[PATCH 6.12 2/2] kunit/fortify: Add back "volatile" for sizeof() constants
Nathan Chancellor <[email protected]>
| Newsgroups | org.kernel.vger.stable |
|---|---|
| Message-ID | <[email protected]> |
From: Kees Cook <[email protected]> commit 10299c07c94aa0997fa43523b53301e713a6415d upstream. It seems the Clang can see through OPTIMIZER_HIDE_VAR when the constant is coming from sizeof. Adding "volatile" back to these variables solves this false positive without reintroducing the issues that originally led to switching to OPTIMIZER_HIDE_VAR in the first place[1]. Reported-by: Nathan Chancellor <[email protected]> Closes: https://github.com/ClangBuiltLinux/linux/issues/2075 [1] Cc: Jannik Glückert <[email protected]> Suggested-by: Nathan Chancellor <[email protected]> Fixes: 6ee149f61bcc ("kunit/fortify: Replace "volatile" with OPTIMIZER_HIDE_VAR()") Reviewed-by: Nathan Chancellor <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Kees Cook <[email protected]> Signed-off-by: Nathan Chancellor <[email protected]> --- lib/fortify_kunit.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c index 1541b2a1694e..d0810e4e65e5 100644 --- a/lib/fortify_kunit.c +++ b/lib/fortify_kunit.c @@ -986,8 +986,8 @@ static void fortify_test_memcmp(struct kunit *test) { char one[] = "My mind is going ..."; char two[] = "My mind is going ... I can feel it."; - size_t one_len = sizeof(one) - 1; - size_t two_len = sizeof(two) - 1; + volatile size_t one_len = sizeof(one) - 1; + volatile size_t two_len = sizeof(two) - 1; OPTIMIZER_HIDE_VAR(one_len); OPTIMIZER_HIDE_VAR(two_len); -- 2.55.0