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1ccea77e | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
dcc914f4 JP |
2 | /* |
3 | * Copyright (C) 2015-2017 Josh Poimboeuf <jpoimboe@redhat.com> | |
dcc914f4 JP |
4 | */ |
5 | ||
6 | #include <string.h> | |
7 | #include <stdlib.h> | |
8 | ||
7786032e VG |
9 | #include <arch/elf.h> |
10 | #include <objtool/builtin.h> | |
11 | #include <objtool/cfi.h> | |
12 | #include <objtool/arch.h> | |
13 | #include <objtool/check.h> | |
14 | #include <objtool/special.h> | |
15 | #include <objtool/warn.h> | |
16 | #include <objtool/endianness.h> | |
dcc914f4 | 17 | |
ee819aed | 18 | #include <linux/objtool.h> |
dcc914f4 JP |
19 | #include <linux/hashtable.h> |
20 | #include <linux/kernel.h> | |
1e7e4788 | 21 | #include <linux/static_call_types.h> |
dcc914f4 | 22 | |
dcc914f4 JP |
23 | struct alternative { |
24 | struct list_head list; | |
25 | struct instruction *insn; | |
764eef4b | 26 | bool skip_orig; |
dcc914f4 JP |
27 | }; |
28 | ||
a3608f59 | 29 | struct cfi_init_state initial_func_cfi; |
dcc914f4 | 30 | |
627fce14 JP |
31 | struct instruction *find_insn(struct objtool_file *file, |
32 | struct section *sec, unsigned long offset) | |
dcc914f4 JP |
33 | { |
34 | struct instruction *insn; | |
35 | ||
87ecb582 | 36 | hash_for_each_possible(file->insn_hash, insn, hash, sec_offset_hash(sec, offset)) { |
dcc914f4 JP |
37 | if (insn->sec == sec && insn->offset == offset) |
38 | return insn; | |
87ecb582 | 39 | } |
dcc914f4 JP |
40 | |
41 | return NULL; | |
42 | } | |
43 | ||
44 | static struct instruction *next_insn_same_sec(struct objtool_file *file, | |
45 | struct instruction *insn) | |
46 | { | |
47 | struct instruction *next = list_next_entry(insn, list); | |
48 | ||
baa41469 | 49 | if (!next || &next->list == &file->insn_list || next->sec != insn->sec) |
dcc914f4 JP |
50 | return NULL; |
51 | ||
52 | return next; | |
53 | } | |
54 | ||
13810435 JP |
55 | static struct instruction *next_insn_same_func(struct objtool_file *file, |
56 | struct instruction *insn) | |
57 | { | |
58 | struct instruction *next = list_next_entry(insn, list); | |
59 | struct symbol *func = insn->func; | |
60 | ||
61 | if (!func) | |
62 | return NULL; | |
63 | ||
64 | if (&next->list != &file->insn_list && next->func == func) | |
65 | return next; | |
66 | ||
67 | /* Check if we're already in the subfunction: */ | |
68 | if (func == func->cfunc) | |
69 | return NULL; | |
70 | ||
71 | /* Move to the subfunction: */ | |
72 | return find_insn(file, func->cfunc->sec, func->cfunc->offset); | |
73 | } | |
74 | ||
1119d265 JP |
75 | static struct instruction *prev_insn_same_sym(struct objtool_file *file, |
76 | struct instruction *insn) | |
77 | { | |
78 | struct instruction *prev = list_prev_entry(insn, list); | |
79 | ||
80 | if (&prev->list != &file->insn_list && prev->func == insn->func) | |
81 | return prev; | |
82 | ||
83 | return NULL; | |
84 | } | |
85 | ||
f0f70adb | 86 | #define func_for_each_insn(file, func, insn) \ |
13810435 JP |
87 | for (insn = find_insn(file, func->sec, func->offset); \ |
88 | insn; \ | |
89 | insn = next_insn_same_func(file, insn)) | |
90 | ||
dbf4aeb0 PZ |
91 | #define sym_for_each_insn(file, sym, insn) \ |
92 | for (insn = find_insn(file, sym->sec, sym->offset); \ | |
dcc914f4 | 93 | insn && &insn->list != &file->insn_list && \ |
dbf4aeb0 PZ |
94 | insn->sec == sym->sec && \ |
95 | insn->offset < sym->offset + sym->len; \ | |
dcc914f4 JP |
96 | insn = list_next_entry(insn, list)) |
97 | ||
dbf4aeb0 | 98 | #define sym_for_each_insn_continue_reverse(file, sym, insn) \ |
dcc914f4 JP |
99 | for (insn = list_prev_entry(insn, list); \ |
100 | &insn->list != &file->insn_list && \ | |
dbf4aeb0 | 101 | insn->sec == sym->sec && insn->offset >= sym->offset; \ |
dcc914f4 JP |
102 | insn = list_prev_entry(insn, list)) |
103 | ||
104 | #define sec_for_each_insn_from(file, insn) \ | |
105 | for (; insn; insn = next_insn_same_sec(file, insn)) | |
106 | ||
baa41469 JP |
107 | #define sec_for_each_insn_continue(file, insn) \ |
108 | for (insn = next_insn_same_sec(file, insn); insn; \ | |
109 | insn = next_insn_same_sec(file, insn)) | |
dcc914f4 | 110 | |
99033461 JP |
111 | static bool is_jump_table_jump(struct instruction *insn) |
112 | { | |
113 | struct alt_group *alt_group = insn->alt_group; | |
114 | ||
115 | if (insn->jump_table) | |
116 | return true; | |
117 | ||
118 | /* Retpoline alternative for a jump table? */ | |
119 | return alt_group && alt_group->orig_group && | |
120 | alt_group->orig_group->first_insn->jump_table; | |
121 | } | |
122 | ||
0c1ddd33 JP |
123 | static bool is_sibling_call(struct instruction *insn) |
124 | { | |
ecf11ba4 JP |
125 | /* |
126 | * Assume only ELF functions can make sibling calls. This ensures | |
127 | * sibling call detection consistency between vmlinux.o and individual | |
128 | * objects. | |
129 | */ | |
130 | if (!insn->func) | |
131 | return false; | |
132 | ||
0c1ddd33 JP |
133 | /* An indirect jump is either a sibling call or a jump to a table. */ |
134 | if (insn->type == INSN_JUMP_DYNAMIC) | |
99033461 | 135 | return !is_jump_table_jump(insn); |
0c1ddd33 | 136 | |
0c1ddd33 | 137 | /* add_jump_destinations() sets insn->call_dest for sibling calls. */ |
ecf11ba4 | 138 | return (is_static_jump(insn) && insn->call_dest); |
0c1ddd33 JP |
139 | } |
140 | ||
dcc914f4 JP |
141 | /* |
142 | * This checks to see if the given function is a "noreturn" function. | |
143 | * | |
144 | * For global functions which are outside the scope of this object file, we | |
145 | * have to keep a manual list of them. | |
146 | * | |
147 | * For local functions, we have to detect them manually by simply looking for | |
148 | * the lack of a return instruction. | |
dcc914f4 | 149 | */ |
8e25c9f8 JP |
150 | static bool __dead_end_function(struct objtool_file *file, struct symbol *func, |
151 | int recursion) | |
dcc914f4 JP |
152 | { |
153 | int i; | |
154 | struct instruction *insn; | |
155 | bool empty = true; | |
156 | ||
157 | /* | |
158 | * Unfortunately these have to be hard coded because the noreturn | |
159 | * attribute isn't provided in ELF data. | |
160 | */ | |
161 | static const char * const global_noreturns[] = { | |
162 | "__stack_chk_fail", | |
163 | "panic", | |
164 | "do_exit", | |
165 | "do_task_dead", | |
166 | "__module_put_and_exit", | |
167 | "complete_and_exit", | |
dcc914f4 JP |
168 | "__reiserfs_panic", |
169 | "lbug_with_loc", | |
170 | "fortify_panic", | |
b394d468 | 171 | "usercopy_abort", |
684fb246 | 172 | "machine_real_restart", |
4fa5ecda | 173 | "rewind_stack_do_exit", |
33adf80f | 174 | "kunit_try_catch_throw", |
c26acfbb | 175 | "xen_start_kernel", |
f12babfb | 176 | "cpu_bringup_and_idle", |
dcc914f4 JP |
177 | }; |
178 | ||
c9bab22b JP |
179 | if (!func) |
180 | return false; | |
181 | ||
dcc914f4 | 182 | if (func->bind == STB_WEAK) |
8e25c9f8 | 183 | return false; |
dcc914f4 JP |
184 | |
185 | if (func->bind == STB_GLOBAL) | |
186 | for (i = 0; i < ARRAY_SIZE(global_noreturns); i++) | |
187 | if (!strcmp(func->name, global_noreturns[i])) | |
8e25c9f8 | 188 | return true; |
dcc914f4 | 189 | |
13810435 | 190 | if (!func->len) |
8e25c9f8 | 191 | return false; |
dcc914f4 | 192 | |
13810435 JP |
193 | insn = find_insn(file, func->sec, func->offset); |
194 | if (!insn->func) | |
8e25c9f8 | 195 | return false; |
13810435 | 196 | |
f0f70adb | 197 | func_for_each_insn(file, func, insn) { |
dcc914f4 JP |
198 | empty = false; |
199 | ||
200 | if (insn->type == INSN_RETURN) | |
8e25c9f8 | 201 | return false; |
dcc914f4 JP |
202 | } |
203 | ||
204 | if (empty) | |
8e25c9f8 | 205 | return false; |
dcc914f4 JP |
206 | |
207 | /* | |
208 | * A function can have a sibling call instead of a return. In that | |
209 | * case, the function's dead-end status depends on whether the target | |
210 | * of the sibling call returns. | |
211 | */ | |
f0f70adb | 212 | func_for_each_insn(file, func, insn) { |
0c1ddd33 | 213 | if (is_sibling_call(insn)) { |
dcc914f4 | 214 | struct instruction *dest = insn->jump_dest; |
dcc914f4 JP |
215 | |
216 | if (!dest) | |
217 | /* sibling call to another file */ | |
8e25c9f8 | 218 | return false; |
dcc914f4 | 219 | |
0c1ddd33 JP |
220 | /* local sibling call */ |
221 | if (recursion == 5) { | |
222 | /* | |
223 | * Infinite recursion: two functions have | |
224 | * sibling calls to each other. This is a very | |
225 | * rare case. It means they aren't dead ends. | |
226 | */ | |
227 | return false; | |
dcc914f4 | 228 | } |
dcc914f4 | 229 | |
0c1ddd33 JP |
230 | return __dead_end_function(file, dest->func, recursion+1); |
231 | } | |
dcc914f4 JP |
232 | } |
233 | ||
8e25c9f8 | 234 | return true; |
dcc914f4 JP |
235 | } |
236 | ||
8e25c9f8 | 237 | static bool dead_end_function(struct objtool_file *file, struct symbol *func) |
dcc914f4 JP |
238 | { |
239 | return __dead_end_function(file, func, 0); | |
240 | } | |
241 | ||
e7c0219b | 242 | static void init_cfi_state(struct cfi_state *cfi) |
baa41469 JP |
243 | { |
244 | int i; | |
245 | ||
dd88a0a0 | 246 | for (i = 0; i < CFI_NUM_REGS; i++) { |
e7c0219b PZ |
247 | cfi->regs[i].base = CFI_UNDEFINED; |
248 | cfi->vals[i].base = CFI_UNDEFINED; | |
dd88a0a0 | 249 | } |
e7c0219b PZ |
250 | cfi->cfa.base = CFI_UNDEFINED; |
251 | cfi->drap_reg = CFI_UNDEFINED; | |
252 | cfi->drap_offset = -1; | |
253 | } | |
254 | ||
932f8e98 | 255 | static void init_insn_state(struct insn_state *state, struct section *sec) |
e7c0219b PZ |
256 | { |
257 | memset(state, 0, sizeof(*state)); | |
258 | init_cfi_state(&state->cfi); | |
932f8e98 PZ |
259 | |
260 | /* | |
261 | * We need the full vmlinux for noinstr validation, otherwise we can | |
262 | * not correctly determine insn->call_dest->sec (external symbols do | |
263 | * not have a section). | |
264 | */ | |
41425ebe | 265 | if (vmlinux && noinstr && sec) |
932f8e98 | 266 | state->noinstr = sec->noinstr; |
baa41469 JP |
267 | } |
268 | ||
dcc914f4 JP |
269 | /* |
270 | * Call the arch-specific instruction decoder for all the instructions and add | |
271 | * them to the global instruction list. | |
272 | */ | |
273 | static int decode_instructions(struct objtool_file *file) | |
274 | { | |
275 | struct section *sec; | |
276 | struct symbol *func; | |
277 | unsigned long offset; | |
278 | struct instruction *insn; | |
1e11f3fd | 279 | unsigned long nr_insns = 0; |
dcc914f4 JP |
280 | int ret; |
281 | ||
baa41469 | 282 | for_each_sec(file, sec) { |
dcc914f4 JP |
283 | |
284 | if (!(sec->sh.sh_flags & SHF_EXECINSTR)) | |
285 | continue; | |
286 | ||
627fce14 JP |
287 | if (strcmp(sec->name, ".altinstr_replacement") && |
288 | strcmp(sec->name, ".altinstr_aux") && | |
289 | strncmp(sec->name, ".discard.", 9)) | |
290 | sec->text = true; | |
291 | ||
0cc9ac8d TG |
292 | if (!strcmp(sec->name, ".noinstr.text") || |
293 | !strcmp(sec->name, ".entry.text")) | |
c4a33939 PZ |
294 | sec->noinstr = true; |
295 | ||
fe255fe6 | 296 | for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) { |
dcc914f4 | 297 | insn = malloc(sizeof(*insn)); |
baa41469 JP |
298 | if (!insn) { |
299 | WARN("malloc failed"); | |
300 | return -1; | |
301 | } | |
dcc914f4 | 302 | memset(insn, 0, sizeof(*insn)); |
dcc914f4 | 303 | INIT_LIST_HEAD(&insn->alts); |
65ea47dc | 304 | INIT_LIST_HEAD(&insn->stack_ops); |
e7c0219b | 305 | init_cfi_state(&insn->cfi); |
baa41469 | 306 | |
dcc914f4 JP |
307 | insn->sec = sec; |
308 | insn->offset = offset; | |
309 | ||
310 | ret = arch_decode_instruction(file->elf, sec, offset, | |
fe255fe6 | 311 | sec->sh.sh_size - offset, |
dcc914f4 | 312 | &insn->len, &insn->type, |
baa41469 | 313 | &insn->immediate, |
65ea47dc | 314 | &insn->stack_ops); |
dcc914f4 | 315 | if (ret) |
b7037983 | 316 | goto err; |
dcc914f4 | 317 | |
87ecb582 | 318 | hash_add(file->insn_hash, &insn->hash, sec_offset_hash(sec, insn->offset)); |
dcc914f4 | 319 | list_add_tail(&insn->list, &file->insn_list); |
1e11f3fd | 320 | nr_insns++; |
dcc914f4 JP |
321 | } |
322 | ||
323 | list_for_each_entry(func, &sec->symbol_list, list) { | |
e10cd8fe | 324 | if (func->type != STT_FUNC || func->alias != func) |
dcc914f4 JP |
325 | continue; |
326 | ||
327 | if (!find_insn(file, sec, func->offset)) { | |
328 | WARN("%s(): can't find starting instruction", | |
329 | func->name); | |
330 | return -1; | |
331 | } | |
332 | ||
dbf4aeb0 | 333 | sym_for_each_insn(file, func, insn) |
e10cd8fe | 334 | insn->func = func; |
dcc914f4 JP |
335 | } |
336 | } | |
337 | ||
1e11f3fd PZ |
338 | if (stats) |
339 | printf("nr_insns: %lu\n", nr_insns); | |
340 | ||
dcc914f4 | 341 | return 0; |
b7037983 KB |
342 | |
343 | err: | |
344 | free(insn); | |
345 | return ret; | |
dcc914f4 JP |
346 | } |
347 | ||
6b5dd716 ST |
348 | static struct instruction *find_last_insn(struct objtool_file *file, |
349 | struct section *sec) | |
350 | { | |
351 | struct instruction *insn = NULL; | |
352 | unsigned int offset; | |
fe255fe6 | 353 | unsigned int end = (sec->sh.sh_size > 10) ? sec->sh.sh_size - 10 : 0; |
6b5dd716 | 354 | |
fe255fe6 | 355 | for (offset = sec->sh.sh_size - 1; offset >= end && !insn; offset--) |
6b5dd716 ST |
356 | insn = find_insn(file, sec, offset); |
357 | ||
358 | return insn; | |
359 | } | |
360 | ||
dcc914f4 | 361 | /* |
649ea4d5 | 362 | * Mark "ud2" instructions and manually annotated dead ends. |
dcc914f4 JP |
363 | */ |
364 | static int add_dead_ends(struct objtool_file *file) | |
365 | { | |
366 | struct section *sec; | |
f1974222 | 367 | struct reloc *reloc; |
dcc914f4 | 368 | struct instruction *insn; |
dcc914f4 | 369 | |
649ea4d5 JP |
370 | /* |
371 | * By default, "ud2" is a dead end unless otherwise annotated, because | |
372 | * GCC 7 inserts it for certain divide-by-zero cases. | |
373 | */ | |
374 | for_each_insn(file, insn) | |
375 | if (insn->type == INSN_BUG) | |
376 | insn->dead_end = true; | |
377 | ||
378 | /* | |
379 | * Check for manually annotated dead ends. | |
380 | */ | |
dcc914f4 JP |
381 | sec = find_section_by_name(file->elf, ".rela.discard.unreachable"); |
382 | if (!sec) | |
649ea4d5 | 383 | goto reachable; |
dcc914f4 | 384 | |
f1974222 MH |
385 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
386 | if (reloc->sym->type != STT_SECTION) { | |
dcc914f4 JP |
387 | WARN("unexpected relocation symbol type in %s", sec->name); |
388 | return -1; | |
389 | } | |
f1974222 | 390 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
dcc914f4 JP |
391 | if (insn) |
392 | insn = list_prev_entry(insn, list); | |
fe255fe6 | 393 | else if (reloc->addend == reloc->sym->sec->sh.sh_size) { |
f1974222 | 394 | insn = find_last_insn(file, reloc->sym->sec); |
6b5dd716 | 395 | if (!insn) { |
dcc914f4 | 396 | WARN("can't find unreachable insn at %s+0x%x", |
f1974222 | 397 | reloc->sym->sec->name, reloc->addend); |
dcc914f4 JP |
398 | return -1; |
399 | } | |
400 | } else { | |
401 | WARN("can't find unreachable insn at %s+0x%x", | |
f1974222 | 402 | reloc->sym->sec->name, reloc->addend); |
dcc914f4 JP |
403 | return -1; |
404 | } | |
405 | ||
406 | insn->dead_end = true; | |
407 | } | |
408 | ||
649ea4d5 JP |
409 | reachable: |
410 | /* | |
411 | * These manually annotated reachable checks are needed for GCC 4.4, | |
412 | * where the Linux unreachable() macro isn't supported. In that case | |
413 | * GCC doesn't know the "ud2" is fatal, so it generates code as if it's | |
414 | * not a dead end. | |
415 | */ | |
416 | sec = find_section_by_name(file->elf, ".rela.discard.reachable"); | |
417 | if (!sec) | |
418 | return 0; | |
419 | ||
f1974222 MH |
420 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
421 | if (reloc->sym->type != STT_SECTION) { | |
649ea4d5 JP |
422 | WARN("unexpected relocation symbol type in %s", sec->name); |
423 | return -1; | |
424 | } | |
f1974222 | 425 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
649ea4d5 JP |
426 | if (insn) |
427 | insn = list_prev_entry(insn, list); | |
fe255fe6 | 428 | else if (reloc->addend == reloc->sym->sec->sh.sh_size) { |
f1974222 | 429 | insn = find_last_insn(file, reloc->sym->sec); |
6b5dd716 | 430 | if (!insn) { |
649ea4d5 | 431 | WARN("can't find reachable insn at %s+0x%x", |
f1974222 | 432 | reloc->sym->sec->name, reloc->addend); |
649ea4d5 JP |
433 | return -1; |
434 | } | |
435 | } else { | |
436 | WARN("can't find reachable insn at %s+0x%x", | |
f1974222 | 437 | reloc->sym->sec->name, reloc->addend); |
649ea4d5 JP |
438 | return -1; |
439 | } | |
440 | ||
441 | insn->dead_end = false; | |
442 | } | |
443 | ||
dcc914f4 JP |
444 | return 0; |
445 | } | |
446 | ||
1e7e4788 JP |
447 | static int create_static_call_sections(struct objtool_file *file) |
448 | { | |
ef47cc01 | 449 | struct section *sec; |
1e7e4788 JP |
450 | struct static_call_site *site; |
451 | struct instruction *insn; | |
452 | struct symbol *key_sym; | |
453 | char *key_name, *tmp; | |
454 | int idx; | |
455 | ||
456 | sec = find_section_by_name(file->elf, ".static_call_sites"); | |
457 | if (sec) { | |
458 | INIT_LIST_HEAD(&file->static_call_list); | |
459 | WARN("file already has .static_call_sites section, skipping"); | |
460 | return 0; | |
461 | } | |
462 | ||
463 | if (list_empty(&file->static_call_list)) | |
464 | return 0; | |
465 | ||
466 | idx = 0; | |
43d5430a | 467 | list_for_each_entry(insn, &file->static_call_list, call_node) |
1e7e4788 JP |
468 | idx++; |
469 | ||
470 | sec = elf_create_section(file->elf, ".static_call_sites", SHF_WRITE, | |
471 | sizeof(struct static_call_site), idx); | |
472 | if (!sec) | |
473 | return -1; | |
474 | ||
1e7e4788 | 475 | idx = 0; |
43d5430a | 476 | list_for_each_entry(insn, &file->static_call_list, call_node) { |
1e7e4788 JP |
477 | |
478 | site = (struct static_call_site *)sec->data->d_buf + idx; | |
479 | memset(site, 0, sizeof(struct static_call_site)); | |
480 | ||
481 | /* populate reloc for 'addr' */ | |
ef47cc01 PZ |
482 | if (elf_add_reloc_to_insn(file->elf, sec, |
483 | idx * sizeof(struct static_call_site), | |
484 | R_X86_64_PC32, | |
485 | insn->sec, insn->offset)) | |
44f6a7c0 | 486 | return -1; |
1e7e4788 JP |
487 | |
488 | /* find key symbol */ | |
489 | key_name = strdup(insn->call_dest->name); | |
490 | if (!key_name) { | |
491 | perror("strdup"); | |
492 | return -1; | |
493 | } | |
494 | if (strncmp(key_name, STATIC_CALL_TRAMP_PREFIX_STR, | |
495 | STATIC_CALL_TRAMP_PREFIX_LEN)) { | |
496 | WARN("static_call: trampoline name malformed: %s", key_name); | |
497 | return -1; | |
498 | } | |
499 | tmp = key_name + STATIC_CALL_TRAMP_PREFIX_LEN - STATIC_CALL_KEY_PREFIX_LEN; | |
500 | memcpy(tmp, STATIC_CALL_KEY_PREFIX_STR, STATIC_CALL_KEY_PREFIX_LEN); | |
501 | ||
502 | key_sym = find_symbol_by_name(file->elf, tmp); | |
503 | if (!key_sym) { | |
73f44fe1 JP |
504 | if (!module) { |
505 | WARN("static_call: can't find static_call_key symbol: %s", tmp); | |
506 | return -1; | |
507 | } | |
508 | ||
509 | /* | |
510 | * For modules(), the key might not be exported, which | |
511 | * means the module can make static calls but isn't | |
512 | * allowed to change them. | |
513 | * | |
514 | * In that case we temporarily set the key to be the | |
515 | * trampoline address. This is fixed up in | |
516 | * static_call_add_module(). | |
517 | */ | |
518 | key_sym = insn->call_dest; | |
1e7e4788 JP |
519 | } |
520 | free(key_name); | |
521 | ||
522 | /* populate reloc for 'key' */ | |
ef47cc01 PZ |
523 | if (elf_add_reloc(file->elf, sec, |
524 | idx * sizeof(struct static_call_site) + 4, | |
525 | R_X86_64_PC32, key_sym, | |
526 | is_sibling_call(insn) * STATIC_CALL_SITE_TAIL)) | |
1e7e4788 | 527 | return -1; |
1e7e4788 JP |
528 | |
529 | idx++; | |
530 | } | |
531 | ||
1e7e4788 JP |
532 | return 0; |
533 | } | |
534 | ||
99d00215 PZ |
535 | static int create_mcount_loc_sections(struct objtool_file *file) |
536 | { | |
ef47cc01 | 537 | struct section *sec; |
99d00215 PZ |
538 | unsigned long *loc; |
539 | struct instruction *insn; | |
540 | int idx; | |
541 | ||
542 | sec = find_section_by_name(file->elf, "__mcount_loc"); | |
543 | if (sec) { | |
544 | INIT_LIST_HEAD(&file->mcount_loc_list); | |
545 | WARN("file already has __mcount_loc section, skipping"); | |
546 | return 0; | |
547 | } | |
548 | ||
549 | if (list_empty(&file->mcount_loc_list)) | |
550 | return 0; | |
551 | ||
552 | idx = 0; | |
553 | list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) | |
554 | idx++; | |
555 | ||
556 | sec = elf_create_section(file->elf, "__mcount_loc", 0, sizeof(unsigned long), idx); | |
557 | if (!sec) | |
558 | return -1; | |
559 | ||
99d00215 PZ |
560 | idx = 0; |
561 | list_for_each_entry(insn, &file->mcount_loc_list, mcount_loc_node) { | |
562 | ||
563 | loc = (unsigned long *)sec->data->d_buf + idx; | |
564 | memset(loc, 0, sizeof(unsigned long)); | |
565 | ||
ef47cc01 PZ |
566 | if (elf_add_reloc_to_insn(file->elf, sec, |
567 | idx * sizeof(unsigned long), | |
568 | R_X86_64_64, | |
569 | insn->sec, insn->offset)) | |
99d00215 | 570 | return -1; |
99d00215 PZ |
571 | |
572 | idx++; | |
573 | } | |
574 | ||
99d00215 PZ |
575 | return 0; |
576 | } | |
577 | ||
dcc914f4 JP |
578 | /* |
579 | * Warnings shouldn't be reported for ignored functions. | |
580 | */ | |
581 | static void add_ignores(struct objtool_file *file) | |
582 | { | |
583 | struct instruction *insn; | |
584 | struct section *sec; | |
585 | struct symbol *func; | |
f1974222 | 586 | struct reloc *reloc; |
dcc914f4 | 587 | |
aaf5c623 PZ |
588 | sec = find_section_by_name(file->elf, ".rela.discard.func_stack_frame_non_standard"); |
589 | if (!sec) | |
590 | return; | |
dcc914f4 | 591 | |
f1974222 MH |
592 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
593 | switch (reloc->sym->type) { | |
aaf5c623 | 594 | case STT_FUNC: |
f1974222 | 595 | func = reloc->sym; |
aaf5c623 PZ |
596 | break; |
597 | ||
598 | case STT_SECTION: | |
f1974222 | 599 | func = find_func_by_offset(reloc->sym->sec, reloc->addend); |
7acfe531 | 600 | if (!func) |
dcc914f4 | 601 | continue; |
aaf5c623 | 602 | break; |
dcc914f4 | 603 | |
aaf5c623 | 604 | default: |
f1974222 | 605 | WARN("unexpected relocation symbol type in %s: %d", sec->name, reloc->sym->type); |
aaf5c623 | 606 | continue; |
dcc914f4 | 607 | } |
aaf5c623 | 608 | |
f0f70adb | 609 | func_for_each_insn(file, func, insn) |
aaf5c623 | 610 | insn->ignore = true; |
dcc914f4 JP |
611 | } |
612 | } | |
613 | ||
ea24213d PZ |
614 | /* |
615 | * This is a whitelist of functions that is allowed to be called with AC set. | |
616 | * The list is meant to be minimal and only contains compiler instrumentation | |
617 | * ABI and a few functions used to implement *_{to,from}_user() functions. | |
618 | * | |
619 | * These functions must not directly change AC, but may PUSHF/POPF. | |
620 | */ | |
621 | static const char *uaccess_safe_builtin[] = { | |
622 | /* KASAN */ | |
623 | "kasan_report", | |
f00748bf | 624 | "kasan_check_range", |
ea24213d PZ |
625 | /* KASAN out-of-line */ |
626 | "__asan_loadN_noabort", | |
627 | "__asan_load1_noabort", | |
628 | "__asan_load2_noabort", | |
629 | "__asan_load4_noabort", | |
630 | "__asan_load8_noabort", | |
631 | "__asan_load16_noabort", | |
632 | "__asan_storeN_noabort", | |
633 | "__asan_store1_noabort", | |
634 | "__asan_store2_noabort", | |
635 | "__asan_store4_noabort", | |
636 | "__asan_store8_noabort", | |
637 | "__asan_store16_noabort", | |
b0b8e56b JH |
638 | "__kasan_check_read", |
639 | "__kasan_check_write", | |
ea24213d PZ |
640 | /* KASAN in-line */ |
641 | "__asan_report_load_n_noabort", | |
642 | "__asan_report_load1_noabort", | |
643 | "__asan_report_load2_noabort", | |
644 | "__asan_report_load4_noabort", | |
645 | "__asan_report_load8_noabort", | |
646 | "__asan_report_load16_noabort", | |
647 | "__asan_report_store_n_noabort", | |
648 | "__asan_report_store1_noabort", | |
649 | "__asan_report_store2_noabort", | |
650 | "__asan_report_store4_noabort", | |
651 | "__asan_report_store8_noabort", | |
652 | "__asan_report_store16_noabort", | |
5f5c9712 | 653 | /* KCSAN */ |
9967683c | 654 | "__kcsan_check_access", |
5f5c9712 ME |
655 | "kcsan_found_watchpoint", |
656 | "kcsan_setup_watchpoint", | |
9967683c | 657 | "kcsan_check_scoped_accesses", |
50a19ad4 ME |
658 | "kcsan_disable_current", |
659 | "kcsan_enable_current_nowarn", | |
5f5c9712 ME |
660 | /* KCSAN/TSAN */ |
661 | "__tsan_func_entry", | |
662 | "__tsan_func_exit", | |
663 | "__tsan_read_range", | |
664 | "__tsan_write_range", | |
665 | "__tsan_read1", | |
666 | "__tsan_read2", | |
667 | "__tsan_read4", | |
668 | "__tsan_read8", | |
669 | "__tsan_read16", | |
670 | "__tsan_write1", | |
671 | "__tsan_write2", | |
672 | "__tsan_write4", | |
673 | "__tsan_write8", | |
674 | "__tsan_write16", | |
a81b3759 ME |
675 | "__tsan_read_write1", |
676 | "__tsan_read_write2", | |
677 | "__tsan_read_write4", | |
678 | "__tsan_read_write8", | |
679 | "__tsan_read_write16", | |
883957b1 ME |
680 | "__tsan_atomic8_load", |
681 | "__tsan_atomic16_load", | |
682 | "__tsan_atomic32_load", | |
683 | "__tsan_atomic64_load", | |
684 | "__tsan_atomic8_store", | |
685 | "__tsan_atomic16_store", | |
686 | "__tsan_atomic32_store", | |
687 | "__tsan_atomic64_store", | |
688 | "__tsan_atomic8_exchange", | |
689 | "__tsan_atomic16_exchange", | |
690 | "__tsan_atomic32_exchange", | |
691 | "__tsan_atomic64_exchange", | |
692 | "__tsan_atomic8_fetch_add", | |
693 | "__tsan_atomic16_fetch_add", | |
694 | "__tsan_atomic32_fetch_add", | |
695 | "__tsan_atomic64_fetch_add", | |
696 | "__tsan_atomic8_fetch_sub", | |
697 | "__tsan_atomic16_fetch_sub", | |
698 | "__tsan_atomic32_fetch_sub", | |
699 | "__tsan_atomic64_fetch_sub", | |
700 | "__tsan_atomic8_fetch_and", | |
701 | "__tsan_atomic16_fetch_and", | |
702 | "__tsan_atomic32_fetch_and", | |
703 | "__tsan_atomic64_fetch_and", | |
704 | "__tsan_atomic8_fetch_or", | |
705 | "__tsan_atomic16_fetch_or", | |
706 | "__tsan_atomic32_fetch_or", | |
707 | "__tsan_atomic64_fetch_or", | |
708 | "__tsan_atomic8_fetch_xor", | |
709 | "__tsan_atomic16_fetch_xor", | |
710 | "__tsan_atomic32_fetch_xor", | |
711 | "__tsan_atomic64_fetch_xor", | |
712 | "__tsan_atomic8_fetch_nand", | |
713 | "__tsan_atomic16_fetch_nand", | |
714 | "__tsan_atomic32_fetch_nand", | |
715 | "__tsan_atomic64_fetch_nand", | |
716 | "__tsan_atomic8_compare_exchange_strong", | |
717 | "__tsan_atomic16_compare_exchange_strong", | |
718 | "__tsan_atomic32_compare_exchange_strong", | |
719 | "__tsan_atomic64_compare_exchange_strong", | |
720 | "__tsan_atomic8_compare_exchange_weak", | |
721 | "__tsan_atomic16_compare_exchange_weak", | |
722 | "__tsan_atomic32_compare_exchange_weak", | |
723 | "__tsan_atomic64_compare_exchange_weak", | |
724 | "__tsan_atomic8_compare_exchange_val", | |
725 | "__tsan_atomic16_compare_exchange_val", | |
726 | "__tsan_atomic32_compare_exchange_val", | |
727 | "__tsan_atomic64_compare_exchange_val", | |
728 | "__tsan_atomic_thread_fence", | |
729 | "__tsan_atomic_signal_fence", | |
ea24213d PZ |
730 | /* KCOV */ |
731 | "write_comp_data", | |
ae033f08 | 732 | "check_kcov_mode", |
ea24213d PZ |
733 | "__sanitizer_cov_trace_pc", |
734 | "__sanitizer_cov_trace_const_cmp1", | |
735 | "__sanitizer_cov_trace_const_cmp2", | |
736 | "__sanitizer_cov_trace_const_cmp4", | |
737 | "__sanitizer_cov_trace_const_cmp8", | |
738 | "__sanitizer_cov_trace_cmp1", | |
739 | "__sanitizer_cov_trace_cmp2", | |
740 | "__sanitizer_cov_trace_cmp4", | |
741 | "__sanitizer_cov_trace_cmp8", | |
36b1c700 | 742 | "__sanitizer_cov_trace_switch", |
ea24213d PZ |
743 | /* UBSAN */ |
744 | "ubsan_type_mismatch_common", | |
745 | "__ubsan_handle_type_mismatch", | |
746 | "__ubsan_handle_type_mismatch_v1", | |
9a50dcaf | 747 | "__ubsan_handle_shift_out_of_bounds", |
ea24213d PZ |
748 | /* misc */ |
749 | "csum_partial_copy_generic", | |
ec6347bb DW |
750 | "copy_mc_fragile", |
751 | "copy_mc_fragile_handle_tail", | |
5da8e4a6 | 752 | "copy_mc_enhanced_fast_string", |
ea24213d PZ |
753 | "ftrace_likely_update", /* CONFIG_TRACE_BRANCH_PROFILING */ |
754 | NULL | |
755 | }; | |
756 | ||
757 | static void add_uaccess_safe(struct objtool_file *file) | |
758 | { | |
759 | struct symbol *func; | |
760 | const char **name; | |
761 | ||
762 | if (!uaccess) | |
763 | return; | |
764 | ||
765 | for (name = uaccess_safe_builtin; *name; name++) { | |
766 | func = find_symbol_by_name(file->elf, *name); | |
767 | if (!func) | |
768 | continue; | |
769 | ||
e10cd8fe | 770 | func->uaccess_safe = true; |
dcc914f4 JP |
771 | } |
772 | } | |
773 | ||
258c7605 JP |
774 | /* |
775 | * FIXME: For now, just ignore any alternatives which add retpolines. This is | |
776 | * a temporary hack, as it doesn't allow ORC to unwind from inside a retpoline. | |
777 | * But it at least allows objtool to understand the control flow *around* the | |
778 | * retpoline. | |
779 | */ | |
ff05ab23 | 780 | static int add_ignore_alternatives(struct objtool_file *file) |
258c7605 JP |
781 | { |
782 | struct section *sec; | |
f1974222 | 783 | struct reloc *reloc; |
258c7605 JP |
784 | struct instruction *insn; |
785 | ||
ff05ab23 | 786 | sec = find_section_by_name(file->elf, ".rela.discard.ignore_alts"); |
258c7605 JP |
787 | if (!sec) |
788 | return 0; | |
789 | ||
f1974222 MH |
790 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
791 | if (reloc->sym->type != STT_SECTION) { | |
258c7605 JP |
792 | WARN("unexpected relocation symbol type in %s", sec->name); |
793 | return -1; | |
794 | } | |
795 | ||
f1974222 | 796 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
258c7605 | 797 | if (!insn) { |
ff05ab23 | 798 | WARN("bad .discard.ignore_alts entry"); |
258c7605 JP |
799 | return -1; |
800 | } | |
801 | ||
802 | insn->ignore_alts = true; | |
803 | } | |
804 | ||
805 | return 0; | |
806 | } | |
807 | ||
530b4ddd PZ |
808 | __weak bool arch_is_retpoline(struct symbol *sym) |
809 | { | |
810 | return false; | |
811 | } | |
812 | ||
7bd2a600 PZ |
813 | #define NEGATIVE_RELOC ((void *)-1L) |
814 | ||
815 | static struct reloc *insn_reloc(struct objtool_file *file, struct instruction *insn) | |
816 | { | |
817 | if (insn->reloc == NEGATIVE_RELOC) | |
818 | return NULL; | |
819 | ||
820 | if (!insn->reloc) { | |
821 | insn->reloc = find_reloc_by_dest_range(file->elf, insn->sec, | |
822 | insn->offset, insn->len); | |
823 | if (!insn->reloc) { | |
824 | insn->reloc = NEGATIVE_RELOC; | |
825 | return NULL; | |
826 | } | |
827 | } | |
828 | ||
829 | return insn->reloc; | |
830 | } | |
831 | ||
3f86188b PZ |
832 | static void remove_insn_ops(struct instruction *insn) |
833 | { | |
834 | struct stack_op *op, *tmp; | |
835 | ||
836 | list_for_each_entry_safe(op, tmp, &insn->stack_ops, list) { | |
837 | list_del(&op->list); | |
838 | free(op); | |
839 | } | |
840 | } | |
841 | ||
842 | static void add_call_dest(struct objtool_file *file, struct instruction *insn, | |
843 | struct symbol *dest, bool sibling) | |
844 | { | |
845 | struct reloc *reloc = insn_reloc(file, insn); | |
846 | ||
847 | insn->call_dest = dest; | |
848 | if (!dest) | |
849 | return; | |
850 | ||
851 | if (insn->call_dest->static_call_tramp) { | |
852 | list_add_tail(&insn->call_node, | |
853 | &file->static_call_list); | |
854 | } | |
855 | ||
856 | /* | |
857 | * Many compilers cannot disable KCOV with a function attribute | |
858 | * so they need a little help, NOP out any KCOV calls from noinstr | |
859 | * text. | |
860 | */ | |
2e532bd1 | 861 | if (insn->sec->noinstr && insn->call_dest->kcov) { |
3f86188b PZ |
862 | if (reloc) { |
863 | reloc->type = R_NONE; | |
864 | elf_write_reloc(file->elf, reloc); | |
865 | } | |
866 | ||
867 | elf_write_insn(file->elf, insn->sec, | |
868 | insn->offset, insn->len, | |
869 | sibling ? arch_ret_insn(insn->len) | |
870 | : arch_nop_insn(insn->len)); | |
871 | ||
872 | insn->type = sibling ? INSN_RETURN : INSN_NOP; | |
873 | } | |
874 | ||
2e532bd1 | 875 | if (mcount && insn->call_dest->fentry) { |
3f86188b PZ |
876 | if (sibling) |
877 | WARN_FUNC("Tail call to __fentry__ !?!?", insn->sec, insn->offset); | |
878 | ||
879 | if (reloc) { | |
880 | reloc->type = R_NONE; | |
881 | elf_write_reloc(file->elf, reloc); | |
882 | } | |
883 | ||
884 | elf_write_insn(file->elf, insn->sec, | |
885 | insn->offset, insn->len, | |
886 | arch_nop_insn(insn->len)); | |
887 | ||
888 | insn->type = INSN_NOP; | |
889 | ||
890 | list_add_tail(&insn->mcount_loc_node, | |
891 | &file->mcount_loc_list); | |
892 | } | |
893 | ||
894 | /* | |
895 | * Whatever stack impact regular CALLs have, should be undone | |
896 | * by the RETURN of the called function. | |
897 | * | |
898 | * Annotated intra-function calls retain the stack_ops but | |
899 | * are converted to JUMP, see read_intra_function_calls(). | |
900 | */ | |
901 | remove_insn_ops(insn); | |
902 | } | |
903 | ||
dcc914f4 JP |
904 | /* |
905 | * Find the destination instructions for all jumps. | |
906 | */ | |
907 | static int add_jump_destinations(struct objtool_file *file) | |
908 | { | |
909 | struct instruction *insn; | |
f1974222 | 910 | struct reloc *reloc; |
dcc914f4 JP |
911 | struct section *dest_sec; |
912 | unsigned long dest_off; | |
913 | ||
914 | for_each_insn(file, insn) { | |
a2296140 | 915 | if (!is_static_jump(insn)) |
dcc914f4 JP |
916 | continue; |
917 | ||
7bd2a600 | 918 | reloc = insn_reloc(file, insn); |
f1974222 | 919 | if (!reloc) { |
dcc914f4 | 920 | dest_sec = insn->sec; |
bfb08f22 | 921 | dest_off = arch_jump_destination(insn); |
f1974222 MH |
922 | } else if (reloc->sym->type == STT_SECTION) { |
923 | dest_sec = reloc->sym->sec; | |
924 | dest_off = arch_dest_reloc_offset(reloc->addend); | |
2e532bd1 | 925 | } else if (reloc->sym->retpoline_thunk) { |
39b73533 JP |
926 | /* |
927 | * Retpoline jumps are really dynamic jumps in | |
928 | * disguise, so convert them accordingly. | |
929 | */ | |
b68b9907 JP |
930 | if (insn->type == INSN_JUMP_UNCONDITIONAL) |
931 | insn->type = INSN_JUMP_DYNAMIC; | |
932 | else | |
933 | insn->type = INSN_JUMP_DYNAMIC_CONDITIONAL; | |
934 | ||
43d5430a PZ |
935 | list_add_tail(&insn->call_node, |
936 | &file->retpoline_call_list); | |
937 | ||
b5bc2231 | 938 | insn->retpoline_safe = true; |
39b73533 | 939 | continue; |
ecf11ba4 JP |
940 | } else if (insn->func) { |
941 | /* internal or external sibling call (with reloc) */ | |
3f86188b | 942 | add_call_dest(file, insn, reloc->sym, true); |
dcc914f4 | 943 | continue; |
ecf11ba4 JP |
944 | } else if (reloc->sym->sec->idx) { |
945 | dest_sec = reloc->sym->sec; | |
946 | dest_off = reloc->sym->sym.st_value + | |
947 | arch_dest_reloc_offset(reloc->addend); | |
948 | } else { | |
949 | /* non-func asm code jumping to another file */ | |
950 | continue; | |
dcc914f4 JP |
951 | } |
952 | ||
953 | insn->jump_dest = find_insn(file, dest_sec, dest_off); | |
954 | if (!insn->jump_dest) { | |
955 | ||
956 | /* | |
957 | * This is a special case where an alt instruction | |
958 | * jumps past the end of the section. These are | |
959 | * handled later in handle_group_alt(). | |
960 | */ | |
961 | if (!strcmp(insn->sec->name, ".altinstr_replacement")) | |
962 | continue; | |
963 | ||
964 | WARN_FUNC("can't find jump dest instruction at %s+0x%lx", | |
965 | insn->sec, insn->offset, dest_sec->name, | |
966 | dest_off); | |
967 | return -1; | |
968 | } | |
cd77849a JP |
969 | |
970 | /* | |
54262aa2 | 971 | * Cross-function jump. |
cd77849a JP |
972 | */ |
973 | if (insn->func && insn->jump_dest->func && | |
54262aa2 PZ |
974 | insn->func != insn->jump_dest->func) { |
975 | ||
976 | /* | |
977 | * For GCC 8+, create parent/child links for any cold | |
978 | * subfunctions. This is _mostly_ redundant with a | |
979 | * similar initialization in read_symbols(). | |
980 | * | |
981 | * If a function has aliases, we want the *first* such | |
982 | * function in the symbol table to be the subfunction's | |
983 | * parent. In that case we overwrite the | |
984 | * initialization done in read_symbols(). | |
985 | * | |
986 | * However this code can't completely replace the | |
987 | * read_symbols() code because this doesn't detect the | |
988 | * case where the parent function's only reference to a | |
e7c2bc37 | 989 | * subfunction is through a jump table. |
54262aa2 | 990 | */ |
34ca59e1 JP |
991 | if (!strstr(insn->func->name, ".cold") && |
992 | strstr(insn->jump_dest->func->name, ".cold")) { | |
54262aa2 PZ |
993 | insn->func->cfunc = insn->jump_dest->func; |
994 | insn->jump_dest->func->pfunc = insn->func; | |
995 | ||
996 | } else if (insn->jump_dest->func->pfunc != insn->func->pfunc && | |
997 | insn->jump_dest->offset == insn->jump_dest->func->offset) { | |
ecf11ba4 | 998 | /* internal sibling call (without reloc) */ |
3f86188b | 999 | add_call_dest(file, insn, insn->jump_dest->func, true); |
54262aa2 | 1000 | } |
cd77849a | 1001 | } |
dcc914f4 JP |
1002 | } |
1003 | ||
1004 | return 0; | |
1005 | } | |
1006 | ||
2b232a22 JT |
1007 | static struct symbol *find_call_destination(struct section *sec, unsigned long offset) |
1008 | { | |
1009 | struct symbol *call_dest; | |
1010 | ||
1011 | call_dest = find_func_by_offset(sec, offset); | |
1012 | if (!call_dest) | |
1013 | call_dest = find_symbol_by_offset(sec, offset); | |
1014 | ||
1015 | return call_dest; | |
1016 | } | |
1017 | ||
dcc914f4 JP |
1018 | /* |
1019 | * Find the destination instructions for all calls. | |
1020 | */ | |
1021 | static int add_call_destinations(struct objtool_file *file) | |
1022 | { | |
1023 | struct instruction *insn; | |
1024 | unsigned long dest_off; | |
3f86188b | 1025 | struct symbol *dest; |
f1974222 | 1026 | struct reloc *reloc; |
dcc914f4 JP |
1027 | |
1028 | for_each_insn(file, insn) { | |
1029 | if (insn->type != INSN_CALL) | |
1030 | continue; | |
1031 | ||
7bd2a600 | 1032 | reloc = insn_reloc(file, insn); |
f1974222 | 1033 | if (!reloc) { |
bfb08f22 | 1034 | dest_off = arch_jump_destination(insn); |
3f86188b PZ |
1035 | dest = find_call_destination(insn->sec, dest_off); |
1036 | ||
1037 | add_call_dest(file, insn, dest, false); | |
a845c7cf | 1038 | |
7acfe531 JP |
1039 | if (insn->ignore) |
1040 | continue; | |
1041 | ||
1042 | if (!insn->call_dest) { | |
8aa8eb2a | 1043 | WARN_FUNC("unannotated intra-function call", insn->sec, insn->offset); |
dcc914f4 JP |
1044 | return -1; |
1045 | } | |
a845c7cf | 1046 | |
7acfe531 JP |
1047 | if (insn->func && insn->call_dest->type != STT_FUNC) { |
1048 | WARN_FUNC("unsupported call to non-function", | |
1049 | insn->sec, insn->offset); | |
1050 | return -1; | |
1051 | } | |
1052 | ||
f1974222 MH |
1053 | } else if (reloc->sym->type == STT_SECTION) { |
1054 | dest_off = arch_dest_reloc_offset(reloc->addend); | |
3f86188b PZ |
1055 | dest = find_call_destination(reloc->sym->sec, dest_off); |
1056 | if (!dest) { | |
bfb08f22 | 1057 | WARN_FUNC("can't find call dest symbol at %s+0x%lx", |
dcc914f4 | 1058 | insn->sec, insn->offset, |
f1974222 | 1059 | reloc->sym->sec->name, |
bfb08f22 | 1060 | dest_off); |
dcc914f4 JP |
1061 | return -1; |
1062 | } | |
bcb1b6ff | 1063 | |
3f86188b PZ |
1064 | add_call_dest(file, insn, dest, false); |
1065 | ||
2e532bd1 | 1066 | } else if (reloc->sym->retpoline_thunk) { |
bcb1b6ff PZ |
1067 | /* |
1068 | * Retpoline calls are really dynamic calls in | |
1069 | * disguise, so convert them accordingly. | |
1070 | */ | |
1071 | insn->type = INSN_CALL_DYNAMIC; | |
1072 | insn->retpoline_safe = true; | |
1073 | ||
43d5430a PZ |
1074 | list_add_tail(&insn->call_node, |
1075 | &file->retpoline_call_list); | |
1076 | ||
bcb1b6ff PZ |
1077 | remove_insn_ops(insn); |
1078 | continue; | |
1079 | ||
dcc914f4 | 1080 | } else |
3f86188b | 1081 | add_call_dest(file, insn, reloc->sym, false); |
dcc914f4 JP |
1082 | } |
1083 | ||
1084 | return 0; | |
1085 | } | |
1086 | ||
1087 | /* | |
c9c324dc JP |
1088 | * The .alternatives section requires some extra special care over and above |
1089 | * other special sections because alternatives are patched in place. | |
dcc914f4 JP |
1090 | */ |
1091 | static int handle_group_alt(struct objtool_file *file, | |
1092 | struct special_alt *special_alt, | |
1093 | struct instruction *orig_insn, | |
1094 | struct instruction **new_insn) | |
1095 | { | |
c9c324dc | 1096 | struct instruction *last_orig_insn, *last_new_insn = NULL, *insn, *nop = NULL; |
b23cc71c | 1097 | struct alt_group *orig_alt_group, *new_alt_group; |
dcc914f4 JP |
1098 | unsigned long dest_off; |
1099 | ||
b23cc71c JP |
1100 | |
1101 | orig_alt_group = malloc(sizeof(*orig_alt_group)); | |
1102 | if (!orig_alt_group) { | |
1103 | WARN("malloc failed"); | |
1104 | return -1; | |
1105 | } | |
c9c324dc JP |
1106 | orig_alt_group->cfi = calloc(special_alt->orig_len, |
1107 | sizeof(struct cfi_state *)); | |
1108 | if (!orig_alt_group->cfi) { | |
1109 | WARN("calloc failed"); | |
1110 | return -1; | |
1111 | } | |
1112 | ||
dcc914f4 JP |
1113 | last_orig_insn = NULL; |
1114 | insn = orig_insn; | |
1115 | sec_for_each_insn_from(file, insn) { | |
1116 | if (insn->offset >= special_alt->orig_off + special_alt->orig_len) | |
1117 | break; | |
1118 | ||
b23cc71c | 1119 | insn->alt_group = orig_alt_group; |
dcc914f4 JP |
1120 | last_orig_insn = insn; |
1121 | } | |
b23cc71c JP |
1122 | orig_alt_group->orig_group = NULL; |
1123 | orig_alt_group->first_insn = orig_insn; | |
1124 | orig_alt_group->last_insn = last_orig_insn; | |
dcc914f4 | 1125 | |
17bc3391 | 1126 | |
c9c324dc JP |
1127 | new_alt_group = malloc(sizeof(*new_alt_group)); |
1128 | if (!new_alt_group) { | |
1129 | WARN("malloc failed"); | |
1130 | return -1; | |
dcc914f4 | 1131 | } |
dcc914f4 | 1132 | |
c9c324dc JP |
1133 | if (special_alt->new_len < special_alt->orig_len) { |
1134 | /* | |
1135 | * Insert a fake nop at the end to make the replacement | |
1136 | * alt_group the same size as the original. This is needed to | |
1137 | * allow propagate_alt_cfi() to do its magic. When the last | |
1138 | * instruction affects the stack, the instruction after it (the | |
1139 | * nop) will propagate the new state to the shared CFI array. | |
1140 | */ | |
1141 | nop = malloc(sizeof(*nop)); | |
1142 | if (!nop) { | |
1143 | WARN("malloc failed"); | |
17bc3391 JP |
1144 | return -1; |
1145 | } | |
c9c324dc JP |
1146 | memset(nop, 0, sizeof(*nop)); |
1147 | INIT_LIST_HEAD(&nop->alts); | |
1148 | INIT_LIST_HEAD(&nop->stack_ops); | |
1149 | init_cfi_state(&nop->cfi); | |
1150 | ||
1151 | nop->sec = special_alt->new_sec; | |
1152 | nop->offset = special_alt->new_off + special_alt->new_len; | |
1153 | nop->len = special_alt->orig_len - special_alt->new_len; | |
1154 | nop->type = INSN_NOP; | |
1155 | nop->func = orig_insn->func; | |
1156 | nop->alt_group = new_alt_group; | |
1157 | nop->ignore = orig_insn->ignore_alts; | |
dcc914f4 | 1158 | } |
17bc3391 | 1159 | |
c9c324dc JP |
1160 | if (!special_alt->new_len) { |
1161 | *new_insn = nop; | |
1162 | goto end; | |
dcc914f4 JP |
1163 | } |
1164 | ||
dcc914f4 JP |
1165 | insn = *new_insn; |
1166 | sec_for_each_insn_from(file, insn) { | |
45245f51 JT |
1167 | struct reloc *alt_reloc; |
1168 | ||
dcc914f4 JP |
1169 | if (insn->offset >= special_alt->new_off + special_alt->new_len) |
1170 | break; | |
1171 | ||
1172 | last_new_insn = insn; | |
1173 | ||
a845c7cf | 1174 | insn->ignore = orig_insn->ignore_alts; |
a4d09dde | 1175 | insn->func = orig_insn->func; |
b23cc71c | 1176 | insn->alt_group = new_alt_group; |
a845c7cf | 1177 | |
dc419723 JP |
1178 | /* |
1179 | * Since alternative replacement code is copy/pasted by the | |
1180 | * kernel after applying relocations, generally such code can't | |
1181 | * have relative-address relocation references to outside the | |
1182 | * .altinstr_replacement section, unless the arch's | |
1183 | * alternatives code can adjust the relative offsets | |
1184 | * accordingly. | |
dc419723 | 1185 | */ |
7bd2a600 | 1186 | alt_reloc = insn_reloc(file, insn); |
45245f51 JT |
1187 | if (alt_reloc && |
1188 | !arch_support_alt_relocation(special_alt, insn, alt_reloc)) { | |
dc419723 JP |
1189 | |
1190 | WARN_FUNC("unsupported relocation in alternatives section", | |
1191 | insn->sec, insn->offset); | |
1192 | return -1; | |
1193 | } | |
1194 | ||
a2296140 | 1195 | if (!is_static_jump(insn)) |
dcc914f4 JP |
1196 | continue; |
1197 | ||
1198 | if (!insn->immediate) | |
1199 | continue; | |
1200 | ||
bfb08f22 | 1201 | dest_off = arch_jump_destination(insn); |
c9c324dc JP |
1202 | if (dest_off == special_alt->new_off + special_alt->new_len) |
1203 | insn->jump_dest = next_insn_same_sec(file, last_orig_insn); | |
dcc914f4 JP |
1204 | |
1205 | if (!insn->jump_dest) { | |
1206 | WARN_FUNC("can't find alternative jump destination", | |
1207 | insn->sec, insn->offset); | |
1208 | return -1; | |
1209 | } | |
1210 | } | |
1211 | ||
1212 | if (!last_new_insn) { | |
1213 | WARN_FUNC("can't find last new alternative instruction", | |
1214 | special_alt->new_sec, special_alt->new_off); | |
1215 | return -1; | |
1216 | } | |
1217 | ||
c9c324dc JP |
1218 | if (nop) |
1219 | list_add(&nop->list, &last_new_insn->list); | |
1220 | end: | |
b23cc71c JP |
1221 | new_alt_group->orig_group = orig_alt_group; |
1222 | new_alt_group->first_insn = *new_insn; | |
c9c324dc JP |
1223 | new_alt_group->last_insn = nop ? : last_new_insn; |
1224 | new_alt_group->cfi = orig_alt_group->cfi; | |
dcc914f4 JP |
1225 | return 0; |
1226 | } | |
1227 | ||
1228 | /* | |
1229 | * A jump table entry can either convert a nop to a jump or a jump to a nop. | |
1230 | * If the original instruction is a jump, make the alt entry an effective nop | |
1231 | * by just skipping the original instruction. | |
1232 | */ | |
1233 | static int handle_jump_alt(struct objtool_file *file, | |
1234 | struct special_alt *special_alt, | |
1235 | struct instruction *orig_insn, | |
1236 | struct instruction **new_insn) | |
1237 | { | |
48001d26 PZ |
1238 | if (orig_insn->type != INSN_JUMP_UNCONDITIONAL && |
1239 | orig_insn->type != INSN_NOP) { | |
e2d9494b | 1240 | |
dcc914f4 JP |
1241 | WARN_FUNC("unsupported instruction at jump label", |
1242 | orig_insn->sec, orig_insn->offset); | |
1243 | return -1; | |
1244 | } | |
1245 | ||
6d37b83c PZ |
1246 | if (special_alt->key_addend & 2) { |
1247 | struct reloc *reloc = insn_reloc(file, orig_insn); | |
1248 | ||
1249 | if (reloc) { | |
1250 | reloc->type = R_NONE; | |
1251 | elf_write_reloc(file->elf, reloc); | |
1252 | } | |
1253 | elf_write_insn(file->elf, orig_insn->sec, | |
1254 | orig_insn->offset, orig_insn->len, | |
1255 | arch_nop_insn(orig_insn->len)); | |
1256 | orig_insn->type = INSN_NOP; | |
48001d26 PZ |
1257 | } |
1258 | ||
1259 | if (orig_insn->type == INSN_NOP) { | |
1260 | if (orig_insn->len == 2) | |
1261 | file->jl_nop_short++; | |
1262 | else | |
1263 | file->jl_nop_long++; | |
1264 | ||
1265 | return 0; | |
6d37b83c PZ |
1266 | } |
1267 | ||
e2d9494b PZ |
1268 | if (orig_insn->len == 2) |
1269 | file->jl_short++; | |
1270 | else | |
1271 | file->jl_long++; | |
1272 | ||
dcc914f4 JP |
1273 | *new_insn = list_next_entry(orig_insn, list); |
1274 | return 0; | |
1275 | } | |
1276 | ||
1277 | /* | |
1278 | * Read all the special sections which have alternate instructions which can be | |
1279 | * patched in or redirected to at runtime. Each instruction having alternate | |
1280 | * instruction(s) has them added to its insn->alts list, which will be | |
1281 | * traversed in validate_branch(). | |
1282 | */ | |
1283 | static int add_special_section_alts(struct objtool_file *file) | |
1284 | { | |
1285 | struct list_head special_alts; | |
1286 | struct instruction *orig_insn, *new_insn; | |
1287 | struct special_alt *special_alt, *tmp; | |
1288 | struct alternative *alt; | |
1289 | int ret; | |
1290 | ||
1291 | ret = special_get_alts(file->elf, &special_alts); | |
1292 | if (ret) | |
1293 | return ret; | |
1294 | ||
1295 | list_for_each_entry_safe(special_alt, tmp, &special_alts, list) { | |
dcc914f4 JP |
1296 | |
1297 | orig_insn = find_insn(file, special_alt->orig_sec, | |
1298 | special_alt->orig_off); | |
1299 | if (!orig_insn) { | |
1300 | WARN_FUNC("special: can't find orig instruction", | |
1301 | special_alt->orig_sec, special_alt->orig_off); | |
1302 | ret = -1; | |
1303 | goto out; | |
1304 | } | |
1305 | ||
1306 | new_insn = NULL; | |
1307 | if (!special_alt->group || special_alt->new_len) { | |
1308 | new_insn = find_insn(file, special_alt->new_sec, | |
1309 | special_alt->new_off); | |
1310 | if (!new_insn) { | |
1311 | WARN_FUNC("special: can't find new instruction", | |
1312 | special_alt->new_sec, | |
1313 | special_alt->new_off); | |
1314 | ret = -1; | |
1315 | goto out; | |
1316 | } | |
1317 | } | |
1318 | ||
1319 | if (special_alt->group) { | |
7170cf47 JT |
1320 | if (!special_alt->orig_len) { |
1321 | WARN_FUNC("empty alternative entry", | |
1322 | orig_insn->sec, orig_insn->offset); | |
1323 | continue; | |
1324 | } | |
1325 | ||
dcc914f4 JP |
1326 | ret = handle_group_alt(file, special_alt, orig_insn, |
1327 | &new_insn); | |
1328 | if (ret) | |
1329 | goto out; | |
1330 | } else if (special_alt->jump_or_nop) { | |
1331 | ret = handle_jump_alt(file, special_alt, orig_insn, | |
1332 | &new_insn); | |
1333 | if (ret) | |
1334 | goto out; | |
1335 | } | |
1336 | ||
258c7605 JP |
1337 | alt = malloc(sizeof(*alt)); |
1338 | if (!alt) { | |
1339 | WARN("malloc failed"); | |
1340 | ret = -1; | |
1341 | goto out; | |
1342 | } | |
1343 | ||
dcc914f4 | 1344 | alt->insn = new_insn; |
764eef4b | 1345 | alt->skip_orig = special_alt->skip_orig; |
ea24213d | 1346 | orig_insn->ignore_alts |= special_alt->skip_alt; |
dcc914f4 JP |
1347 | list_add_tail(&alt->list, &orig_insn->alts); |
1348 | ||
1349 | list_del(&special_alt->list); | |
1350 | free(special_alt); | |
1351 | } | |
1352 | ||
e2d9494b PZ |
1353 | if (stats) { |
1354 | printf("jl\\\tNOP\tJMP\n"); | |
1355 | printf("short:\t%ld\t%ld\n", file->jl_nop_short, file->jl_short); | |
1356 | printf("long:\t%ld\t%ld\n", file->jl_nop_long, file->jl_long); | |
1357 | } | |
1358 | ||
dcc914f4 JP |
1359 | out: |
1360 | return ret; | |
1361 | } | |
1362 | ||
e7c2bc37 | 1363 | static int add_jump_table(struct objtool_file *file, struct instruction *insn, |
f1974222 | 1364 | struct reloc *table) |
dcc914f4 | 1365 | { |
f1974222 | 1366 | struct reloc *reloc = table; |
e7c2bc37 | 1367 | struct instruction *dest_insn; |
dcc914f4 | 1368 | struct alternative *alt; |
fd35c88b JP |
1369 | struct symbol *pfunc = insn->func->pfunc; |
1370 | unsigned int prev_offset = 0; | |
dcc914f4 | 1371 | |
e7c2bc37 | 1372 | /* |
f1974222 | 1373 | * Each @reloc is a switch table relocation which points to the target |
e7c2bc37 JP |
1374 | * instruction. |
1375 | */ | |
f1974222 | 1376 | list_for_each_entry_from(reloc, &table->sec->reloc_list, list) { |
bd98c813 JH |
1377 | |
1378 | /* Check for the end of the table: */ | |
f1974222 | 1379 | if (reloc != table && reloc->jump_table_start) |
dcc914f4 JP |
1380 | break; |
1381 | ||
e7c2bc37 | 1382 | /* Make sure the table entries are consecutive: */ |
f1974222 | 1383 | if (prev_offset && reloc->offset != prev_offset + 8) |
fd35c88b JP |
1384 | break; |
1385 | ||
1386 | /* Detect function pointers from contiguous objects: */ | |
f1974222 MH |
1387 | if (reloc->sym->sec == pfunc->sec && |
1388 | reloc->addend == pfunc->offset) | |
fd35c88b JP |
1389 | break; |
1390 | ||
f1974222 | 1391 | dest_insn = find_insn(file, reloc->sym->sec, reloc->addend); |
e7c2bc37 | 1392 | if (!dest_insn) |
dcc914f4 JP |
1393 | break; |
1394 | ||
e7c2bc37 | 1395 | /* Make sure the destination is in the same function: */ |
e65050b9 | 1396 | if (!dest_insn->func || dest_insn->func->pfunc != pfunc) |
13810435 | 1397 | break; |
dcc914f4 JP |
1398 | |
1399 | alt = malloc(sizeof(*alt)); | |
1400 | if (!alt) { | |
1401 | WARN("malloc failed"); | |
1402 | return -1; | |
1403 | } | |
1404 | ||
e7c2bc37 | 1405 | alt->insn = dest_insn; |
dcc914f4 | 1406 | list_add_tail(&alt->list, &insn->alts); |
f1974222 | 1407 | prev_offset = reloc->offset; |
fd35c88b JP |
1408 | } |
1409 | ||
1410 | if (!prev_offset) { | |
1411 | WARN_FUNC("can't find switch jump table", | |
1412 | insn->sec, insn->offset); | |
1413 | return -1; | |
dcc914f4 JP |
1414 | } |
1415 | ||
1416 | return 0; | |
1417 | } | |
1418 | ||
1419 | /* | |
d871f7b5 RG |
1420 | * find_jump_table() - Given a dynamic jump, find the switch jump table |
1421 | * associated with it. | |
dcc914f4 | 1422 | */ |
f1974222 | 1423 | static struct reloc *find_jump_table(struct objtool_file *file, |
dcc914f4 JP |
1424 | struct symbol *func, |
1425 | struct instruction *insn) | |
1426 | { | |
d871f7b5 | 1427 | struct reloc *table_reloc; |
113d4bc9 | 1428 | struct instruction *dest_insn, *orig_insn = insn; |
dcc914f4 | 1429 | |
99ce7962 PZ |
1430 | /* |
1431 | * Backward search using the @first_jump_src links, these help avoid | |
1432 | * much of the 'in between' code. Which avoids us getting confused by | |
1433 | * it. | |
1434 | */ | |
7dec80cc | 1435 | for (; |
1119d265 JP |
1436 | insn && insn->func && insn->func->pfunc == func; |
1437 | insn = insn->first_jump_src ?: prev_insn_same_sym(file, insn)) { | |
99ce7962 | 1438 | |
7dec80cc | 1439 | if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC) |
dcc914f4 JP |
1440 | break; |
1441 | ||
1442 | /* allow small jumps within the range */ | |
1443 | if (insn->type == INSN_JUMP_UNCONDITIONAL && | |
1444 | insn->jump_dest && | |
1445 | (insn->jump_dest->offset <= insn->offset || | |
1446 | insn->jump_dest->offset > orig_insn->offset)) | |
1447 | break; | |
1448 | ||
d871f7b5 | 1449 | table_reloc = arch_find_switch_table(file, insn); |
f1974222 | 1450 | if (!table_reloc) |
e7c2bc37 | 1451 | continue; |
f1974222 | 1452 | dest_insn = find_insn(file, table_reloc->sym->sec, table_reloc->addend); |
113d4bc9 JP |
1453 | if (!dest_insn || !dest_insn->func || dest_insn->func->pfunc != func) |
1454 | continue; | |
7dec80cc | 1455 | |
f1974222 | 1456 | return table_reloc; |
dcc914f4 JP |
1457 | } |
1458 | ||
1459 | return NULL; | |
1460 | } | |
1461 | ||
bd98c813 JH |
1462 | /* |
1463 | * First pass: Mark the head of each jump table so that in the next pass, | |
1464 | * we know when a given jump table ends and the next one starts. | |
1465 | */ | |
1466 | static void mark_func_jump_tables(struct objtool_file *file, | |
1467 | struct symbol *func) | |
dcc914f4 | 1468 | { |
bd98c813 | 1469 | struct instruction *insn, *last = NULL; |
f1974222 | 1470 | struct reloc *reloc; |
dcc914f4 | 1471 | |
f0f70adb | 1472 | func_for_each_insn(file, func, insn) { |
99ce7962 PZ |
1473 | if (!last) |
1474 | last = insn; | |
1475 | ||
1476 | /* | |
1477 | * Store back-pointers for unconditional forward jumps such | |
e7c2bc37 | 1478 | * that find_jump_table() can back-track using those and |
99ce7962 PZ |
1479 | * avoid some potentially confusing code. |
1480 | */ | |
1481 | if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest && | |
1482 | insn->offset > last->offset && | |
1483 | insn->jump_dest->offset > insn->offset && | |
1484 | !insn->jump_dest->first_jump_src) { | |
1485 | ||
1486 | insn->jump_dest->first_jump_src = insn; | |
1487 | last = insn->jump_dest; | |
1488 | } | |
1489 | ||
dcc914f4 JP |
1490 | if (insn->type != INSN_JUMP_DYNAMIC) |
1491 | continue; | |
1492 | ||
f1974222 MH |
1493 | reloc = find_jump_table(file, func, insn); |
1494 | if (reloc) { | |
1495 | reloc->jump_table_start = true; | |
1496 | insn->jump_table = reloc; | |
dcc914f4 | 1497 | } |
dcc914f4 | 1498 | } |
bd98c813 JH |
1499 | } |
1500 | ||
1501 | static int add_func_jump_tables(struct objtool_file *file, | |
1502 | struct symbol *func) | |
1503 | { | |
1504 | struct instruction *insn; | |
1505 | int ret; | |
1506 | ||
f0f70adb | 1507 | func_for_each_insn(file, func, insn) { |
bd98c813 JH |
1508 | if (!insn->jump_table) |
1509 | continue; | |
dcc914f4 | 1510 | |
bd98c813 | 1511 | ret = add_jump_table(file, insn, insn->jump_table); |
dcc914f4 JP |
1512 | if (ret) |
1513 | return ret; | |
1514 | } | |
1515 | ||
1516 | return 0; | |
1517 | } | |
1518 | ||
1519 | /* | |
1520 | * For some switch statements, gcc generates a jump table in the .rodata | |
1521 | * section which contains a list of addresses within the function to jump to. | |
1522 | * This finds these jump tables and adds them to the insn->alts lists. | |
1523 | */ | |
e7c2bc37 | 1524 | static int add_jump_table_alts(struct objtool_file *file) |
dcc914f4 JP |
1525 | { |
1526 | struct section *sec; | |
1527 | struct symbol *func; | |
1528 | int ret; | |
1529 | ||
4a60aa05 | 1530 | if (!file->rodata) |
dcc914f4 JP |
1531 | return 0; |
1532 | ||
baa41469 | 1533 | for_each_sec(file, sec) { |
dcc914f4 JP |
1534 | list_for_each_entry(func, &sec->symbol_list, list) { |
1535 | if (func->type != STT_FUNC) | |
1536 | continue; | |
1537 | ||
bd98c813 | 1538 | mark_func_jump_tables(file, func); |
e7c2bc37 | 1539 | ret = add_func_jump_tables(file, func); |
dcc914f4 JP |
1540 | if (ret) |
1541 | return ret; | |
1542 | } | |
1543 | } | |
1544 | ||
1545 | return 0; | |
1546 | } | |
1547 | ||
b735bd3e JP |
1548 | static void set_func_state(struct cfi_state *state) |
1549 | { | |
1550 | state->cfa = initial_func_cfi.cfa; | |
1551 | memcpy(&state->regs, &initial_func_cfi.regs, | |
1552 | CFI_NUM_REGS * sizeof(struct cfi_reg)); | |
1553 | state->stack_size = initial_func_cfi.cfa.offset; | |
1554 | } | |
1555 | ||
39358a03 JP |
1556 | static int read_unwind_hints(struct objtool_file *file) |
1557 | { | |
f1974222 MH |
1558 | struct section *sec, *relocsec; |
1559 | struct reloc *reloc; | |
39358a03 JP |
1560 | struct unwind_hint *hint; |
1561 | struct instruction *insn; | |
39358a03 JP |
1562 | int i; |
1563 | ||
1564 | sec = find_section_by_name(file->elf, ".discard.unwind_hints"); | |
1565 | if (!sec) | |
1566 | return 0; | |
1567 | ||
f1974222 MH |
1568 | relocsec = sec->reloc; |
1569 | if (!relocsec) { | |
39358a03 JP |
1570 | WARN("missing .rela.discard.unwind_hints section"); |
1571 | return -1; | |
1572 | } | |
1573 | ||
fe255fe6 | 1574 | if (sec->sh.sh_size % sizeof(struct unwind_hint)) { |
39358a03 JP |
1575 | WARN("struct unwind_hint size mismatch"); |
1576 | return -1; | |
1577 | } | |
1578 | ||
1579 | file->hints = true; | |
1580 | ||
fe255fe6 | 1581 | for (i = 0; i < sec->sh.sh_size / sizeof(struct unwind_hint); i++) { |
39358a03 JP |
1582 | hint = (struct unwind_hint *)sec->data->d_buf + i; |
1583 | ||
f1974222 MH |
1584 | reloc = find_reloc_by_dest(file->elf, sec, i * sizeof(*hint)); |
1585 | if (!reloc) { | |
1586 | WARN("can't find reloc for unwind_hints[%d]", i); | |
39358a03 JP |
1587 | return -1; |
1588 | } | |
1589 | ||
f1974222 | 1590 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
39358a03 JP |
1591 | if (!insn) { |
1592 | WARN("can't find insn for unwind_hints[%d]", i); | |
1593 | return -1; | |
1594 | } | |
1595 | ||
b735bd3e | 1596 | insn->hint = true; |
39358a03 | 1597 | |
b735bd3e JP |
1598 | if (hint->type == UNWIND_HINT_TYPE_FUNC) { |
1599 | set_func_state(&insn->cfi); | |
39358a03 JP |
1600 | continue; |
1601 | } | |
1602 | ||
edea9e6b | 1603 | if (arch_decode_hint_reg(insn, hint->sp_reg)) { |
39358a03 JP |
1604 | WARN_FUNC("unsupported unwind_hint sp base reg %d", |
1605 | insn->sec, insn->offset, hint->sp_reg); | |
1606 | return -1; | |
1607 | } | |
1608 | ||
b735bd3e | 1609 | insn->cfi.cfa.offset = bswap_if_needed(hint->sp_offset); |
e7c0219b PZ |
1610 | insn->cfi.type = hint->type; |
1611 | insn->cfi.end = hint->end; | |
39358a03 JP |
1612 | } |
1613 | ||
1614 | return 0; | |
1615 | } | |
1616 | ||
b5bc2231 PZ |
1617 | static int read_retpoline_hints(struct objtool_file *file) |
1618 | { | |
63474dc4 | 1619 | struct section *sec; |
b5bc2231 | 1620 | struct instruction *insn; |
f1974222 | 1621 | struct reloc *reloc; |
b5bc2231 | 1622 | |
63474dc4 | 1623 | sec = find_section_by_name(file->elf, ".rela.discard.retpoline_safe"); |
b5bc2231 PZ |
1624 | if (!sec) |
1625 | return 0; | |
1626 | ||
f1974222 MH |
1627 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
1628 | if (reloc->sym->type != STT_SECTION) { | |
63474dc4 | 1629 | WARN("unexpected relocation symbol type in %s", sec->name); |
b5bc2231 PZ |
1630 | return -1; |
1631 | } | |
1632 | ||
f1974222 | 1633 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
b5bc2231 | 1634 | if (!insn) { |
63474dc4 | 1635 | WARN("bad .discard.retpoline_safe entry"); |
b5bc2231 PZ |
1636 | return -1; |
1637 | } | |
1638 | ||
1639 | if (insn->type != INSN_JUMP_DYNAMIC && | |
1640 | insn->type != INSN_CALL_DYNAMIC) { | |
63474dc4 | 1641 | WARN_FUNC("retpoline_safe hint not an indirect jump/call", |
b5bc2231 PZ |
1642 | insn->sec, insn->offset); |
1643 | return -1; | |
1644 | } | |
1645 | ||
1646 | insn->retpoline_safe = true; | |
1647 | } | |
1648 | ||
1649 | return 0; | |
1650 | } | |
1651 | ||
c4a33939 PZ |
1652 | static int read_instr_hints(struct objtool_file *file) |
1653 | { | |
1654 | struct section *sec; | |
1655 | struct instruction *insn; | |
f1974222 | 1656 | struct reloc *reloc; |
c4a33939 PZ |
1657 | |
1658 | sec = find_section_by_name(file->elf, ".rela.discard.instr_end"); | |
1659 | if (!sec) | |
1660 | return 0; | |
1661 | ||
f1974222 MH |
1662 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
1663 | if (reloc->sym->type != STT_SECTION) { | |
c4a33939 PZ |
1664 | WARN("unexpected relocation symbol type in %s", sec->name); |
1665 | return -1; | |
1666 | } | |
1667 | ||
f1974222 | 1668 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
c4a33939 PZ |
1669 | if (!insn) { |
1670 | WARN("bad .discard.instr_end entry"); | |
1671 | return -1; | |
1672 | } | |
1673 | ||
1674 | insn->instr--; | |
1675 | } | |
1676 | ||
1677 | sec = find_section_by_name(file->elf, ".rela.discard.instr_begin"); | |
1678 | if (!sec) | |
1679 | return 0; | |
1680 | ||
f1974222 MH |
1681 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
1682 | if (reloc->sym->type != STT_SECTION) { | |
c4a33939 PZ |
1683 | WARN("unexpected relocation symbol type in %s", sec->name); |
1684 | return -1; | |
1685 | } | |
1686 | ||
f1974222 | 1687 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
c4a33939 PZ |
1688 | if (!insn) { |
1689 | WARN("bad .discard.instr_begin entry"); | |
1690 | return -1; | |
1691 | } | |
1692 | ||
1693 | insn->instr++; | |
1694 | } | |
1695 | ||
1696 | return 0; | |
1697 | } | |
1698 | ||
8aa8eb2a AC |
1699 | static int read_intra_function_calls(struct objtool_file *file) |
1700 | { | |
1701 | struct instruction *insn; | |
1702 | struct section *sec; | |
f1974222 | 1703 | struct reloc *reloc; |
8aa8eb2a AC |
1704 | |
1705 | sec = find_section_by_name(file->elf, ".rela.discard.intra_function_calls"); | |
1706 | if (!sec) | |
1707 | return 0; | |
1708 | ||
f1974222 | 1709 | list_for_each_entry(reloc, &sec->reloc_list, list) { |
8aa8eb2a AC |
1710 | unsigned long dest_off; |
1711 | ||
f1974222 | 1712 | if (reloc->sym->type != STT_SECTION) { |
8aa8eb2a AC |
1713 | WARN("unexpected relocation symbol type in %s", |
1714 | sec->name); | |
1715 | return -1; | |
1716 | } | |
1717 | ||
f1974222 | 1718 | insn = find_insn(file, reloc->sym->sec, reloc->addend); |
8aa8eb2a AC |
1719 | if (!insn) { |
1720 | WARN("bad .discard.intra_function_call entry"); | |
1721 | return -1; | |
1722 | } | |
1723 | ||
1724 | if (insn->type != INSN_CALL) { | |
1725 | WARN_FUNC("intra_function_call not a direct call", | |
1726 | insn->sec, insn->offset); | |
1727 | return -1; | |
1728 | } | |
1729 | ||
1730 | /* | |
1731 | * Treat intra-function CALLs as JMPs, but with a stack_op. | |
1732 | * See add_call_destinations(), which strips stack_ops from | |
1733 | * normal CALLs. | |
1734 | */ | |
1735 | insn->type = INSN_JUMP_UNCONDITIONAL; | |
1736 | ||
1737 | dest_off = insn->offset + insn->len + insn->immediate; | |
1738 | insn->jump_dest = find_insn(file, insn->sec, dest_off); | |
1739 | if (!insn->jump_dest) { | |
1740 | WARN_FUNC("can't find call dest at %s+0x%lx", | |
1741 | insn->sec, insn->offset, | |
1742 | insn->sec->name, dest_off); | |
1743 | return -1; | |
1744 | } | |
1745 | } | |
1746 | ||
1747 | return 0; | |
1748 | } | |
1749 | ||
2e532bd1 | 1750 | static int classify_symbols(struct objtool_file *file) |
1e7e4788 JP |
1751 | { |
1752 | struct section *sec; | |
1753 | struct symbol *func; | |
1754 | ||
1755 | for_each_sec(file, sec) { | |
1756 | list_for_each_entry(func, &sec->symbol_list, list) { | |
2e532bd1 PZ |
1757 | if (func->bind != STB_GLOBAL) |
1758 | continue; | |
1759 | ||
1760 | if (!strncmp(func->name, STATIC_CALL_TRAMP_PREFIX_STR, | |
1e7e4788 JP |
1761 | strlen(STATIC_CALL_TRAMP_PREFIX_STR))) |
1762 | func->static_call_tramp = true; | |
2e532bd1 PZ |
1763 | |
1764 | if (arch_is_retpoline(func)) | |
1765 | func->retpoline_thunk = true; | |
1766 | ||
1767 | if (!strcmp(func->name, "__fentry__")) | |
1768 | func->fentry = true; | |
1769 | ||
1770 | if (!strncmp(func->name, "__sanitizer_cov_", 16)) | |
1771 | func->kcov = true; | |
1e7e4788 JP |
1772 | } |
1773 | } | |
1774 | ||
1775 | return 0; | |
1776 | } | |
1777 | ||
4a60aa05 AX |
1778 | static void mark_rodata(struct objtool_file *file) |
1779 | { | |
1780 | struct section *sec; | |
1781 | bool found = false; | |
1782 | ||
1783 | /* | |
87b512de JP |
1784 | * Search for the following rodata sections, each of which can |
1785 | * potentially contain jump tables: | |
1786 | * | |
1787 | * - .rodata: can contain GCC switch tables | |
1788 | * - .rodata.<func>: same, if -fdata-sections is being used | |
1789 | * - .rodata..c_jump_table: contains C annotated jump tables | |
1790 | * | |
1791 | * .rodata.str1.* sections are ignored; they don't contain jump tables. | |
4a60aa05 AX |
1792 | */ |
1793 | for_each_sec(file, sec) { | |
1ee44470 MS |
1794 | if (!strncmp(sec->name, ".rodata", 7) && |
1795 | !strstr(sec->name, ".str1.")) { | |
4a60aa05 AX |
1796 | sec->rodata = true; |
1797 | found = true; | |
1798 | } | |
1799 | } | |
1800 | ||
1801 | file->rodata = found; | |
1802 | } | |
1803 | ||
43d5430a PZ |
1804 | __weak int arch_rewrite_retpolines(struct objtool_file *file) |
1805 | { | |
1806 | return 0; | |
1807 | } | |
1808 | ||
dcc914f4 JP |
1809 | static int decode_sections(struct objtool_file *file) |
1810 | { | |
1811 | int ret; | |
1812 | ||
4a60aa05 AX |
1813 | mark_rodata(file); |
1814 | ||
dcc914f4 JP |
1815 | ret = decode_instructions(file); |
1816 | if (ret) | |
1817 | return ret; | |
1818 | ||
1819 | ret = add_dead_ends(file); | |
1820 | if (ret) | |
1821 | return ret; | |
1822 | ||
1823 | add_ignores(file); | |
ea24213d | 1824 | add_uaccess_safe(file); |
dcc914f4 | 1825 | |
ff05ab23 | 1826 | ret = add_ignore_alternatives(file); |
258c7605 JP |
1827 | if (ret) |
1828 | return ret; | |
1829 | ||
a958c4fe PZ |
1830 | /* |
1831 | * Must be before add_{jump_call}_destination. | |
1832 | */ | |
2e532bd1 | 1833 | ret = classify_symbols(file); |
5b06fd3b PZ |
1834 | if (ret) |
1835 | return ret; | |
1836 | ||
43d5430a PZ |
1837 | /* |
1838 | * Must be before add_special_section_alts() as that depends on | |
1839 | * jump_dest being set. | |
1840 | */ | |
dcc914f4 JP |
1841 | ret = add_jump_destinations(file); |
1842 | if (ret) | |
1843 | return ret; | |
1844 | ||
a845c7cf | 1845 | ret = add_special_section_alts(file); |
dcc914f4 JP |
1846 | if (ret) |
1847 | return ret; | |
1848 | ||
a958c4fe PZ |
1849 | /* |
1850 | * Must be before add_call_destination(); it changes INSN_CALL to | |
1851 | * INSN_JUMP. | |
1852 | */ | |
8aa8eb2a AC |
1853 | ret = read_intra_function_calls(file); |
1854 | if (ret) | |
1855 | return ret; | |
1856 | ||
a845c7cf | 1857 | ret = add_call_destinations(file); |
dcc914f4 JP |
1858 | if (ret) |
1859 | return ret; | |
1860 | ||
e7c2bc37 | 1861 | ret = add_jump_table_alts(file); |
dcc914f4 JP |
1862 | if (ret) |
1863 | return ret; | |
1864 | ||
39358a03 JP |
1865 | ret = read_unwind_hints(file); |
1866 | if (ret) | |
1867 | return ret; | |
1868 | ||
b5bc2231 PZ |
1869 | ret = read_retpoline_hints(file); |
1870 | if (ret) | |
1871 | return ret; | |
1872 | ||
c4a33939 PZ |
1873 | ret = read_instr_hints(file); |
1874 | if (ret) | |
1875 | return ret; | |
1876 | ||
43d5430a PZ |
1877 | /* |
1878 | * Must be after add_special_section_alts(), since this will emit | |
1879 | * alternatives. Must be after add_{jump,call}_destination(), since | |
1880 | * those create the call insn lists. | |
1881 | */ | |
1882 | ret = arch_rewrite_retpolines(file); | |
1883 | if (ret) | |
1884 | return ret; | |
1885 | ||
dcc914f4 JP |
1886 | return 0; |
1887 | } | |
1888 | ||
1889 | static bool is_fentry_call(struct instruction *insn) | |
1890 | { | |
2e532bd1 PZ |
1891 | if (insn->type == INSN_CALL && |
1892 | insn->call_dest && | |
1893 | insn->call_dest->fentry) | |
dcc914f4 JP |
1894 | return true; |
1895 | ||
1896 | return false; | |
1897 | } | |
1898 | ||
e25eea89 | 1899 | static bool has_modified_stack_frame(struct instruction *insn, struct insn_state *state) |
dcc914f4 | 1900 | { |
e7c0219b | 1901 | struct cfi_state *cfi = &state->cfi; |
baa41469 JP |
1902 | int i; |
1903 | ||
e7c0219b | 1904 | if (cfi->cfa.base != initial_func_cfi.cfa.base || cfi->drap) |
e25eea89 PZ |
1905 | return true; |
1906 | ||
b735bd3e | 1907 | if (cfi->cfa.offset != initial_func_cfi.cfa.offset) |
baa41469 JP |
1908 | return true; |
1909 | ||
b735bd3e | 1910 | if (cfi->stack_size != initial_func_cfi.cfa.offset) |
e25eea89 PZ |
1911 | return true; |
1912 | ||
1913 | for (i = 0; i < CFI_NUM_REGS; i++) { | |
e7c0219b PZ |
1914 | if (cfi->regs[i].base != initial_func_cfi.regs[i].base || |
1915 | cfi->regs[i].offset != initial_func_cfi.regs[i].offset) | |
baa41469 | 1916 | return true; |
e25eea89 | 1917 | } |
baa41469 JP |
1918 | |
1919 | return false; | |
1920 | } | |
1921 | ||
fb084fde JT |
1922 | static bool check_reg_frame_pos(const struct cfi_reg *reg, |
1923 | int expected_offset) | |
1924 | { | |
1925 | return reg->base == CFI_CFA && | |
1926 | reg->offset == expected_offset; | |
1927 | } | |
1928 | ||
baa41469 JP |
1929 | static bool has_valid_stack_frame(struct insn_state *state) |
1930 | { | |
e7c0219b PZ |
1931 | struct cfi_state *cfi = &state->cfi; |
1932 | ||
fb084fde JT |
1933 | if (cfi->cfa.base == CFI_BP && |
1934 | check_reg_frame_pos(&cfi->regs[CFI_BP], -cfi->cfa.offset) && | |
1935 | check_reg_frame_pos(&cfi->regs[CFI_RA], -cfi->cfa.offset + 8)) | |
baa41469 JP |
1936 | return true; |
1937 | ||
e7c0219b | 1938 | if (cfi->drap && cfi->regs[CFI_BP].base == CFI_BP) |
baa41469 JP |
1939 | return true; |
1940 | ||
1941 | return false; | |
dcc914f4 JP |
1942 | } |
1943 | ||
e7c0219b PZ |
1944 | static int update_cfi_state_regs(struct instruction *insn, |
1945 | struct cfi_state *cfi, | |
65ea47dc | 1946 | struct stack_op *op) |
627fce14 | 1947 | { |
e7c0219b | 1948 | struct cfi_reg *cfa = &cfi->cfa; |
627fce14 | 1949 | |
d8dd25a4 | 1950 | if (cfa->base != CFI_SP && cfa->base != CFI_SP_INDIRECT) |
627fce14 JP |
1951 | return 0; |
1952 | ||
1953 | /* push */ | |
ea24213d | 1954 | if (op->dest.type == OP_DEST_PUSH || op->dest.type == OP_DEST_PUSHF) |
627fce14 JP |
1955 | cfa->offset += 8; |
1956 | ||
1957 | /* pop */ | |
ea24213d | 1958 | if (op->src.type == OP_SRC_POP || op->src.type == OP_SRC_POPF) |
627fce14 JP |
1959 | cfa->offset -= 8; |
1960 | ||
1961 | /* add immediate to sp */ | |
1962 | if (op->dest.type == OP_DEST_REG && op->src.type == OP_SRC_ADD && | |
1963 | op->dest.reg == CFI_SP && op->src.reg == CFI_SP) | |
1964 | cfa->offset -= op->src.offset; | |
1965 | ||
1966 | return 0; | |
1967 | } | |
1968 | ||
e7c0219b | 1969 | static void save_reg(struct cfi_state *cfi, unsigned char reg, int base, int offset) |
dcc914f4 | 1970 | { |
bf4d1a83 | 1971 | if (arch_callee_saved_reg(reg) && |
e7c0219b PZ |
1972 | cfi->regs[reg].base == CFI_UNDEFINED) { |
1973 | cfi->regs[reg].base = base; | |
1974 | cfi->regs[reg].offset = offset; | |
baa41469 | 1975 | } |
dcc914f4 JP |
1976 | } |
1977 | ||
e7c0219b | 1978 | static void restore_reg(struct cfi_state *cfi, unsigned char reg) |
dcc914f4 | 1979 | { |
e7c0219b PZ |
1980 | cfi->regs[reg].base = initial_func_cfi.regs[reg].base; |
1981 | cfi->regs[reg].offset = initial_func_cfi.regs[reg].offset; | |
baa41469 JP |
1982 | } |
1983 | ||
1984 | /* | |
1985 | * A note about DRAP stack alignment: | |
1986 | * | |
1987 | * GCC has the concept of a DRAP register, which is used to help keep track of | |
1988 | * the stack pointer when aligning the stack. r10 or r13 is used as the DRAP | |
1989 | * register. The typical DRAP pattern is: | |
1990 | * | |
1991 | * 4c 8d 54 24 08 lea 0x8(%rsp),%r10 | |
1992 | * 48 83 e4 c0 and $0xffffffffffffffc0,%rsp | |
1993 | * 41 ff 72 f8 pushq -0x8(%r10) | |
1994 | * 55 push %rbp | |
1995 | * 48 89 e5 mov %rsp,%rbp | |
1996 | * (more pushes) | |
1997 | * 41 52 push %r10 | |
1998 | * ... | |
1999 | * 41 5a pop %r10 | |
2000 | * (more pops) | |
2001 | * 5d pop %rbp | |
2002 | * 49 8d 62 f8 lea -0x8(%r10),%rsp | |
2003 | * c3 retq | |
2004 | * | |
2005 | * There are some variations in the epilogues, like: | |
2006 | * | |
2007 | * 5b pop %rbx | |
2008 | * 41 5a pop %r10 | |
2009 | * 41 5c pop %r12 | |
2010 | * 41 5d pop %r13 | |
2011 | * 41 5e pop %r14 | |
2012 | * c9 leaveq | |
2013 | * 49 8d 62 f8 lea -0x8(%r10),%rsp | |
2014 | * c3 retq | |
2015 | * | |
2016 | * and: | |
2017 | * | |
2018 | * 4c 8b 55 e8 mov -0x18(%rbp),%r10 | |
2019 | * 48 8b 5d e0 mov -0x20(%rbp),%rbx | |
2020 | * 4c 8b 65 f0 mov -0x10(%rbp),%r12 | |
2021 | * 4c 8b 6d f8 mov -0x8(%rbp),%r13 | |
2022 | * c9 leaveq | |
2023 | * 49 8d 62 f8 lea -0x8(%r10),%rsp | |
2024 | * c3 retq | |
2025 | * | |
2026 | * Sometimes r13 is used as the DRAP register, in which case it's saved and | |
2027 | * restored beforehand: | |
2028 | * | |
2029 | * 41 55 push %r13 | |
2030 | * 4c 8d 6c 24 10 lea 0x10(%rsp),%r13 | |
2031 | * 48 83 e4 f0 and $0xfffffffffffffff0,%rsp | |
2032 | * ... | |
2033 | * 49 8d 65 f0 lea -0x10(%r13),%rsp | |
2034 | * 41 5d pop %r13 | |
2035 | * c3 retq | |
2036 | */ | |
d54dba41 PZ |
2037 | static int update_cfi_state(struct instruction *insn, |
2038 | struct instruction *next_insn, | |
2039 | struct cfi_state *cfi, struct stack_op *op) | |
baa41469 | 2040 | { |
e7c0219b PZ |
2041 | struct cfi_reg *cfa = &cfi->cfa; |
2042 | struct cfi_reg *regs = cfi->regs; | |
baa41469 JP |
2043 | |
2044 | /* stack operations don't make sense with an undefined CFA */ | |
2045 | if (cfa->base == CFI_UNDEFINED) { | |
2046 | if (insn->func) { | |
2047 | WARN_FUNC("undefined stack state", insn->sec, insn->offset); | |
2048 | return -1; | |
2049 | } | |
2050 | return 0; | |
2051 | } | |
2052 | ||
ee819aed JT |
2053 | if (cfi->type == UNWIND_HINT_TYPE_REGS || |
2054 | cfi->type == UNWIND_HINT_TYPE_REGS_PARTIAL) | |
e7c0219b | 2055 | return update_cfi_state_regs(insn, cfi, op); |
627fce14 | 2056 | |
baa41469 JP |
2057 | switch (op->dest.type) { |
2058 | ||
2059 | case OP_DEST_REG: | |
2060 | switch (op->src.type) { | |
2061 | ||
2062 | case OP_SRC_REG: | |
0d0970ee JP |
2063 | if (op->src.reg == CFI_SP && op->dest.reg == CFI_BP && |
2064 | cfa->base == CFI_SP && | |
fb084fde | 2065 | check_reg_frame_pos(®s[CFI_BP], -cfa->offset)) { |
0d0970ee JP |
2066 | |
2067 | /* mov %rsp, %rbp */ | |
2068 | cfa->base = op->dest.reg; | |
e7c0219b | 2069 | cfi->bp_scratch = false; |
0d0970ee | 2070 | } |
dd88a0a0 | 2071 | |
0d0970ee | 2072 | else if (op->src.reg == CFI_SP && |
e7c0219b | 2073 | op->dest.reg == CFI_BP && cfi->drap) { |
dd88a0a0 | 2074 | |
0d0970ee JP |
2075 | /* drap: mov %rsp, %rbp */ |
2076 | regs[CFI_BP].base = CFI_BP; | |
e7c0219b PZ |
2077 | regs[CFI_BP].offset = -cfi->stack_size; |
2078 | cfi->bp_scratch = false; | |
0d0970ee | 2079 | } |
dd88a0a0 | 2080 | |
0d0970ee JP |
2081 | else if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { |
2082 | ||
2083 | /* | |
2084 | * mov %rsp, %reg | |
2085 | * | |
2086 | * This is needed for the rare case where GCC | |
2087 | * does: | |
2088 | * | |
2089 | * mov %rsp, %rax | |
2090 | * ... | |
2091 | * mov %rax, %rsp | |
2092 | */ | |
e7c0219b PZ |
2093 | cfi->vals[op->dest.reg].base = CFI_CFA; |
2094 | cfi->vals[op->dest.reg].offset = -cfi->stack_size; | |
dd88a0a0 JP |
2095 | } |
2096 | ||
3c1f0583 | 2097 | else if (op->src.reg == CFI_BP && op->dest.reg == CFI_SP && |
ffc7e74f | 2098 | (cfa->base == CFI_BP || cfa->base == cfi->drap_reg)) { |
3c1f0583 JP |
2099 | |
2100 | /* | |
2101 | * mov %rbp, %rsp | |
2102 | * | |
2103 | * Restore the original stack pointer (Clang). | |
2104 | */ | |
e7c0219b | 2105 | cfi->stack_size = -cfi->regs[CFI_BP].offset; |
3c1f0583 JP |
2106 | } |
2107 | ||
dd88a0a0 JP |
2108 | else if (op->dest.reg == cfa->base) { |
2109 | ||
2110 | /* mov %reg, %rsp */ | |
2111 | if (cfa->base == CFI_SP && | |
e7c0219b | 2112 | cfi->vals[op->src.reg].base == CFI_CFA) { |
dd88a0a0 JP |
2113 | |
2114 | /* | |
2115 | * This is needed for the rare case | |
2116 | * where GCC does something dumb like: | |
2117 | * | |
2118 | * lea 0x8(%rsp), %rcx | |
2119 | * ... | |
2120 | * mov %rcx, %rsp | |
2121 | */ | |
e7c0219b PZ |
2122 | cfa->offset = -cfi->vals[op->src.reg].offset; |
2123 | cfi->stack_size = cfa->offset; | |
dd88a0a0 | 2124 | |
aafeb14e PZ |
2125 | } else if (cfa->base == CFI_SP && |
2126 | cfi->vals[op->src.reg].base == CFI_SP_INDIRECT && | |
2127 | cfi->vals[op->src.reg].offset == cfa->offset) { | |
2128 | ||
2129 | /* | |
2130 | * Stack swizzle: | |
2131 | * | |
2132 | * 1: mov %rsp, (%[tos]) | |
2133 | * 2: mov %[tos], %rsp | |
2134 | * ... | |
2135 | * 3: pop %rsp | |
2136 | * | |
2137 | * Where: | |
2138 | * | |
2139 | * 1 - places a pointer to the previous | |
2140 | * stack at the Top-of-Stack of the | |
2141 | * new stack. | |
2142 | * | |
2143 | * 2 - switches to the new stack. | |
2144 | * | |
2145 | * 3 - pops the Top-of-Stack to restore | |
2146 | * the original stack. | |
2147 | * | |
2148 | * Note: we set base to SP_INDIRECT | |
2149 | * here and preserve offset. Therefore | |
2150 | * when the unwinder reaches ToS it | |
2151 | * will dereference SP and then add the | |
2152 | * offset to find the next frame, IOW: | |
2153 | * (%rsp) + offset. | |
2154 | */ | |
2155 | cfa->base = CFI_SP_INDIRECT; | |
2156 | ||
dd88a0a0 JP |
2157 | } else { |
2158 | cfa->base = CFI_UNDEFINED; | |
2159 | cfa->offset = 0; | |
2160 | } | |
baa41469 JP |
2161 | } |
2162 | ||
724c8a23 PZ |
2163 | else if (op->dest.reg == CFI_SP && |
2164 | cfi->vals[op->src.reg].base == CFI_SP_INDIRECT && | |
2165 | cfi->vals[op->src.reg].offset == cfa->offset) { | |
2166 | ||
2167 | /* | |
2168 | * The same stack swizzle case 2) as above. But | |
2169 | * because we can't change cfa->base, case 3) | |
2170 | * will become a regular POP. Pretend we're a | |
2171 | * PUSH so things don't go unbalanced. | |
2172 | */ | |
2173 | cfi->stack_size += 8; | |
2174 | } | |
2175 | ||
2176 | ||
baa41469 JP |
2177 | break; |
2178 | ||
2179 | case OP_SRC_ADD: | |
2180 | if (op->dest.reg == CFI_SP && op->src.reg == CFI_SP) { | |
2181 | ||
2182 | /* add imm, %rsp */ | |
e7c0219b | 2183 | cfi->stack_size -= op->src.offset; |
baa41469 JP |
2184 | if (cfa->base == CFI_SP) |
2185 | cfa->offset -= op->src.offset; | |
2186 | break; | |
2187 | } | |
2188 | ||
2189 | if (op->dest.reg == CFI_SP && op->src.reg == CFI_BP) { | |
2190 | ||
2191 | /* lea disp(%rbp), %rsp */ | |
e7c0219b | 2192 | cfi->stack_size = -(op->src.offset + regs[CFI_BP].offset); |
baa41469 JP |
2193 | break; |
2194 | } | |
2195 | ||
468af56a JT |
2196 | if (!cfi->drap && op->src.reg == CFI_SP && |
2197 | op->dest.reg == CFI_BP && cfa->base == CFI_SP && | |
2198 | check_reg_frame_pos(®s[CFI_BP], -cfa->offset + op->src.offset)) { | |
2199 | ||
2200 | /* lea disp(%rsp), %rbp */ | |
2201 | cfa->base = CFI_BP; | |
2202 | cfa->offset -= op->src.offset; | |
2203 | cfi->bp_scratch = false; | |
2204 | break; | |
2205 | } | |
2206 | ||
dd88a0a0 | 2207 | if (op->src.reg == CFI_SP && cfa->base == CFI_SP) { |
baa41469 JP |
2208 | |
2209 | /* drap: lea disp(%rsp), %drap */ | |
e7c0219b | 2210 | cfi->drap_reg = op->dest.reg; |
dd88a0a0 JP |
2211 | |
2212 | /* | |
2213 | * lea disp(%rsp), %reg | |
2214 | * | |
2215 | * This is needed for the rare case where GCC | |
2216 | * does something dumb like: | |
2217 | * | |
2218 | * lea 0x8(%rsp), %rcx | |
2219 | * ... | |
2220 | * mov %rcx, %rsp | |
2221 | */ | |
e7c0219b PZ |
2222 | cfi->vals[op->dest.reg].base = CFI_CFA; |
2223 | cfi->vals[op->dest.reg].offset = \ | |
2224 | -cfi->stack_size + op->src.offset; | |
dd88a0a0 | 2225 | |
baa41469 JP |
2226 | break; |
2227 | } | |
2228 | ||
e7c0219b PZ |
2229 | if (cfi->drap && op->dest.reg == CFI_SP && |
2230 | op->src.reg == cfi->drap_reg) { | |
baa41469 JP |
2231 | |
2232 | /* drap: lea disp(%drap), %rsp */ | |
2233 | cfa->base = CFI_SP; | |
e7c0219b PZ |
2234 | cfa->offset = cfi->stack_size = -op->src.offset; |
2235 | cfi->drap_reg = CFI_UNDEFINED; | |
2236 | cfi->drap = false; | |
baa41469 JP |
2237 | break; |
2238 | } | |
2239 | ||
d54dba41 | 2240 | if (op->dest.reg == cfi->cfa.base && !(next_insn && next_insn->hint)) { |
baa41469 JP |
2241 | WARN_FUNC("unsupported stack register modification", |
2242 | insn->sec, insn->offset); | |
2243 | return -1; | |
2244 | } | |
2245 | ||
2246 | break; | |
2247 | ||
2248 | case OP_SRC_AND: | |
2249 | if (op->dest.reg != CFI_SP || | |
e7c0219b PZ |
2250 | (cfi->drap_reg != CFI_UNDEFINED && cfa->base != CFI_SP) || |
2251 | (cfi->drap_reg == CFI_UNDEFINED && cfa->base != CFI_BP)) { | |
baa41469 JP |
2252 | WARN_FUNC("unsupported stack pointer realignment", |
2253 | insn->sec, insn->offset); | |
2254 | return -1; | |
2255 | } | |
2256 | ||
e7c0219b | 2257 | if (cfi->drap_reg != CFI_UNDEFINED) { |
baa41469 | 2258 | /* drap: and imm, %rsp */ |
e7c0219b PZ |
2259 | cfa->base = cfi->drap_reg; |
2260 | cfa->offset = cfi->stack_size = 0; | |
2261 | cfi->drap = true; | |
baa41469 JP |
2262 | } |
2263 | ||
2264 | /* | |
2265 | * Older versions of GCC (4.8ish) realign the stack | |
2266 | * without DRAP, with a frame pointer. | |
2267 | */ | |
2268 | ||
2269 | break; | |
2270 | ||
2271 | case OP_SRC_POP: | |
ea24213d | 2272 | case OP_SRC_POPF: |
aafeb14e PZ |
2273 | if (op->dest.reg == CFI_SP && cfa->base == CFI_SP_INDIRECT) { |
2274 | ||
2275 | /* pop %rsp; # restore from a stack swizzle */ | |
2276 | cfa->base = CFI_SP; | |
2277 | break; | |
2278 | } | |
2279 | ||
e7c0219b | 2280 | if (!cfi->drap && op->dest.reg == cfa->base) { |
baa41469 JP |
2281 | |
2282 | /* pop %rbp */ | |
2283 | cfa->base = CFI_SP; | |
2284 | } | |
2285 | ||
e7c0219b PZ |
2286 | if (cfi->drap && cfa->base == CFI_BP_INDIRECT && |
2287 | op->dest.reg == cfi->drap_reg && | |
2288 | cfi->drap_offset == -cfi->stack_size) { | |
baa41469 | 2289 | |
bf4d1a83 | 2290 | /* drap: pop %drap */ |
e7c0219b | 2291 | cfa->base = cfi->drap_reg; |
bf4d1a83 | 2292 | cfa->offset = 0; |
e7c0219b | 2293 | cfi->drap_offset = -1; |
baa41469 | 2294 | |
ffc7e74f | 2295 | } else if (cfi->stack_size == -regs[op->dest.reg].offset) { |
baa41469 | 2296 | |
bf4d1a83 | 2297 | /* pop %reg */ |
e7c0219b | 2298 | restore_reg(cfi, op->dest.reg); |
baa41469 JP |
2299 | } |
2300 | ||
e7c0219b | 2301 | cfi->stack_size -= 8; |
baa41469 JP |
2302 | if (cfa->base == CFI_SP) |
2303 | cfa->offset -= 8; | |
2304 | ||
2305 | break; | |
2306 | ||
2307 | case OP_SRC_REG_INDIRECT: | |
201ef5a9 JT |
2308 | if (!cfi->drap && op->dest.reg == cfa->base && |
2309 | op->dest.reg == CFI_BP) { | |
2310 | ||
2311 | /* mov disp(%rsp), %rbp */ | |
2312 | cfa->base = CFI_SP; | |
2313 | cfa->offset = cfi->stack_size; | |
2314 | } | |
2315 | ||
e7c0219b PZ |
2316 | if (cfi->drap && op->src.reg == CFI_BP && |
2317 | op->src.offset == cfi->drap_offset) { | |
bf4d1a83 JP |
2318 | |
2319 | /* drap: mov disp(%rbp), %drap */ | |
e7c0219b | 2320 | cfa->base = cfi->drap_reg; |
bf4d1a83 | 2321 | cfa->offset = 0; |
e7c0219b | 2322 | cfi->drap_offset = -1; |
bf4d1a83 JP |
2323 | } |
2324 | ||
e7c0219b | 2325 | if (cfi->drap && op->src.reg == CFI_BP && |
baa41469 JP |
2326 | op->src.offset == regs[op->dest.reg].offset) { |
2327 | ||
2328 | /* drap: mov disp(%rbp), %reg */ | |
e7c0219b | 2329 | restore_reg(cfi, op->dest.reg); |
baa41469 JP |
2330 | |
2331 | } else if (op->src.reg == cfa->base && | |
2332 | op->src.offset == regs[op->dest.reg].offset + cfa->offset) { | |
2333 | ||
2334 | /* mov disp(%rbp), %reg */ | |
2335 | /* mov disp(%rsp), %reg */ | |
e7c0219b | 2336 | restore_reg(cfi, op->dest.reg); |
201ef5a9 JT |
2337 | |
2338 | } else if (op->src.reg == CFI_SP && | |
2339 | op->src.offset == regs[op->dest.reg].offset + cfi->stack_size) { | |
2340 | ||
2341 | /* mov disp(%rsp), %reg */ | |
2342 | restore_reg(cfi, op->dest.reg); | |
baa41469 JP |
2343 | } |
2344 | ||
2345 | break; | |
2346 | ||
2347 | default: | |
2348 | WARN_FUNC("unknown stack-related instruction", | |
2349 | insn->sec, insn->offset); | |
2350 | return -1; | |
2351 | } | |
2352 | ||
2353 | break; | |
2354 | ||
2355 | case OP_DEST_PUSH: | |
ea24213d | 2356 | case OP_DEST_PUSHF: |
e7c0219b | 2357 | cfi->stack_size += 8; |
baa41469 JP |
2358 | if (cfa->base == CFI_SP) |
2359 | cfa->offset += 8; | |
2360 | ||
2361 | if (op->src.type != OP_SRC_REG) | |
2362 | break; | |
2363 | ||
e7c0219b PZ |
2364 | if (cfi->drap) { |
2365 | if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) { | |
baa41469 JP |
2366 | |
2367 | /* drap: push %drap */ | |
2368 | cfa->base = CFI_BP_INDIRECT; | |
e7c0219b | 2369 | cfa->offset = -cfi->stack_size; |
baa41469 | 2370 | |
bf4d1a83 | 2371 | /* save drap so we know when to restore it */ |
e7c0219b | 2372 | cfi->drap_offset = -cfi->stack_size; |
baa41469 | 2373 | |
e7c0219b | 2374 | } else if (op->src.reg == CFI_BP && cfa->base == cfi->drap_reg) { |
baa41469 JP |
2375 | |
2376 | /* drap: push %rbp */ | |
e7c0219b | 2377 | cfi->stack_size = 0; |
baa41469 | 2378 | |
f4f80398 | 2379 | } else { |
baa41469 JP |
2380 | |
2381 | /* drap: push %reg */ | |
e7c0219b | 2382 | save_reg(cfi, op->src.reg, CFI_BP, -cfi->stack_size); |
baa41469 JP |
2383 | } |
2384 | ||
2385 | } else { | |
2386 | ||
2387 | /* push %reg */ | |
e7c0219b | 2388 | save_reg(cfi, op->src.reg, CFI_CFA, -cfi->stack_size); |
baa41469 JP |
2389 | } |
2390 | ||
2391 | /* detect when asm code uses rbp as a scratch register */ | |
867ac9d7 | 2392 | if (!no_fp && insn->func && op->src.reg == CFI_BP && |
baa41469 | 2393 | cfa->base != CFI_BP) |
e7c0219b | 2394 | cfi->bp_scratch = true; |
baa41469 JP |
2395 | break; |
2396 | ||
2397 | case OP_DEST_REG_INDIRECT: | |
2398 | ||
e7c0219b PZ |
2399 | if (cfi->drap) { |
2400 | if (op->src.reg == cfa->base && op->src.reg == cfi->drap_reg) { | |
baa41469 JP |
2401 | |
2402 | /* drap: mov %drap, disp(%rbp) */ | |
2403 | cfa->base = CFI_BP_INDIRECT; | |
2404 | cfa->offset = op->dest.offset; | |
2405 | ||
bf4d1a83 | 2406 | /* save drap offset so we know when to restore it */ |
e7c0219b | 2407 | cfi->drap_offset = op->dest.offset; |
f4f80398 | 2408 | } else { |
baa41469 JP |
2409 | |
2410 | /* drap: mov reg, disp(%rbp) */ | |
e7c0219b | 2411 | save_reg(cfi, op->src.reg, CFI_BP, op->dest.offset); |
baa41469 JP |
2412 | } |
2413 | ||
2414 | } else if (op->dest.reg == cfa->base) { | |
2415 | ||
2416 | /* mov reg, disp(%rbp) */ | |
2417 | /* mov reg, disp(%rsp) */ | |
e7c0219b PZ |
2418 | save_reg(cfi, op->src.reg, CFI_CFA, |
2419 | op->dest.offset - cfi->cfa.offset); | |
201ef5a9 JT |
2420 | |
2421 | } else if (op->dest.reg == CFI_SP) { | |
2422 | ||
2423 | /* mov reg, disp(%rsp) */ | |
2424 | save_reg(cfi, op->src.reg, CFI_CFA, | |
2425 | op->dest.offset - cfi->stack_size); | |
aafeb14e PZ |
2426 | |
2427 | } else if (op->src.reg == CFI_SP && op->dest.offset == 0) { | |
2428 | ||
2429 | /* mov %rsp, (%reg); # setup a stack swizzle. */ | |
2430 | cfi->vals[op->dest.reg].base = CFI_SP_INDIRECT; | |
2431 | cfi->vals[op->dest.reg].offset = cfa->offset; | |
baa41469 JP |
2432 | } |
2433 | ||
2434 | break; | |
2435 | ||
baa41469 | 2436 | case OP_DEST_MEM: |
ea24213d | 2437 | if (op->src.type != OP_SRC_POP && op->src.type != OP_SRC_POPF) { |
baa41469 JP |
2438 | WARN_FUNC("unknown stack-related memory operation", |
2439 | insn->sec, insn->offset); | |
2440 | return -1; | |
2441 | } | |
2442 | ||
2443 | /* pop mem */ | |
e7c0219b | 2444 | cfi->stack_size -= 8; |
baa41469 JP |
2445 | if (cfa->base == CFI_SP) |
2446 | cfa->offset -= 8; | |
2447 | ||
2448 | break; | |
2449 | ||
2450 | default: | |
2451 | WARN_FUNC("unknown stack-related instruction", | |
2452 | insn->sec, insn->offset); | |
2453 | return -1; | |
2454 | } | |
2455 | ||
2456 | return 0; | |
2457 | } | |
2458 | ||
c9c324dc JP |
2459 | /* |
2460 | * The stack layouts of alternatives instructions can sometimes diverge when | |
2461 | * they have stack modifications. That's fine as long as the potential stack | |
2462 | * layouts don't conflict at any given potential instruction boundary. | |
2463 | * | |
2464 | * Flatten the CFIs of the different alternative code streams (both original | |
2465 | * and replacement) into a single shared CFI array which can be used to detect | |
2466 | * conflicts and nicely feed a linear array of ORC entries to the unwinder. | |
2467 | */ | |
2468 | static int propagate_alt_cfi(struct objtool_file *file, struct instruction *insn) | |
65ea47dc | 2469 | { |
c9c324dc JP |
2470 | struct cfi_state **alt_cfi; |
2471 | int group_off; | |
65ea47dc | 2472 | |
c9c324dc JP |
2473 | if (!insn->alt_group) |
2474 | return 0; | |
65ea47dc | 2475 | |
c9c324dc JP |
2476 | alt_cfi = insn->alt_group->cfi; |
2477 | group_off = insn->offset - insn->alt_group->first_insn->offset; | |
65ea47dc | 2478 | |
c9c324dc JP |
2479 | if (!alt_cfi[group_off]) { |
2480 | alt_cfi[group_off] = &insn->cfi; | |
2481 | } else { | |
2482 | if (memcmp(alt_cfi[group_off], &insn->cfi, sizeof(struct cfi_state))) { | |
2483 | WARN_FUNC("stack layout conflict in alternatives", | |
2484 | insn->sec, insn->offset); | |
ab3852ab PZ |
2485 | return -1; |
2486 | } | |
c9c324dc JP |
2487 | } |
2488 | ||
2489 | return 0; | |
2490 | } | |
2491 | ||
d54dba41 PZ |
2492 | static int handle_insn_ops(struct instruction *insn, |
2493 | struct instruction *next_insn, | |
2494 | struct insn_state *state) | |
c9c324dc JP |
2495 | { |
2496 | struct stack_op *op; | |
2497 | ||
2498 | list_for_each_entry(op, &insn->stack_ops, list) { | |
2499 | ||
d54dba41 | 2500 | if (update_cfi_state(insn, next_insn, &state->cfi, op)) |
c9c324dc | 2501 | return 1; |
ab3852ab | 2502 | |
ba08abca PZ |
2503 | if (!insn->alt_group) |
2504 | continue; | |
2505 | ||
65ea47dc JT |
2506 | if (op->dest.type == OP_DEST_PUSHF) { |
2507 | if (!state->uaccess_stack) { | |
2508 | state->uaccess_stack = 1; | |
2509 | } else if (state->uaccess_stack >> 31) { | |
2510 | WARN_FUNC("PUSHF stack exhausted", | |
2511 | insn->sec, insn->offset); | |
2512 | return 1; | |
2513 | } | |
2514 | state->uaccess_stack <<= 1; | |
2515 | state->uaccess_stack |= state->uaccess; | |
2516 | } | |
2517 | ||
2518 | if (op->src.type == OP_SRC_POPF) { | |
2519 | if (state->uaccess_stack) { | |
2520 | state->uaccess = state->uaccess_stack & 1; | |
2521 | state->uaccess_stack >>= 1; | |
2522 | if (state->uaccess_stack == 1) | |
2523 | state->uaccess_stack = 0; | |
2524 | } | |
2525 | } | |
2526 | } | |
2527 | ||
2528 | return 0; | |
2529 | } | |
2530 | ||
e7c0219b | 2531 | static bool insn_cfi_match(struct instruction *insn, struct cfi_state *cfi2) |
baa41469 | 2532 | { |
e7c0219b | 2533 | struct cfi_state *cfi1 = &insn->cfi; |
baa41469 JP |
2534 | int i; |
2535 | ||
e7c0219b PZ |
2536 | if (memcmp(&cfi1->cfa, &cfi2->cfa, sizeof(cfi1->cfa))) { |
2537 | ||
baa41469 JP |
2538 | WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d", |
2539 | insn->sec, insn->offset, | |
e7c0219b PZ |
2540 | cfi1->cfa.base, cfi1->cfa.offset, |
2541 | cfi2->cfa.base, cfi2->cfa.offset); | |
baa41469 | 2542 | |
e7c0219b | 2543 | } else if (memcmp(&cfi1->regs, &cfi2->regs, sizeof(cfi1->regs))) { |
baa41469 | 2544 | for (i = 0; i < CFI_NUM_REGS; i++) { |
e7c0219b | 2545 | if (!memcmp(&cfi1->regs[i], &cfi2->regs[i], |
baa41469 JP |
2546 | sizeof(struct cfi_reg))) |
2547 | continue; | |
2548 | ||
2549 | WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d", | |
2550 | insn->sec, insn->offset, | |
e7c0219b PZ |
2551 | i, cfi1->regs[i].base, cfi1->regs[i].offset, |
2552 | i, cfi2->regs[i].base, cfi2->regs[i].offset); | |
baa41469 JP |
2553 | break; |
2554 | } | |
2555 | ||
e7c0219b PZ |
2556 | } else if (cfi1->type != cfi2->type) { |
2557 | ||
627fce14 | 2558 | WARN_FUNC("stack state mismatch: type1=%d type2=%d", |
e7c0219b PZ |
2559 | insn->sec, insn->offset, cfi1->type, cfi2->type); |
2560 | ||
2561 | } else if (cfi1->drap != cfi2->drap || | |
2562 | (cfi1->drap && cfi1->drap_reg != cfi2->drap_reg) || | |
2563 | (cfi1->drap && cfi1->drap_offset != cfi2->drap_offset)) { | |
627fce14 | 2564 | |
bf4d1a83 | 2565 | WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)", |
baa41469 | 2566 | insn->sec, insn->offset, |
e7c0219b PZ |
2567 | cfi1->drap, cfi1->drap_reg, cfi1->drap_offset, |
2568 | cfi2->drap, cfi2->drap_reg, cfi2->drap_offset); | |
baa41469 JP |
2569 | |
2570 | } else | |
2571 | return true; | |
2572 | ||
2573 | return false; | |
dcc914f4 JP |
2574 | } |
2575 | ||
ea24213d PZ |
2576 | static inline bool func_uaccess_safe(struct symbol *func) |
2577 | { | |
2578 | if (func) | |
e10cd8fe | 2579 | return func->uaccess_safe; |
ea24213d PZ |
2580 | |
2581 | return false; | |
2582 | } | |
2583 | ||
0c1ddd33 | 2584 | static inline const char *call_dest_name(struct instruction *insn) |
ea24213d PZ |
2585 | { |
2586 | if (insn->call_dest) | |
2587 | return insn->call_dest->name; | |
2588 | ||
2589 | return "{dynamic}"; | |
2590 | } | |
2591 | ||
6b643a07 PZ |
2592 | static inline bool noinstr_call_dest(struct symbol *func) |
2593 | { | |
2594 | /* | |
2595 | * We can't deal with indirect function calls at present; | |
2596 | * assume they're instrumented. | |
2597 | */ | |
2598 | if (!func) | |
2599 | return false; | |
2600 | ||
2601 | /* | |
2602 | * If the symbol is from a noinstr section; we good. | |
2603 | */ | |
2604 | if (func->sec->noinstr) | |
2605 | return true; | |
2606 | ||
2607 | /* | |
2608 | * The __ubsan_handle_*() calls are like WARN(), they only happen when | |
2609 | * something 'BAD' happened. At the risk of taking the machine down, | |
2610 | * let them proceed to get the message out. | |
2611 | */ | |
2612 | if (!strncmp(func->name, "__ubsan_handle_", 15)) | |
2613 | return true; | |
2614 | ||
2615 | return false; | |
2616 | } | |
2617 | ||
ea24213d PZ |
2618 | static int validate_call(struct instruction *insn, struct insn_state *state) |
2619 | { | |
c4a33939 | 2620 | if (state->noinstr && state->instr <= 0 && |
6b643a07 | 2621 | !noinstr_call_dest(insn->call_dest)) { |
c4a33939 PZ |
2622 | WARN_FUNC("call to %s() leaves .noinstr.text section", |
2623 | insn->sec, insn->offset, call_dest_name(insn)); | |
2624 | return 1; | |
2625 | } | |
2626 | ||
ea24213d PZ |
2627 | if (state->uaccess && !func_uaccess_safe(insn->call_dest)) { |
2628 | WARN_FUNC("call to %s() with UACCESS enabled", | |
0c1ddd33 | 2629 | insn->sec, insn->offset, call_dest_name(insn)); |
ea24213d PZ |
2630 | return 1; |
2631 | } | |
2632 | ||
2f0f9e9a PZ |
2633 | if (state->df) { |
2634 | WARN_FUNC("call to %s() with DF set", | |
0c1ddd33 | 2635 | insn->sec, insn->offset, call_dest_name(insn)); |
2f0f9e9a PZ |
2636 | return 1; |
2637 | } | |
2638 | ||
ea24213d PZ |
2639 | return 0; |
2640 | } | |
2641 | ||
54262aa2 PZ |
2642 | static int validate_sibling_call(struct instruction *insn, struct insn_state *state) |
2643 | { | |
e25eea89 | 2644 | if (has_modified_stack_frame(insn, state)) { |
54262aa2 PZ |
2645 | WARN_FUNC("sibling call from callable instruction with modified stack frame", |
2646 | insn->sec, insn->offset); | |
2647 | return 1; | |
2648 | } | |
2649 | ||
ea24213d | 2650 | return validate_call(insn, state); |
54262aa2 PZ |
2651 | } |
2652 | ||
a92e92d1 PZ |
2653 | static int validate_return(struct symbol *func, struct instruction *insn, struct insn_state *state) |
2654 | { | |
c4a33939 PZ |
2655 | if (state->noinstr && state->instr > 0) { |
2656 | WARN_FUNC("return with instrumentation enabled", | |
2657 | insn->sec, insn->offset); | |
2658 | return 1; | |
2659 | } | |
2660 | ||
a92e92d1 PZ |
2661 | if (state->uaccess && !func_uaccess_safe(func)) { |
2662 | WARN_FUNC("return with UACCESS enabled", | |
2663 | insn->sec, insn->offset); | |
2664 | return 1; | |
2665 | } | |
2666 | ||
2667 | if (!state->uaccess && func_uaccess_safe(func)) { | |
2668 | WARN_FUNC("return with UACCESS disabled from a UACCESS-safe function", | |
2669 | insn->sec, insn->offset); | |
2670 | return 1; | |
2671 | } | |
2672 | ||
2673 | if (state->df) { | |
2674 | WARN_FUNC("return with DF set", | |
2675 | insn->sec, insn->offset); | |
2676 | return 1; | |
2677 | } | |
2678 | ||
e25eea89 | 2679 | if (func && has_modified_stack_frame(insn, state)) { |
a92e92d1 PZ |
2680 | WARN_FUNC("return with modified stack frame", |
2681 | insn->sec, insn->offset); | |
2682 | return 1; | |
2683 | } | |
2684 | ||
e7c0219b | 2685 | if (state->cfi.bp_scratch) { |
b2966952 JP |
2686 | WARN_FUNC("BP used as a scratch register", |
2687 | insn->sec, insn->offset); | |
a92e92d1 PZ |
2688 | return 1; |
2689 | } | |
2690 | ||
2691 | return 0; | |
2692 | } | |
2693 | ||
c9c324dc JP |
2694 | static struct instruction *next_insn_to_validate(struct objtool_file *file, |
2695 | struct instruction *insn) | |
7117f16b | 2696 | { |
b23cc71c | 2697 | struct alt_group *alt_group = insn->alt_group; |
7117f16b | 2698 | |
c9c324dc JP |
2699 | /* |
2700 | * Simulate the fact that alternatives are patched in-place. When the | |
2701 | * end of a replacement alt_group is reached, redirect objtool flow to | |
2702 | * the end of the original alt_group. | |
2703 | */ | |
2704 | if (alt_group && insn == alt_group->last_insn && alt_group->orig_group) | |
2705 | return next_insn_same_sec(file, alt_group->orig_group->last_insn); | |
2706 | ||
2707 | return next_insn_same_sec(file, insn); | |
7117f16b PZ |
2708 | } |
2709 | ||
dcc914f4 JP |
2710 | /* |
2711 | * Follow the branch starting at the given instruction, and recursively follow | |
2712 | * any other branches (jumps). Meanwhile, track the frame pointer state at | |
2713 | * each instruction and validate all the rules described in | |
2714 | * tools/objtool/Documentation/stack-validation.txt. | |
2715 | */ | |
c705cecc | 2716 | static int validate_branch(struct objtool_file *file, struct symbol *func, |
b7460462 | 2717 | struct instruction *insn, struct insn_state state) |
dcc914f4 JP |
2718 | { |
2719 | struct alternative *alt; | |
b7460462 | 2720 | struct instruction *next_insn; |
dcc914f4 | 2721 | struct section *sec; |
882a0db9 | 2722 | u8 visited; |
dcc914f4 JP |
2723 | int ret; |
2724 | ||
dcc914f4 | 2725 | sec = insn->sec; |
dcc914f4 | 2726 | |
dcc914f4 | 2727 | while (1) { |
c9c324dc | 2728 | next_insn = next_insn_to_validate(file, insn); |
39358a03 | 2729 | |
13810435 | 2730 | if (file->c_file && func && insn->func && func != insn->func->pfunc) { |
ee97638b JP |
2731 | WARN("%s() falls through to next function %s()", |
2732 | func->name, insn->func->name); | |
2733 | return 1; | |
dcc914f4 JP |
2734 | } |
2735 | ||
4855022a JP |
2736 | if (func && insn->ignore) { |
2737 | WARN_FUNC("BUG: why am I validating an ignored function?", | |
2738 | sec, insn->offset); | |
12b25729 | 2739 | return 1; |
4855022a JP |
2740 | } |
2741 | ||
882a0db9 | 2742 | visited = 1 << state.uaccess; |
dcc914f4 | 2743 | if (insn->visited) { |
e7c0219b | 2744 | if (!insn->hint && !insn_cfi_match(insn, &state.cfi)) |
dcc914f4 | 2745 | return 1; |
dcc914f4 | 2746 | |
882a0db9 | 2747 | if (insn->visited & visited) |
ea24213d | 2748 | return 0; |
dcc914f4 JP |
2749 | } |
2750 | ||
c4a33939 PZ |
2751 | if (state.noinstr) |
2752 | state.instr += insn->instr; | |
2753 | ||
c536ed2f | 2754 | if (insn->hint) |
e7c0219b | 2755 | state.cfi = insn->cfi; |
c536ed2f | 2756 | else |
e7c0219b | 2757 | insn->cfi = state.cfi; |
dcc914f4 | 2758 | |
882a0db9 | 2759 | insn->visited |= visited; |
baa41469 | 2760 | |
c9c324dc JP |
2761 | if (propagate_alt_cfi(file, insn)) |
2762 | return 1; | |
2763 | ||
7117f16b | 2764 | if (!insn->ignore_alts && !list_empty(&insn->alts)) { |
764eef4b PZ |
2765 | bool skip_orig = false; |
2766 | ||
a845c7cf | 2767 | list_for_each_entry(alt, &insn->alts, list) { |
764eef4b PZ |
2768 | if (alt->skip_orig) |
2769 | skip_orig = true; | |
2770 | ||
c705cecc | 2771 | ret = validate_branch(file, func, alt->insn, state); |
7697eee3 PZ |
2772 | if (ret) { |
2773 | if (backtrace) | |
2774 | BT_FUNC("(alt)", insn); | |
2775 | return ret; | |
2776 | } | |
a845c7cf | 2777 | } |
764eef4b PZ |
2778 | |
2779 | if (skip_orig) | |
2780 | return 0; | |
dcc914f4 JP |
2781 | } |
2782 | ||
d54dba41 | 2783 | if (handle_insn_ops(insn, next_insn, &state)) |
60041bcd PZ |
2784 | return 1; |
2785 | ||
dcc914f4 JP |
2786 | switch (insn->type) { |
2787 | ||
dcc914f4 | 2788 | case INSN_RETURN: |
a92e92d1 | 2789 | return validate_return(func, insn, &state); |
dcc914f4 JP |
2790 | |
2791 | case INSN_CALL: | |
ea24213d PZ |
2792 | case INSN_CALL_DYNAMIC: |
2793 | ret = validate_call(insn, &state); | |
2794 | if (ret) | |
2795 | return ret; | |
dcc914f4 | 2796 | |
c9bab22b JP |
2797 | if (!no_fp && func && !is_fentry_call(insn) && |
2798 | !has_valid_stack_frame(&state)) { | |
dcc914f4 JP |
2799 | WARN_FUNC("call without frame pointer save/setup", |
2800 | sec, insn->offset); | |
2801 | return 1; | |
2802 | } | |
c9bab22b JP |
2803 | |
2804 | if (dead_end_function(file, insn->call_dest)) | |
2805 | return 0; | |
2806 | ||
dcc914f4 JP |
2807 | break; |
2808 | ||
2809 | case INSN_JUMP_CONDITIONAL: | |
2810 | case INSN_JUMP_UNCONDITIONAL: | |
ecf11ba4 | 2811 | if (is_sibling_call(insn)) { |
54262aa2 | 2812 | ret = validate_sibling_call(insn, &state); |
dcc914f4 | 2813 | if (ret) |
54262aa2 | 2814 | return ret; |
4855022a | 2815 | |
0c1ddd33 | 2816 | } else if (insn->jump_dest) { |
c705cecc JP |
2817 | ret = validate_branch(file, func, |
2818 | insn->jump_dest, state); | |
7697eee3 PZ |
2819 | if (ret) { |
2820 | if (backtrace) | |
2821 | BT_FUNC("(branch)", insn); | |
2822 | return ret; | |
2823 | } | |
4855022a | 2824 | } |
dcc914f4 JP |
2825 | |
2826 | if (insn->type == INSN_JUMP_UNCONDITIONAL) | |
2827 | return 0; | |
2828 | ||
2829 | break; | |
2830 | ||
2831 | case INSN_JUMP_DYNAMIC: | |
b68b9907 | 2832 | case INSN_JUMP_DYNAMIC_CONDITIONAL: |
ecf11ba4 | 2833 | if (is_sibling_call(insn)) { |
54262aa2 PZ |
2834 | ret = validate_sibling_call(insn, &state); |
2835 | if (ret) | |
2836 | return ret; | |
dcc914f4 JP |
2837 | } |
2838 | ||
b68b9907 JP |
2839 | if (insn->type == INSN_JUMP_DYNAMIC) |
2840 | return 0; | |
2841 | ||
2842 | break; | |
dcc914f4 | 2843 | |
39358a03 JP |
2844 | case INSN_CONTEXT_SWITCH: |
2845 | if (func && (!next_insn || !next_insn->hint)) { | |
2846 | WARN_FUNC("unsupported instruction in callable function", | |
2847 | sec, insn->offset); | |
2848 | return 1; | |
2849 | } | |
2850 | return 0; | |
2851 | ||
ea24213d PZ |
2852 | case INSN_STAC: |
2853 | if (state.uaccess) { | |
2854 | WARN_FUNC("recursive UACCESS enable", sec, insn->offset); | |
2855 | return 1; | |
2856 | } | |
2857 | ||
2858 | state.uaccess = true; | |
2859 | break; | |
2860 | ||
2861 | case INSN_CLAC: | |
c705cecc | 2862 | if (!state.uaccess && func) { |
ea24213d PZ |
2863 | WARN_FUNC("redundant UACCESS disable", sec, insn->offset); |
2864 | return 1; | |
2865 | } | |
2866 | ||
2867 | if (func_uaccess_safe(func) && !state.uaccess_stack) { | |
2868 | WARN_FUNC("UACCESS-safe disables UACCESS", sec, insn->offset); | |
2869 | return 1; | |
2870 | } | |
2871 | ||
2872 | state.uaccess = false; | |
baa41469 JP |
2873 | break; |
2874 | ||
2f0f9e9a | 2875 | case INSN_STD: |
6f567c93 | 2876 | if (state.df) { |
2f0f9e9a | 2877 | WARN_FUNC("recursive STD", sec, insn->offset); |
6f567c93 JP |
2878 | return 1; |
2879 | } | |
2f0f9e9a PZ |
2880 | |
2881 | state.df = true; | |
2882 | break; | |
2883 | ||
2884 | case INSN_CLD: | |
6f567c93 | 2885 | if (!state.df && func) { |
2f0f9e9a | 2886 | WARN_FUNC("redundant CLD", sec, insn->offset); |
6f567c93 JP |
2887 | return 1; |
2888 | } | |
2f0f9e9a PZ |
2889 | |
2890 | state.df = false; | |
baa41469 JP |
2891 | break; |
2892 | ||
dcc914f4 JP |
2893 | default: |
2894 | break; | |
2895 | } | |
2896 | ||
2897 | if (insn->dead_end) | |
2898 | return 0; | |
2899 | ||
00d96180 | 2900 | if (!next_insn) { |
e7c0219b | 2901 | if (state.cfi.cfa.base == CFI_UNDEFINED) |
00d96180 | 2902 | return 0; |
dcc914f4 JP |
2903 | WARN("%s: unexpected end of section", sec->name); |
2904 | return 1; | |
2905 | } | |
00d96180 JP |
2906 | |
2907 | insn = next_insn; | |
dcc914f4 JP |
2908 | } |
2909 | ||
2910 | return 0; | |
2911 | } | |
2912 | ||
932f8e98 | 2913 | static int validate_unwind_hints(struct objtool_file *file, struct section *sec) |
39358a03 JP |
2914 | { |
2915 | struct instruction *insn; | |
39358a03 | 2916 | struct insn_state state; |
932f8e98 | 2917 | int ret, warnings = 0; |
39358a03 JP |
2918 | |
2919 | if (!file->hints) | |
2920 | return 0; | |
2921 | ||
932f8e98 | 2922 | init_insn_state(&state, sec); |
39358a03 | 2923 | |
932f8e98 PZ |
2924 | if (sec) { |
2925 | insn = find_insn(file, sec, 0); | |
2926 | if (!insn) | |
2927 | return 0; | |
2928 | } else { | |
2929 | insn = list_first_entry(&file->insn_list, typeof(*insn), list); | |
2930 | } | |
2931 | ||
2932 | while (&insn->list != &file->insn_list && (!sec || insn->sec == sec)) { | |
39358a03 | 2933 | if (insn->hint && !insn->visited) { |
c705cecc | 2934 | ret = validate_branch(file, insn->func, insn, state); |
7697eee3 PZ |
2935 | if (ret && backtrace) |
2936 | BT_FUNC("<=== (hint)", insn); | |
39358a03 JP |
2937 | warnings += ret; |
2938 | } | |
932f8e98 PZ |
2939 | |
2940 | insn = list_next_entry(insn, list); | |
39358a03 JP |
2941 | } |
2942 | ||
2943 | return warnings; | |
2944 | } | |
2945 | ||
b5bc2231 PZ |
2946 | static int validate_retpoline(struct objtool_file *file) |
2947 | { | |
2948 | struct instruction *insn; | |
2949 | int warnings = 0; | |
2950 | ||
2951 | for_each_insn(file, insn) { | |
2952 | if (insn->type != INSN_JUMP_DYNAMIC && | |
2953 | insn->type != INSN_CALL_DYNAMIC) | |
2954 | continue; | |
2955 | ||
2956 | if (insn->retpoline_safe) | |
2957 | continue; | |
2958 | ||
ca41b97e PZ |
2959 | /* |
2960 | * .init.text code is ran before userspace and thus doesn't | |
2961 | * strictly need retpolines, except for modules which are | |
2962 | * loaded late, they very much do need retpoline in their | |
2963 | * .init.text | |
2964 | */ | |
2965 | if (!strcmp(insn->sec->name, ".init.text") && !module) | |
2966 | continue; | |
2967 | ||
b5bc2231 PZ |
2968 | WARN_FUNC("indirect %s found in RETPOLINE build", |
2969 | insn->sec, insn->offset, | |
2970 | insn->type == INSN_JUMP_DYNAMIC ? "jump" : "call"); | |
2971 | ||
2972 | warnings++; | |
2973 | } | |
2974 | ||
2975 | return warnings; | |
2976 | } | |
2977 | ||
dcc914f4 JP |
2978 | static bool is_kasan_insn(struct instruction *insn) |
2979 | { | |
2980 | return (insn->type == INSN_CALL && | |
2981 | !strcmp(insn->call_dest->name, "__asan_handle_no_return")); | |
2982 | } | |
2983 | ||
2984 | static bool is_ubsan_insn(struct instruction *insn) | |
2985 | { | |
2986 | return (insn->type == INSN_CALL && | |
2987 | !strcmp(insn->call_dest->name, | |
2988 | "__ubsan_handle_builtin_unreachable")); | |
2989 | } | |
2990 | ||
14db1f0a | 2991 | static bool ignore_unreachable_insn(struct objtool_file *file, struct instruction *insn) |
dcc914f4 JP |
2992 | { |
2993 | int i; | |
14db1f0a | 2994 | struct instruction *prev_insn; |
dcc914f4 | 2995 | |
baa41469 JP |
2996 | if (insn->ignore || insn->type == INSN_NOP) |
2997 | return true; | |
2998 | ||
2999 | /* | |
3000 | * Ignore any unused exceptions. This can happen when a whitelisted | |
3001 | * function has an exception table entry. | |
0e2bb2bc JP |
3002 | * |
3003 | * Also ignore alternative replacement instructions. This can happen | |
3004 | * when a whitelisted function uses one of the ALTERNATIVE macros. | |
baa41469 | 3005 | */ |
0e2bb2bc JP |
3006 | if (!strcmp(insn->sec->name, ".fixup") || |
3007 | !strcmp(insn->sec->name, ".altinstr_replacement") || | |
3008 | !strcmp(insn->sec->name, ".altinstr_aux")) | |
dcc914f4 JP |
3009 | return true; |
3010 | ||
bd841d61 JP |
3011 | if (!insn->func) |
3012 | return false; | |
3013 | ||
3014 | /* | |
3015 | * CONFIG_UBSAN_TRAP inserts a UD2 when it sees | |
3016 | * __builtin_unreachable(). The BUG() macro has an unreachable() after | |
3017 | * the UD2, which causes GCC's undefined trap logic to emit another UD2 | |
3018 | * (or occasionally a JMP to UD2). | |
14db1f0a IH |
3019 | * |
3020 | * It may also insert a UD2 after calling a __noreturn function. | |
bd841d61 | 3021 | */ |
14db1f0a IH |
3022 | prev_insn = list_prev_entry(insn, list); |
3023 | if ((prev_insn->dead_end || dead_end_function(file, prev_insn->call_dest)) && | |
bd841d61 JP |
3024 | (insn->type == INSN_BUG || |
3025 | (insn->type == INSN_JUMP_UNCONDITIONAL && | |
3026 | insn->jump_dest && insn->jump_dest->type == INSN_BUG))) | |
3027 | return true; | |
3028 | ||
dcc914f4 JP |
3029 | /* |
3030 | * Check if this (or a subsequent) instruction is related to | |
3031 | * CONFIG_UBSAN or CONFIG_KASAN. | |
3032 | * | |
3033 | * End the search at 5 instructions to avoid going into the weeds. | |
3034 | */ | |
3035 | for (i = 0; i < 5; i++) { | |
3036 | ||
3037 | if (is_kasan_insn(insn) || is_ubsan_insn(insn)) | |
3038 | return true; | |
3039 | ||
fe24e271 JP |
3040 | if (insn->type == INSN_JUMP_UNCONDITIONAL) { |
3041 | if (insn->jump_dest && | |
3042 | insn->jump_dest->func == insn->func) { | |
3043 | insn = insn->jump_dest; | |
3044 | continue; | |
3045 | } | |
3046 | ||
3047 | break; | |
dcc914f4 JP |
3048 | } |
3049 | ||
baa41469 | 3050 | if (insn->offset + insn->len >= insn->func->offset + insn->func->len) |
dcc914f4 | 3051 | break; |
fe24e271 | 3052 | |
dcc914f4 JP |
3053 | insn = list_next_entry(insn, list); |
3054 | } | |
3055 | ||
3056 | return false; | |
3057 | } | |
3058 | ||
4b5e2e7f PZ |
3059 | static int validate_symbol(struct objtool_file *file, struct section *sec, |
3060 | struct symbol *sym, struct insn_state *state) | |
dcc914f4 | 3061 | { |
dcc914f4 | 3062 | struct instruction *insn; |
4b5e2e7f PZ |
3063 | int ret; |
3064 | ||
3065 | if (!sym->len) { | |
3066 | WARN("%s() is missing an ELF size annotation", sym->name); | |
3067 | return 1; | |
3068 | } | |
3069 | ||
3070 | if (sym->pfunc != sym || sym->alias != sym) | |
3071 | return 0; | |
3072 | ||
3073 | insn = find_insn(file, sec, sym->offset); | |
3074 | if (!insn || insn->ignore || insn->visited) | |
3075 | return 0; | |
3076 | ||
3077 | state->uaccess = sym->uaccess_safe; | |
3078 | ||
3079 | ret = validate_branch(file, insn->func, insn, *state); | |
3080 | if (ret && backtrace) | |
3081 | BT_FUNC("<=== (sym)", insn); | |
3082 | return ret; | |
3083 | } | |
3084 | ||
3085 | static int validate_section(struct objtool_file *file, struct section *sec) | |
3086 | { | |
baa41469 | 3087 | struct insn_state state; |
4b5e2e7f PZ |
3088 | struct symbol *func; |
3089 | int warnings = 0; | |
dcc914f4 | 3090 | |
350994bf PZ |
3091 | list_for_each_entry(func, &sec->symbol_list, list) { |
3092 | if (func->type != STT_FUNC) | |
3093 | continue; | |
e10cd8fe | 3094 | |
932f8e98 | 3095 | init_insn_state(&state, sec); |
b735bd3e | 3096 | set_func_state(&state.cfi); |
0699e551 | 3097 | |
4b5e2e7f | 3098 | warnings += validate_symbol(file, sec, func, &state); |
dcc914f4 JP |
3099 | } |
3100 | ||
dcc914f4 JP |
3101 | return warnings; |
3102 | } | |
3103 | ||
c4a33939 PZ |
3104 | static int validate_vmlinux_functions(struct objtool_file *file) |
3105 | { | |
3106 | struct section *sec; | |
932f8e98 | 3107 | int warnings = 0; |
c4a33939 PZ |
3108 | |
3109 | sec = find_section_by_name(file->elf, ".noinstr.text"); | |
0cc9ac8d TG |
3110 | if (sec) { |
3111 | warnings += validate_section(file, sec); | |
3112 | warnings += validate_unwind_hints(file, sec); | |
3113 | } | |
c4a33939 | 3114 | |
0cc9ac8d TG |
3115 | sec = find_section_by_name(file->elf, ".entry.text"); |
3116 | if (sec) { | |
3117 | warnings += validate_section(file, sec); | |
3118 | warnings += validate_unwind_hints(file, sec); | |
3119 | } | |
932f8e98 PZ |
3120 | |
3121 | return warnings; | |
c4a33939 PZ |
3122 | } |
3123 | ||
350994bf PZ |
3124 | static int validate_functions(struct objtool_file *file) |
3125 | { | |
3126 | struct section *sec; | |
3127 | int warnings = 0; | |
3128 | ||
da837bd6 PZ |
3129 | for_each_sec(file, sec) { |
3130 | if (!(sec->sh.sh_flags & SHF_EXECINSTR)) | |
3131 | continue; | |
3132 | ||
350994bf | 3133 | warnings += validate_section(file, sec); |
da837bd6 | 3134 | } |
350994bf PZ |
3135 | |
3136 | return warnings; | |
3137 | } | |
3138 | ||
baa41469 | 3139 | static int validate_reachable_instructions(struct objtool_file *file) |
dcc914f4 JP |
3140 | { |
3141 | struct instruction *insn; | |
baa41469 JP |
3142 | |
3143 | if (file->ignore_unreachables) | |
3144 | return 0; | |
dcc914f4 JP |
3145 | |
3146 | for_each_insn(file, insn) { | |
14db1f0a | 3147 | if (insn->visited || ignore_unreachable_insn(file, insn)) |
baa41469 JP |
3148 | continue; |
3149 | ||
baa41469 JP |
3150 | WARN_FUNC("unreachable instruction", insn->sec, insn->offset); |
3151 | return 1; | |
dcc914f4 JP |
3152 | } |
3153 | ||
baa41469 | 3154 | return 0; |
dcc914f4 JP |
3155 | } |
3156 | ||
d44becb9 | 3157 | int check(struct objtool_file *file) |
dcc914f4 | 3158 | { |
dcc914f4 JP |
3159 | int ret, warnings = 0; |
3160 | ||
baa41469 JP |
3161 | arch_initial_func_cfi_state(&initial_func_cfi); |
3162 | ||
6545eb03 | 3163 | ret = decode_sections(file); |
dcc914f4 JP |
3164 | if (ret < 0) |
3165 | goto out; | |
3166 | warnings += ret; | |
3167 | ||
6545eb03 | 3168 | if (list_empty(&file->insn_list)) |
dcc914f4 | 3169 | goto out; |
dcc914f4 | 3170 | |
c4a33939 | 3171 | if (vmlinux && !validate_dup) { |
6545eb03 | 3172 | ret = validate_vmlinux_functions(file); |
c4a33939 PZ |
3173 | if (ret < 0) |
3174 | goto out; | |
3175 | ||
3176 | warnings += ret; | |
3177 | goto out; | |
3178 | } | |
3179 | ||
b5bc2231 | 3180 | if (retpoline) { |
6545eb03 | 3181 | ret = validate_retpoline(file); |
b5bc2231 PZ |
3182 | if (ret < 0) |
3183 | return ret; | |
3184 | warnings += ret; | |
3185 | } | |
3186 | ||
6545eb03 | 3187 | ret = validate_functions(file); |
dcc914f4 JP |
3188 | if (ret < 0) |
3189 | goto out; | |
3190 | warnings += ret; | |
3191 | ||
6545eb03 | 3192 | ret = validate_unwind_hints(file, NULL); |
39358a03 JP |
3193 | if (ret < 0) |
3194 | goto out; | |
3195 | warnings += ret; | |
3196 | ||
baa41469 | 3197 | if (!warnings) { |
6545eb03 | 3198 | ret = validate_reachable_instructions(file); |
baa41469 JP |
3199 | if (ret < 0) |
3200 | goto out; | |
3201 | warnings += ret; | |
3202 | } | |
3203 | ||
6545eb03 | 3204 | ret = create_static_call_sections(file); |
1e7e4788 JP |
3205 | if (ret < 0) |
3206 | goto out; | |
3207 | warnings += ret; | |
3208 | ||
99d00215 PZ |
3209 | if (mcount) { |
3210 | ret = create_mcount_loc_sections(file); | |
3211 | if (ret < 0) | |
3212 | goto out; | |
3213 | warnings += ret; | |
3214 | } | |
3215 | ||
dcc914f4 | 3216 | out: |
655cf865 JP |
3217 | /* |
3218 | * For now, don't fail the kernel build on fatal warnings. These | |
3219 | * errors are still fairly common due to the growing matrix of | |
3220 | * supported toolchains and their recent pace of change. | |
3221 | */ | |
dcc914f4 JP |
3222 | return 0; |
3223 | } |