Revision 5e98e916f95bdc50e90f3199d7f3d74b94fa5976 authored by Linus Torvalds on 12 February 2023, 21:52:17 UTC, committed by Linus Torvalds on 12 February 2023, 21:52:17 UTC
Pull tracing fix from Steven Rostedt:
 "Fix showing of TASK_COMM_LEN instead of its value

  The TASK_COMM_LEN was converted from a macro into an enum so that BTF
  would have access to it. But this unfortunately caused TASK_COMM_LEN
  to display in the format fields of trace events, as they are created
  by the TRACE_EVENT() macro and such, macros convert to their values,
  where as enums do not.

  To handle this, instead of using the field itself to be display, save
  the value of the array size as another field in the trace_event_fields
  structure, and use that instead.

  Not only does this fix the issue, but also converts the other trace
  events that have this same problem (but were not breaking tooling).

  With this change, the original work around b3bc8547d3be6 ("tracing:
  Have TRACE_DEFINE_ENUM affect trace event types as well") could be
  reverted (but that should be done in the merge window)"

* tag 'trace-v6.2-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix TASK_COMM_LEN in trace event format file
2 parent s 711e9a4 + b6c7abd
Raw File
net.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/file.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/compat.h>
#include <net/compat.h>
#include <linux/io_uring.h>

#include <uapi/linux/io_uring.h>

#include "io_uring.h"
#include "kbuf.h"
#include "alloc_cache.h"
#include "net.h"
#include "notif.h"
#include "rsrc.h"

#if defined(CONFIG_NET)
struct io_shutdown {
	struct file			*file;
	int				how;
};

struct io_accept {
	struct file			*file;
	struct sockaddr __user		*addr;
	int __user			*addr_len;
	int				flags;
	u32				file_slot;
	unsigned long			nofile;
};

struct io_socket {
	struct file			*file;
	int				domain;
	int				type;
	int				protocol;
	int				flags;
	u32				file_slot;
	unsigned long			nofile;
};

struct io_connect {
	struct file			*file;
	struct sockaddr __user		*addr;
	int				addr_len;
	bool				in_progress;
};

struct io_sr_msg {
	struct file			*file;
	union {
		struct compat_msghdr __user	*umsg_compat;
		struct user_msghdr __user	*umsg;
		void __user			*buf;
	};
	unsigned			len;
	unsigned			done_io;
	unsigned			msg_flags;
	u16				flags;
	/* initialised and used only by !msg send variants */
	u16				addr_len;
	u16				buf_group;
	void __user			*addr;
	/* used only for send zerocopy */
	struct io_kiocb 		*notif;
};

static inline bool io_check_multishot(struct io_kiocb *req,
				      unsigned int issue_flags)
{
	/*
	 * When ->locked_cq is set we only allow to post CQEs from the original
	 * task context. Usual request completions will be handled in other
	 * generic paths but multipoll may decide to post extra cqes.
	 */
	return !(issue_flags & IO_URING_F_IOWQ) ||
		!(issue_flags & IO_URING_F_MULTISHOT) ||
		!req->ctx->task_complete;
}

int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);

	if (unlikely(sqe->off || sqe->addr || sqe->rw_flags ||
		     sqe->buf_index || sqe->splice_fd_in))
		return -EINVAL;

	shutdown->how = READ_ONCE(sqe->len);
	return 0;
}

int io_shutdown(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown);
	struct socket *sock;
	int ret;

	if (issue_flags & IO_URING_F_NONBLOCK)
		return -EAGAIN;

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;

	ret = __sys_shutdown_sock(sock, shutdown->how);
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

static bool io_net_retry(struct socket *sock, int flags)
{
	if (!(flags & MSG_WAITALL))
		return false;
	return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
}

static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_async_msghdr *hdr = req->async_data;

	if (!req_has_async_data(req) || issue_flags & IO_URING_F_UNLOCKED)
		return;

	/* Let normal cleanup path reap it if we fail adding to the cache */
	if (io_alloc_cache_put(&req->ctx->netmsg_cache, &hdr->cache)) {
		req->async_data = NULL;
		req->flags &= ~REQ_F_ASYNC_DATA;
	}
}

static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req,
						  unsigned int issue_flags)
{
	struct io_ring_ctx *ctx = req->ctx;
	struct io_cache_entry *entry;
	struct io_async_msghdr *hdr;

	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
		entry = io_alloc_cache_get(&ctx->netmsg_cache);
		if (entry) {
			hdr = container_of(entry, struct io_async_msghdr, cache);
			hdr->free_iov = NULL;
			req->flags |= REQ_F_ASYNC_DATA;
			req->async_data = hdr;
			return hdr;
		}
	}

	if (!io_alloc_async_data(req)) {
		hdr = req->async_data;
		hdr->free_iov = NULL;
		return hdr;
	}
	return NULL;
}

static inline struct io_async_msghdr *io_msg_alloc_async_prep(struct io_kiocb *req)
{
	/* ->prep_async is always called from the submission context */
	return io_msg_alloc_async(req, 0);
}

static int io_setup_async_msg(struct io_kiocb *req,
			      struct io_async_msghdr *kmsg,
			      unsigned int issue_flags)
{
	struct io_async_msghdr *async_msg;

	if (req_has_async_data(req))
		return -EAGAIN;
	async_msg = io_msg_alloc_async(req, issue_flags);
	if (!async_msg) {
		kfree(kmsg->free_iov);
		return -ENOMEM;
	}
	req->flags |= REQ_F_NEED_CLEANUP;
	memcpy(async_msg, kmsg, sizeof(*kmsg));
	if (async_msg->msg.msg_name)
		async_msg->msg.msg_name = &async_msg->addr;
	/* if were using fast_iov, set it to the new one */
	if (!kmsg->free_iov) {
		size_t fast_idx = kmsg->msg.msg_iter.iov - kmsg->fast_iov;
		async_msg->msg.msg_iter.iov = &async_msg->fast_iov[fast_idx];
	}

	return -EAGAIN;
}

static int io_sendmsg_copy_hdr(struct io_kiocb *req,
			       struct io_async_msghdr *iomsg)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	iomsg->msg.msg_name = &iomsg->addr;
	iomsg->free_iov = iomsg->fast_iov;
	return sendmsg_copy_msghdr(&iomsg->msg, sr->umsg, sr->msg_flags,
					&iomsg->free_iov);
}

int io_send_prep_async(struct io_kiocb *req)
{
	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr *io;
	int ret;

	if (!zc->addr || req_has_async_data(req))
		return 0;
	io = io_msg_alloc_async_prep(req);
	if (!io)
		return -ENOMEM;
	ret = move_addr_to_kernel(zc->addr, zc->addr_len, &io->addr);
	return ret;
}

static int io_setup_async_addr(struct io_kiocb *req,
			      struct sockaddr_storage *addr_storage,
			      unsigned int issue_flags)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr *io;

	if (!sr->addr || req_has_async_data(req))
		return -EAGAIN;
	io = io_msg_alloc_async(req, issue_flags);
	if (!io)
		return -ENOMEM;
	memcpy(&io->addr, addr_storage, sizeof(io->addr));
	return -EAGAIN;
}

int io_sendmsg_prep_async(struct io_kiocb *req)
{
	int ret;

	if (!io_msg_alloc_async_prep(req))
		return -ENOMEM;
	ret = io_sendmsg_copy_hdr(req, req->async_data);
	if (!ret)
		req->flags |= REQ_F_NEED_CLEANUP;
	return ret;
}

void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
{
	struct io_async_msghdr *io = req->async_data;

	kfree(io->free_iov);
}

int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	if (req->opcode == IORING_OP_SEND) {
		if (READ_ONCE(sqe->__pad3[0]))
			return -EINVAL;
		sr->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
		sr->addr_len = READ_ONCE(sqe->addr_len);
	} else if (sqe->addr2 || sqe->file_index) {
		return -EINVAL;
	}

	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
	sr->len = READ_ONCE(sqe->len);
	sr->flags = READ_ONCE(sqe->ioprio);
	if (sr->flags & ~IORING_RECVSEND_POLL_FIRST)
		return -EINVAL;
	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
	if (sr->msg_flags & MSG_DONTWAIT)
		req->flags |= REQ_F_NOWAIT;

#ifdef CONFIG_COMPAT
	if (req->ctx->compat)
		sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
	sr->done_io = 0;
	return 0;
}

int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr iomsg, *kmsg;
	struct socket *sock;
	unsigned flags;
	int min_ret = 0;
	int ret;

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;

	if (req_has_async_data(req)) {
		kmsg = req->async_data;
	} else {
		ret = io_sendmsg_copy_hdr(req, &iomsg);
		if (ret)
			return ret;
		kmsg = &iomsg;
	}

	if (!(req->flags & REQ_F_POLLED) &&
	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
		return io_setup_async_msg(req, kmsg, issue_flags);

	flags = sr->msg_flags;
	if (issue_flags & IO_URING_F_NONBLOCK)
		flags |= MSG_DONTWAIT;
	if (flags & MSG_WAITALL)
		min_ret = iov_iter_count(&kmsg->msg.msg_iter);

	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);

	if (ret < min_ret) {
		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
			return io_setup_async_msg(req, kmsg, issue_flags);
		if (ret > 0 && io_net_retry(sock, flags)) {
			sr->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return io_setup_async_msg(req, kmsg, issue_flags);
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	}
	/* fast path, check for non-NULL to avoid function call */
	if (kmsg->free_iov)
		kfree(kmsg->free_iov);
	req->flags &= ~REQ_F_NEED_CLEANUP;
	io_netmsg_recycle(req, issue_flags);
	if (ret >= 0)
		ret += sr->done_io;
	else if (sr->done_io)
		ret = sr->done_io;
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

int io_send(struct io_kiocb *req, unsigned int issue_flags)
{
	struct sockaddr_storage __address;
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct msghdr msg;
	struct iovec iov;
	struct socket *sock;
	unsigned flags;
	int min_ret = 0;
	int ret;

	msg.msg_name = NULL;
	msg.msg_control = NULL;
	msg.msg_controllen = 0;
	msg.msg_namelen = 0;
	msg.msg_ubuf = NULL;

	if (sr->addr) {
		if (req_has_async_data(req)) {
			struct io_async_msghdr *io = req->async_data;

			msg.msg_name = &io->addr;
		} else {
			ret = move_addr_to_kernel(sr->addr, sr->addr_len, &__address);
			if (unlikely(ret < 0))
				return ret;
			msg.msg_name = (struct sockaddr *)&__address;
		}
		msg.msg_namelen = sr->addr_len;
	}

	if (!(req->flags & REQ_F_POLLED) &&
	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
		return io_setup_async_addr(req, &__address, issue_flags);

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;

	ret = import_single_range(ITER_SOURCE, sr->buf, sr->len, &iov, &msg.msg_iter);
	if (unlikely(ret))
		return ret;

	flags = sr->msg_flags;
	if (issue_flags & IO_URING_F_NONBLOCK)
		flags |= MSG_DONTWAIT;
	if (flags & MSG_WAITALL)
		min_ret = iov_iter_count(&msg.msg_iter);

	msg.msg_flags = flags;
	ret = sock_sendmsg(sock, &msg);
	if (ret < min_ret) {
		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
			return io_setup_async_addr(req, &__address, issue_flags);

		if (ret > 0 && io_net_retry(sock, flags)) {
			sr->len -= ret;
			sr->buf += ret;
			sr->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return io_setup_async_addr(req, &__address, issue_flags);
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	}
	if (ret >= 0)
		ret += sr->done_io;
	else if (sr->done_io)
		ret = sr->done_io;
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

static bool io_recvmsg_multishot_overflow(struct io_async_msghdr *iomsg)
{
	int hdr;

	if (iomsg->namelen < 0)
		return true;
	if (check_add_overflow((int)sizeof(struct io_uring_recvmsg_out),
			       iomsg->namelen, &hdr))
		return true;
	if (check_add_overflow(hdr, (int)iomsg->controllen, &hdr))
		return true;

	return false;
}

static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
				 struct io_async_msghdr *iomsg)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct user_msghdr msg;
	int ret;

	if (copy_from_user(&msg, sr->umsg, sizeof(*sr->umsg)))
		return -EFAULT;

	ret = __copy_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
	if (ret)
		return ret;

	if (req->flags & REQ_F_BUFFER_SELECT) {
		if (msg.msg_iovlen == 0) {
			sr->len = iomsg->fast_iov[0].iov_len = 0;
			iomsg->fast_iov[0].iov_base = NULL;
			iomsg->free_iov = NULL;
		} else if (msg.msg_iovlen > 1) {
			return -EINVAL;
		} else {
			if (copy_from_user(iomsg->fast_iov, msg.msg_iov, sizeof(*msg.msg_iov)))
				return -EFAULT;
			sr->len = iomsg->fast_iov[0].iov_len;
			iomsg->free_iov = NULL;
		}

		if (req->flags & REQ_F_APOLL_MULTISHOT) {
			iomsg->namelen = msg.msg_namelen;
			iomsg->controllen = msg.msg_controllen;
			if (io_recvmsg_multishot_overflow(iomsg))
				return -EOVERFLOW;
		}
	} else {
		iomsg->free_iov = iomsg->fast_iov;
		ret = __import_iovec(ITER_DEST, msg.msg_iov, msg.msg_iovlen, UIO_FASTIOV,
				     &iomsg->free_iov, &iomsg->msg.msg_iter,
				     false);
		if (ret > 0)
			ret = 0;
	}

	return ret;
}

#ifdef CONFIG_COMPAT
static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
					struct io_async_msghdr *iomsg)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct compat_msghdr msg;
	struct compat_iovec __user *uiov;
	int ret;

	if (copy_from_user(&msg, sr->umsg_compat, sizeof(msg)))
		return -EFAULT;

	ret = __get_compat_msghdr(&iomsg->msg, &msg, &iomsg->uaddr);
	if (ret)
		return ret;

	uiov = compat_ptr(msg.msg_iov);
	if (req->flags & REQ_F_BUFFER_SELECT) {
		compat_ssize_t clen;

		iomsg->free_iov = NULL;
		if (msg.msg_iovlen == 0) {
			sr->len = 0;
		} else if (msg.msg_iovlen > 1) {
			return -EINVAL;
		} else {
			if (!access_ok(uiov, sizeof(*uiov)))
				return -EFAULT;
			if (__get_user(clen, &uiov->iov_len))
				return -EFAULT;
			if (clen < 0)
				return -EINVAL;
			sr->len = clen;
		}

		if (req->flags & REQ_F_APOLL_MULTISHOT) {
			iomsg->namelen = msg.msg_namelen;
			iomsg->controllen = msg.msg_controllen;
			if (io_recvmsg_multishot_overflow(iomsg))
				return -EOVERFLOW;
		}
	} else {
		iomsg->free_iov = iomsg->fast_iov;
		ret = __import_iovec(ITER_DEST, (struct iovec __user *)uiov, msg.msg_iovlen,
				   UIO_FASTIOV, &iomsg->free_iov,
				   &iomsg->msg.msg_iter, true);
		if (ret < 0)
			return ret;
	}

	return 0;
}
#endif

static int io_recvmsg_copy_hdr(struct io_kiocb *req,
			       struct io_async_msghdr *iomsg)
{
	iomsg->msg.msg_name = &iomsg->addr;

#ifdef CONFIG_COMPAT
	if (req->ctx->compat)
		return __io_compat_recvmsg_copy_hdr(req, iomsg);
#endif

	return __io_recvmsg_copy_hdr(req, iomsg);
}

int io_recvmsg_prep_async(struct io_kiocb *req)
{
	int ret;

	if (!io_msg_alloc_async_prep(req))
		return -ENOMEM;
	ret = io_recvmsg_copy_hdr(req, req->async_data);
	if (!ret)
		req->flags |= REQ_F_NEED_CLEANUP;
	return ret;
}

#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT)

int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	if (unlikely(sqe->file_index || sqe->addr2))
		return -EINVAL;

	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
	sr->len = READ_ONCE(sqe->len);
	sr->flags = READ_ONCE(sqe->ioprio);
	if (sr->flags & ~(RECVMSG_FLAGS))
		return -EINVAL;
	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
	if (sr->msg_flags & MSG_DONTWAIT)
		req->flags |= REQ_F_NOWAIT;
	if (sr->msg_flags & MSG_ERRQUEUE)
		req->flags |= REQ_F_CLEAR_POLLIN;
	if (sr->flags & IORING_RECV_MULTISHOT) {
		if (!(req->flags & REQ_F_BUFFER_SELECT))
			return -EINVAL;
		if (sr->msg_flags & MSG_WAITALL)
			return -EINVAL;
		if (req->opcode == IORING_OP_RECV && sr->len)
			return -EINVAL;
		req->flags |= REQ_F_APOLL_MULTISHOT;
		/*
		 * Store the buffer group for this multishot receive separately,
		 * as if we end up doing an io-wq based issue that selects a
		 * buffer, it has to be committed immediately and that will
		 * clear ->buf_list. This means we lose the link to the buffer
		 * list, and the eventual buffer put on completion then cannot
		 * restore it.
		 */
		sr->buf_group = req->buf_index;
	}

#ifdef CONFIG_COMPAT
	if (req->ctx->compat)
		sr->msg_flags |= MSG_CMSG_COMPAT;
#endif
	sr->done_io = 0;
	return 0;
}

static inline void io_recv_prep_retry(struct io_kiocb *req)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	sr->done_io = 0;
	sr->len = 0; /* get from the provided buffer */
	req->buf_index = sr->buf_group;
}

/*
 * Finishes io_recv and io_recvmsg.
 *
 * Returns true if it is actually finished, or false if it should run
 * again (for multishot).
 */
static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
				  unsigned int cflags, bool mshot_finished,
				  unsigned issue_flags)
{
	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
		io_req_set_res(req, *ret, cflags);
		*ret = IOU_OK;
		return true;
	}

	if (!mshot_finished) {
		if (io_aux_cqe(req->ctx, issue_flags & IO_URING_F_COMPLETE_DEFER,
			       req->cqe.user_data, *ret, cflags | IORING_CQE_F_MORE, true)) {
			io_recv_prep_retry(req);
			return false;
		}
		/* Otherwise stop multishot but use the current result. */
	}

	io_req_set_res(req, *ret, cflags);

	if (issue_flags & IO_URING_F_MULTISHOT)
		*ret = IOU_STOP_MULTISHOT;
	else
		*ret = IOU_OK;
	return true;
}

static int io_recvmsg_prep_multishot(struct io_async_msghdr *kmsg,
				     struct io_sr_msg *sr, void __user **buf,
				     size_t *len)
{
	unsigned long ubuf = (unsigned long) *buf;
	unsigned long hdr;

	hdr = sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
		kmsg->controllen;
	if (*len < hdr)
		return -EFAULT;

	if (kmsg->controllen) {
		unsigned long control = ubuf + hdr - kmsg->controllen;

		kmsg->msg.msg_control_user = (void __user *) control;
		kmsg->msg.msg_controllen = kmsg->controllen;
	}

	sr->buf = *buf; /* stash for later copy */
	*buf = (void __user *) (ubuf + hdr);
	kmsg->payloadlen = *len = *len - hdr;
	return 0;
}

struct io_recvmsg_multishot_hdr {
	struct io_uring_recvmsg_out msg;
	struct sockaddr_storage addr;
};

static int io_recvmsg_multishot(struct socket *sock, struct io_sr_msg *io,
				struct io_async_msghdr *kmsg,
				unsigned int flags, bool *finished)
{
	int err;
	int copy_len;
	struct io_recvmsg_multishot_hdr hdr;

	if (kmsg->namelen)
		kmsg->msg.msg_name = &hdr.addr;
	kmsg->msg.msg_flags = flags & (MSG_CMSG_CLOEXEC|MSG_CMSG_COMPAT);
	kmsg->msg.msg_namelen = 0;

	if (sock->file->f_flags & O_NONBLOCK)
		flags |= MSG_DONTWAIT;

	err = sock_recvmsg(sock, &kmsg->msg, flags);
	*finished = err <= 0;
	if (err < 0)
		return err;

	hdr.msg = (struct io_uring_recvmsg_out) {
		.controllen = kmsg->controllen - kmsg->msg.msg_controllen,
		.flags = kmsg->msg.msg_flags & ~MSG_CMSG_COMPAT
	};

	hdr.msg.payloadlen = err;
	if (err > kmsg->payloadlen)
		err = kmsg->payloadlen;

	copy_len = sizeof(struct io_uring_recvmsg_out);
	if (kmsg->msg.msg_namelen > kmsg->namelen)
		copy_len += kmsg->namelen;
	else
		copy_len += kmsg->msg.msg_namelen;

	/*
	 *      "fromlen shall refer to the value before truncation.."
	 *                      1003.1g
	 */
	hdr.msg.namelen = kmsg->msg.msg_namelen;

	/* ensure that there is no gap between hdr and sockaddr_storage */
	BUILD_BUG_ON(offsetof(struct io_recvmsg_multishot_hdr, addr) !=
		     sizeof(struct io_uring_recvmsg_out));
	if (copy_to_user(io->buf, &hdr, copy_len)) {
		*finished = true;
		return -EFAULT;
	}

	return sizeof(struct io_uring_recvmsg_out) + kmsg->namelen +
			kmsg->controllen + err;
}

int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr iomsg, *kmsg;
	struct socket *sock;
	unsigned int cflags;
	unsigned flags;
	int ret, min_ret = 0;
	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
	bool mshot_finished = true;

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;

	if (req_has_async_data(req)) {
		kmsg = req->async_data;
	} else {
		ret = io_recvmsg_copy_hdr(req, &iomsg);
		if (ret)
			return ret;
		kmsg = &iomsg;
	}

	if (!(req->flags & REQ_F_POLLED) &&
	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
		return io_setup_async_msg(req, kmsg, issue_flags);

	if (!io_check_multishot(req, issue_flags))
		return io_setup_async_msg(req, kmsg, issue_flags);

retry_multishot:
	if (io_do_buffer_select(req)) {
		void __user *buf;
		size_t len = sr->len;

		buf = io_buffer_select(req, &len, issue_flags);
		if (!buf)
			return -ENOBUFS;

		if (req->flags & REQ_F_APOLL_MULTISHOT) {
			ret = io_recvmsg_prep_multishot(kmsg, sr, &buf, &len);
			if (ret) {
				io_kbuf_recycle(req, issue_flags);
				return ret;
			}
		}

		kmsg->fast_iov[0].iov_base = buf;
		kmsg->fast_iov[0].iov_len = len;
		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, kmsg->fast_iov, 1,
				len);
	}

	flags = sr->msg_flags;
	if (force_nonblock)
		flags |= MSG_DONTWAIT;
	if (flags & MSG_WAITALL)
		min_ret = iov_iter_count(&kmsg->msg.msg_iter);

	kmsg->msg.msg_get_inq = 1;
	if (req->flags & REQ_F_APOLL_MULTISHOT)
		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
					   &mshot_finished);
	else
		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
					 kmsg->uaddr, flags);

	if (ret < min_ret) {
		if (ret == -EAGAIN && force_nonblock) {
			ret = io_setup_async_msg(req, kmsg, issue_flags);
			if (ret == -EAGAIN && (issue_flags & IO_URING_F_MULTISHOT)) {
				io_kbuf_recycle(req, issue_flags);
				return IOU_ISSUE_SKIP_COMPLETE;
			}
			return ret;
		}
		if (ret > 0 && io_net_retry(sock, flags)) {
			sr->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return io_setup_async_msg(req, kmsg, issue_flags);
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
		req_set_fail(req);
	}

	if (ret > 0)
		ret += sr->done_io;
	else if (sr->done_io)
		ret = sr->done_io;
	else
		io_kbuf_recycle(req, issue_flags);

	cflags = io_put_kbuf(req, issue_flags);
	if (kmsg->msg.msg_inq)
		cflags |= IORING_CQE_F_SOCK_NONEMPTY;

	if (!io_recv_finish(req, &ret, cflags, mshot_finished, issue_flags))
		goto retry_multishot;

	if (mshot_finished) {
		/* fast path, check for non-NULL to avoid function call */
		if (kmsg->free_iov)
			kfree(kmsg->free_iov);
		io_netmsg_recycle(req, issue_flags);
		req->flags &= ~REQ_F_NEED_CLEANUP;
	}

	return ret;
}

int io_recv(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct msghdr msg;
	struct socket *sock;
	struct iovec iov;
	unsigned int cflags;
	unsigned flags;
	int ret, min_ret = 0;
	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
	size_t len = sr->len;

	if (!(req->flags & REQ_F_POLLED) &&
	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
		return -EAGAIN;

	if (!io_check_multishot(req, issue_flags))
		return -EAGAIN;

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;

retry_multishot:
	if (io_do_buffer_select(req)) {
		void __user *buf;

		buf = io_buffer_select(req, &len, issue_flags);
		if (!buf)
			return -ENOBUFS;
		sr->buf = buf;
	}

	ret = import_single_range(ITER_DEST, sr->buf, len, &iov, &msg.msg_iter);
	if (unlikely(ret))
		goto out_free;

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = NULL;
	msg.msg_get_inq = 1;
	msg.msg_flags = 0;
	msg.msg_controllen = 0;
	msg.msg_iocb = NULL;
	msg.msg_ubuf = NULL;

	flags = sr->msg_flags;
	if (force_nonblock)
		flags |= MSG_DONTWAIT;
	if (flags & MSG_WAITALL)
		min_ret = iov_iter_count(&msg.msg_iter);

	ret = sock_recvmsg(sock, &msg, flags);
	if (ret < min_ret) {
		if (ret == -EAGAIN && force_nonblock) {
			if (issue_flags & IO_URING_F_MULTISHOT) {
				io_kbuf_recycle(req, issue_flags);
				return IOU_ISSUE_SKIP_COMPLETE;
			}

			return -EAGAIN;
		}
		if (ret > 0 && io_net_retry(sock, flags)) {
			sr->len -= ret;
			sr->buf += ret;
			sr->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return -EAGAIN;
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if ((flags & MSG_WAITALL) && (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
out_free:
		req_set_fail(req);
	}

	if (ret > 0)
		ret += sr->done_io;
	else if (sr->done_io)
		ret = sr->done_io;
	else
		io_kbuf_recycle(req, issue_flags);

	cflags = io_put_kbuf(req, issue_flags);
	if (msg.msg_inq)
		cflags |= IORING_CQE_F_SOCK_NONEMPTY;

	if (!io_recv_finish(req, &ret, cflags, ret <= 0, issue_flags))
		goto retry_multishot;

	return ret;
}

void io_send_zc_cleanup(struct io_kiocb *req)
{
	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr *io;

	if (req_has_async_data(req)) {
		io = req->async_data;
		/* might be ->fast_iov if *msg_copy_hdr failed */
		if (io->free_iov != io->fast_iov)
			kfree(io->free_iov);
	}
	if (zc->notif) {
		io_notif_flush(zc->notif);
		zc->notif = NULL;
	}
}

#define IO_ZC_FLAGS_COMMON (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_FIXED_BUF)
#define IO_ZC_FLAGS_VALID  (IO_ZC_FLAGS_COMMON | IORING_SEND_ZC_REPORT_USAGE)

int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_ring_ctx *ctx = req->ctx;
	struct io_kiocb *notif;

	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
		return -EINVAL;
	/* we don't support IOSQE_CQE_SKIP_SUCCESS just yet */
	if (req->flags & REQ_F_CQE_SKIP)
		return -EINVAL;

	notif = zc->notif = io_alloc_notif(ctx);
	if (!notif)
		return -ENOMEM;
	notif->cqe.user_data = req->cqe.user_data;
	notif->cqe.res = 0;
	notif->cqe.flags = IORING_CQE_F_NOTIF;
	req->flags |= REQ_F_NEED_CLEANUP;

	zc->flags = READ_ONCE(sqe->ioprio);
	if (unlikely(zc->flags & ~IO_ZC_FLAGS_COMMON)) {
		if (zc->flags & ~IO_ZC_FLAGS_VALID)
			return -EINVAL;
		if (zc->flags & IORING_SEND_ZC_REPORT_USAGE) {
			io_notif_set_extended(notif);
			io_notif_to_data(notif)->zc_report = true;
		}
	}

	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
		unsigned idx = READ_ONCE(sqe->buf_index);

		if (unlikely(idx >= ctx->nr_user_bufs))
			return -EFAULT;
		idx = array_index_nospec(idx, ctx->nr_user_bufs);
		req->imu = READ_ONCE(ctx->user_bufs[idx]);
		io_req_set_rsrc_node(notif, ctx, 0);
	}

	if (req->opcode == IORING_OP_SEND_ZC) {
		if (READ_ONCE(sqe->__pad3[0]))
			return -EINVAL;
		zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
		zc->addr_len = READ_ONCE(sqe->addr_len);
	} else {
		if (unlikely(sqe->addr2 || sqe->file_index))
			return -EINVAL;
		if (unlikely(zc->flags & IORING_RECVSEND_FIXED_BUF))
			return -EINVAL;
	}

	zc->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
	zc->len = READ_ONCE(sqe->len);
	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
	if (zc->msg_flags & MSG_DONTWAIT)
		req->flags |= REQ_F_NOWAIT;

	zc->done_io = 0;

#ifdef CONFIG_COMPAT
	if (req->ctx->compat)
		zc->msg_flags |= MSG_CMSG_COMPAT;
#endif
	return 0;
}

static int io_sg_from_iter_iovec(struct sock *sk, struct sk_buff *skb,
				 struct iov_iter *from, size_t length)
{
	skb_zcopy_downgrade_managed(skb);
	return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);
}

static int io_sg_from_iter(struct sock *sk, struct sk_buff *skb,
			   struct iov_iter *from, size_t length)
{
	struct skb_shared_info *shinfo = skb_shinfo(skb);
	int frag = shinfo->nr_frags;
	int ret = 0;
	struct bvec_iter bi;
	ssize_t copied = 0;
	unsigned long truesize = 0;

	if (!frag)
		shinfo->flags |= SKBFL_MANAGED_FRAG_REFS;
	else if (unlikely(!skb_zcopy_managed(skb)))
		return __zerocopy_sg_from_iter(NULL, sk, skb, from, length);

	bi.bi_size = min(from->count, length);
	bi.bi_bvec_done = from->iov_offset;
	bi.bi_idx = 0;

	while (bi.bi_size && frag < MAX_SKB_FRAGS) {
		struct bio_vec v = mp_bvec_iter_bvec(from->bvec, bi);

		copied += v.bv_len;
		truesize += PAGE_ALIGN(v.bv_len + v.bv_offset);
		__skb_fill_page_desc_noacc(shinfo, frag++, v.bv_page,
					   v.bv_offset, v.bv_len);
		bvec_iter_advance_single(from->bvec, &bi, v.bv_len);
	}
	if (bi.bi_size)
		ret = -EMSGSIZE;

	shinfo->nr_frags = frag;
	from->bvec += bi.bi_idx;
	from->nr_segs -= bi.bi_idx;
	from->count -= copied;
	from->iov_offset = bi.bi_bvec_done;

	skb->data_len += copied;
	skb->len += copied;
	skb->truesize += truesize;

	if (sk && sk->sk_type == SOCK_STREAM) {
		sk_wmem_queued_add(sk, truesize);
		if (!skb_zcopy_pure(skb))
			sk_mem_charge(sk, truesize);
	} else {
		refcount_add(truesize, &skb->sk->sk_wmem_alloc);
	}
	return ret;
}

int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
{
	struct sockaddr_storage __address;
	struct io_sr_msg *zc = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct msghdr msg;
	struct iovec iov;
	struct socket *sock;
	unsigned msg_flags;
	int ret, min_ret = 0;

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;
	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
		return -EOPNOTSUPP;

	msg.msg_name = NULL;
	msg.msg_control = NULL;
	msg.msg_controllen = 0;
	msg.msg_namelen = 0;

	if (zc->addr) {
		if (req_has_async_data(req)) {
			struct io_async_msghdr *io = req->async_data;

			msg.msg_name = &io->addr;
		} else {
			ret = move_addr_to_kernel(zc->addr, zc->addr_len, &__address);
			if (unlikely(ret < 0))
				return ret;
			msg.msg_name = (struct sockaddr *)&__address;
		}
		msg.msg_namelen = zc->addr_len;
	}

	if (!(req->flags & REQ_F_POLLED) &&
	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
		return io_setup_async_addr(req, &__address, issue_flags);

	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
		ret = io_import_fixed(ITER_SOURCE, &msg.msg_iter, req->imu,
					(u64)(uintptr_t)zc->buf, zc->len);
		if (unlikely(ret))
			return ret;
		msg.sg_from_iter = io_sg_from_iter;
	} else {
		io_notif_set_extended(zc->notif);
		ret = import_single_range(ITER_SOURCE, zc->buf, zc->len, &iov,
					  &msg.msg_iter);
		if (unlikely(ret))
			return ret;
		ret = io_notif_account_mem(zc->notif, zc->len);
		if (unlikely(ret))
			return ret;
		msg.sg_from_iter = io_sg_from_iter_iovec;
	}

	msg_flags = zc->msg_flags | MSG_ZEROCOPY;
	if (issue_flags & IO_URING_F_NONBLOCK)
		msg_flags |= MSG_DONTWAIT;
	if (msg_flags & MSG_WAITALL)
		min_ret = iov_iter_count(&msg.msg_iter);

	msg.msg_flags = msg_flags;
	msg.msg_ubuf = &io_notif_to_data(zc->notif)->uarg;
	ret = sock_sendmsg(sock, &msg);

	if (unlikely(ret < min_ret)) {
		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
			return io_setup_async_addr(req, &__address, issue_flags);

		if (ret > 0 && io_net_retry(sock, msg.msg_flags)) {
			zc->len -= ret;
			zc->buf += ret;
			zc->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return io_setup_async_addr(req, &__address, issue_flags);
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	}

	if (ret >= 0)
		ret += zc->done_io;
	else if (zc->done_io)
		ret = zc->done_io;

	/*
	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
	 * flushing notif to io_send_zc_cleanup()
	 */
	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
		io_notif_flush(zc->notif);
		req->flags &= ~REQ_F_NEED_CLEANUP;
	}
	io_req_set_res(req, ret, IORING_CQE_F_MORE);
	return IOU_OK;
}

int io_sendmsg_zc(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
	struct io_async_msghdr iomsg, *kmsg;
	struct socket *sock;
	unsigned flags;
	int ret, min_ret = 0;

	io_notif_set_extended(sr->notif);

	sock = sock_from_file(req->file);
	if (unlikely(!sock))
		return -ENOTSOCK;
	if (!test_bit(SOCK_SUPPORT_ZC, &sock->flags))
		return -EOPNOTSUPP;

	if (req_has_async_data(req)) {
		kmsg = req->async_data;
	} else {
		ret = io_sendmsg_copy_hdr(req, &iomsg);
		if (ret)
			return ret;
		kmsg = &iomsg;
	}

	if (!(req->flags & REQ_F_POLLED) &&
	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
		return io_setup_async_msg(req, kmsg, issue_flags);

	flags = sr->msg_flags | MSG_ZEROCOPY;
	if (issue_flags & IO_URING_F_NONBLOCK)
		flags |= MSG_DONTWAIT;
	if (flags & MSG_WAITALL)
		min_ret = iov_iter_count(&kmsg->msg.msg_iter);

	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
	kmsg->msg.sg_from_iter = io_sg_from_iter_iovec;
	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);

	if (unlikely(ret < min_ret)) {
		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
			return io_setup_async_msg(req, kmsg, issue_flags);

		if (ret > 0 && io_net_retry(sock, flags)) {
			sr->done_io += ret;
			req->flags |= REQ_F_PARTIAL_IO;
			return io_setup_async_msg(req, kmsg, issue_flags);
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	}
	/* fast path, check for non-NULL to avoid function call */
	if (kmsg->free_iov) {
		kfree(kmsg->free_iov);
		kmsg->free_iov = NULL;
	}

	io_netmsg_recycle(req, issue_flags);
	if (ret >= 0)
		ret += sr->done_io;
	else if (sr->done_io)
		ret = sr->done_io;

	/*
	 * If we're in io-wq we can't rely on tw ordering guarantees, defer
	 * flushing notif to io_send_zc_cleanup()
	 */
	if (!(issue_flags & IO_URING_F_UNLOCKED)) {
		io_notif_flush(sr->notif);
		req->flags &= ~REQ_F_NEED_CLEANUP;
	}
	io_req_set_res(req, ret, IORING_CQE_F_MORE);
	return IOU_OK;
}

void io_sendrecv_fail(struct io_kiocb *req)
{
	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);

	if (req->flags & REQ_F_PARTIAL_IO)
		req->cqe.res = sr->done_io;

	if ((req->flags & REQ_F_NEED_CLEANUP) &&
	    (req->opcode == IORING_OP_SEND_ZC || req->opcode == IORING_OP_SENDMSG_ZC))
		req->cqe.flags |= IORING_CQE_F_MORE;
}

int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
	unsigned flags;

	if (sqe->len || sqe->buf_index)
		return -EINVAL;

	accept->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
	accept->addr_len = u64_to_user_ptr(READ_ONCE(sqe->addr2));
	accept->flags = READ_ONCE(sqe->accept_flags);
	accept->nofile = rlimit(RLIMIT_NOFILE);
	flags = READ_ONCE(sqe->ioprio);
	if (flags & ~IORING_ACCEPT_MULTISHOT)
		return -EINVAL;

	accept->file_slot = READ_ONCE(sqe->file_index);
	if (accept->file_slot) {
		if (accept->flags & SOCK_CLOEXEC)
			return -EINVAL;
		if (flags & IORING_ACCEPT_MULTISHOT &&
		    accept->file_slot != IORING_FILE_INDEX_ALLOC)
			return -EINVAL;
	}
	if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
		return -EINVAL;
	if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
		accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
	if (flags & IORING_ACCEPT_MULTISHOT)
		req->flags |= REQ_F_APOLL_MULTISHOT;
	return 0;
}

int io_accept(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_ring_ctx *ctx = req->ctx;
	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
	unsigned int file_flags = force_nonblock ? O_NONBLOCK : 0;
	bool fixed = !!accept->file_slot;
	struct file *file;
	int ret, fd;

	if (!io_check_multishot(req, issue_flags))
		return -EAGAIN;
retry:
	if (!fixed) {
		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
		if (unlikely(fd < 0))
			return fd;
	}
	file = do_accept(req->file, file_flags, accept->addr, accept->addr_len,
			 accept->flags);
	if (IS_ERR(file)) {
		if (!fixed)
			put_unused_fd(fd);
		ret = PTR_ERR(file);
		if (ret == -EAGAIN && force_nonblock) {
			/*
			 * if it's multishot and polled, we don't need to
			 * return EAGAIN to arm the poll infra since it
			 * has already been done
			 */
			if (issue_flags & IO_URING_F_MULTISHOT)
				ret = IOU_ISSUE_SKIP_COMPLETE;
			return ret;
		}
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if (!fixed) {
		fd_install(fd, file);
		ret = fd;
	} else {
		ret = io_fixed_fd_install(req, issue_flags, file,
						accept->file_slot);
	}

	if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
		io_req_set_res(req, ret, 0);
		return IOU_OK;
	}

	if (ret < 0)
		return ret;
	if (io_aux_cqe(ctx, issue_flags & IO_URING_F_COMPLETE_DEFER,
		       req->cqe.user_data, ret, IORING_CQE_F_MORE, true))
		goto retry;

	return -ECANCELED;
}

int io_socket_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);

	if (sqe->addr || sqe->rw_flags || sqe->buf_index)
		return -EINVAL;

	sock->domain = READ_ONCE(sqe->fd);
	sock->type = READ_ONCE(sqe->off);
	sock->protocol = READ_ONCE(sqe->len);
	sock->file_slot = READ_ONCE(sqe->file_index);
	sock->nofile = rlimit(RLIMIT_NOFILE);

	sock->flags = sock->type & ~SOCK_TYPE_MASK;
	if (sock->file_slot && (sock->flags & SOCK_CLOEXEC))
		return -EINVAL;
	if (sock->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
		return -EINVAL;
	return 0;
}

int io_socket(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
	bool fixed = !!sock->file_slot;
	struct file *file;
	int ret, fd;

	if (!fixed) {
		fd = __get_unused_fd_flags(sock->flags, sock->nofile);
		if (unlikely(fd < 0))
			return fd;
	}
	file = __sys_socket_file(sock->domain, sock->type, sock->protocol);
	if (IS_ERR(file)) {
		if (!fixed)
			put_unused_fd(fd);
		ret = PTR_ERR(file);
		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
			return -EAGAIN;
		if (ret == -ERESTARTSYS)
			ret = -EINTR;
		req_set_fail(req);
	} else if (!fixed) {
		fd_install(fd, file);
		ret = fd;
	} else {
		ret = io_fixed_fd_install(req, issue_flags, file,
					    sock->file_slot);
	}
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

int io_connect_prep_async(struct io_kiocb *req)
{
	struct io_async_connect *io = req->async_data;
	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);

	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->address);
}

int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);

	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
		return -EINVAL;

	conn->addr = u64_to_user_ptr(READ_ONCE(sqe->addr));
	conn->addr_len =  READ_ONCE(sqe->addr2);
	conn->in_progress = false;
	return 0;
}

int io_connect(struct io_kiocb *req, unsigned int issue_flags)
{
	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
	struct io_async_connect __io, *io;
	unsigned file_flags;
	int ret;
	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;

	if (connect->in_progress) {
		struct socket *socket;

		ret = -ENOTSOCK;
		socket = sock_from_file(req->file);
		if (socket)
			ret = sock_error(socket->sk);
		goto out;
	}

	if (req_has_async_data(req)) {
		io = req->async_data;
	} else {
		ret = move_addr_to_kernel(connect->addr,
						connect->addr_len,
						&__io.address);
		if (ret)
			goto out;
		io = &__io;
	}

	file_flags = force_nonblock ? O_NONBLOCK : 0;

	ret = __sys_connect_file(req->file, &io->address,
					connect->addr_len, file_flags);
	if ((ret == -EAGAIN || ret == -EINPROGRESS) && force_nonblock) {
		if (ret == -EINPROGRESS) {
			connect->in_progress = true;
		} else {
			if (req_has_async_data(req))
				return -EAGAIN;
			if (io_alloc_async_data(req)) {
				ret = -ENOMEM;
				goto out;
			}
			memcpy(req->async_data, &__io, sizeof(__io));
		}
		return -EAGAIN;
	}
	if (ret == -ERESTARTSYS)
		ret = -EINTR;
out:
	if (ret < 0)
		req_set_fail(req);
	io_req_set_res(req, ret, 0);
	return IOU_OK;
}

void io_netmsg_cache_free(struct io_cache_entry *entry)
{
	kfree(container_of(entry, struct io_async_msghdr, cache));
}
#endif
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