From: Thomas Hebb <tommyhebb@gmail.com> [ Upstream commit 272a72103012862e3a24ea06635253ead0b6e808 ] NULL expressions are taken to always be true, as implemented by the expr_is_yes() macro and by several other functions in expr.c. As such, they ought to be valid inputs to expr_eq(), which compares two expressions. Signed-off-by: Thomas Hebb <tommyhebb@gmail.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- scripts/kconfig/expr.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/scripts/kconfig/expr.c b/scripts/kconfig/expr.c index e1a39e9..7e38070 100644 --- a/scripts/kconfig/expr.c +++ b/scripts/kconfig/expr.c @@ -252,6 +252,13 @@ static int expr_eq(struct expr *e1, struct expr *e2) { int res, old_count; + /* + * A NULL expr is taken to be yes, but there's also a different way to + * represent yes. expr_is_yes() checks for either representation. + */ + if (!e1 || !e2) + return expr_is_yes(e1) && expr_is_yes(e2); + if (e1->type != e2->type) return 0; switch (e1->type) { -- 1.8.3