2 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version 2
7 * of the License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 * This command analyzes every .o file and ensures the validity of its stack
22 * trace metadata. It enforces a set of rules on asm code and C inline
23 * assembly code so that stack traces can be reliable.
25 * For more information, see tools/objtool/Documentation/stack-validation.txt.
29 #include <subcmd/parse-options.h>
37 #include <linux/hashtable.h>
39 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
41 #define STATE_FP_SAVED 0x1
42 #define STATE_FP_SETUP 0x2
43 #define STATE_FENTRY 0x4
46 struct list_head list;
47 struct hlist_node hash;
50 unsigned int len, state;
52 unsigned long immediate;
53 bool alt_group, visited;
54 struct symbol *call_dest;
55 struct instruction *jump_dest;
56 struct list_head alts;
61 struct list_head list;
62 struct instruction *insn;
67 struct list_head insn_list;
68 DECLARE_HASHTABLE(insn_hash, 16);
69 struct section *rodata, *whitelist;
70 bool ignore_unreachables, c_file;
76 static struct instruction *find_insn(struct objtool_file *file,
77 struct section *sec, unsigned long offset)
79 struct instruction *insn;
81 hash_for_each_possible(file->insn_hash, insn, hash, offset)
82 if (insn->sec == sec && insn->offset == offset)
88 static struct instruction *next_insn_same_sec(struct objtool_file *file,
89 struct instruction *insn)
91 struct instruction *next = list_next_entry(insn, list);
93 if (&next->list == &file->insn_list || next->sec != insn->sec)
99 #define for_each_insn(file, insn) \
100 list_for_each_entry(insn, &file->insn_list, list)
102 #define func_for_each_insn(file, func, insn) \
103 for (insn = find_insn(file, func->sec, func->offset); \
104 insn && &insn->list != &file->insn_list && \
105 insn->sec == func->sec && \
106 insn->offset < func->offset + func->len; \
107 insn = list_next_entry(insn, list))
109 #define sec_for_each_insn_from(file, insn) \
110 for (; insn; insn = next_insn_same_sec(file, insn))
114 * Check if the function has been manually whitelisted with the
115 * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted
116 * due to its use of a context switching instruction.
118 static bool ignore_func(struct objtool_file *file, struct symbol *func)
121 struct instruction *insn;
123 /* check for STACK_FRAME_NON_STANDARD */
124 if (file->whitelist && file->whitelist->rela)
125 list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) {
126 if (rela->sym->type == STT_SECTION &&
127 rela->sym->sec == func->sec &&
128 rela->addend == func->offset)
130 if (rela->sym->type == STT_FUNC && rela->sym == func)
134 /* check if it has a context switching instruction */
135 func_for_each_insn(file, func, insn)
136 if (insn->type == INSN_CONTEXT_SWITCH)
143 * This checks to see if the given function is a "noreturn" function.
145 * For global functions which are outside the scope of this object file, we
146 * have to keep a manual list of them.
148 * For local functions, we have to detect them manually by simply looking for
149 * the lack of a return instruction.
156 static int __dead_end_function(struct objtool_file *file, struct symbol *func,
160 struct instruction *insn;
164 * Unfortunately these have to be hard coded because the noreturn
165 * attribute isn't provided in ELF data.
167 static const char * const global_noreturns[] = {
171 "__module_put_and_exit",
173 "kvm_spurious_fault",
178 if (func->bind == STB_WEAK)
181 if (func->bind == STB_GLOBAL)
182 for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
183 if (!strcmp(func->name, global_noreturns[i]))
189 func_for_each_insn(file, func, insn) {
192 if (insn->type == INSN_RETURN)
200 * A function can have a sibling call instead of a return. In that
201 * case, the function's dead-end status depends on whether the target
202 * of the sibling call returns.
204 func_for_each_insn(file, func, insn) {
205 if (insn->sec != func->sec ||
206 insn->offset >= func->offset + func->len)
209 if (insn->type == INSN_JUMP_UNCONDITIONAL) {
210 struct instruction *dest = insn->jump_dest;
211 struct symbol *dest_func;
214 /* sibling call to another file */
217 if (dest->sec != func->sec ||
218 dest->offset < func->offset ||
219 dest->offset >= func->offset + func->len) {
220 /* local sibling call */
221 dest_func = find_symbol_by_offset(dest->sec,
226 if (recursion == 5) {
227 WARN_FUNC("infinite recursion (objtool bug!)",
228 dest->sec, dest->offset);
232 return __dead_end_function(file, dest_func,
237 if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
245 static int dead_end_function(struct objtool_file *file, struct symbol *func)
247 return __dead_end_function(file, func, 0);
251 * Call the arch-specific instruction decoder for all the instructions and add
252 * them to the global instruction list.
254 static int decode_instructions(struct objtool_file *file)
258 unsigned long offset;
259 struct instruction *insn;
262 list_for_each_entry(sec, &file->elf->sections, list) {
264 if (!(sec->sh.sh_flags & SHF_EXECINSTR))
267 for (offset = 0; offset < sec->len; offset += insn->len) {
268 insn = malloc(sizeof(*insn));
269 memset(insn, 0, sizeof(*insn));
271 INIT_LIST_HEAD(&insn->alts);
273 insn->offset = offset;
275 ret = arch_decode_instruction(file->elf, sec, offset,
277 &insn->len, &insn->type,
282 if (!insn->type || insn->type > INSN_LAST) {
283 WARN_FUNC("invalid instruction type %d",
284 insn->sec, insn->offset, insn->type);
288 hash_add(file->insn_hash, &insn->hash, insn->offset);
289 list_add_tail(&insn->list, &file->insn_list);
292 list_for_each_entry(func, &sec->symbol_list, list) {
293 if (func->type != STT_FUNC)
296 if (!find_insn(file, sec, func->offset)) {
297 WARN("%s(): can't find starting instruction",
302 func_for_each_insn(file, func, insn)
312 * Warnings shouldn't be reported for ignored functions.
314 static void add_ignores(struct objtool_file *file)
316 struct instruction *insn;
320 list_for_each_entry(sec, &file->elf->sections, list) {
321 list_for_each_entry(func, &sec->symbol_list, list) {
322 if (func->type != STT_FUNC)
325 if (!ignore_func(file, func))
328 func_for_each_insn(file, func, insn)
329 insn->visited = true;
335 * Find the destination instructions for all jumps.
337 static int add_jump_destinations(struct objtool_file *file)
339 struct instruction *insn;
341 struct section *dest_sec;
342 unsigned long dest_off;
344 for_each_insn(file, insn) {
345 if (insn->type != INSN_JUMP_CONDITIONAL &&
346 insn->type != INSN_JUMP_UNCONDITIONAL)
353 rela = find_rela_by_dest_range(insn->sec, insn->offset,
356 dest_sec = insn->sec;
357 dest_off = insn->offset + insn->len + insn->immediate;
358 } else if (rela->sym->type == STT_SECTION) {
359 dest_sec = rela->sym->sec;
360 dest_off = rela->addend + 4;
361 } else if (rela->sym->sec->idx) {
362 dest_sec = rela->sym->sec;
363 dest_off = rela->sym->sym.st_value + rela->addend + 4;
370 insn->jump_dest = find_insn(file, dest_sec, dest_off);
371 if (!insn->jump_dest) {
374 * This is a special case where an alt instruction
375 * jumps past the end of the section. These are
376 * handled later in handle_group_alt().
378 if (!strcmp(insn->sec->name, ".altinstr_replacement"))
381 WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
382 insn->sec, insn->offset, dest_sec->name,
392 * Find the destination instructions for all calls.
394 static int add_call_destinations(struct objtool_file *file)
396 struct instruction *insn;
397 unsigned long dest_off;
400 for_each_insn(file, insn) {
401 if (insn->type != INSN_CALL)
404 rela = find_rela_by_dest_range(insn->sec, insn->offset,
407 dest_off = insn->offset + insn->len + insn->immediate;
408 insn->call_dest = find_symbol_by_offset(insn->sec,
410 if (!insn->call_dest) {
411 WARN_FUNC("can't find call dest symbol at offset 0x%lx",
412 insn->sec, insn->offset, dest_off);
415 } else if (rela->sym->type == STT_SECTION) {
416 insn->call_dest = find_symbol_by_offset(rela->sym->sec,
418 if (!insn->call_dest ||
419 insn->call_dest->type != STT_FUNC) {
420 WARN_FUNC("can't find call dest symbol at %s+0x%x",
421 insn->sec, insn->offset,
422 rela->sym->sec->name,
427 insn->call_dest = rela->sym;
434 * The .alternatives section requires some extra special care, over and above
435 * what other special sections require:
437 * 1. Because alternatives are patched in-place, we need to insert a fake jump
438 * instruction at the end so that validate_branch() skips all the original
439 * replaced instructions when validating the new instruction path.
441 * 2. An added wrinkle is that the new instruction length might be zero. In
442 * that case the old instructions are replaced with noops. We simulate that
443 * by creating a fake jump as the only new instruction.
445 * 3. In some cases, the alternative section includes an instruction which
446 * conditionally jumps to the _end_ of the entry. We have to modify these
447 * jumps' destinations to point back to .text rather than the end of the
448 * entry in .altinstr_replacement.
450 * 4. It has been requested that we don't validate the !POPCNT feature path
451 * which is a "very very small percentage of machines".
453 static int handle_group_alt(struct objtool_file *file,
454 struct special_alt *special_alt,
455 struct instruction *orig_insn,
456 struct instruction **new_insn)
458 struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump;
459 unsigned long dest_off;
461 last_orig_insn = NULL;
463 sec_for_each_insn_from(file, insn) {
464 if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
467 if (special_alt->skip_orig)
468 insn->type = INSN_NOP;
470 insn->alt_group = true;
471 last_orig_insn = insn;
474 if (!next_insn_same_sec(file, last_orig_insn)) {
475 WARN("%s: don't know how to handle alternatives at end of section",
476 special_alt->orig_sec->name);
480 fake_jump = malloc(sizeof(*fake_jump));
482 WARN("malloc failed");
485 memset(fake_jump, 0, sizeof(*fake_jump));
486 INIT_LIST_HEAD(&fake_jump->alts);
487 fake_jump->sec = special_alt->new_sec;
488 fake_jump->offset = -1;
489 fake_jump->type = INSN_JUMP_UNCONDITIONAL;
490 fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
492 if (!special_alt->new_len) {
493 *new_insn = fake_jump;
497 last_new_insn = NULL;
499 sec_for_each_insn_from(file, insn) {
500 if (insn->offset >= special_alt->new_off + special_alt->new_len)
503 last_new_insn = insn;
505 if (insn->type != INSN_JUMP_CONDITIONAL &&
506 insn->type != INSN_JUMP_UNCONDITIONAL)
509 if (!insn->immediate)
512 dest_off = insn->offset + insn->len + insn->immediate;
513 if (dest_off == special_alt->new_off + special_alt->new_len)
514 insn->jump_dest = fake_jump;
516 if (!insn->jump_dest) {
517 WARN_FUNC("can't find alternative jump destination",
518 insn->sec, insn->offset);
523 if (!last_new_insn) {
524 WARN_FUNC("can't find last new alternative instruction",
525 special_alt->new_sec, special_alt->new_off);
529 list_add(&fake_jump->list, &last_new_insn->list);
535 * A jump table entry can either convert a nop to a jump or a jump to a nop.
536 * If the original instruction is a jump, make the alt entry an effective nop
537 * by just skipping the original instruction.
539 static int handle_jump_alt(struct objtool_file *file,
540 struct special_alt *special_alt,
541 struct instruction *orig_insn,
542 struct instruction **new_insn)
544 if (orig_insn->type == INSN_NOP)
547 if (orig_insn->type != INSN_JUMP_UNCONDITIONAL) {
548 WARN_FUNC("unsupported instruction at jump label",
549 orig_insn->sec, orig_insn->offset);
553 *new_insn = list_next_entry(orig_insn, list);
558 * Read all the special sections which have alternate instructions which can be
559 * patched in or redirected to at runtime. Each instruction having alternate
560 * instruction(s) has them added to its insn->alts list, which will be
561 * traversed in validate_branch().
563 static int add_special_section_alts(struct objtool_file *file)
565 struct list_head special_alts;
566 struct instruction *orig_insn, *new_insn;
567 struct special_alt *special_alt, *tmp;
568 struct alternative *alt;
571 ret = special_get_alts(file->elf, &special_alts);
575 list_for_each_entry_safe(special_alt, tmp, &special_alts, list) {
576 alt = malloc(sizeof(*alt));
578 WARN("malloc failed");
583 orig_insn = find_insn(file, special_alt->orig_sec,
584 special_alt->orig_off);
586 WARN_FUNC("special: can't find orig instruction",
587 special_alt->orig_sec, special_alt->orig_off);
593 if (!special_alt->group || special_alt->new_len) {
594 new_insn = find_insn(file, special_alt->new_sec,
595 special_alt->new_off);
597 WARN_FUNC("special: can't find new instruction",
598 special_alt->new_sec,
599 special_alt->new_off);
605 if (special_alt->group) {
606 ret = handle_group_alt(file, special_alt, orig_insn,
610 } else if (special_alt->jump_or_nop) {
611 ret = handle_jump_alt(file, special_alt, orig_insn,
617 alt->insn = new_insn;
618 list_add_tail(&alt->list, &orig_insn->alts);
620 list_del(&special_alt->list);
628 static int add_switch_table(struct objtool_file *file, struct symbol *func,
629 struct instruction *insn, struct rela *table,
630 struct rela *next_table)
632 struct rela *rela = table;
633 struct instruction *alt_insn;
634 struct alternative *alt;
636 list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) {
637 if (rela == next_table)
640 if (rela->sym->sec != insn->sec ||
641 rela->addend <= func->offset ||
642 rela->addend >= func->offset + func->len)
645 alt_insn = find_insn(file, insn->sec, rela->addend);
647 WARN("%s: can't find instruction at %s+0x%x",
648 file->rodata->rela->name, insn->sec->name,
653 alt = malloc(sizeof(*alt));
655 WARN("malloc failed");
659 alt->insn = alt_insn;
660 list_add_tail(&alt->list, &insn->alts);
666 static int add_func_switch_tables(struct objtool_file *file,
669 struct instruction *insn, *prev_jump;
670 struct rela *text_rela, *rodata_rela, *prev_rela;
675 func_for_each_insn(file, func, insn) {
676 if (insn->type != INSN_JUMP_DYNAMIC)
679 text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
681 if (!text_rela || text_rela->sym != file->rodata->sym)
684 /* common case: jmpq *[addr](,%rax,8) */
685 rodata_rela = find_rela_by_dest(file->rodata,
689 * rare case: jmpq *[addr](%rip)
691 * This check is for a rare gcc quirk, currently only seen in
692 * three driver functions in the kernel, only with certain
693 * obscure non-distro configs.
695 * As part of an optimization, gcc makes a copy of an existing
696 * switch jump table, modifies it, and then hard-codes the jump
697 * (albeit with an indirect jump) to use a single entry in the
698 * table. The rest of the jump table and some of its jump
699 * targets remain as dead code.
701 * In such a case we can just crudely ignore all unreachable
702 * instruction warnings for the entire object file. Ideally we
703 * would just ignore them for the function, but that would
704 * require redesigning the code quite a bit. And honestly
705 * that's just not worth doing: unreachable instruction
706 * warnings are of questionable value anyway, and this is such
710 * - https://lkml.kernel.org/r/201603231906.LWcVUpxm%25fengguang.wu@intel.com
711 * - https://lkml.kernel.org/r/201603271114.K9i45biy%25fengguang.wu@intel.com
712 * - https://lkml.kernel.org/r/201603291058.zuJ6ben1%25fengguang.wu@intel.com
715 * - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70604
718 rodata_rela = find_rela_by_dest(file->rodata,
719 text_rela->addend + 4);
721 file->ignore_unreachables = true;
728 * We found a switch table, but we don't know yet how big it
729 * is. Don't add it until we reach the end of the function or
730 * the beginning of another switch table in the same function.
733 ret = add_switch_table(file, func, prev_jump, prev_rela,
740 prev_rela = rodata_rela;
744 ret = add_switch_table(file, func, prev_jump, prev_rela, NULL);
753 * For some switch statements, gcc generates a jump table in the .rodata
754 * section which contains a list of addresses within the function to jump to.
755 * This finds these jump tables and adds them to the insn->alts lists.
757 static int add_switch_table_alts(struct objtool_file *file)
763 if (!file->rodata || !file->rodata->rela)
766 list_for_each_entry(sec, &file->elf->sections, list) {
767 list_for_each_entry(func, &sec->symbol_list, list) {
768 if (func->type != STT_FUNC)
771 ret = add_func_switch_tables(file, func);
780 static int decode_sections(struct objtool_file *file)
784 ret = decode_instructions(file);
790 ret = add_jump_destinations(file);
794 ret = add_call_destinations(file);
798 ret = add_special_section_alts(file);
802 ret = add_switch_table_alts(file);
809 static bool is_fentry_call(struct instruction *insn)
811 if (insn->type == INSN_CALL &&
812 insn->call_dest->type == STT_NOTYPE &&
813 !strcmp(insn->call_dest->name, "__fentry__"))
819 static bool has_modified_stack_frame(struct instruction *insn)
821 return (insn->state & STATE_FP_SAVED) ||
822 (insn->state & STATE_FP_SETUP);
825 static bool has_valid_stack_frame(struct instruction *insn)
827 return (insn->state & STATE_FP_SAVED) &&
828 (insn->state & STATE_FP_SETUP);
831 static unsigned int frame_state(unsigned long state)
833 return (state & (STATE_FP_SAVED | STATE_FP_SETUP));
837 * Follow the branch starting at the given instruction, and recursively follow
838 * any other branches (jumps). Meanwhile, track the frame pointer state at
839 * each instruction and validate all the rules described in
840 * tools/objtool/Documentation/stack-validation.txt.
842 static int validate_branch(struct objtool_file *file,
843 struct instruction *first, unsigned char first_state)
845 struct alternative *alt;
846 struct instruction *insn;
848 struct symbol *func = NULL;
856 if (insn->alt_group && list_empty(&insn->alts)) {
857 WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
863 if (file->c_file && insn->func) {
864 if (func && func != insn->func) {
865 WARN("%s() falls through to next function %s()",
866 func->name, insn->func->name);
874 if (frame_state(insn->state) != frame_state(state)) {
875 WARN_FUNC("frame pointer state mismatch",
883 insn->visited = true;
886 list_for_each_entry(alt, &insn->alts, list) {
887 ret = validate_branch(file, alt->insn, state);
892 switch (insn->type) {
896 if (state & STATE_FP_SAVED) {
897 WARN_FUNC("duplicate frame pointer save",
901 state |= STATE_FP_SAVED;
907 if (state & STATE_FP_SETUP) {
908 WARN_FUNC("duplicate frame pointer setup",
912 state |= STATE_FP_SETUP;
916 case INSN_FP_RESTORE:
918 if (has_valid_stack_frame(insn))
919 state &= ~STATE_FP_SETUP;
921 state &= ~STATE_FP_SAVED;
926 if (!nofp && has_modified_stack_frame(insn)) {
927 WARN_FUNC("return without frame pointer restore",
934 if (is_fentry_call(insn)) {
935 state |= STATE_FENTRY;
939 ret = dead_end_function(file, insn->call_dest);
946 case INSN_CALL_DYNAMIC:
947 if (!nofp && !has_valid_stack_frame(insn)) {
948 WARN_FUNC("call without frame pointer save/setup",
954 case INSN_JUMP_CONDITIONAL:
955 case INSN_JUMP_UNCONDITIONAL:
956 if (insn->jump_dest) {
957 ret = validate_branch(file, insn->jump_dest,
961 } else if (has_modified_stack_frame(insn)) {
962 WARN_FUNC("sibling call from callable instruction with changed frame pointer",
965 } /* else it's a sibling call */
967 if (insn->type == INSN_JUMP_UNCONDITIONAL)
972 case INSN_JUMP_DYNAMIC:
973 if (list_empty(&insn->alts) &&
974 has_modified_stack_frame(insn)) {
975 WARN_FUNC("sibling call from callable instruction with changed frame pointer",
989 insn = next_insn_same_sec(file, insn);
991 WARN("%s: unexpected end of section", sec->name);
999 static bool is_gcov_insn(struct instruction *insn)
1002 struct section *sec;
1004 unsigned long offset;
1006 rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len);
1010 if (rela->sym->type != STT_SECTION)
1013 sec = rela->sym->sec;
1014 offset = rela->addend + insn->offset + insn->len - rela->offset;
1016 list_for_each_entry(sym, &sec->symbol_list, list) {
1017 if (sym->type != STT_OBJECT)
1020 if (offset >= sym->offset && offset < sym->offset + sym->len)
1021 return (!memcmp(sym->name, "__gcov0.", 8));
1027 static bool is_kasan_insn(struct instruction *insn)
1029 return (insn->type == INSN_CALL &&
1030 !strcmp(insn->call_dest->name, "__asan_handle_no_return"));
1033 static bool is_ubsan_insn(struct instruction *insn)
1035 return (insn->type == INSN_CALL &&
1036 !strcmp(insn->call_dest->name,
1037 "__ubsan_handle_builtin_unreachable"));
1040 static bool ignore_unreachable_insn(struct symbol *func,
1041 struct instruction *insn)
1045 if (insn->type == INSN_NOP)
1048 if (is_gcov_insn(insn))
1052 * Check if this (or a subsequent) instruction is related to
1053 * CONFIG_UBSAN or CONFIG_KASAN.
1055 * End the search at 5 instructions to avoid going into the weeds.
1057 for (i = 0; i < 5; i++) {
1059 if (is_kasan_insn(insn) || is_ubsan_insn(insn))
1062 if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) {
1063 insn = insn->jump_dest;
1067 if (insn->offset + insn->len >= func->offset + func->len)
1069 insn = list_next_entry(insn, list);
1075 static int validate_functions(struct objtool_file *file)
1077 struct section *sec;
1078 struct symbol *func;
1079 struct instruction *insn;
1080 int ret, warnings = 0;
1082 list_for_each_entry(sec, &file->elf->sections, list) {
1083 list_for_each_entry(func, &sec->symbol_list, list) {
1084 if (func->type != STT_FUNC)
1087 insn = find_insn(file, sec, func->offset);
1091 ret = validate_branch(file, insn, 0);
1096 list_for_each_entry(sec, &file->elf->sections, list) {
1097 list_for_each_entry(func, &sec->symbol_list, list) {
1098 if (func->type != STT_FUNC)
1101 func_for_each_insn(file, func, insn) {
1105 insn->visited = true;
1107 if (file->ignore_unreachables || warnings ||
1108 ignore_unreachable_insn(func, insn))
1111 WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset);
1120 static int validate_uncallable_instructions(struct objtool_file *file)
1122 struct instruction *insn;
1125 for_each_insn(file, insn) {
1126 if (!insn->visited && insn->type == INSN_RETURN) {
1127 WARN_FUNC("return instruction outside of a callable function",
1128 insn->sec, insn->offset);
1136 static void cleanup(struct objtool_file *file)
1138 struct instruction *insn, *tmpinsn;
1139 struct alternative *alt, *tmpalt;
1141 list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) {
1142 list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) {
1143 list_del(&alt->list);
1146 list_del(&insn->list);
1147 hash_del(&insn->hash);
1150 elf_close(file->elf);
1153 const char * const check_usage[] = {
1154 "objtool check [<options>] file.o",
1158 int cmd_check(int argc, const char **argv)
1160 struct objtool_file file;
1161 int ret, warnings = 0;
1163 const struct option options[] = {
1164 OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"),
1168 argc = parse_options(argc, argv, options, check_usage, 0);
1171 usage_with_options(check_usage, options);
1175 file.elf = elf_open(objname);
1177 fprintf(stderr, "error reading elf file %s\n", objname);
1181 INIT_LIST_HEAD(&file.insn_list);
1182 hash_init(file.insn_hash);
1183 file.whitelist = find_section_by_name(file.elf, "__func_stack_frame_non_standard");
1184 file.rodata = find_section_by_name(file.elf, ".rodata");
1185 file.ignore_unreachables = false;
1186 file.c_file = find_section_by_name(file.elf, ".comment");
1188 ret = decode_sections(&file);
1193 ret = validate_functions(&file);
1198 ret = validate_uncallable_instructions(&file);
1206 /* ignore warnings for now until we get all the code cleaned up */
1207 if (ret || warnings)