| Message ID | 20241117113813.work.735-kees@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | lib: stackinit: Hide never-taken branch from compiler | expand |
diff --git a/lib/stackinit_kunit.c b/lib/stackinit_kunit.c index c14c6f8e6308..c40818ec9c18 100644 --- a/lib/stackinit_kunit.c +++ b/lib/stackinit_kunit.c @@ -212,6 +212,7 @@ static noinline void test_ ## name (struct kunit *test) \ static noinline DO_NOTHING_TYPE_ ## which(var_type) \ do_nothing_ ## name(var_type *ptr) \ { \ + OPTIMIZER_HIDE_VAR(ptr); \ /* Will always be true, but compiler doesn't know. */ \ if ((unsigned long)ptr > 0x2) \ return DO_NOTHING_RETURN_ ## which(ptr); \
The never-taken branch leads to an invalid bounds condition, which is by design. To avoid the unwanted warning from the compiler, hide the variable from the optimizer. ../lib/stackinit_kunit.c: In function 'do_nothing_u16_zero': ../lib/stackinit_kunit.c:51:49: error: array subscript 1 is outside array bounds of 'u16[0]' {aka 'short unsigned int[]'} [-Werror=array-bounds=] 51 | #define DO_NOTHING_RETURN_SCALAR(ptr) *(ptr) | ^~~~~~ ../lib/stackinit_kunit.c:219:24: note: in expansion of macro 'DO_NOTHING_RETURN_SCALAR' 219 | return DO_NOTHING_RETURN_ ## which(ptr + 1); \ | ^~~~~~~~~~~~~~~~~~ Signed-off-by: Kees Cook <kees@kernel.org> --- lib/stackinit_kunit.c | 1 + 1 file changed, 1 insertion(+)