[PATCH 5.15 40/89] objtool: Treat .text.__x86.* as noinstr

From: Greg Kroah-Hartman
Date: Fri Jul 22 2022 - 05:23:30 EST


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit 951ddecf435659553ed15a9214e153a3af43a9a1 upstream.

Needed because zen_untrain_ret() will be called from noinstr code.

Also makes sense since the thunks MUST NOT contain instrumentation nor
be poked with dynamic instrumentation.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/objtool/check.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -367,7 +367,8 @@ static int decode_instructions(struct ob
sec->text = true;

if (!strcmp(sec->name, ".noinstr.text") ||
- !strcmp(sec->name, ".entry.text"))
+ !strcmp(sec->name, ".entry.text") ||
+ !strncmp(sec->name, ".text.__x86.", 12))
sec->noinstr = true;

for (offset = 0; offset < sec->sh.sh_size; offset += insn->len) {