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/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.158576102... 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 @@ -938,10 +938,7 @@ 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)