[PATCH 08/22] objtool: Properly disable uaccess validation

Josh Poimboeuf posted 22 patches 8 months, 3 weeks ago
[PATCH 08/22] objtool: Properly disable uaccess validation
Posted by Josh Poimboeuf 8 months, 3 weeks ago
If opts.uaccess isn't set, the uaccess validation is disabled, but only
partially: it doesn't read the uaccess_safe_builtin list but still tries
to do the validation.  Disable it completely to prevent false warnings.

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
---
 tools/objtool/check.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 032b3be409f2..3966fc81a77e 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3195,7 +3195,7 @@ static int handle_insn_ops(struct instruction *insn,
 		if (update_cfi_state(insn, next_insn, &state->cfi, op))
 			return 1;
 
-		if (!insn->alt_group)
+		if (!opts.uaccess || !insn->alt_group)
 			continue;
 
 		if (op->dest.type == OP_DEST_PUSHF) {
@@ -3655,6 +3655,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 			return 0;
 
 		case INSN_STAC:
+			if (!opts.uaccess)
+				break;
+
 			if (state.uaccess) {
 				WARN_INSN(insn, "recursive UACCESS enable");
 				return 1;
@@ -3664,6 +3667,9 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
 			break;
 
 		case INSN_CLAC:
+			if (!opts.uaccess)
+				break;
+
 			if (!state.uaccess && func) {
 				WARN_INSN(insn, "redundant UACCESS disable");
 				return 1;
@@ -4122,7 +4128,8 @@ static int validate_symbol(struct objtool_file *file, struct section *sec,
 	if (!insn || insn->visited)
 		return 0;
 
-	state->uaccess = sym->uaccess_safe;
+	if (opts.uaccess)
+		state->uaccess = sym->uaccess_safe;
 
 	ret = validate_branch(file, insn_func(insn), insn, *state);
 	if (ret)
-- 
2.48.1