The patch titled
Subject: include/uapi/linux/swab.h: move explicit cast outside ternary
has been added to the -mm mm-nonmm-unstable branch. Its filename is
include-uapi-linux-swabh-move-explicit-cast-outside-ternary.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/include-uapi-linux-swabh-move-explicit-cast-outside-ternary.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: Justin Stitt <jstitt007@xxxxxxxxx>
Subject: include/uapi/linux/swab.h: move explicit cast outside ternary
Date: Wed, 8 Jun 2022 15:35:39 -0700
A cast inside __builtin_constant_p doesn't do anything since it should
evaluate as constant at compile time irrespective of this cast. Instead,
I moved this cast outside the ternary to ensure the return type is as
expected.
Additionally, if __HAVE_BUILTIN_BSWAP16__ was not defined then __swab16 is
actually returning an `int` not a `u16` due to integer promotion.
As Al Viro notes:
You *can't* get smaller-than-int out of ? :, same as you can't get it
out of addition, etc.
This also fixes some clang -Wformat warnings involving default
argument promotion.
Link: https://github.com/ClangBuiltLinux/linux/issues/378
Link: https://lkml.kernel.org/r/20220608223539.470472-1-justinstitt@xxxxxxxxxx
Signed-off-by: Justin Stitt <jstitt007@xxxxxxxxx>
Suggested-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Suggested-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/uapi/linux/swab.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/include/uapi/linux/swab.h~include-uapi-linux-swabh-move-explicit-cast-outside-ternary
+++ a/include/uapi/linux/swab.h
@@ -102,7 +102,7 @@ static inline __attribute_const__ __u32
#define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
#else
#define __swab16(x) \
- (__builtin_constant_p((__u16)(x)) ? \
+ (__u16)(__builtin_constant_p(x) ? \
___constant_swab16(x) : \
__fswab16(x))
#endif
@@ -115,7 +115,7 @@ static inline __attribute_const__ __u32
#define __swab32(x) (__u32)__builtin_bswap32((__u32)(x))
#else
#define __swab32(x) \
- (__builtin_constant_p((__u32)(x)) ? \
+ (__u32)(__builtin_constant_p(x) ? \
___constant_swab32(x) : \
__fswab32(x))
#endif
@@ -128,7 +128,7 @@ static inline __attribute_const__ __u32
#define __swab64(x) (__u64)__builtin_bswap64((__u64)(x))
#else
#define __swab64(x) \
- (__builtin_constant_p((__u64)(x)) ? \
+ (__u64)(__builtin_constant_p(x) ? \
___constant_swab64(x) : \
__fswab64(x))
#endif
_
Patches currently in -mm which might be from jstitt007@xxxxxxxxx are
include-uapi-linux-swabh-move-explicit-cast-outside-ternary.patch
