2 * Copyright (C) 2015-2017 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/>.
27 #include <linux/hashtable.h>
28 #include <linux/kernel.h>
31 struct list_head list
;
32 struct instruction
*insn
;
37 struct cfi_state initial_func_cfi
;
39 struct instruction
*find_insn(struct objtool_file
*file
,
40 struct section
*sec
, unsigned long offset
)
42 struct instruction
*insn
;
44 hash_for_each_possible(file
->insn_hash
, insn
, hash
, offset
)
45 if (insn
->sec
== sec
&& insn
->offset
== offset
)
51 static struct instruction
*next_insn_same_sec(struct objtool_file
*file
,
52 struct instruction
*insn
)
54 struct instruction
*next
= list_next_entry(insn
, list
);
56 if (!next
|| &next
->list
== &file
->insn_list
|| next
->sec
!= insn
->sec
)
62 #define func_for_each_insn(file, func, insn) \
63 for (insn = find_insn(file, func->sec, func->offset); \
64 insn && &insn->list != &file->insn_list && \
65 insn->sec == func->sec && \
66 insn->offset < func->offset + func->len; \
67 insn = list_next_entry(insn, list))
69 #define func_for_each_insn_continue_reverse(file, func, insn) \
70 for (insn = list_prev_entry(insn, list); \
71 &insn->list != &file->insn_list && \
72 insn->sec == func->sec && insn->offset >= func->offset; \
73 insn = list_prev_entry(insn, list))
75 #define sec_for_each_insn_from(file, insn) \
76 for (; insn; insn = next_insn_same_sec(file, insn))
78 #define sec_for_each_insn_continue(file, insn) \
79 for (insn = next_insn_same_sec(file, insn); insn; \
80 insn = next_insn_same_sec(file, insn))
83 * Check if the function has been manually whitelisted with the
84 * STACK_FRAME_NON_STANDARD macro, or if it should be automatically whitelisted
85 * due to its use of a context switching instruction.
87 static bool ignore_func(struct objtool_file
*file
, struct symbol
*func
)
91 /* check for STACK_FRAME_NON_STANDARD */
92 if (file
->whitelist
&& file
->whitelist
->rela
)
93 list_for_each_entry(rela
, &file
->whitelist
->rela
->rela_list
, list
) {
94 if (rela
->sym
->type
== STT_SECTION
&&
95 rela
->sym
->sec
== func
->sec
&&
96 rela
->addend
== func
->offset
)
98 if (rela
->sym
->type
== STT_FUNC
&& rela
->sym
== func
)
106 * This checks to see if the given function is a "noreturn" function.
108 * For global functions which are outside the scope of this object file, we
109 * have to keep a manual list of them.
111 * For local functions, we have to detect them manually by simply looking for
112 * the lack of a return instruction.
119 static int __dead_end_function(struct objtool_file
*file
, struct symbol
*func
,
123 struct instruction
*insn
;
127 * Unfortunately these have to be hard coded because the noreturn
128 * attribute isn't provided in ELF data.
130 static const char * const global_noreturns
[] = {
135 "__module_put_and_exit",
137 "kvm_spurious_fault",
143 if (func
->bind
== STB_WEAK
)
146 if (func
->bind
== STB_GLOBAL
)
147 for (i
= 0; i
< ARRAY_SIZE(global_noreturns
); i
++)
148 if (!strcmp(func
->name
, global_noreturns
[i
]))
154 func_for_each_insn(file
, func
, insn
) {
157 if (insn
->type
== INSN_RETURN
)
165 * A function can have a sibling call instead of a return. In that
166 * case, the function's dead-end status depends on whether the target
167 * of the sibling call returns.
169 func_for_each_insn(file
, func
, insn
) {
170 if (insn
->sec
!= func
->sec
||
171 insn
->offset
>= func
->offset
+ func
->len
)
174 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
) {
175 struct instruction
*dest
= insn
->jump_dest
;
176 struct symbol
*dest_func
;
179 /* sibling call to another file */
182 if (dest
->sec
!= func
->sec
||
183 dest
->offset
< func
->offset
||
184 dest
->offset
>= func
->offset
+ func
->len
) {
185 /* local sibling call */
186 dest_func
= find_symbol_by_offset(dest
->sec
,
191 if (recursion
== 5) {
192 WARN_FUNC("infinite recursion (objtool bug!)",
193 dest
->sec
, dest
->offset
);
197 return __dead_end_function(file
, dest_func
,
202 if (insn
->type
== INSN_JUMP_DYNAMIC
&& list_empty(&insn
->alts
))
210 static int dead_end_function(struct objtool_file
*file
, struct symbol
*func
)
212 return __dead_end_function(file
, func
, 0);
215 static void clear_insn_state(struct insn_state
*state
)
219 memset(state
, 0, sizeof(*state
));
220 state
->cfa
.base
= CFI_UNDEFINED
;
221 for (i
= 0; i
< CFI_NUM_REGS
; i
++) {
222 state
->regs
[i
].base
= CFI_UNDEFINED
;
223 state
->vals
[i
].base
= CFI_UNDEFINED
;
225 state
->drap_reg
= CFI_UNDEFINED
;
226 state
->drap_offset
= -1;
230 * Call the arch-specific instruction decoder for all the instructions and add
231 * them to the global instruction list.
233 static int decode_instructions(struct objtool_file
*file
)
237 unsigned long offset
;
238 struct instruction
*insn
;
241 for_each_sec(file
, sec
) {
243 if (!(sec
->sh
.sh_flags
& SHF_EXECINSTR
))
246 if (strcmp(sec
->name
, ".altinstr_replacement") &&
247 strcmp(sec
->name
, ".altinstr_aux") &&
248 strncmp(sec
->name
, ".discard.", 9))
251 for (offset
= 0; offset
< sec
->len
; offset
+= insn
->len
) {
252 insn
= malloc(sizeof(*insn
));
254 WARN("malloc failed");
257 memset(insn
, 0, sizeof(*insn
));
258 INIT_LIST_HEAD(&insn
->alts
);
259 clear_insn_state(&insn
->state
);
262 insn
->offset
= offset
;
264 ret
= arch_decode_instruction(file
->elf
, sec
, offset
,
266 &insn
->len
, &insn
->type
,
272 if (!insn
->type
|| insn
->type
> INSN_LAST
) {
273 WARN_FUNC("invalid instruction type %d",
274 insn
->sec
, insn
->offset
, insn
->type
);
279 hash_add(file
->insn_hash
, &insn
->hash
, insn
->offset
);
280 list_add_tail(&insn
->list
, &file
->insn_list
);
283 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
284 if (func
->type
!= STT_FUNC
)
287 if (!find_insn(file
, sec
, func
->offset
)) {
288 WARN("%s(): can't find starting instruction",
293 func_for_each_insn(file
, func
, insn
)
307 * Mark "ud2" instructions and manually annotated dead ends.
309 static int add_dead_ends(struct objtool_file
*file
)
313 struct instruction
*insn
;
317 * By default, "ud2" is a dead end unless otherwise annotated, because
318 * GCC 7 inserts it for certain divide-by-zero cases.
320 for_each_insn(file
, insn
)
321 if (insn
->type
== INSN_BUG
)
322 insn
->dead_end
= true;
325 * Check for manually annotated dead ends.
327 sec
= find_section_by_name(file
->elf
, ".rela.discard.unreachable");
331 list_for_each_entry(rela
, &sec
->rela_list
, list
) {
332 if (rela
->sym
->type
!= STT_SECTION
) {
333 WARN("unexpected relocation symbol type in %s", sec
->name
);
336 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
338 insn
= list_prev_entry(insn
, list
);
339 else if (rela
->addend
== rela
->sym
->sec
->len
) {
341 list_for_each_entry_reverse(insn
, &file
->insn_list
, list
) {
342 if (insn
->sec
== rela
->sym
->sec
) {
349 WARN("can't find unreachable insn at %s+0x%x",
350 rela
->sym
->sec
->name
, rela
->addend
);
354 WARN("can't find unreachable insn at %s+0x%x",
355 rela
->sym
->sec
->name
, rela
->addend
);
359 insn
->dead_end
= true;
364 * These manually annotated reachable checks are needed for GCC 4.4,
365 * where the Linux unreachable() macro isn't supported. In that case
366 * GCC doesn't know the "ud2" is fatal, so it generates code as if it's
369 sec
= find_section_by_name(file
->elf
, ".rela.discard.reachable");
373 list_for_each_entry(rela
, &sec
->rela_list
, list
) {
374 if (rela
->sym
->type
!= STT_SECTION
) {
375 WARN("unexpected relocation symbol type in %s", sec
->name
);
378 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
380 insn
= list_prev_entry(insn
, list
);
381 else if (rela
->addend
== rela
->sym
->sec
->len
) {
383 list_for_each_entry_reverse(insn
, &file
->insn_list
, list
) {
384 if (insn
->sec
== rela
->sym
->sec
) {
391 WARN("can't find reachable insn at %s+0x%x",
392 rela
->sym
->sec
->name
, rela
->addend
);
396 WARN("can't find reachable insn at %s+0x%x",
397 rela
->sym
->sec
->name
, rela
->addend
);
401 insn
->dead_end
= false;
408 * Warnings shouldn't be reported for ignored functions.
410 static void add_ignores(struct objtool_file
*file
)
412 struct instruction
*insn
;
416 for_each_sec(file
, sec
) {
417 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
418 if (func
->type
!= STT_FUNC
)
421 if (!ignore_func(file
, func
))
424 func_for_each_insn(file
, func
, insn
)
431 * Find the destination instructions for all jumps.
433 static int add_jump_destinations(struct objtool_file
*file
)
435 struct instruction
*insn
;
437 struct section
*dest_sec
;
438 unsigned long dest_off
;
440 for_each_insn(file
, insn
) {
441 if (insn
->type
!= INSN_JUMP_CONDITIONAL
&&
442 insn
->type
!= INSN_JUMP_UNCONDITIONAL
)
448 rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
451 dest_sec
= insn
->sec
;
452 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
453 } else if (rela
->sym
->type
== STT_SECTION
) {
454 dest_sec
= rela
->sym
->sec
;
455 dest_off
= rela
->addend
+ 4;
456 } else if (rela
->sym
->sec
->idx
) {
457 dest_sec
= rela
->sym
->sec
;
458 dest_off
= rela
->sym
->sym
.st_value
+ rela
->addend
+ 4;
465 insn
->jump_dest
= find_insn(file
, dest_sec
, dest_off
);
466 if (!insn
->jump_dest
) {
469 * This is a special case where an alt instruction
470 * jumps past the end of the section. These are
471 * handled later in handle_group_alt().
473 if (!strcmp(insn
->sec
->name
, ".altinstr_replacement"))
476 WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
477 insn
->sec
, insn
->offset
, dest_sec
->name
,
487 * Find the destination instructions for all calls.
489 static int add_call_destinations(struct objtool_file
*file
)
491 struct instruction
*insn
;
492 unsigned long dest_off
;
495 for_each_insn(file
, insn
) {
496 if (insn
->type
!= INSN_CALL
)
499 rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
502 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
503 insn
->call_dest
= find_symbol_by_offset(insn
->sec
,
505 if (!insn
->call_dest
) {
506 WARN_FUNC("can't find call dest symbol at offset 0x%lx",
507 insn
->sec
, insn
->offset
, dest_off
);
510 } else if (rela
->sym
->type
== STT_SECTION
) {
511 insn
->call_dest
= find_symbol_by_offset(rela
->sym
->sec
,
513 if (!insn
->call_dest
||
514 insn
->call_dest
->type
!= STT_FUNC
) {
515 WARN_FUNC("can't find call dest symbol at %s+0x%x",
516 insn
->sec
, insn
->offset
,
517 rela
->sym
->sec
->name
,
522 insn
->call_dest
= rela
->sym
;
529 * The .alternatives section requires some extra special care, over and above
530 * what other special sections require:
532 * 1. Because alternatives are patched in-place, we need to insert a fake jump
533 * instruction at the end so that validate_branch() skips all the original
534 * replaced instructions when validating the new instruction path.
536 * 2. An added wrinkle is that the new instruction length might be zero. In
537 * that case the old instructions are replaced with noops. We simulate that
538 * by creating a fake jump as the only new instruction.
540 * 3. In some cases, the alternative section includes an instruction which
541 * conditionally jumps to the _end_ of the entry. We have to modify these
542 * jumps' destinations to point back to .text rather than the end of the
543 * entry in .altinstr_replacement.
545 * 4. It has been requested that we don't validate the !POPCNT feature path
546 * which is a "very very small percentage of machines".
548 static int handle_group_alt(struct objtool_file
*file
,
549 struct special_alt
*special_alt
,
550 struct instruction
*orig_insn
,
551 struct instruction
**new_insn
)
553 struct instruction
*last_orig_insn
, *last_new_insn
, *insn
, *fake_jump
;
554 unsigned long dest_off
;
556 last_orig_insn
= NULL
;
558 sec_for_each_insn_from(file
, insn
) {
559 if (insn
->offset
>= special_alt
->orig_off
+ special_alt
->orig_len
)
562 if (special_alt
->skip_orig
)
563 insn
->type
= INSN_NOP
;
565 insn
->alt_group
= true;
566 last_orig_insn
= insn
;
569 if (!next_insn_same_sec(file
, last_orig_insn
)) {
570 WARN("%s: don't know how to handle alternatives at end of section",
571 special_alt
->orig_sec
->name
);
575 fake_jump
= malloc(sizeof(*fake_jump
));
577 WARN("malloc failed");
580 memset(fake_jump
, 0, sizeof(*fake_jump
));
581 INIT_LIST_HEAD(&fake_jump
->alts
);
582 clear_insn_state(&fake_jump
->state
);
584 fake_jump
->sec
= special_alt
->new_sec
;
585 fake_jump
->offset
= -1;
586 fake_jump
->type
= INSN_JUMP_UNCONDITIONAL
;
587 fake_jump
->jump_dest
= list_next_entry(last_orig_insn
, list
);
588 fake_jump
->ignore
= true;
590 if (!special_alt
->new_len
) {
591 *new_insn
= fake_jump
;
595 last_new_insn
= NULL
;
597 sec_for_each_insn_from(file
, insn
) {
598 if (insn
->offset
>= special_alt
->new_off
+ special_alt
->new_len
)
601 last_new_insn
= insn
;
603 if (insn
->type
!= INSN_JUMP_CONDITIONAL
&&
604 insn
->type
!= INSN_JUMP_UNCONDITIONAL
)
607 if (!insn
->immediate
)
610 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
611 if (dest_off
== special_alt
->new_off
+ special_alt
->new_len
)
612 insn
->jump_dest
= fake_jump
;
614 if (!insn
->jump_dest
) {
615 WARN_FUNC("can't find alternative jump destination",
616 insn
->sec
, insn
->offset
);
621 if (!last_new_insn
) {
622 WARN_FUNC("can't find last new alternative instruction",
623 special_alt
->new_sec
, special_alt
->new_off
);
627 list_add(&fake_jump
->list
, &last_new_insn
->list
);
633 * A jump table entry can either convert a nop to a jump or a jump to a nop.
634 * If the original instruction is a jump, make the alt entry an effective nop
635 * by just skipping the original instruction.
637 static int handle_jump_alt(struct objtool_file
*file
,
638 struct special_alt
*special_alt
,
639 struct instruction
*orig_insn
,
640 struct instruction
**new_insn
)
642 if (orig_insn
->type
== INSN_NOP
)
645 if (orig_insn
->type
!= INSN_JUMP_UNCONDITIONAL
) {
646 WARN_FUNC("unsupported instruction at jump label",
647 orig_insn
->sec
, orig_insn
->offset
);
651 *new_insn
= list_next_entry(orig_insn
, list
);
656 * Read all the special sections which have alternate instructions which can be
657 * patched in or redirected to at runtime. Each instruction having alternate
658 * instruction(s) has them added to its insn->alts list, which will be
659 * traversed in validate_branch().
661 static int add_special_section_alts(struct objtool_file
*file
)
663 struct list_head special_alts
;
664 struct instruction
*orig_insn
, *new_insn
;
665 struct special_alt
*special_alt
, *tmp
;
666 struct alternative
*alt
;
669 ret
= special_get_alts(file
->elf
, &special_alts
);
673 list_for_each_entry_safe(special_alt
, tmp
, &special_alts
, list
) {
674 alt
= malloc(sizeof(*alt
));
676 WARN("malloc failed");
681 orig_insn
= find_insn(file
, special_alt
->orig_sec
,
682 special_alt
->orig_off
);
684 WARN_FUNC("special: can't find orig instruction",
685 special_alt
->orig_sec
, special_alt
->orig_off
);
691 if (!special_alt
->group
|| special_alt
->new_len
) {
692 new_insn
= find_insn(file
, special_alt
->new_sec
,
693 special_alt
->new_off
);
695 WARN_FUNC("special: can't find new instruction",
696 special_alt
->new_sec
,
697 special_alt
->new_off
);
703 if (special_alt
->group
) {
704 ret
= handle_group_alt(file
, special_alt
, orig_insn
,
708 } else if (special_alt
->jump_or_nop
) {
709 ret
= handle_jump_alt(file
, special_alt
, orig_insn
,
715 alt
->insn
= new_insn
;
716 list_add_tail(&alt
->list
, &orig_insn
->alts
);
718 list_del(&special_alt
->list
);
726 static int add_switch_table(struct objtool_file
*file
, struct symbol
*func
,
727 struct instruction
*insn
, struct rela
*table
,
728 struct rela
*next_table
)
730 struct rela
*rela
= table
;
731 struct instruction
*alt_insn
;
732 struct alternative
*alt
;
734 list_for_each_entry_from(rela
, &file
->rodata
->rela
->rela_list
, list
) {
735 if (rela
== next_table
)
738 if (rela
->sym
->sec
!= insn
->sec
||
739 rela
->addend
<= func
->offset
||
740 rela
->addend
>= func
->offset
+ func
->len
)
743 alt_insn
= find_insn(file
, insn
->sec
, rela
->addend
);
745 WARN("%s: can't find instruction at %s+0x%x",
746 file
->rodata
->rela
->name
, insn
->sec
->name
,
751 alt
= malloc(sizeof(*alt
));
753 WARN("malloc failed");
757 alt
->insn
= alt_insn
;
758 list_add_tail(&alt
->list
, &insn
->alts
);
765 * find_switch_table() - Given a dynamic jump, find the switch jump table in
766 * .rodata associated with it.
768 * There are 3 basic patterns:
770 * 1. jmpq *[rodata addr](,%reg,8)
772 * This is the most common case by far. It jumps to an address in a simple
773 * jump table which is stored in .rodata.
775 * 2. jmpq *[rodata addr](%rip)
777 * This is caused by a rare GCC quirk, currently only seen in three driver
778 * functions in the kernel, only with certain obscure non-distro configs.
780 * As part of an optimization, GCC makes a copy of an existing switch jump
781 * table, modifies it, and then hard-codes the jump (albeit with an indirect
782 * jump) to use a single entry in the table. The rest of the jump table and
783 * some of its jump targets remain as dead code.
785 * In such a case we can just crudely ignore all unreachable instruction
786 * warnings for the entire object file. Ideally we would just ignore them
787 * for the function, but that would require redesigning the code quite a
788 * bit. And honestly that's just not worth doing: unreachable instruction
789 * warnings are of questionable value anyway, and this is such a rare issue.
791 * 3. mov [rodata addr],%reg1
792 * ... some instructions ...
793 * jmpq *(%reg1,%reg2,8)
795 * This is a fairly uncommon pattern which is new for GCC 6. As of this
796 * writing, there are 11 occurrences of it in the allmodconfig kernel.
798 * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
799 * ensure the same register is used in the mov and jump instructions.
801 static struct rela
*find_switch_table(struct objtool_file
*file
,
803 struct instruction
*insn
)
805 struct rela
*text_rela
, *rodata_rela
;
806 struct instruction
*orig_insn
= insn
;
808 text_rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
, insn
->len
);
809 if (text_rela
&& text_rela
->sym
== file
->rodata
->sym
) {
811 rodata_rela
= find_rela_by_dest(file
->rodata
,
817 rodata_rela
= find_rela_by_dest(file
->rodata
,
818 text_rela
->addend
+ 4);
821 file
->ignore_unreachables
= true;
826 func_for_each_insn_continue_reverse(file
, func
, insn
) {
827 if (insn
->type
== INSN_JUMP_DYNAMIC
)
830 /* allow small jumps within the range */
831 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
&&
833 (insn
->jump_dest
->offset
<= insn
->offset
||
834 insn
->jump_dest
->offset
> orig_insn
->offset
))
837 /* look for a relocation which references .rodata */
838 text_rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
840 if (!text_rela
|| text_rela
->sym
!= file
->rodata
->sym
)
844 * Make sure the .rodata address isn't associated with a
845 * symbol. gcc jump tables are anonymous data.
847 if (find_symbol_containing(file
->rodata
, text_rela
->addend
))
850 return find_rela_by_dest(file
->rodata
, text_rela
->addend
);
856 static int add_func_switch_tables(struct objtool_file
*file
,
859 struct instruction
*insn
, *prev_jump
= NULL
;
860 struct rela
*rela
, *prev_rela
= NULL
;
863 func_for_each_insn(file
, func
, insn
) {
864 if (insn
->type
!= INSN_JUMP_DYNAMIC
)
867 rela
= find_switch_table(file
, func
, insn
);
872 * We found a switch table, but we don't know yet how big it
873 * is. Don't add it until we reach the end of the function or
874 * the beginning of another switch table in the same function.
877 ret
= add_switch_table(file
, func
, prev_jump
, prev_rela
,
888 ret
= add_switch_table(file
, func
, prev_jump
, prev_rela
, NULL
);
897 * For some switch statements, gcc generates a jump table in the .rodata
898 * section which contains a list of addresses within the function to jump to.
899 * This finds these jump tables and adds them to the insn->alts lists.
901 static int add_switch_table_alts(struct objtool_file
*file
)
907 if (!file
->rodata
|| !file
->rodata
->rela
)
910 for_each_sec(file
, sec
) {
911 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
912 if (func
->type
!= STT_FUNC
)
915 ret
= add_func_switch_tables(file
, func
);
924 static int read_unwind_hints(struct objtool_file
*file
)
926 struct section
*sec
, *relasec
;
928 struct unwind_hint
*hint
;
929 struct instruction
*insn
;
933 sec
= find_section_by_name(file
->elf
, ".discard.unwind_hints");
939 WARN("missing .rela.discard.unwind_hints section");
943 if (sec
->len
% sizeof(struct unwind_hint
)) {
944 WARN("struct unwind_hint size mismatch");
950 for (i
= 0; i
< sec
->len
/ sizeof(struct unwind_hint
); i
++) {
951 hint
= (struct unwind_hint
*)sec
->data
->d_buf
+ i
;
953 rela
= find_rela_by_dest(sec
, i
* sizeof(*hint
));
955 WARN("can't find rela for unwind_hints[%d]", i
);
959 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
961 WARN("can't find insn for unwind_hints[%d]", i
);
965 cfa
= &insn
->state
.cfa
;
967 if (hint
->type
== UNWIND_HINT_TYPE_SAVE
) {
971 } else if (hint
->type
== UNWIND_HINT_TYPE_RESTORE
) {
972 insn
->restore
= true;
979 switch (hint
->sp_reg
) {
980 case ORC_REG_UNDEFINED
:
981 cfa
->base
= CFI_UNDEFINED
;
989 case ORC_REG_SP_INDIRECT
:
990 cfa
->base
= CFI_SP_INDIRECT
;
1005 WARN_FUNC("unsupported unwind_hint sp base reg %d",
1006 insn
->sec
, insn
->offset
, hint
->sp_reg
);
1010 cfa
->offset
= hint
->sp_offset
;
1011 insn
->state
.type
= hint
->type
;
1017 static int decode_sections(struct objtool_file
*file
)
1021 ret
= decode_instructions(file
);
1025 ret
= add_dead_ends(file
);
1031 ret
= add_jump_destinations(file
);
1035 ret
= add_call_destinations(file
);
1039 ret
= add_special_section_alts(file
);
1043 ret
= add_switch_table_alts(file
);
1047 ret
= read_unwind_hints(file
);
1054 static bool is_fentry_call(struct instruction
*insn
)
1056 if (insn
->type
== INSN_CALL
&&
1057 insn
->call_dest
->type
== STT_NOTYPE
&&
1058 !strcmp(insn
->call_dest
->name
, "__fentry__"))
1064 static bool has_modified_stack_frame(struct insn_state
*state
)
1068 if (state
->cfa
.base
!= initial_func_cfi
.cfa
.base
||
1069 state
->cfa
.offset
!= initial_func_cfi
.cfa
.offset
||
1070 state
->stack_size
!= initial_func_cfi
.cfa
.offset
||
1074 for (i
= 0; i
< CFI_NUM_REGS
; i
++)
1075 if (state
->regs
[i
].base
!= initial_func_cfi
.regs
[i
].base
||
1076 state
->regs
[i
].offset
!= initial_func_cfi
.regs
[i
].offset
)
1082 static bool has_valid_stack_frame(struct insn_state
*state
)
1084 if (state
->cfa
.base
== CFI_BP
&& state
->regs
[CFI_BP
].base
== CFI_CFA
&&
1085 state
->regs
[CFI_BP
].offset
== -16)
1088 if (state
->drap
&& state
->regs
[CFI_BP
].base
== CFI_BP
)
1094 static int update_insn_state_regs(struct instruction
*insn
, struct insn_state
*state
)
1096 struct cfi_reg
*cfa
= &state
->cfa
;
1097 struct stack_op
*op
= &insn
->stack_op
;
1099 if (cfa
->base
!= CFI_SP
)
1103 if (op
->dest
.type
== OP_DEST_PUSH
)
1107 if (op
->src
.type
== OP_SRC_POP
)
1110 /* add immediate to sp */
1111 if (op
->dest
.type
== OP_DEST_REG
&& op
->src
.type
== OP_SRC_ADD
&&
1112 op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_SP
)
1113 cfa
->offset
-= op
->src
.offset
;
1118 static void save_reg(struct insn_state
*state
, unsigned char reg
, int base
,
1121 if (arch_callee_saved_reg(reg
) &&
1122 state
->regs
[reg
].base
== CFI_UNDEFINED
) {
1123 state
->regs
[reg
].base
= base
;
1124 state
->regs
[reg
].offset
= offset
;
1128 static void restore_reg(struct insn_state
*state
, unsigned char reg
)
1130 state
->regs
[reg
].base
= CFI_UNDEFINED
;
1131 state
->regs
[reg
].offset
= 0;
1135 * A note about DRAP stack alignment:
1137 * GCC has the concept of a DRAP register, which is used to help keep track of
1138 * the stack pointer when aligning the stack. r10 or r13 is used as the DRAP
1139 * register. The typical DRAP pattern is:
1141 * 4c 8d 54 24 08 lea 0x8(%rsp),%r10
1142 * 48 83 e4 c0 and $0xffffffffffffffc0,%rsp
1143 * 41 ff 72 f8 pushq -0x8(%r10)
1145 * 48 89 e5 mov %rsp,%rbp
1152 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1155 * There are some variations in the epilogues, like:
1163 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1168 * 4c 8b 55 e8 mov -0x18(%rbp),%r10
1169 * 48 8b 5d e0 mov -0x20(%rbp),%rbx
1170 * 4c 8b 65 f0 mov -0x10(%rbp),%r12
1171 * 4c 8b 6d f8 mov -0x8(%rbp),%r13
1173 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1176 * Sometimes r13 is used as the DRAP register, in which case it's saved and
1177 * restored beforehand:
1180 * 4c 8d 6c 24 10 lea 0x10(%rsp),%r13
1181 * 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
1183 * 49 8d 65 f0 lea -0x10(%r13),%rsp
1187 static int update_insn_state(struct instruction
*insn
, struct insn_state
*state
)
1189 struct stack_op
*op
= &insn
->stack_op
;
1190 struct cfi_reg
*cfa
= &state
->cfa
;
1191 struct cfi_reg
*regs
= state
->regs
;
1193 /* stack operations don't make sense with an undefined CFA */
1194 if (cfa
->base
== CFI_UNDEFINED
) {
1196 WARN_FUNC("undefined stack state", insn
->sec
, insn
->offset
);
1202 if (state
->type
== ORC_TYPE_REGS
|| state
->type
== ORC_TYPE_REGS_IRET
)
1203 return update_insn_state_regs(insn
, state
);
1205 switch (op
->dest
.type
) {
1208 switch (op
->src
.type
) {
1211 if (op
->src
.reg
== CFI_SP
&& op
->dest
.reg
== CFI_BP
&&
1212 cfa
->base
== CFI_SP
&&
1213 regs
[CFI_BP
].base
== CFI_CFA
&&
1214 regs
[CFI_BP
].offset
== -cfa
->offset
) {
1216 /* mov %rsp, %rbp */
1217 cfa
->base
= op
->dest
.reg
;
1218 state
->bp_scratch
= false;
1221 else if (op
->src
.reg
== CFI_SP
&&
1222 op
->dest
.reg
== CFI_BP
&& state
->drap
) {
1224 /* drap: mov %rsp, %rbp */
1225 regs
[CFI_BP
].base
= CFI_BP
;
1226 regs
[CFI_BP
].offset
= -state
->stack_size
;
1227 state
->bp_scratch
= false;
1230 else if (op
->src
.reg
== CFI_SP
&& cfa
->base
== CFI_SP
) {
1235 * This is needed for the rare case where GCC
1242 state
->vals
[op
->dest
.reg
].base
= CFI_CFA
;
1243 state
->vals
[op
->dest
.reg
].offset
= -state
->stack_size
;
1246 else if (op
->dest
.reg
== cfa
->base
) {
1248 /* mov %reg, %rsp */
1249 if (cfa
->base
== CFI_SP
&&
1250 state
->vals
[op
->src
.reg
].base
== CFI_CFA
) {
1253 * This is needed for the rare case
1254 * where GCC does something dumb like:
1256 * lea 0x8(%rsp), %rcx
1260 cfa
->offset
= -state
->vals
[op
->src
.reg
].offset
;
1261 state
->stack_size
= cfa
->offset
;
1264 cfa
->base
= CFI_UNDEFINED
;
1272 if (op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_SP
) {
1275 state
->stack_size
-= op
->src
.offset
;
1276 if (cfa
->base
== CFI_SP
)
1277 cfa
->offset
-= op
->src
.offset
;
1281 if (op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_BP
) {
1283 /* lea disp(%rbp), %rsp */
1284 state
->stack_size
= -(op
->src
.offset
+ regs
[CFI_BP
].offset
);
1288 if (op
->src
.reg
== CFI_SP
&& cfa
->base
== CFI_SP
) {
1290 /* drap: lea disp(%rsp), %drap */
1291 state
->drap_reg
= op
->dest
.reg
;
1294 * lea disp(%rsp), %reg
1296 * This is needed for the rare case where GCC
1297 * does something dumb like:
1299 * lea 0x8(%rsp), %rcx
1303 state
->vals
[op
->dest
.reg
].base
= CFI_CFA
;
1304 state
->vals
[op
->dest
.reg
].offset
= \
1305 -state
->stack_size
+ op
->src
.offset
;
1310 if (state
->drap
&& op
->dest
.reg
== CFI_SP
&&
1311 op
->src
.reg
== state
->drap_reg
) {
1313 /* drap: lea disp(%drap), %rsp */
1315 cfa
->offset
= state
->stack_size
= -op
->src
.offset
;
1316 state
->drap_reg
= CFI_UNDEFINED
;
1317 state
->drap
= false;
1321 if (op
->dest
.reg
== state
->cfa
.base
) {
1322 WARN_FUNC("unsupported stack register modification",
1323 insn
->sec
, insn
->offset
);
1330 if (op
->dest
.reg
!= CFI_SP
||
1331 (state
->drap_reg
!= CFI_UNDEFINED
&& cfa
->base
!= CFI_SP
) ||
1332 (state
->drap_reg
== CFI_UNDEFINED
&& cfa
->base
!= CFI_BP
)) {
1333 WARN_FUNC("unsupported stack pointer realignment",
1334 insn
->sec
, insn
->offset
);
1338 if (state
->drap_reg
!= CFI_UNDEFINED
) {
1339 /* drap: and imm, %rsp */
1340 cfa
->base
= state
->drap_reg
;
1341 cfa
->offset
= state
->stack_size
= 0;
1346 * Older versions of GCC (4.8ish) realign the stack
1347 * without DRAP, with a frame pointer.
1353 if (!state
->drap
&& op
->dest
.type
== OP_DEST_REG
&&
1354 op
->dest
.reg
== cfa
->base
) {
1360 if (state
->drap
&& cfa
->base
== CFI_BP_INDIRECT
&&
1361 op
->dest
.type
== OP_DEST_REG
&&
1362 op
->dest
.reg
== state
->drap_reg
&&
1363 state
->drap_offset
== -state
->stack_size
) {
1365 /* drap: pop %drap */
1366 cfa
->base
= state
->drap_reg
;
1368 state
->drap_offset
= -1;
1370 } else if (regs
[op
->dest
.reg
].offset
== -state
->stack_size
) {
1373 restore_reg(state
, op
->dest
.reg
);
1376 state
->stack_size
-= 8;
1377 if (cfa
->base
== CFI_SP
)
1382 case OP_SRC_REG_INDIRECT
:
1383 if (state
->drap
&& op
->src
.reg
== CFI_BP
&&
1384 op
->src
.offset
== state
->drap_offset
) {
1386 /* drap: mov disp(%rbp), %drap */
1387 cfa
->base
= state
->drap_reg
;
1389 state
->drap_offset
= -1;
1392 if (state
->drap
&& op
->src
.reg
== CFI_BP
&&
1393 op
->src
.offset
== regs
[op
->dest
.reg
].offset
) {
1395 /* drap: mov disp(%rbp), %reg */
1396 restore_reg(state
, op
->dest
.reg
);
1398 } else if (op
->src
.reg
== cfa
->base
&&
1399 op
->src
.offset
== regs
[op
->dest
.reg
].offset
+ cfa
->offset
) {
1401 /* mov disp(%rbp), %reg */
1402 /* mov disp(%rsp), %reg */
1403 restore_reg(state
, op
->dest
.reg
);
1409 WARN_FUNC("unknown stack-related instruction",
1410 insn
->sec
, insn
->offset
);
1417 state
->stack_size
+= 8;
1418 if (cfa
->base
== CFI_SP
)
1421 if (op
->src
.type
!= OP_SRC_REG
)
1425 if (op
->src
.reg
== cfa
->base
&& op
->src
.reg
== state
->drap_reg
) {
1427 /* drap: push %drap */
1428 cfa
->base
= CFI_BP_INDIRECT
;
1429 cfa
->offset
= -state
->stack_size
;
1431 /* save drap so we know when to restore it */
1432 state
->drap_offset
= -state
->stack_size
;
1434 } else if (op
->src
.reg
== CFI_BP
&& cfa
->base
== state
->drap_reg
) {
1436 /* drap: push %rbp */
1437 state
->stack_size
= 0;
1439 } else if (regs
[op
->src
.reg
].base
== CFI_UNDEFINED
) {
1441 /* drap: push %reg */
1442 save_reg(state
, op
->src
.reg
, CFI_BP
, -state
->stack_size
);
1448 save_reg(state
, op
->src
.reg
, CFI_CFA
, -state
->stack_size
);
1451 /* detect when asm code uses rbp as a scratch register */
1452 if (!no_fp
&& insn
->func
&& op
->src
.reg
== CFI_BP
&&
1453 cfa
->base
!= CFI_BP
)
1454 state
->bp_scratch
= true;
1457 case OP_DEST_REG_INDIRECT
:
1460 if (op
->src
.reg
== cfa
->base
&& op
->src
.reg
== state
->drap_reg
) {
1462 /* drap: mov %drap, disp(%rbp) */
1463 cfa
->base
= CFI_BP_INDIRECT
;
1464 cfa
->offset
= op
->dest
.offset
;
1466 /* save drap offset so we know when to restore it */
1467 state
->drap_offset
= op
->dest
.offset
;
1470 else if (regs
[op
->src
.reg
].base
== CFI_UNDEFINED
) {
1472 /* drap: mov reg, disp(%rbp) */
1473 save_reg(state
, op
->src
.reg
, CFI_BP
, op
->dest
.offset
);
1476 } else if (op
->dest
.reg
== cfa
->base
) {
1478 /* mov reg, disp(%rbp) */
1479 /* mov reg, disp(%rsp) */
1480 save_reg(state
, op
->src
.reg
, CFI_CFA
,
1481 op
->dest
.offset
- state
->cfa
.offset
);
1487 if ((!state
->drap
&& cfa
->base
!= CFI_BP
) ||
1488 (state
->drap
&& cfa
->base
!= state
->drap_reg
)) {
1489 WARN_FUNC("leave instruction with modified stack frame",
1490 insn
->sec
, insn
->offset
);
1494 /* leave (mov %rbp, %rsp; pop %rbp) */
1496 state
->stack_size
= -state
->regs
[CFI_BP
].offset
- 8;
1497 restore_reg(state
, CFI_BP
);
1507 if (op
->src
.type
!= OP_SRC_POP
) {
1508 WARN_FUNC("unknown stack-related memory operation",
1509 insn
->sec
, insn
->offset
);
1514 state
->stack_size
-= 8;
1515 if (cfa
->base
== CFI_SP
)
1521 WARN_FUNC("unknown stack-related instruction",
1522 insn
->sec
, insn
->offset
);
1529 static bool insn_state_match(struct instruction
*insn
, struct insn_state
*state
)
1531 struct insn_state
*state1
= &insn
->state
, *state2
= state
;
1534 if (memcmp(&state1
->cfa
, &state2
->cfa
, sizeof(state1
->cfa
))) {
1535 WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
1536 insn
->sec
, insn
->offset
,
1537 state1
->cfa
.base
, state1
->cfa
.offset
,
1538 state2
->cfa
.base
, state2
->cfa
.offset
);
1540 } else if (memcmp(&state1
->regs
, &state2
->regs
, sizeof(state1
->regs
))) {
1541 for (i
= 0; i
< CFI_NUM_REGS
; i
++) {
1542 if (!memcmp(&state1
->regs
[i
], &state2
->regs
[i
],
1543 sizeof(struct cfi_reg
)))
1546 WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
1547 insn
->sec
, insn
->offset
,
1548 i
, state1
->regs
[i
].base
, state1
->regs
[i
].offset
,
1549 i
, state2
->regs
[i
].base
, state2
->regs
[i
].offset
);
1553 } else if (state1
->type
!= state2
->type
) {
1554 WARN_FUNC("stack state mismatch: type1=%d type2=%d",
1555 insn
->sec
, insn
->offset
, state1
->type
, state2
->type
);
1557 } else if (state1
->drap
!= state2
->drap
||
1558 (state1
->drap
&& state1
->drap_reg
!= state2
->drap_reg
) ||
1559 (state1
->drap
&& state1
->drap_offset
!= state2
->drap_offset
)) {
1560 WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
1561 insn
->sec
, insn
->offset
,
1562 state1
->drap
, state1
->drap_reg
, state1
->drap_offset
,
1563 state2
->drap
, state2
->drap_reg
, state2
->drap_offset
);
1572 * Follow the branch starting at the given instruction, and recursively follow
1573 * any other branches (jumps). Meanwhile, track the frame pointer state at
1574 * each instruction and validate all the rules described in
1575 * tools/objtool/Documentation/stack-validation.txt.
1577 static int validate_branch(struct objtool_file
*file
, struct instruction
*first
,
1578 struct insn_state state
)
1580 struct alternative
*alt
;
1581 struct instruction
*insn
, *next_insn
;
1582 struct section
*sec
;
1583 struct symbol
*func
= NULL
;
1589 if (insn
->alt_group
&& list_empty(&insn
->alts
)) {
1590 WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
1596 next_insn
= next_insn_same_sec(file
, insn
);
1599 if (file
->c_file
&& func
&& insn
->func
&& func
!= insn
->func
) {
1600 WARN("%s() falls through to next function %s()",
1601 func
->name
, insn
->func
->name
);
1608 if (func
&& insn
->ignore
) {
1609 WARN_FUNC("BUG: why am I validating an ignored function?",
1614 if (insn
->visited
) {
1615 if (!insn
->hint
&& !insn_state_match(insn
, &state
))
1622 if (insn
->restore
) {
1623 struct instruction
*save_insn
, *i
;
1627 func_for_each_insn_continue_reverse(file
, func
, i
) {
1635 WARN_FUNC("no corresponding CFI save for CFI restore",
1640 if (!save_insn
->visited
) {
1642 * Oops, no state to copy yet.
1643 * Hopefully we can reach this
1644 * instruction from another branch
1645 * after the save insn has been
1651 WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
1656 insn
->state
= save_insn
->state
;
1659 state
= insn
->state
;
1662 insn
->state
= state
;
1664 insn
->visited
= true;
1666 list_for_each_entry(alt
, &insn
->alts
, list
) {
1667 ret
= validate_branch(file
, alt
->insn
, state
);
1672 switch (insn
->type
) {
1675 if (func
&& has_modified_stack_frame(&state
)) {
1676 WARN_FUNC("return with modified stack frame",
1681 if (state
.bp_scratch
) {
1682 WARN("%s uses BP as a scratch register",
1690 if (is_fentry_call(insn
))
1693 ret
= dead_end_function(file
, insn
->call_dest
);
1700 case INSN_CALL_DYNAMIC
:
1701 if (!no_fp
&& func
&& !has_valid_stack_frame(&state
)) {
1702 WARN_FUNC("call without frame pointer save/setup",
1708 case INSN_JUMP_CONDITIONAL
:
1709 case INSN_JUMP_UNCONDITIONAL
:
1710 if (insn
->jump_dest
&&
1711 (!func
|| !insn
->jump_dest
->func
||
1712 func
== insn
->jump_dest
->func
)) {
1713 ret
= validate_branch(file
, insn
->jump_dest
,
1718 } else if (func
&& has_modified_stack_frame(&state
)) {
1719 WARN_FUNC("sibling call from callable instruction with modified stack frame",
1724 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
)
1729 case INSN_JUMP_DYNAMIC
:
1730 if (func
&& list_empty(&insn
->alts
) &&
1731 has_modified_stack_frame(&state
)) {
1732 WARN_FUNC("sibling call from callable instruction with modified stack frame",
1739 case INSN_CONTEXT_SWITCH
:
1740 if (func
&& (!next_insn
|| !next_insn
->hint
)) {
1741 WARN_FUNC("unsupported instruction in callable function",
1748 if (update_insn_state(insn
, &state
))
1762 WARN("%s: unexpected end of section", sec
->name
);
1770 static int validate_unwind_hints(struct objtool_file
*file
)
1772 struct instruction
*insn
;
1773 int ret
, warnings
= 0;
1774 struct insn_state state
;
1779 clear_insn_state(&state
);
1781 for_each_insn(file
, insn
) {
1782 if (insn
->hint
&& !insn
->visited
) {
1783 ret
= validate_branch(file
, insn
, state
);
1791 static bool is_kasan_insn(struct instruction
*insn
)
1793 return (insn
->type
== INSN_CALL
&&
1794 !strcmp(insn
->call_dest
->name
, "__asan_handle_no_return"));
1797 static bool is_ubsan_insn(struct instruction
*insn
)
1799 return (insn
->type
== INSN_CALL
&&
1800 !strcmp(insn
->call_dest
->name
,
1801 "__ubsan_handle_builtin_unreachable"));
1804 static bool ignore_unreachable_insn(struct instruction
*insn
)
1808 if (insn
->ignore
|| insn
->type
== INSN_NOP
)
1812 * Ignore any unused exceptions. This can happen when a whitelisted
1813 * function has an exception table entry.
1815 * Also ignore alternative replacement instructions. This can happen
1816 * when a whitelisted function uses one of the ALTERNATIVE macros.
1818 if (!strcmp(insn
->sec
->name
, ".fixup") ||
1819 !strcmp(insn
->sec
->name
, ".altinstr_replacement") ||
1820 !strcmp(insn
->sec
->name
, ".altinstr_aux"))
1824 * Check if this (or a subsequent) instruction is related to
1825 * CONFIG_UBSAN or CONFIG_KASAN.
1827 * End the search at 5 instructions to avoid going into the weeds.
1831 for (i
= 0; i
< 5; i
++) {
1833 if (is_kasan_insn(insn
) || is_ubsan_insn(insn
))
1836 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
&& insn
->jump_dest
) {
1837 insn
= insn
->jump_dest
;
1841 if (insn
->offset
+ insn
->len
>= insn
->func
->offset
+ insn
->func
->len
)
1843 insn
= list_next_entry(insn
, list
);
1849 static int validate_functions(struct objtool_file
*file
)
1851 struct section
*sec
;
1852 struct symbol
*func
;
1853 struct instruction
*insn
;
1854 struct insn_state state
;
1855 int ret
, warnings
= 0;
1857 clear_insn_state(&state
);
1859 state
.cfa
= initial_func_cfi
.cfa
;
1860 memcpy(&state
.regs
, &initial_func_cfi
.regs
,
1861 CFI_NUM_REGS
* sizeof(struct cfi_reg
));
1862 state
.stack_size
= initial_func_cfi
.cfa
.offset
;
1864 for_each_sec(file
, sec
) {
1865 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
1866 if (func
->type
!= STT_FUNC
)
1869 insn
= find_insn(file
, sec
, func
->offset
);
1870 if (!insn
|| insn
->ignore
)
1873 ret
= validate_branch(file
, insn
, state
);
1881 static int validate_reachable_instructions(struct objtool_file
*file
)
1883 struct instruction
*insn
;
1885 if (file
->ignore_unreachables
)
1888 for_each_insn(file
, insn
) {
1889 if (insn
->visited
|| ignore_unreachable_insn(insn
))
1892 WARN_FUNC("unreachable instruction", insn
->sec
, insn
->offset
);
1899 static void cleanup(struct objtool_file
*file
)
1901 struct instruction
*insn
, *tmpinsn
;
1902 struct alternative
*alt
, *tmpalt
;
1904 list_for_each_entry_safe(insn
, tmpinsn
, &file
->insn_list
, list
) {
1905 list_for_each_entry_safe(alt
, tmpalt
, &insn
->alts
, list
) {
1906 list_del(&alt
->list
);
1909 list_del(&insn
->list
);
1910 hash_del(&insn
->hash
);
1913 elf_close(file
->elf
);
1916 int check(const char *_objname
, bool _no_fp
, bool no_unreachable
, bool orc
)
1918 struct objtool_file file
;
1919 int ret
, warnings
= 0;
1924 file
.elf
= elf_open(objname
, orc
? O_RDWR
: O_RDONLY
);
1928 INIT_LIST_HEAD(&file
.insn_list
);
1929 hash_init(file
.insn_hash
);
1930 file
.whitelist
= find_section_by_name(file
.elf
, ".discard.func_stack_frame_non_standard");
1931 file
.rodata
= find_section_by_name(file
.elf
, ".rodata");
1932 file
.c_file
= find_section_by_name(file
.elf
, ".comment");
1933 file
.ignore_unreachables
= no_unreachable
;
1936 arch_initial_func_cfi_state(&initial_func_cfi
);
1938 ret
= decode_sections(&file
);
1943 if (list_empty(&file
.insn_list
))
1946 ret
= validate_functions(&file
);
1951 ret
= validate_unwind_hints(&file
);
1957 ret
= validate_reachable_instructions(&file
);
1964 ret
= create_orc(&file
);
1968 ret
= create_orc_sections(&file
);
1972 ret
= elf_write(file
.elf
);
1980 /* ignore warnings for now until we get all the code cleaned up */
1981 if (ret
|| warnings
)