Commit 0462b6bd authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David S. Miller
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3242956b

include/linux/socket.h

+4 −1
Original line number Diff line number Diff line
@@ -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))

net/core/scm.c

+2 −2
Original line number Diff line number Diff line
@@ -236,7 +236,7 @@ int put_cmsg(struct msghdr * msg, int level, int type, int len, void *data) 
	err = -EFAULT;

	if (copy_to_user(cm, &cmhdr, sizeof cmhdr))

		goto out;

	if (copy_to_user(CMSG_DATA(cm), data, cmlen - sizeof(struct cmsghdr)))

	if (copy_to_user(CMSG_USER_DATA(cm), data, cmlen - sizeof(*cm)))

		goto out;

	cmlen = CMSG_SPACE(len);

	if (msg->msg_controllen < cmlen)
@@ -300,7 +300,7 @@ void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) 
	if (fdnum < fdmax)

		fdmax = fdnum;



	for (i=0, cmfptr=(__force int __user *)CMSG_DATA(cm); i<fdmax;

	for (i=0, cmfptr =(int __user *)CMSG_USER_DATA(cm); i<fdmax;

	     i++, cmfptr++)

	{

		struct socket *sock;

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