From ad762b990fa9da53e203b934583838d4dd371e20 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 15 Dec 2017 13:52:56 +0000 Subject: [PATCH] linux-user: Don't use CMSG_ALIGN(sizeof struct cmsghdr) The Linux struct cmsghdr is already guaranteed to be sufficiently aligned that CMSG_ALIGN(sizeof struct cmsghdr) is always equal to sizeof struct cmsghdr. Stop doing the unnecessary alignment arithmetic for host and target cmsghdr. This follows kernel commit 1ff8cebf49ed9e9ca2 and brings our TARGET_CMSG_* macros back into line with the kernel ones, as well as making them easier to understand. Signed-off-by: Peter Maydell Reviewed-by: Laurent Vivier Message-Id: <1513345976-22958-3-git-send-email-peter.maydell@linaro.org> Signed-off-by: Laurent Vivier --- linux-user/syscall.c | 4 ++-- linux-user/syscall_defs.h | 6 +++--- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index a1b9772a85..39553c81b6 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -1692,7 +1692,7 @@ static inline abi_long target_to_host_cmsg(struct msghdr *msgh, void *target_data = TARGET_CMSG_DATA(target_cmsg); int len = tswapal(target_cmsg->cmsg_len) - - TARGET_CMSG_ALIGN(sizeof (struct target_cmsghdr)); + - sizeof(struct target_cmsghdr); space += CMSG_SPACE(len); if (space > msgh->msg_controllen) { @@ -1773,7 +1773,7 @@ static inline abi_long host_to_target_cmsg(struct target_msghdr *target_msgh, void *data = CMSG_DATA(cmsg); void *target_data = TARGET_CMSG_DATA(target_cmsg); - int len = cmsg->cmsg_len - CMSG_ALIGN(sizeof (struct cmsghdr)); + int len = cmsg->cmsg_len - sizeof(struct cmsghdr); int tgt_len, tgt_space; /* We never copy a half-header but may copy half-data; diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index bec3680b94..a35c52a60a 100644 --- a/linux-user/syscall_defs.h +++ b/linux-user/syscall_defs.h @@ -303,9 +303,9 @@ struct target_cmsghdr { __target_cmsg_nxthdr(mhdr, cmsg, cmsg_start) #define TARGET_CMSG_ALIGN(len) (((len) + sizeof (abi_long) - 1) \ & (size_t) ~(sizeof (abi_long) - 1)) -#define TARGET_CMSG_SPACE(len) (TARGET_CMSG_ALIGN (len) \ - + TARGET_CMSG_ALIGN (sizeof (struct target_cmsghdr))) -#define TARGET_CMSG_LEN(len) (TARGET_CMSG_ALIGN (sizeof (struct target_cmsghdr)) + (len)) +#define TARGET_CMSG_SPACE(len) (sizeof(struct target_cmsghdr) + \ + TARGET_CMSG_ALIGN(len)) +#define TARGET_CMSG_LEN(len) (sizeof(struct target_cmsghdr) + (len)) static __inline__ struct target_cmsghdr * __target_cmsg_nxthdr(struct target_msghdr *__mhdr,