[PATCH 1/6] [net] drop 'size' argument of sock_recvmsg()

From: Al Viro
Date: Sat Apr 09 2016 - 16:50:36 EST


all callers have it equal to msg_data_left(msg).

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target_util.c | 5 ++---
include/linux/net.h | 3 +--
net/socket.c | 23 ++++++++++-------------
3 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
index 428b0d9..5772038 100644
--- a/drivers/target/iscsi/iscsi_target_util.c
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -1283,9 +1283,8 @@ static int iscsit_do_rx_data(
iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC,
count->iov, count->iov_count, data);

- while (total_rx < data) {
- rx_loop = sock_recvmsg(conn->sock, &msg,
- (data - total_rx), MSG_WAITALL);
+ while (msg_data_left(&msg)) {
+ rx_loop = sock_recvmsg(conn->sock, &msg, MSG_WAITALL);
if (rx_loop <= 0) {
pr_debug("rx_loop: %d total_rx: %d\n",
rx_loop, total_rx);
diff --git a/include/linux/net.h b/include/linux/net.h
index 49175e4..72c1e06 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -218,8 +218,7 @@ int sock_create_lite(int family, int type, int proto, struct socket **res);
struct socket *sock_alloc(void);
void sock_release(struct socket *sock);
int sock_sendmsg(struct socket *sock, struct msghdr *msg);
-int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
- int flags);
+int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags);
struct file *sock_alloc_file(struct socket *sock, int flags, const char *dname);
struct socket *sockfd_lookup(int fd, int *err);
struct socket *sock_from_file(struct file *file, int *err);
diff --git a/net/socket.c b/net/socket.c
index 5f77a8e..956426e3 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -709,17 +709,16 @@ void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
EXPORT_SYMBOL_GPL(__sock_recv_ts_and_drops);

static inline int sock_recvmsg_nosec(struct socket *sock, struct msghdr *msg,
- size_t size, int flags)
+ int flags)
{
- return sock->ops->recvmsg(sock, msg, size, flags);
+ return sock->ops->recvmsg(sock, msg, msg_data_left(msg), flags);
}

-int sock_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
- int flags)
+int sock_recvmsg(struct socket *sock, struct msghdr *msg, int flags)
{
- int err = security_socket_recvmsg(sock, msg, size, flags);
+ int err = security_socket_recvmsg(sock, msg, msg_data_left(msg), flags);

- return err ?: sock_recvmsg_nosec(sock, msg, size, flags);
+ return err ?: sock_recvmsg_nosec(sock, msg, flags);
}
EXPORT_SYMBOL(sock_recvmsg);

@@ -746,7 +745,7 @@ int kernel_recvmsg(struct socket *sock, struct msghdr *msg,

iov_iter_kvec(&msg->msg_iter, READ | ITER_KVEC, vec, num, size);
set_fs(KERNEL_DS);
- result = sock_recvmsg(sock, msg, size, flags);
+ result = sock_recvmsg(sock, msg, flags);
set_fs(oldfs);
return result;
}
@@ -796,7 +795,7 @@ static ssize_t sock_read_iter(struct kiocb *iocb, struct iov_iter *to)
if (!iov_iter_count(to)) /* Match SYS5 behaviour */
return 0;

- res = sock_recvmsg(sock, &msg, iov_iter_count(to), msg.msg_flags);
+ res = sock_recvmsg(sock, &msg, msg.msg_flags);
*to = msg.msg_iter;
return res;
}
@@ -1696,7 +1695,7 @@ SYSCALL_DEFINE6(recvfrom, int, fd, void __user *, ubuf, size_t, size,
msg.msg_iocb = NULL;
if (sock->file->f_flags & O_NONBLOCK)
flags |= MSG_DONTWAIT;
- err = sock_recvmsg(sock, &msg, iov_iter_count(&msg.msg_iter), flags);
+ err = sock_recvmsg(sock, &msg, flags);

if (err >= 0 && addr != NULL) {
err2 = move_addr_to_user(&address,
@@ -2073,7 +2072,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
struct iovec iovstack[UIO_FASTIOV];
struct iovec *iov = iovstack;
unsigned long cmsg_ptr;
- int total_len, len;
+ int len;
ssize_t err;

/* kernel mode address */
@@ -2091,7 +2090,6 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,
err = copy_msghdr_from_user(msg_sys, msg, &uaddr, &iov);
if (err < 0)
return err;
- total_len = iov_iter_count(&msg_sys->msg_iter);

cmsg_ptr = (unsigned long)msg_sys->msg_control;
msg_sys->msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
@@ -2101,8 +2099,7 @@ static int ___sys_recvmsg(struct socket *sock, struct user_msghdr __user *msg,

if (sock->file->f_flags & O_NONBLOCK)
flags |= MSG_DONTWAIT;
- err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys,
- total_len, flags);
+ err = (nosec ? sock_recvmsg_nosec : sock_recvmsg)(sock, msg_sys, flags);
if (err < 0)
goto out_freeiov;
len = err;
--
2.8.0.rc3