net: add a CMSG_USER_DATA macro

Add a variant of CMSG_DATA that operates on user pointer to avoid
sparse warnings about casting to/from user pointers.  Also fix up
CMSG_DATA to rely on the gcc extension that allows void pointer
arithmetics to cut down on the amount of casts.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Christoph Hellwig
2020-05-11 13:59:11 +02:00
committed by David S. Miller
parent 3242956bd6
commit 0462b6bdb6
2 changed files with 6 additions and 3 deletions

View File

@@ -94,7 +94,10 @@ struct cmsghdr {
#define CMSG_ALIGN(len) ( ((len)+sizeof(long)-1) & ~(sizeof(long)-1) )
#define CMSG_DATA(cmsg) ((void *)((char *)(cmsg) + sizeof(struct cmsghdr)))
#define CMSG_DATA(cmsg) \
((void *)(cmsg) + sizeof(struct cmsghdr))
#define CMSG_USER_DATA(cmsg) \
((void __user *)(cmsg) + sizeof(struct cmsghdr))
#define CMSG_SPACE(len) (sizeof(struct cmsghdr) + CMSG_ALIGN(len))
#define CMSG_LEN(len) (sizeof(struct cmsghdr) + (len))