| Message ID | 1513345976-22958-3-git-send-email-peter.maydell@linaro.org |
|---|---|
| State | Accepted |
| Headers | show |
| Series | linux-user: Fix length calculations in host_to_target_cmsg() | expand |
Le 15/12/2017 à 14:52, Peter Maydell a écrit : > 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 <peter.maydell@linaro.org> > --- > linux-user/syscall_defs.h | 6 +++--- > linux-user/syscall.c | 4 ++-- > 2 files changed, 5 insertions(+), 5 deletions(-) Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Le 15/12/2017 à 14:52, Peter Maydell a écrit : > 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 <peter.maydell@linaro.org> > --- > linux-user/syscall_defs.h | 6 +++--- > linux-user/syscall.c | 4 ++-- > 2 files changed, 5 insertions(+), 5 deletions(-) > > diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h > index bec3680..a35c52a 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, > diff --git a/linux-user/syscall.c b/linux-user/syscall.c > index a1b9772..39553c8 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; > Applied to my linux-user branch. Thanks, Laurent
diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h index bec3680..a35c52a 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, diff --git a/linux-user/syscall.c b/linux-user/syscall.c index a1b9772..39553c8 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;
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 <peter.maydell@linaro.org> --- linux-user/syscall_defs.h | 6 +++--- linux-user/syscall.c | 4 ++-- 2 files changed, 5 insertions(+), 5 deletions(-) -- 2.7.4