From 7690585f2197278305d514bd8222e4fcd7fd58ed Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Wed, 1 Apr 2020 13:23:28 -0500 Subject: [PATCH] objtool: Fix switch table detection in .text.unlikely 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 Signed-off-by: Borislav Petkov Reviewed-by: Miroslav Benes Acked-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/157c35d42ca9b6354bbb1604fe9ad7d1153ccb21.1585761021.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman --- tools/objtool/check.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/tools/objtool/check.c b/tools/objtool/check.c index 09782ff427d0..db105207757b 100644 --- a/tools/objtool/check.c +++ b/tools/objtool/check.c @@ -914,10 +914,7 @@ static struct rela *find_switch_table(struct objtool_file *file, * 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) -- 2.20.1