716 | text_rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); |
717 | if (text_rela && text_rela->sym == file->rodata->sym) { | |
718 | /* case 1 */ | |
719 | rodata_rela = find_rela_by_dest(file->rodata, | |
720 | text_rela->addend); | |
721 | if (rodata_rela) | |
722 | return rodata_rela; | |
8133fbb4 | 723 | |
6d01f28b JP |
724 | /* case 2 */ |
725 | rodata_rela = find_rela_by_dest(file->rodata, | |
726 | text_rela->addend + 4); | |
727 | if (!rodata_rela) | |
728 | return NULL; | |
729 | file->ignore_unreachables = true; | |
730 | return rodata_rela; | |
731 | } | |
732 | ||
733 | /* case 3 */ | |
734 | func_for_each_insn_continue_reverse(file, func, insn) { | |
735 | if (insn->type == INSN_JUMP_UNCONDITIONAL || | |
736 | insn->type == INSN_JUMP_DYNAMIC) | |
737 | break; | |
442f04c3 | 738 | |
a196e171 JP |
739 | text_rela = find_rela_by_dest_range(insn->sec, insn->offset, |
740 | insn->len); | |
6d01f28b JP |
741 | if (text_rela && text_rela->sym == file->rodata->sym) |
742 | return find_rela_by_dest(file->rodata, | |
743 | text_rela->addend); | |
744 | } | |
442f04c3 | 745 | |
6d01f28b JP |
746 | return NULL; |
747 | } | |
8133fbb4 | 748 | |
6d01f28b JP |
749 | static int add_func_switch_tables(struct objtool_file *file, |
750 | struct symbol *func) | |
751 | { | |
752 | struct instruction *insn, *prev_jump = NULL; | |
753 | struct rela *rela, *prev_rela = NULL; | |
754 | int ret; | |
8133fbb4 | 755 | |
6d01f28b JP |
756 | func_for_each_insn(file, func, insn) { |
757 | if (insn->type != INSN_JUMP_DYNAMIC) | |
758 | continue; | |
759 | ||
760 | rela = find_switch_table(file, func, insn); | |
761 | if (!rela) | |
442f04c3 JP |
762 | continue; |
763 | ||
8133fbb4 JP |
764 | /* |
765 | * We found a switch table, but we don't know yet how big it | |
766 | * is. Don't add it until we reach the end of the function or | |
767 | * the beginning of another switch table in the same function. | |
768 | */ | |
769 | if (prev_jump) { | |
770 | ret = add_switch_table(file, func, prev_jump, prev_rela, | |
6d01f28b | 771 | rela); |
8133fbb4 JP |
772 | if (ret) |
773 | return ret; | |
442f04c3 JP |
774 | } |
775 | ||
8133fbb4 | 776 | prev_jump = insn; |
6d01f28b | 777 | prev_rela = rela; |
8133fbb4 | 778 | } |
442f04c3 | 779 | |
8133fbb4 JP |
780 | if (prev_jump) { |
781 | ret = add_switch_table(file, func, prev_jump, prev_rela, NULL); | |
782 | if (ret) | |
783 | return ret; | |
784 | } | |
785 | ||
786 | return 0; | |
787 | } | |
442f04c3 | 788 | |
8133fbb4 JP |
789 | /* |
790 | * For some switch statements, gcc generates a jump table in the .rodata | |
791 | * section which contains a list of addresses within the function to jump to. | |
792 | * This finds these jump tables and adds them to the insn->alts lists. | |
793 | */ | |
794 | static int add_switch_table_alts(struct objtool_file *file) | |
795 | { | |
796 | struct section *sec; | |
797 | struct symbol *func; | |
798 | int ret; | |
799 | ||
800 | if (!file->rodata || !file->rodata->rela) | |
801 | return 0; | |
802 | ||
803 | list_for_each_entry(sec, &file->elf->sections, list) { | |
804 | list_for_each_entry(func, &sec->symbol_list, list) { | |
805 | if (func->type != STT_FUNC) | |
806 | continue; | |
807 | ||
808 | ret = add_func_switch_tables(file, func); | |
809 | if (ret) | |
810 | return ret; | |
442f04c3 JP |
811 | } |
812 | } | |
813 | ||
814 | return 0; | |
815 | } | |
816 | ||
817 | static int decode_sections(struct objtool_file *file) | |
818 | { | |
819 | int ret; | |
820 | ||
821 | ret = decode_instructions(file); | |
822 | if (ret) | |
823 | return ret; | |
824 | ||
a196e171 | 825 | add_ignores(file); |
442f04c3 | 826 | |
a196e171 | 827 | ret = add_jump_destinations(file); |
442f04c3 JP |
828 | if (ret) |
829 | return ret; | |
830 | ||
a196e171 | 831 | ret = add_call_destinations(file); |
442f04c3 JP |
832 | if (ret) |
833 | return ret; | |
834 | ||
a196e171 | 835 | ret = add_special_section_alts(file); |
442f04c3 JP |
836 | if (ret) |
837 | return ret; | |
838 | ||
a196e171 | 839 | ret = add_switch_table_alts(file); |
442f04c3 JP |
840 | if (ret) |
841 | return ret; | |
842 | ||
843 | return 0; | |
844 | } | |
845 | ||
846 | static bool is_fentry_call(struct instruction *insn) | |
847 | { | |
848 | if (insn->type == INSN_CALL && | |
849 | insn->call_dest->type == STT_NOTYPE && | |
850 | !strcmp(insn->call_dest->name, "__fentry__")) | |
851 | return true; | |
852 | ||
853 | return false; | |
854 | } | |
855 | ||
856 | static bool has_modified_stack_frame(struct instruction *insn) | |
857 | { | |
858 | return (insn->state & STATE_FP_SAVED) || | |
859 | (insn->state & STATE_FP_SETUP); | |
860 | } | |
861 | ||
862 | static bool has_valid_stack_frame(struct instruction *insn) | |
863 | { | |
864 | return (insn->state & STATE_FP_SAVED) && | |
865 | (insn->state & STATE_FP_SETUP); | |
866 | } | |
867 | ||
d8d1b2cb JP |
868 | static unsigned int frame_state(unsigned long state) |
869 | { | |
870 | return (state & (STATE_FP_SAVED | STATE_FP_SETUP)); | |
871 | } | |
872 | ||
442f04c3 JP |
873 | /* |
874 | * Follow the branch starting at the given instruction, and recursively follow | |
875 | * any other branches (jumps). Meanwhile, track the frame pointer state at | |
876 | * each instruction and validate all the rules described in | |
877 | * tools/objtool/Documentation/stack-validation.txt. | |
878 | */ | |
879 | static int validate_branch(struct objtool_file *file, | |
880 | struct instruction *first, unsigned char first_state) | |
881 | { | |
882 | struct alternative *alt; | |
883 | struct instruction *insn; | |
884 | struct section *sec; | |
b1547d31 | 885 | struct symbol *func = NULL; |
442f04c3 | 886 | unsigned char state; |
1bcb58a0 | 887 | int ret; |
442f04c3 JP |
888 | |
889 | insn = first; | |
890 | sec = insn->sec; | |
891 | state = first_state; | |
892 | ||
893 | if (insn->alt_group && list_empty(&insn->alts)) { | |
894 | WARN_FUNC("don't know how to handle branch to middle of alternative instruction group", | |
895 | sec, insn->offset); | |
1bcb58a0 | 896 | return 1; |
442f04c3 JP |
897 | } |
898 | ||
899 | while (1) { | |
b1547d31 JP |
900 | if (file->c_file && insn->func) { |
901 | if (func && func != insn->func) { | |
902 | WARN("%s() falls through to next function %s()", | |
903 | func->name, insn->func->name); | |
904 | return 1; | |
905 | } | |
906 | ||
907 | func = insn->func; | |
908 | } | |
909 | ||
442f04c3 | 910 | if (insn->visited) { |
d8d1b2cb | 911 | if (frame_state(insn->state) != frame_state(state)) { |
442f04c3 JP |
912 | WARN_FUNC("frame pointer state mismatch", |
913 | sec, insn->offset); | |
1bcb58a0 | 914 | return 1; |
442f04c3 JP |
915 | } |
916 | ||
1bcb58a0 | 917 | return 0; |
442f04c3 JP |
918 | } |
919 | ||
442f04c3 JP |
920 | insn->visited = true; |
921 | insn->state = state; | |
922 | ||
923 | list_for_each_entry(alt, &insn->alts, list) { | |
924 | ret = validate_branch(file, alt->insn, state); | |
1bcb58a0 JP |
925 | if (ret) |
926 | return 1; | |
442f04c3 JP |
927 | } |
928 | ||
929 | switch (insn->type) { | |
930 | ||
931 | case INSN_FP_SAVE: | |
932 | if (!nofp) { | |
933 | if (state & STATE_FP_SAVED) { | |
934 | WARN_FUNC("duplicate frame pointer save", | |
935 | sec, insn->offset); | |
1bcb58a0 | 936 | return 1; |
442f04c3 JP |
937 | } |
938 | state |= STATE_FP_SAVED; | |
939 | } | |
940 | break; | |
941 | ||
942 | case INSN_FP_SETUP: | |
943 | if (!nofp) { | |
944 | if (state & STATE_FP_SETUP) { | |
945 | WARN_FUNC("duplicate frame pointer setup", | |
946 | sec, insn->offset); | |
1bcb58a0 | 947 | return 1; |
442f04c3 JP |
948 | } |
949 | state |= STATE_FP_SETUP; | |
950 | } | |
951 | break; | |
952 | ||
953 | case INSN_FP_RESTORE: | |
954 | if (!nofp) { | |
955 | if (has_valid_stack_frame(insn)) | |
956 | state &= ~STATE_FP_SETUP; | |
957 | ||
958 | state &= ~STATE_FP_SAVED; | |
959 | } | |
960 | break; | |
961 | ||
962 | case INSN_RETURN: | |
963 | if (!nofp && has_modified_stack_frame(insn)) { | |
964 | WARN_FUNC("return without frame pointer restore", | |
965 | sec, insn->offset); | |
1bcb58a0 | 966 | return 1; |
442f04c3 | 967 | } |
1bcb58a0 | 968 | return 0; |
442f04c3 JP |
969 | |
970 | case INSN_CALL: | |
971 | if (is_fentry_call(insn)) { | |
972 | state |= STATE_FENTRY; | |
973 | break; | |
974 | } | |
975 | ||
b1e03249 JP |
976 | ret = dead_end_function(file, insn->call_dest); |
977 | if (ret == 1) | |
1bcb58a0 | 978 | return 0; |
b1e03249 | 979 | if (ret == -1) |
1bcb58a0 | 980 | return 1; |
442f04c3 JP |
981 | |
982 | /* fallthrough */ | |
983 | case INSN_CALL_DYNAMIC: | |
984 | if (!nofp && !has_valid_stack_frame(insn)) { | |
985 | WARN_FUNC("call without frame pointer save/setup", | |
986 | sec, insn->offset); | |
1bcb58a0 | 987 | return 1; |
442f04c3 JP |
988 | } |
989 | break; | |
990 | ||
991 | case INSN_JUMP_CONDITIONAL: | |
992 | case INSN_JUMP_UNCONDITIONAL: | |
993 | if (insn->jump_dest) { | |
994 | ret = validate_branch(file, insn->jump_dest, | |
995 | state); | |
1bcb58a0 JP |
996 | if (ret) |
997 | return 1; | |
442f04c3 JP |
998 | } else if (has_modified_stack_frame(insn)) { |
999 | WARN_FUNC("sibling call from callable instruction with changed frame pointer", | |
1000 | sec, insn->offset); | |
1bcb58a0 | 1001 | return 1; |
442f04c3 JP |
1002 | } /* else it's a sibling call */ |
1003 | ||
1004 | if (insn->type == INSN_JUMP_UNCONDITIONAL) | |
1bcb58a0 | 1005 | return 0; |
442f04c3 JP |
1006 | |
1007 | break; | |
1008 | ||
1009 | case INSN_JUMP_DYNAMIC: | |
1010 | if (list_empty(&insn->alts) && | |
1011 | has_modified_stack_frame(insn)) { | |
1012 | WARN_FUNC("sibling call from callable instruction with changed frame pointer", | |
1013 | sec, insn->offset); | |
1bcb58a0 | 1014 | return 1; |
442f04c3 JP |
1015 | } |
1016 | ||
1bcb58a0 | 1017 | return 0; |
442f04c3 JP |
1018 | |
1019 | case INSN_BUG: | |
1bcb58a0 | 1020 | return 0; |
442f04c3 JP |
1021 | |
1022 | default: | |
1023 | break; | |
1024 | } | |
1025 | ||
74aec058 JP |
1026 | insn = next_insn_same_sec(file, insn); |
1027 | if (!insn) { | |
442f04c3 | 1028 | WARN("%s: unexpected end of section", sec->name); |
1bcb58a0 | 1029 | return 1; |
442f04c3 JP |
1030 | } |
1031 | } | |
1032 | ||
1bcb58a0 | 1033 | return 0; |
442f04c3 JP |
1034 | } |
1035 | ||
1036 | static bool is_gcov_insn(struct instruction *insn) | |
1037 | { | |
1038 | struct rela *rela; | |
1039 | struct section *sec; | |
1040 | struct symbol *sym; | |
1041 | unsigned long offset; | |
1042 | ||
1043 | rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len); | |
1044 | if (!rela) | |
1045 | return false; | |
1046 | ||
1047 | if (rela->sym->type != STT_SECTION) | |
1048 | return false; | |
1049 | ||
1050 | sec = rela->sym->sec; | |
1051 | offset = rela->addend + insn->offset + insn->len - rela->offset; | |
1052 | ||
a196e171 | 1053 | list_for_each_entry(sym, &sec->symbol_list, list) { |
442f04c3 JP |
1054 | if (sym->type != STT_OBJECT) |
1055 | continue; | |
1056 | ||
1057 | if (offset >= sym->offset && offset < sym->offset + sym->len) | |
1058 | return (!memcmp(sym->name, "__gcov0.", 8)); | |
1059 | } | |
1060 | ||
1061 | return false; | |
1062 | } | |
1063 | ||
1064 | static bool is_kasan_insn(struct instruction *insn) | |
1065 | { | |
1066 | return (insn->type == INSN_CALL && | |
1067 | !strcmp(insn->call_dest->name, "__asan_handle_no_return")); | |
1068 | } | |
1069 | ||
1070 | static bool is_ubsan_insn(struct instruction *insn) | |
1071 | { | |
1072 | return (insn->type == INSN_CALL && | |
1073 | !strcmp(insn->call_dest->name, | |
1074 | "__ubsan_handle_builtin_unreachable")); | |
1075 | } | |
1076 | ||
74aec058 JP |
1077 | static bool ignore_unreachable_insn(struct symbol *func, |
1078 | struct instruction *insn) | |
442f04c3 JP |
1079 | { |
1080 | int i; | |
1081 | ||
1082 | if (insn->type == INSN_NOP) | |
1083 | return true; | |
1084 | ||
1085 | if (is_gcov_insn(insn)) | |
1086 | return true; | |
1087 | ||
1088 | /* | |
1089 | * Check if this (or a subsequent) instruction is related to | |
1090 | * CONFIG_UBSAN or CONFIG_KASAN. | |
1091 | * | |
1092 | * End the search at 5 instructions to avoid going into the weeds. | |
1093 | */ | |
1094 | for (i = 0; i < 5; i++) { | |
1095 | ||
1096 | if (is_kasan_insn(insn) || is_ubsan_insn(insn)) | |
1097 | return true; | |
1098 | ||
1099 | if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) { | |
1100 | insn = insn->jump_dest; | |
1101 | continue; | |
1102 | } | |
1103 | ||
74aec058 | 1104 | if (insn->offset + insn->len >= func->offset + func->len) |
442f04c3 JP |
1105 | break; |
1106 | insn = list_next_entry(insn, list); | |
1107 | } | |
1108 | ||
1109 | return false; | |
1110 | } | |
1111 | ||
1112 | static int validate_functions(struct objtool_file *file) | |
1113 | { | |
1114 | struct section *sec; | |
1115 | struct symbol *func; | |
1116 | struct instruction *insn; | |
442f04c3 JP |
1117 | int ret, warnings = 0; |
1118 | ||
1119 | list_for_each_entry(sec, &file->elf->sections, list) { | |
a196e171 | 1120 | list_for_each_entry(func, &sec->symbol_list, list) { |
442f04c3 JP |
1121 | if (func->type != STT_FUNC) |
1122 | continue; | |
1123 | ||
74aec058 | 1124 | insn = find_insn(file, sec, func->offset); |
b1547d31 | 1125 | if (!insn) |
442f04c3 | 1126 | continue; |
442f04c3 JP |
1127 | |
1128 | ret = validate_branch(file, insn, 0); | |
1129 | warnings += ret; | |
1130 | } | |
1131 | } | |
1132 | ||
1133 | list_for_each_entry(sec, &file->elf->sections, list) { | |
a196e171 | 1134 | list_for_each_entry(func, &sec->symbol_list, list) { |
442f04c3 JP |
1135 | if (func->type != STT_FUNC) |
1136 | continue; | |
1137 | ||
74aec058 | 1138 | func_for_each_insn(file, func, insn) { |
442f04c3 JP |
1139 | if (insn->visited) |
1140 | continue; | |
1141 | ||
442f04c3 | 1142 | insn->visited = true; |
7e578441 JP |
1143 | |
1144 | if (file->ignore_unreachables || warnings || | |
1145 | ignore_unreachable_insn(func, insn)) | |
1146 | continue; | |
1147 | ||
1148 | WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset); | |
1149 | warnings++; | |
442f04c3 JP |
1150 | } |
1151 | } | |
1152 | } | |
1153 | ||
1154 | return warnings; | |
1155 | } | |
1156 | ||
1157 | static int validate_uncallable_instructions(struct objtool_file *file) | |
1158 | { | |
1159 | struct instruction *insn; | |
1160 | int warnings = 0; | |
1161 | ||
74aec058 | 1162 | for_each_insn(file, insn) { |
442f04c3 JP |
1163 | if (!insn->visited && insn->type == INSN_RETURN) { |
1164 | WARN_FUNC("return instruction outside of a callable function", | |
1165 | insn->sec, insn->offset); | |
1166 | warnings++; | |
1167 | } | |
1168 | } | |
1169 | ||
1170 | return warnings; | |
1171 | } | |
1172 | ||
1173 | static void cleanup(struct objtool_file *file) | |
1174 | { | |
1175 | struct instruction *insn, *tmpinsn; | |
1176 | struct alternative *alt, *tmpalt; | |
1177 | ||
a196e171 | 1178 | list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) { |
442f04c3 JP |
1179 | list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) { |
1180 | list_del(&alt->list); | |
1181 | free(alt); | |
1182 | } | |
1183 | list_del(&insn->list); | |
042ba73f | 1184 | hash_del(&insn->hash); |
442f04c3 JP |
1185 | free(insn); |
1186 | } | |
1187 | elf_close(file->elf); | |
1188 | } | |
1189 | ||
1190 | const char * const check_usage[] = { | |
1191 | "objtool check [<options>] file.o", | |
1192 | NULL, | |
1193 | }; | |
1194 | ||
1195 | int cmd_check(int argc, const char **argv) | |
1196 | { | |
1197 | struct objtool_file file; | |
1198 | int ret, warnings = 0; | |
1199 | ||
1200 | const struct option options[] = { | |
1201 | OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"), | |
1202 | OPT_END(), | |
1203 | }; | |
1204 | ||
1205 | argc = parse_options(argc, argv, options, check_usage, 0); | |
1206 | ||
1207 | if (argc != 1) | |
1208 | usage_with_options(check_usage, options); | |
1209 | ||
1210 | objname = argv[0]; | |
1211 | ||
1212 | file.elf = elf_open(objname); | |
1213 | if (!file.elf) { | |
1214 | fprintf(stderr, "error reading elf file %s\n", objname); | |
1215 | return 1; | |
1216 | } | |
1217 | ||
a196e171 | 1218 | INIT_LIST_HEAD(&file.insn_list); |
042ba73f | 1219 | hash_init(file.insn_hash); |
7e578441 JP |
1220 | file.whitelist = find_section_by_name(file.elf, "__func_stack_frame_non_standard"); |
1221 | file.rodata = find_section_by_name(file.elf, ".rodata"); | |
1222 | file.ignore_unreachables = false; | |
b1547d31 | 1223 | file.c_file = find_section_by_name(file.elf, ".comment"); |
442f04c3 JP |
1224 | |
1225 | ret = decode_sections(&file); | |
1226 | if (ret < 0) | |
1227 | goto out; | |
1228 | warnings += ret; | |
1229 | ||
1230 | ret = validate_functions(&file); | |
1231 | if (ret < 0) | |
1232 | goto out; | |
1233 | warnings += ret; | |
1234 | ||
1235 | ret = validate_uncallable_instructions(&file); | |
1236 | if (ret < 0) | |
1237 | goto out; | |
1238 | warnings += ret; | |
1239 | ||
1240 | out: | |
1241 | cleanup(&file); | |
1242 | ||
1243 | /* ignore warnings for now until we get all the code cleaned up */ | |
1244 | if (ret || warnings) | |
1245 | return 0; | |
1246 | return 0; | |
1247 | } |