From 56fd61628b7a5c1ff474619580796f11d5c8973a Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 28 Mar 2024 15:30:42 +0100 Subject: [PATCH] kcov: avoid clang out-of-range warning The area_size is never larger than the maximum on 64-bit architectutes: kernel/kcov.c:634:29: error: result of comparison of constant 1152921504606846975 with expression of type '__u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (remote_arg->area_size > LONG_MAX / sizeof(unsigned long)) ~~~~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The compiler can correctly optimize the check away and the code appears correct to me, so just add a cast to avoid the warning. Link: https://lkml.kernel.org/r/20240328143051.1069575-5-arnd@kernel.org Signed-off-by: Arnd Bergmann Reviewed-by: Justin Stitt Cc: Andrey Konovalov Cc: Bill Wendling Cc: Dmitry Vyukov Cc: Nathan Chancellor Cc: Nick Desaulniers Signed-off-by: Andrew Morton --- kernel/kcov.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/kcov.c b/kernel/kcov.c index f9ac2e9e460f..c3124f6d5536 100644 --- a/kernel/kcov.c +++ b/kernel/kcov.c @@ -627,7 +627,8 @@ static int kcov_ioctl_locked(struct kcov *kcov, unsigned int cmd, mode = kcov_get_mode(remote_arg->trace_mode); if (mode < 0) return mode; - if (remote_arg->area_size > LONG_MAX / sizeof(unsigned long)) + if ((unsigned long)remote_arg->area_size > + LONG_MAX / sizeof(unsigned long)) return -EINVAL; kcov->mode = mode; t->kcov = kcov;