+ kcov-avoid-clang-out-of-range-warning.patch added to mm-nonmm-unstable branch

+ kcov-avoid-clang-out-of-range-warning.patch added to mm-nonmm-unstable branch

[Andrew Morton]

The patch titled
     Subject: kcov: avoid clang out-of-range warning
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     kcov-avoid-clang-out-of-range-warning.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kcov-avoid-clang-out-of-range-warning.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Arnd Bergmann <arnd@arndb.de>
Subject: kcov: avoid clang out-of-range warning
Date: Thu, 28 Mar 2024 15:30:42 +0100

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 <arnd@arndb.de>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 kernel/kcov.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/kernel/kcov.c~kcov-avoid-clang-out-of-range-warning
+++ a/kernel/kcov.c
@@ -627,7 +627,8 @@ static int kcov_ioctl_locked(struct kcov
 		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;
_

Patches currently in -mm which might be from arnd@arndb.de are

nilfs2-fix-out-of-range-warning.patch
kcov-avoid-clang-out-of-range-warning.patch