From 3d6f4a20cc287a8980c6186624834cf10a70752b Mon Sep 17 00:00:00 2001 From: David Miller Date: Thu, 24 Jul 2008 23:38:31 -0700 Subject: [PATCH] endian: Always evaluate arguments. Changeset 7fa897b91a3ea0f16c2873b869d7a0eef05acff4 ("ide: trivial sparse annotations") created an IDE bootup regression on big-endian systems. In drivers/ide/ide-iops.c, function ide_fixstring() we now have the loop: for (p = end ; p != s;) be16_to_cpus((u16 *)(p -= 2)); which will never terminate on big-endian because in such a configuration be16_to_cpus() evaluates to "do { } while (0)" Therefore, always evaluate the arguments to nop endian transformation operations. Signed-off-by: David S. Miller Signed-off-by: Linus Torvalds --- include/linux/byteorder/big_endian.h | 12 ++++++------ include/linux/byteorder/little_endian.h | 12 ++++++------ 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/linux/byteorder/big_endian.h b/include/linux/byteorder/big_endian.h index 961ed4b48d8e..44f95b92393b 100644 --- a/include/linux/byteorder/big_endian.h +++ b/include/linux/byteorder/big_endian.h @@ -94,12 +94,12 @@ static inline __u16 __be16_to_cpup(const __be16 *p) #define __le32_to_cpus(x) __swab32s((x)) #define __cpu_to_le16s(x) __swab16s((x)) #define __le16_to_cpus(x) __swab16s((x)) -#define __cpu_to_be64s(x) do {} while (0) -#define __be64_to_cpus(x) do {} while (0) -#define __cpu_to_be32s(x) do {} while (0) -#define __be32_to_cpus(x) do {} while (0) -#define __cpu_to_be16s(x) do {} while (0) -#define __be16_to_cpus(x) do {} while (0) +#define __cpu_to_be64s(x) do { (void)(x); } while (0) +#define __be64_to_cpus(x) do { (void)(x); } while (0) +#define __cpu_to_be32s(x) do { (void)(x); } while (0) +#define __be32_to_cpus(x) do { (void)(x); } while (0) +#define __cpu_to_be16s(x) do { (void)(x); } while (0) +#define __be16_to_cpus(x) do { (void)(x); } while (0) #ifdef __KERNEL__ #include diff --git a/include/linux/byteorder/little_endian.h b/include/linux/byteorder/little_endian.h index 05dc7c35b3b2..4cc170a31762 100644 --- a/include/linux/byteorder/little_endian.h +++ b/include/linux/byteorder/little_endian.h @@ -88,12 +88,12 @@ static inline __u16 __be16_to_cpup(const __be16 *p) { return __swab16p((__u16 *)p); } -#define __cpu_to_le64s(x) do {} while (0) -#define __le64_to_cpus(x) do {} while (0) -#define __cpu_to_le32s(x) do {} while (0) -#define __le32_to_cpus(x) do {} while (0) -#define __cpu_to_le16s(x) do {} while (0) -#define __le16_to_cpus(x) do {} while (0) +#define __cpu_to_le64s(x) do { (void)(x); } while (0) +#define __le64_to_cpus(x) do { (void)(x); } while (0) +#define __cpu_to_le32s(x) do { (void)(x); } while (0) +#define __le32_to_cpus(x) do { (void)(x); } while (0) +#define __cpu_to_le16s(x) do { (void)(x); } while (0) +#define __le16_to_cpus(x) do { (void)(x); } while (0) #define __cpu_to_be64s(x) __swab64s((x)) #define __be64_to_cpus(x) __swab64s((x)) #define __cpu_to_be32s(x) __swab32s((x)) -- 2.20.1