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.
30 #include <subcmd/parse-options.h>
38 #include <linux/hashtable.h>
40 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
42 #define STATE_FP_SAVED 0x1
43 #define STATE_FP_SETUP 0x2
44 #define STATE_FENTRY 0x4
47 struct list_head list;
48 struct hlist_node hash;
51 unsigned int len, state;
53 unsigned long immediate;
54 bool alt_group, visited;
55 struct symbol *call_dest;
56 struct instruction *jump_dest;
57 struct list_head alts;
62 struct list_head list;
63 struct instruction *insn;
68 struct list_head insn_list;
69 DECLARE_HASHTABLE(insn_hash, 16);
70 struct section *rodata, *whitelist;
71 bool ignore_unreachables, c_file;
77 static struct instruction *find_insn(struct objtool_file *file,
78 struct section *sec, unsigned long offset)
80 struct instruction *insn;
82 hash_for_each_possible(file->insn_hash, insn, hash, offset)
83 if (insn->sec == sec && insn->offset == offset)
89 static struct instruction *next_insn_same_sec(struct objtool_file *file,
90 struct instruction *insn)
92 struct instruction *next = list_next_entry(insn, list);
94 if (&next->list == &file->insn_list || next->sec != insn->sec)
100 #define for_each_insn(file, insn) \
101 list_for_each_entry(insn, &file->insn_list, list)
103 #define func_for_each_insn(file, func, insn) \
104 for (insn = find_insn(file, func->sec, func->offset); \
105 insn && &insn->list != &file->insn_list && \
106 insn->sec == func->sec && \
107 insn->offset < func->offset + func->len; \
108 insn = list_next_entry(insn, list))
110 #define sec_for_each_insn_from(file, insn) \
111 for (; insn; insn = next_insn_same_sec(file, insn))
115 * Check if the function has been manually whitelisted with the
116 * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted
117 * due to its use of a context switching instruction.
119 static bool ignore_func(struct objtool_file *file, struct symbol *func)
122 struct instruction *insn;
124 /* check for STACK_FRAME_NON_STANDARD */
125 if (file->whitelist && file->whitelist->rela)
126 list_for_each_entry(rela, &file->whitelist->rela->rela_list, list) {
127 if (rela->sym->type == STT_SECTION &&
128 rela->sym->sec == func->sec &&
129 rela->addend == func->offset)
131 if (rela->sym->type == STT_FUNC && rela->sym == func)
135 /* check if it has a context switching instruction */
136 func_for_each_insn(file, func, insn)
137 if (insn->type == INSN_CONTEXT_SWITCH)
144 * This checks to see if the given function is a "noreturn" function.
146 * For global functions which are outside the scope of this object file, we
147 * have to keep a manual list of them.
149 * For local functions, we have to detect them manually by simply looking for
150 * the lack of a return instruction.
157 static int __dead_end_function(struct objtool_file *file, struct symbol *func,
161 struct instruction *insn;
165 * Unfortunately these have to be hard coded because the noreturn
166 * attribute isn't provided in ELF data.
168 static const char * const global_noreturns[] = {
172 "__module_put_and_exit",
174 "kvm_spurious_fault",
179 if (func->bind == STB_WEAK)
182 if (func->bind == STB_GLOBAL)
183 for (i = 0; i < ARRAY_SIZE(global_noreturns); i++)
184 if (!strcmp(func->name, global_noreturns[i]))
190 func_for_each_insn(file, func, insn) {
193 if (insn->type == INSN_RETURN)
201 * A function can have a sibling call instead of a return. In that
202 * case, the function's dead-end status depends on whether the target
203 * of the sibling call returns.
205 func_for_each_insn(file, func, insn) {
206 if (insn->sec != func->sec ||
207 insn->offset >= func->offset + func->len)
210 if (insn->type == INSN_JUMP_UNCONDITIONAL) {
211 struct instruction *dest = insn->jump_dest;
212 struct symbol *dest_func;
215 /* sibling call to another file */
218 if (dest->sec != func->sec ||
219 dest->offset < func->offset ||
220 dest->offset >= func->offset + func->len) {
221 /* local sibling call */
222 dest_func = find_symbol_by_offset(dest->sec,
227 if (recursion == 5) {
228 WARN_FUNC("infinite recursion (objtool bug!)",
229 dest->sec, dest->offset);
233 return __dead_end_function(file, dest_func,
238 if (insn->type == INSN_JUMP_DYNAMIC && list_empty(&insn->alts))
246 static int dead_end_function(struct objtool_file *file, struct symbol *func)
248 return __dead_end_function(file, func, 0);
252 * Call the arch-specific instruction decoder for all the instructions and add
253 * them to the global instruction list.
255 static int decode_instructions(struct objtool_file *file)
259 unsigned long offset;
260 struct instruction *insn;
263 list_for_each_entry(sec, &file->elf->sections, list) {
265 if (!(sec->sh.sh_flags & SHF_EXECINSTR))
268 for (offset = 0; offset < sec->len; offset += insn->len) {
269 insn = malloc(sizeof(*insn));
270 memset(insn, 0, sizeof(*insn));
272 INIT_LIST_HEAD(&insn->alts);
274 insn->offset = offset;
276 ret = arch_decode_instruction(file->elf, sec, offset,
278 &insn->len, &insn->type,
283 if (!insn->type || insn->type > INSN_LAST) {
284 WARN_FUNC("invalid instruction type %d",
285 insn->sec, insn->offset, insn->type);
289 hash_add(file->insn_hash, &insn->hash, insn->offset);
290 list_add_tail(&insn->list, &file->insn_list);
293 list_for_each_entry(func, &sec->symbol_list, list) {
294 if (func->type != STT_FUNC)
297 if (!find_insn(file, sec, func->offset)) {
298 WARN("%s(): can't find starting instruction",
303 func_for_each_insn(file, func, insn)
313 * Warnings shouldn't be reported for ignored functions.
315 static void add_ignores(struct objtool_file *file)
317 struct instruction *insn;
321 list_for_each_entry(sec, &file->elf->sections, list) {
322 list_for_each_entry(func, &sec->symbol_list, list) {
323 if (func->type != STT_FUNC)
326 if (!ignore_func(file, func))
329 func_for_each_insn(file, func, insn)
330 insn->visited = true;
336 * Find the destination instructions for all jumps.
338 static int add_jump_destinations(struct objtool_file *file)
340 struct instruction *insn;
342 struct section *dest_sec;
343 unsigned long dest_off;
345 for_each_insn(file, insn) {
346 if (insn->type != INSN_JUMP_CONDITIONAL &&
347 insn->type != INSN_JUMP_UNCONDITIONAL)
354 rela = find_rela_by_dest_range(insn->sec, insn->offset,
357 dest_sec = insn->sec;
358 dest_off = insn->offset + insn->len + insn->immediate;
359 } else if (rela->sym->type == STT_SECTION) {
360 dest_sec = rela->sym->sec;
361 dest_off = rela->addend + 4;
362 } else if (rela->sym->sec->idx) {
363 dest_sec = rela->sym->sec;
364 dest_off = rela->sym->sym.st_value + rela->addend + 4;
371 insn->jump_dest = find_insn(file, dest_sec, dest_off);
372 if (!insn->jump_dest) {
375 * This is a special case where an alt instruction
376 * jumps past the end of the section. These are
377 * handled later in handle_group_alt().
379 if (!strcmp(insn->sec->name, ".altinstr_replacement"))
382 WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
383 insn->sec, insn->offset, dest_sec->name,
393 * Find the destination instructions for all calls.
395 static int add_call_destinations(struct objtool_file *file)
397 struct instruction *insn;
398 unsigned long dest_off;
401 for_each_insn(file, insn) {
402 if (insn->type != INSN_CALL)
405 rela = find_rela_by_dest_range(insn->sec, insn->offset,
408 dest_off = insn->offset + insn->len + insn->immediate;
409 insn->call_dest = find_symbol_by_offset(insn->sec,
411 if (!insn->call_dest) {
412 WARN_FUNC("can't find call dest symbol at offset 0x%lx",
413 insn->sec, insn->offset, dest_off);
416 } else if (rela->sym->type == STT_SECTION) {
417 insn->call_dest = find_symbol_by_offset(rela->sym->sec,
419 if (!insn->call_dest ||
420 insn->call_dest->type != STT_FUNC) {
421 WARN_FUNC("can't find call dest symbol at %s+0x%x",
422 insn->sec, insn->offset,
423 rela->sym->sec->name,
428 insn->call_dest = rela->sym;
435 * The .alternatives section requires some extra special care, over and above
436 * what other special sections require:
438 * 1. Because alternatives are patched in-place, we need to insert a fake jump
439 * instruction at the end so that validate_branch() skips all the original
440 * replaced instructions when validating the new instruction path.
442 * 2. An added wrinkle is that the new instruction length might be zero. In
443 * that case the old instructions are replaced with noops. We simulate that
444 * by creating a fake jump as the only new instruction.
446 * 3. In some cases, the alternative section includes an instruction which
447 * conditionally jumps to the _end_ of the entry. We have to modify these
448 * jumps' destinations to point back to .text rather than the end of the
449 * entry in .altinstr_replacement.
451 * 4. It has been requested that we don't validate the !POPCNT feature path
452 * which is a "very very small percentage of machines".
454 static int handle_group_alt(struct objtool_file *file,
455 struct special_alt *special_alt,
456 struct instruction *orig_insn,
457 struct instruction **new_insn)
459 struct instruction *last_orig_insn, *last_new_insn, *insn, *fake_jump;
460 unsigned long dest_off;
462 last_orig_insn = NULL;
464 sec_for_each_insn_from(file, insn) {
465 if (insn->offset >= special_alt->orig_off + special_alt->orig_len)
468 if (special_alt->skip_orig)
469 insn->type = INSN_NOP;
471 insn->alt_group = true;
472 last_orig_insn = insn;
475 if (!next_insn_same_sec(file, last_orig_insn)) {
476 WARN("%s: don't know how to handle alternatives at end of section",
477 special_alt->orig_sec->name);
481 fake_jump = malloc(sizeof(*fake_jump));
483 WARN("malloc failed");
486 memset(fake_jump, 0, sizeof(*fake_jump));
487 INIT_LIST_HEAD(&fake_jump->alts);
488 fake_jump->sec = special_alt->new_sec;
489 fake_jump->offset = -1;
490 fake_jump->type = INSN_JUMP_UNCONDITIONAL;
491 fake_jump->jump_dest = list_next_entry(last_orig_insn, list);
493 if (!special_alt->new_len) {
494 *new_insn = fake_jump;
498 last_new_insn = NULL;
500 sec_for_each_insn_from(file, insn) {
501 if (insn->offset >= special_alt->new_off + special_alt->new_len)
504 last_new_insn = insn;
506 if (insn->type != INSN_JUMP_CONDITIONAL &&
507 insn->type != INSN_JUMP_UNCONDITIONAL)
510 if (!insn->immediate)
513 dest_off = insn->offset + insn->len + insn->immediate;
514 if (dest_off == special_alt->new_off + special_alt->new_len)
515 insn->jump_dest = fake_jump;
517 if (!insn->jump_dest) {
518 WARN_FUNC("can't find alternative jump destination",
519 insn->sec, insn->offset);
524 if (!last_new_insn) {
525 WARN_FUNC("can't find last new alternative instruction",
526 special_alt->new_sec, special_alt->new_off);
530 list_add(&fake_jump->list, &last_new_insn->list);
536 * A jump table entry can either convert a nop to a jump or a jump to a nop.
537 * If the original instruction is a jump, make the alt entry an effective nop
538 * by just skipping the original instruction.
540 static int handle_jump_alt(struct objtool_file *file,
541 struct special_alt *special_alt,
542 struct instruction *orig_insn,
543 struct instruction **new_insn)
545 if (orig_insn->type == INSN_NOP)
548 if (orig_insn->type != INSN_JUMP_UNCONDITIONAL) {
549 WARN_FUNC("unsupported instruction at jump label",
550 orig_insn->sec, orig_insn->offset);
554 *new_insn = list_next_entry(orig_insn, list);
559 * Read all the special sections which have alternate instructions which can be
560 * patched in or redirected to at runtime. Each instruction having alternate
561 * instruction(s) has them added to its insn->alts list, which will be
562 * traversed in validate_branch().
564 static int add_special_section_alts(struct objtool_file *file)
566 struct list_head special_alts;
567 struct instruction *orig_insn, *new_insn;
568 struct special_alt *special_alt, *tmp;
569 struct alternative *alt;
572 ret = special_get_alts(file->elf, &special_alts);
576 list_for_each_entry_safe(special_alt, tmp, &special_alts, list) {
577 alt = malloc(sizeof(*alt));
579 WARN("malloc failed");
584 orig_insn = find_insn(file, special_alt->orig_sec,
585 special_alt->orig_off);
587 WARN_FUNC("special: can't find orig instruction",
588 special_alt->orig_sec, special_alt->orig_off);
594 if (!special_alt->group || special_alt->new_len) {
595 new_insn = find_insn(file, special_alt->new_sec,
596 special_alt->new_off);
598 WARN_FUNC("special: can't find new instruction",
599 special_alt->new_sec,
600 special_alt->new_off);
606 if (special_alt->group) {
607 ret = handle_group_alt(file, special_alt, orig_insn,
611 } else if (special_alt->jump_or_nop) {
612 ret = handle_jump_alt(file, special_alt, orig_insn,
618 alt->insn = new_insn;
619 list_add_tail(&alt->list, &orig_insn->alts);
621 list_del(&special_alt->list);
629 static int add_switch_table(struct objtool_file *file, struct symbol *func,
630 struct instruction *insn, struct rela *table,
631 struct rela *next_table)
633 struct rela *rela = table;
634 struct instruction *alt_insn;
635 struct alternative *alt;
637 list_for_each_entry_from(rela, &file->rodata->rela->rela_list, list) {
638 if (rela == next_table)
641 if (rela->sym->sec != insn->sec ||
642 rela->addend <= func->offset ||
643 rela->addend >= func->offset + func->len)
646 alt_insn = find_insn(file, insn->sec, rela->addend);
648 WARN("%s: can't find instruction at %s+0x%x",
649 file->rodata->rela->name, insn->sec->name,
654 alt = malloc(sizeof(*alt));
656 WARN("malloc failed");
660 alt->insn = alt_insn;
661 list_add_tail(&alt->list, &insn->alts);
667 static int add_func_switch_tables(struct objtool_file *file,
670 struct instruction *insn, *prev_jump;
671 struct rela *text_rela, *rodata_rela, *prev_rela = NULL;
676 func_for_each_insn(file, func, insn) {
677 if (insn->type != INSN_JUMP_DYNAMIC)
680 text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
682 if (!text_rela || text_rela->sym != file->rodata->sym)
685 /* common case: jmpq *[addr](,%rax,8) */
686 rodata_rela = find_rela_by_dest(file->rodata,
690 * rare case: jmpq *[addr](%rip)
692 * This check is for a rare gcc quirk, currently only seen in
693 * three driver functions in the kernel, only with certain
694 * obscure non-distro configs.
696 * As part of an optimization, gcc makes a copy of an existing
697 * switch jump table, modifies it, and then hard-codes the jump
698 * (albeit with an indirect jump) to use a single entry in the
699 * table. The rest of the jump table and some of its jump
700 * targets remain as dead code.
702 * In such a case we can just crudely ignore all unreachable
703 * instruction warnings for the entire object file. Ideally we
704 * would just ignore them for the function, but that would
705 * require redesigning the code quite a bit. And honestly
706 * that's just not worth doing: unreachable instruction
707 * warnings are of questionable value anyway, and this is such
711 * - https://lkml.kernel.org/r/201603231906.LWcVUpxm%25fengguang.wu@intel.com
712 * - https://lkml.kernel.org/r/201603271114.K9i45biy%25fengguang.wu@intel.com
713 * - https://lkml.kernel.org/r/201603291058.zuJ6ben1%25fengguang.wu@intel.com
716 * - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70604
719 rodata_rela = find_rela_by_dest(file->rodata,
720 text_rela->addend + 4);
722 file->ignore_unreachables = true;
729 * We found a switch table, but we don't know yet how big it
730 * is. Don't add it until we reach the end of the function or
731 * the beginning of another switch table in the same function.
734 ret = add_switch_table(file, func, prev_jump, prev_rela,
741 prev_rela = rodata_rela;
745 ret = add_switch_table(file, func, prev_jump, prev_rela, NULL);
754 * For some switch statements, gcc generates a jump table in the .rodata
755 * section which contains a list of addresses within the function to jump to.
756 * This finds these jump tables and adds them to the insn->alts lists.
758 static int add_switch_table_alts(struct objtool_file *file)
764 if (!file->rodata || !file->rodata->rela)
767 list_for_each_entry(sec, &file->elf->sections, list) {
768 list_for_each_entry(func, &sec->symbol_list, list) {
769 if (func->type != STT_FUNC)
772 ret = add_func_switch_tables(file, func);
781 static int decode_sections(struct objtool_file *file)
785 ret = decode_instructions(file);
791 ret = add_jump_destinations(file);
795 ret = add_call_destinations(file);
799 ret = add_special_section_alts(file);
803 ret = add_switch_table_alts(file);
810 static bool is_fentry_call(struct instruction *insn)
812 if (insn->type == INSN_CALL &&
813 insn->call_dest->type == STT_NOTYPE &&
814 !strcmp(insn->call_dest->name, "__fentry__"))
820 static bool has_modified_stack_frame(struct instruction *insn)
822 return (insn->state & STATE_FP_SAVED) ||
823 (insn->state & STATE_FP_SETUP);
826 static bool has_valid_stack_frame(struct instruction *insn)
828 return (insn->state & STATE_FP_SAVED) &&
829 (insn->state & STATE_FP_SETUP);
832 static unsigned int frame_state(unsigned long state)
834 return (state & (STATE_FP_SAVED | STATE_FP_SETUP));
838 * Follow the branch starting at the given instruction, and recursively follow
839 * any other branches (jumps). Meanwhile, track the frame pointer state at
840 * each instruction and validate all the rules described in
841 * tools/objtool/Documentation/stack-validation.txt.
843 static int validate_branch(struct objtool_file *file,
844 struct instruction *first, unsigned char first_state)
846 struct alternative *alt;
847 struct instruction *insn;
849 struct symbol *func = NULL;
857 if (insn->alt_group && list_empty(&insn->alts)) {
858 WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
864 if (file->c_file && insn->func) {
865 if (func && func != insn->func) {
866 WARN("%s() falls through to next function %s()",
867 func->name, insn->func->name);
875 if (frame_state(insn->state) != frame_state(state)) {
876 WARN_FUNC("frame pointer state mismatch",
884 insn->visited = true;
887 list_for_each_entry(alt, &insn->alts, list) {
888 ret = validate_branch(file, alt->insn, state);
893 switch (insn->type) {
897 if (state & STATE_FP_SAVED) {
898 WARN_FUNC("duplicate frame pointer save",
902 state |= STATE_FP_SAVED;
908 if (state & STATE_FP_SETUP) {
909 WARN_FUNC("duplicate frame pointer setup",
913 state |= STATE_FP_SETUP;
917 case INSN_FP_RESTORE:
919 if (has_valid_stack_frame(insn))
920 state &= ~STATE_FP_SETUP;
922 state &= ~STATE_FP_SAVED;
927 if (!nofp && has_modified_stack_frame(insn)) {
928 WARN_FUNC("return without frame pointer restore",
935 if (is_fentry_call(insn)) {
936 state |= STATE_FENTRY;
940 ret = dead_end_function(file, insn->call_dest);
947 case INSN_CALL_DYNAMIC:
948 if (!nofp && !has_valid_stack_frame(insn)) {
949 WARN_FUNC("call without frame pointer save/setup",
955 case INSN_JUMP_CONDITIONAL:
956 case INSN_JUMP_UNCONDITIONAL:
957 if (insn->jump_dest) {
958 ret = validate_branch(file, insn->jump_dest,
962 } else if (has_modified_stack_frame(insn)) {
963 WARN_FUNC("sibling call from callable instruction with changed frame pointer",
966 } /* else it's a sibling call */
968 if (insn->type == INSN_JUMP_UNCONDITIONAL)
973 case INSN_JUMP_DYNAMIC:
974 if (list_empty(&insn->alts) &&
975 has_modified_stack_frame(insn)) {
976 WARN_FUNC("sibling call from callable instruction with changed frame pointer",
990 insn = next_insn_same_sec(file, insn);
992 WARN("%s: unexpected end of section", sec->name);
1000 static bool is_gcov_insn(struct instruction *insn)
1003 struct section *sec;
1005 unsigned long offset;
1007 rela = find_rela_by_dest_range(insn->sec, insn->offset, insn->len);
1011 if (rela->sym->type != STT_SECTION)
1014 sec = rela->sym->sec;
1015 offset = rela->addend + insn->offset + insn->len - rela->offset;
1017 list_for_each_entry(sym, &sec->symbol_list, list) {
1018 if (sym->type != STT_OBJECT)
1021 if (offset >= sym->offset && offset < sym->offset + sym->len)
1022 return (!memcmp(sym->name, "__gcov0.", 8));
1028 static bool is_kasan_insn(struct instruction *insn)
1030 return (insn->type == INSN_CALL &&
1031 !strcmp(insn->call_dest->name, "__asan_handle_no_return"));
1034 static bool is_ubsan_insn(struct instruction *insn)
1036 return (insn->type == INSN_CALL &&
1037 !strcmp(insn->call_dest->name,
1038 "__ubsan_handle_builtin_unreachable"));
1041 static bool ignore_unreachable_insn(struct symbol *func,
1042 struct instruction *insn)
1046 if (insn->type == INSN_NOP)
1049 if (is_gcov_insn(insn))
1053 * Check if this (or a subsequent) instruction is related to
1054 * CONFIG_UBSAN or CONFIG_KASAN.
1056 * End the search at 5 instructions to avoid going into the weeds.
1058 for (i = 0; i < 5; i++) {
1060 if (is_kasan_insn(insn) || is_ubsan_insn(insn))
1063 if (insn->type == INSN_JUMP_UNCONDITIONAL && insn->jump_dest) {
1064 insn = insn->jump_dest;
1068 if (insn->offset + insn->len >= func->offset + func->len)
1070 insn = list_next_entry(insn, list);
1076 static int validate_functions(struct objtool_file *file)
1078 struct section *sec;
1079 struct symbol *func;
1080 struct instruction *insn;
1081 int ret, warnings = 0;
1083 list_for_each_entry(sec, &file->elf->sections, list) {
1084 list_for_each_entry(func, &sec->symbol_list, list) {
1085 if (func->type != STT_FUNC)
1088 insn = find_insn(file, sec, func->offset);
1092 ret = validate_branch(file, insn, 0);
1097 list_for_each_entry(sec, &file->elf->sections, list) {
1098 list_for_each_entry(func, &sec->symbol_list, list) {
1099 if (func->type != STT_FUNC)
1102 func_for_each_insn(file, func, insn) {
1106 insn->visited = true;
1108 if (file->ignore_unreachables || warnings ||
1109 ignore_unreachable_insn(func, insn))
1112 WARN_FUNC("function has unreachable instruction", insn->sec, insn->offset);
1121 static int validate_uncallable_instructions(struct objtool_file *file)
1123 struct instruction *insn;
1126 for_each_insn(file, insn) {
1127 if (!insn->visited && insn->type == INSN_RETURN) {
1128 WARN_FUNC("return instruction outside of a callable function",
1129 insn->sec, insn->offset);
1137 static void cleanup(struct objtool_file *file)
1139 struct instruction *insn, *tmpinsn;
1140 struct alternative *alt, *tmpalt;
1142 list_for_each_entry_safe(insn, tmpinsn, &file->insn_list, list) {
1143 list_for_each_entry_safe(alt, tmpalt, &insn->alts, list) {
1144 list_del(&alt->list);
1147 list_del(&insn->list);
1148 hash_del(&insn->hash);
1151 elf_close(file->elf);
1154 const char * const check_usage[] = {
1155 "objtool check [<options>] file.o",
1159 int cmd_check(int argc, const char **argv)
1161 struct objtool_file file;
1162 int ret, warnings = 0;
1164 const struct option options[] = {
1165 OPT_BOOLEAN('f', "no-fp", &nofp, "Skip frame pointer validation"),
1169 argc = parse_options(argc, argv, options, check_usage, 0);
1172 usage_with_options(check_usage, options);
1176 file.elf = elf_open(objname);
1178 fprintf(stderr, "error reading elf file %s\n", objname);
1182 INIT_LIST_HEAD(&file.insn_list);
1183 hash_init(file.insn_hash);
1184 file.whitelist = find_section_by_name(file.elf, "__func_stack_frame_non_standard");
1185 file.rodata = find_section_by_name(file.elf, ".rodata");
1186 file.ignore_unreachables = false;
1187 file.c_file = find_section_by_name(file.elf, ".comment");
1189 ret = decode_sections(&file);
1194 ret = validate_functions(&file);
1199 ret = validate_uncallable_instructions(&file);
1207 /* ignore warnings for now until we get all the code cleaned up */
1208 if (ret || warnings)