| From b401efc120a399dfda1f4d2858a4de365c9b08ef Mon Sep 17 00:00:00 2001 |
| From: Josh Poimboeuf <jpoimboe@redhat.com> |
| Date: Wed, 1 Apr 2020 13:23:28 -0500 |
| Subject: objtool: Fix switch table detection in .text.unlikely |
| |
| From: Josh Poimboeuf <jpoimboe@redhat.com> |
| |
| commit b401efc120a399dfda1f4d2858a4de365c9b08ef upstream. |
| |
| If a switch jump table's indirect branch is in a ".cold" subfunction in |
| .text.unlikely, objtool doesn't detect it, and instead prints a false |
| warning: |
| |
| drivers/media/v4l2-core/v4l2-ioctl.o: warning: objtool: v4l_print_format.cold()+0xd6: sibling call from callable instruction with modified stack frame |
| drivers/hwmon/max6650.o: warning: objtool: max6650_probe.cold()+0xa5: sibling call from callable instruction with modified stack frame |
| drivers/media/dvb-frontends/drxk_hard.o: warning: objtool: init_drxk.cold()+0x16f: sibling call from callable instruction with modified stack frame |
| |
| Fix it by comparing the function, instead of the section and offset. |
| |
| Fixes: 13810435b9a7 ("objtool: Support GCC 8's cold subfunctions") |
| Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> |
| Signed-off-by: Borislav Petkov <bp@suse.de> |
| Reviewed-by: Miroslav Benes <mbenes@suse.cz> |
| Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
| Link: https://lkml.kernel.org/r/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.1585761021.git.jpoimboe@redhat.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| tools/objtool/check.c | 5 +---- |
| 1 file changed, 1 insertion(+), 4 deletions(-) |
| |
| --- a/tools/objtool/check.c |
| +++ b/tools/objtool/check.c |
| @@ -915,10 +915,7 @@ static struct rela *find_switch_table(st |
| * it. |
| */ |
| for (; |
| - &insn->list != &file->insn_list && |
| - insn->sec == func->sec && |
| - insn->offset >= func->offset; |
| - |
| + &insn->list != &file->insn_list && insn->func && insn->func->pfunc == func; |
| insn = insn->first_jump_src ?: list_prev_entry(insn, list)) { |
| |
| if (insn != orig_insn && insn->type == INSN_JUMP_DYNAMIC) |
