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
);
278 hash_add(file
->insn_hash
, &insn
->hash
, insn
->offset
);
279 list_add_tail(&insn
->list
, &file
->insn_list
);
282 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
283 if (func
->type
!= STT_FUNC
)
286 if (!find_insn(file
, sec
, func
->offset
)) {
287 WARN("%s(): can't find starting instruction",
292 func_for_each_insn(file
, func
, insn
)
302 * Mark "ud2" instructions and manually annotated dead ends.
304 static int add_dead_ends(struct objtool_file
*file
)
308 struct instruction
*insn
;
312 * By default, "ud2" is a dead end unless otherwise annotated, because
313 * GCC 7 inserts it for certain divide-by-zero cases.
315 for_each_insn(file
, insn
)
316 if (insn
->type
== INSN_BUG
)
317 insn
->dead_end
= true;
320 * Check for manually annotated dead ends.
322 sec
= find_section_by_name(file
->elf
, ".rela.discard.unreachable");
326 list_for_each_entry(rela
, &sec
->rela_list
, list
) {
327 if (rela
->sym
->type
!= STT_SECTION
) {
328 WARN("unexpected relocation symbol type in %s", sec
->name
);
331 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
333 insn
= list_prev_entry(insn
, list
);
334 else if (rela
->addend
== rela
->sym
->sec
->len
) {
336 list_for_each_entry_reverse(insn
, &file
->insn_list
, list
) {
337 if (insn
->sec
== rela
->sym
->sec
) {
344 WARN("can't find unreachable insn at %s+0x%x",
345 rela
->sym
->sec
->name
, rela
->addend
);
349 WARN("can't find unreachable insn at %s+0x%x",
350 rela
->sym
->sec
->name
, rela
->addend
);
354 insn
->dead_end
= true;
359 * These manually annotated reachable checks are needed for GCC 4.4,
360 * where the Linux unreachable() macro isn't supported. In that case
361 * GCC doesn't know the "ud2" is fatal, so it generates code as if it's
364 sec
= find_section_by_name(file
->elf
, ".rela.discard.reachable");
368 list_for_each_entry(rela
, &sec
->rela_list
, list
) {
369 if (rela
->sym
->type
!= STT_SECTION
) {
370 WARN("unexpected relocation symbol type in %s", sec
->name
);
373 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
375 insn
= list_prev_entry(insn
, list
);
376 else if (rela
->addend
== rela
->sym
->sec
->len
) {
378 list_for_each_entry_reverse(insn
, &file
->insn_list
, list
) {
379 if (insn
->sec
== rela
->sym
->sec
) {
386 WARN("can't find reachable insn at %s+0x%x",
387 rela
->sym
->sec
->name
, rela
->addend
);
391 WARN("can't find reachable insn at %s+0x%x",
392 rela
->sym
->sec
->name
, rela
->addend
);
396 insn
->dead_end
= false;
403 * Warnings shouldn't be reported for ignored functions.
405 static void add_ignores(struct objtool_file
*file
)
407 struct instruction
*insn
;
411 for_each_sec(file
, sec
) {
412 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
413 if (func
->type
!= STT_FUNC
)
416 if (!ignore_func(file
, func
))
419 func_for_each_insn(file
, func
, insn
)
426 * Find the destination instructions for all jumps.
428 static int add_jump_destinations(struct objtool_file
*file
)
430 struct instruction
*insn
;
432 struct section
*dest_sec
;
433 unsigned long dest_off
;
435 for_each_insn(file
, insn
) {
436 if (insn
->type
!= INSN_JUMP_CONDITIONAL
&&
437 insn
->type
!= INSN_JUMP_UNCONDITIONAL
)
443 rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
446 dest_sec
= insn
->sec
;
447 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
448 } else if (rela
->sym
->type
== STT_SECTION
) {
449 dest_sec
= rela
->sym
->sec
;
450 dest_off
= rela
->addend
+ 4;
451 } else if (rela
->sym
->sec
->idx
) {
452 dest_sec
= rela
->sym
->sec
;
453 dest_off
= rela
->sym
->sym
.st_value
+ rela
->addend
+ 4;
460 insn
->jump_dest
= find_insn(file
, dest_sec
, dest_off
);
461 if (!insn
->jump_dest
) {
464 * This is a special case where an alt instruction
465 * jumps past the end of the section. These are
466 * handled later in handle_group_alt().
468 if (!strcmp(insn
->sec
->name
, ".altinstr_replacement"))
471 WARN_FUNC("can't find jump dest instruction at %s+0x%lx",
472 insn
->sec
, insn
->offset
, dest_sec
->name
,
482 * Find the destination instructions for all calls.
484 static int add_call_destinations(struct objtool_file
*file
)
486 struct instruction
*insn
;
487 unsigned long dest_off
;
490 for_each_insn(file
, insn
) {
491 if (insn
->type
!= INSN_CALL
)
494 rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
497 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
498 insn
->call_dest
= find_symbol_by_offset(insn
->sec
,
500 if (!insn
->call_dest
) {
501 WARN_FUNC("can't find call dest symbol at offset 0x%lx",
502 insn
->sec
, insn
->offset
, dest_off
);
505 } else if (rela
->sym
->type
== STT_SECTION
) {
506 insn
->call_dest
= find_symbol_by_offset(rela
->sym
->sec
,
508 if (!insn
->call_dest
||
509 insn
->call_dest
->type
!= STT_FUNC
) {
510 WARN_FUNC("can't find call dest symbol at %s+0x%x",
511 insn
->sec
, insn
->offset
,
512 rela
->sym
->sec
->name
,
517 insn
->call_dest
= rela
->sym
;
524 * The .alternatives section requires some extra special care, over and above
525 * what other special sections require:
527 * 1. Because alternatives are patched in-place, we need to insert a fake jump
528 * instruction at the end so that validate_branch() skips all the original
529 * replaced instructions when validating the new instruction path.
531 * 2. An added wrinkle is that the new instruction length might be zero. In
532 * that case the old instructions are replaced with noops. We simulate that
533 * by creating a fake jump as the only new instruction.
535 * 3. In some cases, the alternative section includes an instruction which
536 * conditionally jumps to the _end_ of the entry. We have to modify these
537 * jumps' destinations to point back to .text rather than the end of the
538 * entry in .altinstr_replacement.
540 * 4. It has been requested that we don't validate the !POPCNT feature path
541 * which is a "very very small percentage of machines".
543 static int handle_group_alt(struct objtool_file
*file
,
544 struct special_alt
*special_alt
,
545 struct instruction
*orig_insn
,
546 struct instruction
**new_insn
)
548 struct instruction
*last_orig_insn
, *last_new_insn
, *insn
, *fake_jump
;
549 unsigned long dest_off
;
551 last_orig_insn
= NULL
;
553 sec_for_each_insn_from(file
, insn
) {
554 if (insn
->offset
>= special_alt
->orig_off
+ special_alt
->orig_len
)
557 if (special_alt
->skip_orig
)
558 insn
->type
= INSN_NOP
;
560 insn
->alt_group
= true;
561 last_orig_insn
= insn
;
564 if (!next_insn_same_sec(file
, last_orig_insn
)) {
565 WARN("%s: don't know how to handle alternatives at end of section",
566 special_alt
->orig_sec
->name
);
570 fake_jump
= malloc(sizeof(*fake_jump
));
572 WARN("malloc failed");
575 memset(fake_jump
, 0, sizeof(*fake_jump
));
576 INIT_LIST_HEAD(&fake_jump
->alts
);
577 clear_insn_state(&fake_jump
->state
);
579 fake_jump
->sec
= special_alt
->new_sec
;
580 fake_jump
->offset
= -1;
581 fake_jump
->type
= INSN_JUMP_UNCONDITIONAL
;
582 fake_jump
->jump_dest
= list_next_entry(last_orig_insn
, list
);
583 fake_jump
->ignore
= true;
585 if (!special_alt
->new_len
) {
586 *new_insn
= fake_jump
;
590 last_new_insn
= NULL
;
592 sec_for_each_insn_from(file
, insn
) {
593 if (insn
->offset
>= special_alt
->new_off
+ special_alt
->new_len
)
596 last_new_insn
= insn
;
598 if (insn
->type
!= INSN_JUMP_CONDITIONAL
&&
599 insn
->type
!= INSN_JUMP_UNCONDITIONAL
)
602 if (!insn
->immediate
)
605 dest_off
= insn
->offset
+ insn
->len
+ insn
->immediate
;
606 if (dest_off
== special_alt
->new_off
+ special_alt
->new_len
)
607 insn
->jump_dest
= fake_jump
;
609 if (!insn
->jump_dest
) {
610 WARN_FUNC("can't find alternative jump destination",
611 insn
->sec
, insn
->offset
);
616 if (!last_new_insn
) {
617 WARN_FUNC("can't find last new alternative instruction",
618 special_alt
->new_sec
, special_alt
->new_off
);
622 list_add(&fake_jump
->list
, &last_new_insn
->list
);
628 * A jump table entry can either convert a nop to a jump or a jump to a nop.
629 * If the original instruction is a jump, make the alt entry an effective nop
630 * by just skipping the original instruction.
632 static int handle_jump_alt(struct objtool_file
*file
,
633 struct special_alt
*special_alt
,
634 struct instruction
*orig_insn
,
635 struct instruction
**new_insn
)
637 if (orig_insn
->type
== INSN_NOP
)
640 if (orig_insn
->type
!= INSN_JUMP_UNCONDITIONAL
) {
641 WARN_FUNC("unsupported instruction at jump label",
642 orig_insn
->sec
, orig_insn
->offset
);
646 *new_insn
= list_next_entry(orig_insn
, list
);
651 * Read all the special sections which have alternate instructions which can be
652 * patched in or redirected to at runtime. Each instruction having alternate
653 * instruction(s) has them added to its insn->alts list, which will be
654 * traversed in validate_branch().
656 static int add_special_section_alts(struct objtool_file
*file
)
658 struct list_head special_alts
;
659 struct instruction
*orig_insn
, *new_insn
;
660 struct special_alt
*special_alt
, *tmp
;
661 struct alternative
*alt
;
664 ret
= special_get_alts(file
->elf
, &special_alts
);
668 list_for_each_entry_safe(special_alt
, tmp
, &special_alts
, list
) {
669 alt
= malloc(sizeof(*alt
));
671 WARN("malloc failed");
676 orig_insn
= find_insn(file
, special_alt
->orig_sec
,
677 special_alt
->orig_off
);
679 WARN_FUNC("special: can't find orig instruction",
680 special_alt
->orig_sec
, special_alt
->orig_off
);
686 if (!special_alt
->group
|| special_alt
->new_len
) {
687 new_insn
= find_insn(file
, special_alt
->new_sec
,
688 special_alt
->new_off
);
690 WARN_FUNC("special: can't find new instruction",
691 special_alt
->new_sec
,
692 special_alt
->new_off
);
698 if (special_alt
->group
) {
699 ret
= handle_group_alt(file
, special_alt
, orig_insn
,
703 } else if (special_alt
->jump_or_nop
) {
704 ret
= handle_jump_alt(file
, special_alt
, orig_insn
,
710 alt
->insn
= new_insn
;
711 list_add_tail(&alt
->list
, &orig_insn
->alts
);
713 list_del(&special_alt
->list
);
721 static int add_switch_table(struct objtool_file
*file
, struct symbol
*func
,
722 struct instruction
*insn
, struct rela
*table
,
723 struct rela
*next_table
)
725 struct rela
*rela
= table
;
726 struct instruction
*alt_insn
;
727 struct alternative
*alt
;
729 list_for_each_entry_from(rela
, &file
->rodata
->rela
->rela_list
, list
) {
730 if (rela
== next_table
)
733 if (rela
->sym
->sec
!= insn
->sec
||
734 rela
->addend
<= func
->offset
||
735 rela
->addend
>= func
->offset
+ func
->len
)
738 alt_insn
= find_insn(file
, insn
->sec
, rela
->addend
);
740 WARN("%s: can't find instruction at %s+0x%x",
741 file
->rodata
->rela
->name
, insn
->sec
->name
,
746 alt
= malloc(sizeof(*alt
));
748 WARN("malloc failed");
752 alt
->insn
= alt_insn
;
753 list_add_tail(&alt
->list
, &insn
->alts
);
760 * find_switch_table() - Given a dynamic jump, find the switch jump table in
761 * .rodata associated with it.
763 * There are 3 basic patterns:
765 * 1. jmpq *[rodata addr](,%reg,8)
767 * This is the most common case by far. It jumps to an address in a simple
768 * jump table which is stored in .rodata.
770 * 2. jmpq *[rodata addr](%rip)
772 * This is caused by a rare GCC quirk, currently only seen in three driver
773 * functions in the kernel, only with certain obscure non-distro configs.
775 * As part of an optimization, GCC makes a copy of an existing switch jump
776 * table, modifies it, and then hard-codes the jump (albeit with an indirect
777 * jump) to use a single entry in the table. The rest of the jump table and
778 * some of its jump targets remain as dead code.
780 * In such a case we can just crudely ignore all unreachable instruction
781 * warnings for the entire object file. Ideally we would just ignore them
782 * for the function, but that would require redesigning the code quite a
783 * bit. And honestly that's just not worth doing: unreachable instruction
784 * warnings are of questionable value anyway, and this is such a rare issue.
786 * 3. mov [rodata addr],%reg1
787 * ... some instructions ...
788 * jmpq *(%reg1,%reg2,8)
790 * This is a fairly uncommon pattern which is new for GCC 6. As of this
791 * writing, there are 11 occurrences of it in the allmodconfig kernel.
793 * TODO: Once we have DWARF CFI and smarter instruction decoding logic,
794 * ensure the same register is used in the mov and jump instructions.
796 static struct rela
*find_switch_table(struct objtool_file
*file
,
798 struct instruction
*insn
)
800 struct rela
*text_rela
, *rodata_rela
;
801 struct instruction
*orig_insn
= insn
;
803 text_rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
, insn
->len
);
804 if (text_rela
&& text_rela
->sym
== file
->rodata
->sym
) {
806 rodata_rela
= find_rela_by_dest(file
->rodata
,
812 rodata_rela
= find_rela_by_dest(file
->rodata
,
813 text_rela
->addend
+ 4);
816 file
->ignore_unreachables
= true;
821 func_for_each_insn_continue_reverse(file
, func
, insn
) {
822 if (insn
->type
== INSN_JUMP_DYNAMIC
)
825 /* allow small jumps within the range */
826 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
&&
828 (insn
->jump_dest
->offset
<= insn
->offset
||
829 insn
->jump_dest
->offset
> orig_insn
->offset
))
832 /* look for a relocation which references .rodata */
833 text_rela
= find_rela_by_dest_range(insn
->sec
, insn
->offset
,
835 if (!text_rela
|| text_rela
->sym
!= file
->rodata
->sym
)
839 * Make sure the .rodata address isn't associated with a
840 * symbol. gcc jump tables are anonymous data.
842 if (find_symbol_containing(file
->rodata
, text_rela
->addend
))
845 return find_rela_by_dest(file
->rodata
, text_rela
->addend
);
851 static int add_func_switch_tables(struct objtool_file
*file
,
854 struct instruction
*insn
, *prev_jump
= NULL
;
855 struct rela
*rela
, *prev_rela
= NULL
;
858 func_for_each_insn(file
, func
, insn
) {
859 if (insn
->type
!= INSN_JUMP_DYNAMIC
)
862 rela
= find_switch_table(file
, func
, insn
);
867 * We found a switch table, but we don't know yet how big it
868 * is. Don't add it until we reach the end of the function or
869 * the beginning of another switch table in the same function.
872 ret
= add_switch_table(file
, func
, prev_jump
, prev_rela
,
883 ret
= add_switch_table(file
, func
, prev_jump
, prev_rela
, NULL
);
892 * For some switch statements, gcc generates a jump table in the .rodata
893 * section which contains a list of addresses within the function to jump to.
894 * This finds these jump tables and adds them to the insn->alts lists.
896 static int add_switch_table_alts(struct objtool_file
*file
)
902 if (!file
->rodata
|| !file
->rodata
->rela
)
905 for_each_sec(file
, sec
) {
906 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
907 if (func
->type
!= STT_FUNC
)
910 ret
= add_func_switch_tables(file
, func
);
919 static int read_unwind_hints(struct objtool_file
*file
)
921 struct section
*sec
, *relasec
;
923 struct unwind_hint
*hint
;
924 struct instruction
*insn
;
928 sec
= find_section_by_name(file
->elf
, ".discard.unwind_hints");
934 WARN("missing .rela.discard.unwind_hints section");
938 if (sec
->len
% sizeof(struct unwind_hint
)) {
939 WARN("struct unwind_hint size mismatch");
945 for (i
= 0; i
< sec
->len
/ sizeof(struct unwind_hint
); i
++) {
946 hint
= (struct unwind_hint
*)sec
->data
->d_buf
+ i
;
948 rela
= find_rela_by_dest(sec
, i
* sizeof(*hint
));
950 WARN("can't find rela for unwind_hints[%d]", i
);
954 insn
= find_insn(file
, rela
->sym
->sec
, rela
->addend
);
956 WARN("can't find insn for unwind_hints[%d]", i
);
960 cfa
= &insn
->state
.cfa
;
962 if (hint
->type
== UNWIND_HINT_TYPE_SAVE
) {
966 } else if (hint
->type
== UNWIND_HINT_TYPE_RESTORE
) {
967 insn
->restore
= true;
974 switch (hint
->sp_reg
) {
975 case ORC_REG_UNDEFINED
:
976 cfa
->base
= CFI_UNDEFINED
;
984 case ORC_REG_SP_INDIRECT
:
985 cfa
->base
= CFI_SP_INDIRECT
;
1000 WARN_FUNC("unsupported unwind_hint sp base reg %d",
1001 insn
->sec
, insn
->offset
, hint
->sp_reg
);
1005 cfa
->offset
= hint
->sp_offset
;
1006 insn
->state
.type
= hint
->type
;
1012 static int decode_sections(struct objtool_file
*file
)
1016 ret
= decode_instructions(file
);
1020 ret
= add_dead_ends(file
);
1026 ret
= add_jump_destinations(file
);
1030 ret
= add_call_destinations(file
);
1034 ret
= add_special_section_alts(file
);
1038 ret
= add_switch_table_alts(file
);
1042 ret
= read_unwind_hints(file
);
1049 static bool is_fentry_call(struct instruction
*insn
)
1051 if (insn
->type
== INSN_CALL
&&
1052 insn
->call_dest
->type
== STT_NOTYPE
&&
1053 !strcmp(insn
->call_dest
->name
, "__fentry__"))
1059 static bool has_modified_stack_frame(struct insn_state
*state
)
1063 if (state
->cfa
.base
!= initial_func_cfi
.cfa
.base
||
1064 state
->cfa
.offset
!= initial_func_cfi
.cfa
.offset
||
1065 state
->stack_size
!= initial_func_cfi
.cfa
.offset
||
1069 for (i
= 0; i
< CFI_NUM_REGS
; i
++)
1070 if (state
->regs
[i
].base
!= initial_func_cfi
.regs
[i
].base
||
1071 state
->regs
[i
].offset
!= initial_func_cfi
.regs
[i
].offset
)
1077 static bool has_valid_stack_frame(struct insn_state
*state
)
1079 if (state
->cfa
.base
== CFI_BP
&& state
->regs
[CFI_BP
].base
== CFI_CFA
&&
1080 state
->regs
[CFI_BP
].offset
== -16)
1083 if (state
->drap
&& state
->regs
[CFI_BP
].base
== CFI_BP
)
1089 static int update_insn_state_regs(struct instruction
*insn
, struct insn_state
*state
)
1091 struct cfi_reg
*cfa
= &state
->cfa
;
1092 struct stack_op
*op
= &insn
->stack_op
;
1094 if (cfa
->base
!= CFI_SP
)
1098 if (op
->dest
.type
== OP_DEST_PUSH
)
1102 if (op
->src
.type
== OP_SRC_POP
)
1105 /* add immediate to sp */
1106 if (op
->dest
.type
== OP_DEST_REG
&& op
->src
.type
== OP_SRC_ADD
&&
1107 op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_SP
)
1108 cfa
->offset
-= op
->src
.offset
;
1113 static void save_reg(struct insn_state
*state
, unsigned char reg
, int base
,
1116 if (arch_callee_saved_reg(reg
) &&
1117 state
->regs
[reg
].base
== CFI_UNDEFINED
) {
1118 state
->regs
[reg
].base
= base
;
1119 state
->regs
[reg
].offset
= offset
;
1123 static void restore_reg(struct insn_state
*state
, unsigned char reg
)
1125 state
->regs
[reg
].base
= CFI_UNDEFINED
;
1126 state
->regs
[reg
].offset
= 0;
1130 * A note about DRAP stack alignment:
1132 * GCC has the concept of a DRAP register, which is used to help keep track of
1133 * the stack pointer when aligning the stack. r10 or r13 is used as the DRAP
1134 * register. The typical DRAP pattern is:
1136 * 4c 8d 54 24 08 lea 0x8(%rsp),%r10
1137 * 48 83 e4 c0 and $0xffffffffffffffc0,%rsp
1138 * 41 ff 72 f8 pushq -0x8(%r10)
1140 * 48 89 e5 mov %rsp,%rbp
1147 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1150 * There are some variations in the epilogues, like:
1158 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1163 * 4c 8b 55 e8 mov -0x18(%rbp),%r10
1164 * 48 8b 5d e0 mov -0x20(%rbp),%rbx
1165 * 4c 8b 65 f0 mov -0x10(%rbp),%r12
1166 * 4c 8b 6d f8 mov -0x8(%rbp),%r13
1168 * 49 8d 62 f8 lea -0x8(%r10),%rsp
1171 * Sometimes r13 is used as the DRAP register, in which case it's saved and
1172 * restored beforehand:
1175 * 4c 8d 6c 24 10 lea 0x10(%rsp),%r13
1176 * 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
1178 * 49 8d 65 f0 lea -0x10(%r13),%rsp
1182 static int update_insn_state(struct instruction
*insn
, struct insn_state
*state
)
1184 struct stack_op
*op
= &insn
->stack_op
;
1185 struct cfi_reg
*cfa
= &state
->cfa
;
1186 struct cfi_reg
*regs
= state
->regs
;
1188 /* stack operations don't make sense with an undefined CFA */
1189 if (cfa
->base
== CFI_UNDEFINED
) {
1191 WARN_FUNC("undefined stack state", insn
->sec
, insn
->offset
);
1197 if (state
->type
== ORC_TYPE_REGS
|| state
->type
== ORC_TYPE_REGS_IRET
)
1198 return update_insn_state_regs(insn
, state
);
1200 switch (op
->dest
.type
) {
1203 switch (op
->src
.type
) {
1206 if (op
->src
.reg
== CFI_SP
&& op
->dest
.reg
== CFI_BP
&&
1207 cfa
->base
== CFI_SP
&&
1208 regs
[CFI_BP
].base
== CFI_CFA
&&
1209 regs
[CFI_BP
].offset
== -cfa
->offset
) {
1211 /* mov %rsp, %rbp */
1212 cfa
->base
= op
->dest
.reg
;
1213 state
->bp_scratch
= false;
1216 else if (op
->src
.reg
== CFI_SP
&&
1217 op
->dest
.reg
== CFI_BP
&& state
->drap
) {
1219 /* drap: mov %rsp, %rbp */
1220 regs
[CFI_BP
].base
= CFI_BP
;
1221 regs
[CFI_BP
].offset
= -state
->stack_size
;
1222 state
->bp_scratch
= false;
1225 else if (op
->src
.reg
== CFI_SP
&& cfa
->base
== CFI_SP
) {
1230 * This is needed for the rare case where GCC
1237 state
->vals
[op
->dest
.reg
].base
= CFI_CFA
;
1238 state
->vals
[op
->dest
.reg
].offset
= -state
->stack_size
;
1241 else if (op
->dest
.reg
== cfa
->base
) {
1243 /* mov %reg, %rsp */
1244 if (cfa
->base
== CFI_SP
&&
1245 state
->vals
[op
->src
.reg
].base
== CFI_CFA
) {
1248 * This is needed for the rare case
1249 * where GCC does something dumb like:
1251 * lea 0x8(%rsp), %rcx
1255 cfa
->offset
= -state
->vals
[op
->src
.reg
].offset
;
1256 state
->stack_size
= cfa
->offset
;
1259 cfa
->base
= CFI_UNDEFINED
;
1267 if (op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_SP
) {
1270 state
->stack_size
-= op
->src
.offset
;
1271 if (cfa
->base
== CFI_SP
)
1272 cfa
->offset
-= op
->src
.offset
;
1276 if (op
->dest
.reg
== CFI_SP
&& op
->src
.reg
== CFI_BP
) {
1278 /* lea disp(%rbp), %rsp */
1279 state
->stack_size
= -(op
->src
.offset
+ regs
[CFI_BP
].offset
);
1283 if (op
->src
.reg
== CFI_SP
&& cfa
->base
== CFI_SP
) {
1285 /* drap: lea disp(%rsp), %drap */
1286 state
->drap_reg
= op
->dest
.reg
;
1289 * lea disp(%rsp), %reg
1291 * This is needed for the rare case where GCC
1292 * does something dumb like:
1294 * lea 0x8(%rsp), %rcx
1298 state
->vals
[op
->dest
.reg
].base
= CFI_CFA
;
1299 state
->vals
[op
->dest
.reg
].offset
= \
1300 -state
->stack_size
+ op
->src
.offset
;
1305 if (state
->drap
&& op
->dest
.reg
== CFI_SP
&&
1306 op
->src
.reg
== state
->drap_reg
) {
1308 /* drap: lea disp(%drap), %rsp */
1310 cfa
->offset
= state
->stack_size
= -op
->src
.offset
;
1311 state
->drap_reg
= CFI_UNDEFINED
;
1312 state
->drap
= false;
1316 if (op
->dest
.reg
== state
->cfa
.base
) {
1317 WARN_FUNC("unsupported stack register modification",
1318 insn
->sec
, insn
->offset
);
1325 if (op
->dest
.reg
!= CFI_SP
||
1326 (state
->drap_reg
!= CFI_UNDEFINED
&& cfa
->base
!= CFI_SP
) ||
1327 (state
->drap_reg
== CFI_UNDEFINED
&& cfa
->base
!= CFI_BP
)) {
1328 WARN_FUNC("unsupported stack pointer realignment",
1329 insn
->sec
, insn
->offset
);
1333 if (state
->drap_reg
!= CFI_UNDEFINED
) {
1334 /* drap: and imm, %rsp */
1335 cfa
->base
= state
->drap_reg
;
1336 cfa
->offset
= state
->stack_size
= 0;
1341 * Older versions of GCC (4.8ish) realign the stack
1342 * without DRAP, with a frame pointer.
1348 if (!state
->drap
&& op
->dest
.type
== OP_DEST_REG
&&
1349 op
->dest
.reg
== cfa
->base
) {
1355 if (state
->drap
&& cfa
->base
== CFI_BP_INDIRECT
&&
1356 op
->dest
.type
== OP_DEST_REG
&&
1357 op
->dest
.reg
== state
->drap_reg
&&
1358 state
->drap_offset
== -state
->stack_size
) {
1360 /* drap: pop %drap */
1361 cfa
->base
= state
->drap_reg
;
1363 state
->drap_offset
= -1;
1365 } else if (regs
[op
->dest
.reg
].offset
== -state
->stack_size
) {
1368 restore_reg(state
, op
->dest
.reg
);
1371 state
->stack_size
-= 8;
1372 if (cfa
->base
== CFI_SP
)
1377 case OP_SRC_REG_INDIRECT
:
1378 if (state
->drap
&& op
->src
.reg
== CFI_BP
&&
1379 op
->src
.offset
== state
->drap_offset
) {
1381 /* drap: mov disp(%rbp), %drap */
1382 cfa
->base
= state
->drap_reg
;
1384 state
->drap_offset
= -1;
1387 if (state
->drap
&& op
->src
.reg
== CFI_BP
&&
1388 op
->src
.offset
== regs
[op
->dest
.reg
].offset
) {
1390 /* drap: mov disp(%rbp), %reg */
1391 restore_reg(state
, op
->dest
.reg
);
1393 } else if (op
->src
.reg
== cfa
->base
&&
1394 op
->src
.offset
== regs
[op
->dest
.reg
].offset
+ cfa
->offset
) {
1396 /* mov disp(%rbp), %reg */
1397 /* mov disp(%rsp), %reg */
1398 restore_reg(state
, op
->dest
.reg
);
1404 WARN_FUNC("unknown stack-related instruction",
1405 insn
->sec
, insn
->offset
);
1412 state
->stack_size
+= 8;
1413 if (cfa
->base
== CFI_SP
)
1416 if (op
->src
.type
!= OP_SRC_REG
)
1420 if (op
->src
.reg
== cfa
->base
&& op
->src
.reg
== state
->drap_reg
) {
1422 /* drap: push %drap */
1423 cfa
->base
= CFI_BP_INDIRECT
;
1424 cfa
->offset
= -state
->stack_size
;
1426 /* save drap so we know when to restore it */
1427 state
->drap_offset
= -state
->stack_size
;
1429 } else if (op
->src
.reg
== CFI_BP
&& cfa
->base
== state
->drap_reg
) {
1431 /* drap: push %rbp */
1432 state
->stack_size
= 0;
1434 } else if (regs
[op
->src
.reg
].base
== CFI_UNDEFINED
) {
1436 /* drap: push %reg */
1437 save_reg(state
, op
->src
.reg
, CFI_BP
, -state
->stack_size
);
1443 save_reg(state
, op
->src
.reg
, CFI_CFA
, -state
->stack_size
);
1446 /* detect when asm code uses rbp as a scratch register */
1447 if (!no_fp
&& insn
->func
&& op
->src
.reg
== CFI_BP
&&
1448 cfa
->base
!= CFI_BP
)
1449 state
->bp_scratch
= true;
1452 case OP_DEST_REG_INDIRECT
:
1455 if (op
->src
.reg
== cfa
->base
&& op
->src
.reg
== state
->drap_reg
) {
1457 /* drap: mov %drap, disp(%rbp) */
1458 cfa
->base
= CFI_BP_INDIRECT
;
1459 cfa
->offset
= op
->dest
.offset
;
1461 /* save drap offset so we know when to restore it */
1462 state
->drap_offset
= op
->dest
.offset
;
1465 else if (regs
[op
->src
.reg
].base
== CFI_UNDEFINED
) {
1467 /* drap: mov reg, disp(%rbp) */
1468 save_reg(state
, op
->src
.reg
, CFI_BP
, op
->dest
.offset
);
1471 } else if (op
->dest
.reg
== cfa
->base
) {
1473 /* mov reg, disp(%rbp) */
1474 /* mov reg, disp(%rsp) */
1475 save_reg(state
, op
->src
.reg
, CFI_CFA
,
1476 op
->dest
.offset
- state
->cfa
.offset
);
1482 if ((!state
->drap
&& cfa
->base
!= CFI_BP
) ||
1483 (state
->drap
&& cfa
->base
!= state
->drap_reg
)) {
1484 WARN_FUNC("leave instruction with modified stack frame",
1485 insn
->sec
, insn
->offset
);
1489 /* leave (mov %rbp, %rsp; pop %rbp) */
1491 state
->stack_size
= -state
->regs
[CFI_BP
].offset
- 8;
1492 restore_reg(state
, CFI_BP
);
1502 if (op
->src
.type
!= OP_SRC_POP
) {
1503 WARN_FUNC("unknown stack-related memory operation",
1504 insn
->sec
, insn
->offset
);
1509 state
->stack_size
-= 8;
1510 if (cfa
->base
== CFI_SP
)
1516 WARN_FUNC("unknown stack-related instruction",
1517 insn
->sec
, insn
->offset
);
1524 static bool insn_state_match(struct instruction
*insn
, struct insn_state
*state
)
1526 struct insn_state
*state1
= &insn
->state
, *state2
= state
;
1529 if (memcmp(&state1
->cfa
, &state2
->cfa
, sizeof(state1
->cfa
))) {
1530 WARN_FUNC("stack state mismatch: cfa1=%d%+d cfa2=%d%+d",
1531 insn
->sec
, insn
->offset
,
1532 state1
->cfa
.base
, state1
->cfa
.offset
,
1533 state2
->cfa
.base
, state2
->cfa
.offset
);
1535 } else if (memcmp(&state1
->regs
, &state2
->regs
, sizeof(state1
->regs
))) {
1536 for (i
= 0; i
< CFI_NUM_REGS
; i
++) {
1537 if (!memcmp(&state1
->regs
[i
], &state2
->regs
[i
],
1538 sizeof(struct cfi_reg
)))
1541 WARN_FUNC("stack state mismatch: reg1[%d]=%d%+d reg2[%d]=%d%+d",
1542 insn
->sec
, insn
->offset
,
1543 i
, state1
->regs
[i
].base
, state1
->regs
[i
].offset
,
1544 i
, state2
->regs
[i
].base
, state2
->regs
[i
].offset
);
1548 } else if (state1
->type
!= state2
->type
) {
1549 WARN_FUNC("stack state mismatch: type1=%d type2=%d",
1550 insn
->sec
, insn
->offset
, state1
->type
, state2
->type
);
1552 } else if (state1
->drap
!= state2
->drap
||
1553 (state1
->drap
&& state1
->drap_reg
!= state2
->drap_reg
) ||
1554 (state1
->drap
&& state1
->drap_offset
!= state2
->drap_offset
)) {
1555 WARN_FUNC("stack state mismatch: drap1=%d(%d,%d) drap2=%d(%d,%d)",
1556 insn
->sec
, insn
->offset
,
1557 state1
->drap
, state1
->drap_reg
, state1
->drap_offset
,
1558 state2
->drap
, state2
->drap_reg
, state2
->drap_offset
);
1567 * Follow the branch starting at the given instruction, and recursively follow
1568 * any other branches (jumps). Meanwhile, track the frame pointer state at
1569 * each instruction and validate all the rules described in
1570 * tools/objtool/Documentation/stack-validation.txt.
1572 static int validate_branch(struct objtool_file
*file
, struct instruction
*first
,
1573 struct insn_state state
)
1575 struct alternative
*alt
;
1576 struct instruction
*insn
, *next_insn
;
1577 struct section
*sec
;
1578 struct symbol
*func
= NULL
;
1584 if (insn
->alt_group
&& list_empty(&insn
->alts
)) {
1585 WARN_FUNC("don't know how to handle branch to middle of alternative instruction group",
1591 next_insn
= next_insn_same_sec(file
, insn
);
1594 if (file
->c_file
&& func
&& insn
->func
&& func
!= insn
->func
) {
1595 WARN("%s() falls through to next function %s()",
1596 func
->name
, insn
->func
->name
);
1603 if (func
&& insn
->ignore
) {
1604 WARN_FUNC("BUG: why am I validating an ignored function?",
1609 if (insn
->visited
) {
1610 if (!insn
->hint
&& !insn_state_match(insn
, &state
))
1617 if (insn
->restore
) {
1618 struct instruction
*save_insn
, *i
;
1622 func_for_each_insn_continue_reverse(file
, func
, i
) {
1630 WARN_FUNC("no corresponding CFI save for CFI restore",
1635 if (!save_insn
->visited
) {
1637 * Oops, no state to copy yet.
1638 * Hopefully we can reach this
1639 * instruction from another branch
1640 * after the save insn has been
1646 WARN_FUNC("objtool isn't smart enough to handle this CFI save/restore combo",
1651 insn
->state
= save_insn
->state
;
1654 state
= insn
->state
;
1657 insn
->state
= state
;
1659 insn
->visited
= true;
1661 list_for_each_entry(alt
, &insn
->alts
, list
) {
1662 ret
= validate_branch(file
, alt
->insn
, state
);
1667 switch (insn
->type
) {
1670 if (func
&& has_modified_stack_frame(&state
)) {
1671 WARN_FUNC("return with modified stack frame",
1676 if (state
.bp_scratch
) {
1677 WARN("%s uses BP as a scratch register",
1685 if (is_fentry_call(insn
))
1688 ret
= dead_end_function(file
, insn
->call_dest
);
1695 case INSN_CALL_DYNAMIC
:
1696 if (!no_fp
&& func
&& !has_valid_stack_frame(&state
)) {
1697 WARN_FUNC("call without frame pointer save/setup",
1703 case INSN_JUMP_CONDITIONAL
:
1704 case INSN_JUMP_UNCONDITIONAL
:
1705 if (insn
->jump_dest
&&
1706 (!func
|| !insn
->jump_dest
->func
||
1707 func
== insn
->jump_dest
->func
)) {
1708 ret
= validate_branch(file
, insn
->jump_dest
,
1713 } else if (func
&& has_modified_stack_frame(&state
)) {
1714 WARN_FUNC("sibling call from callable instruction with modified stack frame",
1719 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
)
1724 case INSN_JUMP_DYNAMIC
:
1725 if (func
&& list_empty(&insn
->alts
) &&
1726 has_modified_stack_frame(&state
)) {
1727 WARN_FUNC("sibling call from callable instruction with modified stack frame",
1734 case INSN_CONTEXT_SWITCH
:
1735 if (func
&& (!next_insn
|| !next_insn
->hint
)) {
1736 WARN_FUNC("unsupported instruction in callable function",
1743 if (update_insn_state(insn
, &state
))
1757 WARN("%s: unexpected end of section", sec
->name
);
1765 static int validate_unwind_hints(struct objtool_file
*file
)
1767 struct instruction
*insn
;
1768 int ret
, warnings
= 0;
1769 struct insn_state state
;
1774 clear_insn_state(&state
);
1776 for_each_insn(file
, insn
) {
1777 if (insn
->hint
&& !insn
->visited
) {
1778 ret
= validate_branch(file
, insn
, state
);
1786 static bool is_kasan_insn(struct instruction
*insn
)
1788 return (insn
->type
== INSN_CALL
&&
1789 !strcmp(insn
->call_dest
->name
, "__asan_handle_no_return"));
1792 static bool is_ubsan_insn(struct instruction
*insn
)
1794 return (insn
->type
== INSN_CALL
&&
1795 !strcmp(insn
->call_dest
->name
,
1796 "__ubsan_handle_builtin_unreachable"));
1799 static bool ignore_unreachable_insn(struct instruction
*insn
)
1803 if (insn
->ignore
|| insn
->type
== INSN_NOP
)
1807 * Ignore any unused exceptions. This can happen when a whitelisted
1808 * function has an exception table entry.
1810 * Also ignore alternative replacement instructions. This can happen
1811 * when a whitelisted function uses one of the ALTERNATIVE macros.
1813 if (!strcmp(insn
->sec
->name
, ".fixup") ||
1814 !strcmp(insn
->sec
->name
, ".altinstr_replacement") ||
1815 !strcmp(insn
->sec
->name
, ".altinstr_aux"))
1819 * Check if this (or a subsequent) instruction is related to
1820 * CONFIG_UBSAN or CONFIG_KASAN.
1822 * End the search at 5 instructions to avoid going into the weeds.
1826 for (i
= 0; i
< 5; i
++) {
1828 if (is_kasan_insn(insn
) || is_ubsan_insn(insn
))
1831 if (insn
->type
== INSN_JUMP_UNCONDITIONAL
&& insn
->jump_dest
) {
1832 insn
= insn
->jump_dest
;
1836 if (insn
->offset
+ insn
->len
>= insn
->func
->offset
+ insn
->func
->len
)
1838 insn
= list_next_entry(insn
, list
);
1844 static int validate_functions(struct objtool_file
*file
)
1846 struct section
*sec
;
1847 struct symbol
*func
;
1848 struct instruction
*insn
;
1849 struct insn_state state
;
1850 int ret
, warnings
= 0;
1852 clear_insn_state(&state
);
1854 state
.cfa
= initial_func_cfi
.cfa
;
1855 memcpy(&state
.regs
, &initial_func_cfi
.regs
,
1856 CFI_NUM_REGS
* sizeof(struct cfi_reg
));
1857 state
.stack_size
= initial_func_cfi
.cfa
.offset
;
1859 for_each_sec(file
, sec
) {
1860 list_for_each_entry(func
, &sec
->symbol_list
, list
) {
1861 if (func
->type
!= STT_FUNC
)
1864 insn
= find_insn(file
, sec
, func
->offset
);
1865 if (!insn
|| insn
->ignore
)
1868 ret
= validate_branch(file
, insn
, state
);
1876 static int validate_reachable_instructions(struct objtool_file
*file
)
1878 struct instruction
*insn
;
1880 if (file
->ignore_unreachables
)
1883 for_each_insn(file
, insn
) {
1884 if (insn
->visited
|| ignore_unreachable_insn(insn
))
1887 WARN_FUNC("unreachable instruction", insn
->sec
, insn
->offset
);
1894 static void cleanup(struct objtool_file
*file
)
1896 struct instruction
*insn
, *tmpinsn
;
1897 struct alternative
*alt
, *tmpalt
;
1899 list_for_each_entry_safe(insn
, tmpinsn
, &file
->insn_list
, list
) {
1900 list_for_each_entry_safe(alt
, tmpalt
, &insn
->alts
, list
) {
1901 list_del(&alt
->list
);
1904 list_del(&insn
->list
);
1905 hash_del(&insn
->hash
);
1908 elf_close(file
->elf
);
1911 int check(const char *_objname
, bool _no_fp
, bool no_unreachable
, bool orc
)
1913 struct objtool_file file
;
1914 int ret
, warnings
= 0;
1919 file
.elf
= elf_open(objname
, orc
? O_RDWR
: O_RDONLY
);
1923 INIT_LIST_HEAD(&file
.insn_list
);
1924 hash_init(file
.insn_hash
);
1925 file
.whitelist
= find_section_by_name(file
.elf
, ".discard.func_stack_frame_non_standard");
1926 file
.rodata
= find_section_by_name(file
.elf
, ".rodata");
1927 file
.c_file
= find_section_by_name(file
.elf
, ".comment");
1928 file
.ignore_unreachables
= no_unreachable
;
1931 arch_initial_func_cfi_state(&initial_func_cfi
);
1933 ret
= decode_sections(&file
);
1938 if (list_empty(&file
.insn_list
))
1941 ret
= validate_functions(&file
);
1946 ret
= validate_unwind_hints(&file
);
1952 ret
= validate_reachable_instructions(&file
);
1959 ret
= create_orc(&file
);
1963 ret
= create_orc_sections(&file
);
1967 ret
= elf_write(file
.elf
);
1975 /* ignore warnings for now until we get all the code cleaned up */
1976 if (ret
|| warnings
)