net: abstract out normal and compat msghdr import
This splits it into two parts, one that imports the message, and one
that imports the iovec. This allows a caller to only do the first part,
and import the iovec manually afterwards.
No functional changes in this patch.
Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/net/compat.c b/net/compat.c
index 47d99c7..4bed96e 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -33,10 +33,10 @@
#include <linux/uaccess.h>
#include <net/compat.h>
-int get_compat_msghdr(struct msghdr *kmsg,
- struct compat_msghdr __user *umsg,
- struct sockaddr __user **save_addr,
- struct iovec **iov)
+int __get_compat_msghdr(struct msghdr *kmsg,
+ struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ compat_uptr_t *ptr, compat_size_t *len)
{
struct compat_msghdr msg;
ssize_t err;
@@ -79,10 +79,26 @@ int get_compat_msghdr(struct msghdr *kmsg,
return -EMSGSIZE;
kmsg->msg_iocb = NULL;
+ *ptr = msg.msg_iov;
+ *len = msg.msg_iovlen;
+ return 0;
+}
- err = compat_import_iovec(save_addr ? READ : WRITE,
- compat_ptr(msg.msg_iov), msg.msg_iovlen,
- UIO_FASTIOV, iov, &kmsg->msg_iter);
+int get_compat_msghdr(struct msghdr *kmsg,
+ struct compat_msghdr __user *umsg,
+ struct sockaddr __user **save_addr,
+ struct iovec **iov)
+{
+ compat_uptr_t ptr;
+ compat_size_t len;
+ ssize_t err;
+
+ err = __get_compat_msghdr(kmsg, umsg, save_addr, &ptr, &len);
+ if (err)
+ return err;
+
+ err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr),
+ len, UIO_FASTIOV, iov, &kmsg->msg_iter);
return err < 0 ? err : 0;
}