Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 1974 insertions, 0 deletions

diff --git a/io_uring/net.c b/io_uring/net.c
new file mode 100644
index 000000000..050ed2741
--- /dev/null
+++ b/io_uring/net.c
@@ -0,0 +1,1974 @@
+// 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/un.h>
+#include <linux/compat.h>
+#include <net/compat.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "filetable.h"
+#include "io_uring.h"
+#include "kbuf.h"
+#include "alloc_cache.h"
+#include "net.h"
+#include "notif.h"
+#include "rsrc.h"
+#include "zcrx.h"
+
+struct io_shutdown {
+	struct file			*file;
+	int				how;
+};
+
+struct io_accept {
+	struct file			*file;
+	struct sockaddr __user		*addr;
+	int __user			*addr_len;
+	int				flags;
+	int				iou_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;
+	bool				seen_econnaborted;
+};
+
+struct io_bind {
+	struct file			*file;
+	int				addr_len;
+};
+
+struct io_listen {
+	struct file			*file;
+	int				backlog;
+};
+
+struct io_sr_msg {
+	struct file			*file;
+	union {
+		struct compat_msghdr __user	*umsg_compat;
+		struct user_msghdr __user	*umsg;
+		void __user			*buf;
+	};
+	int				len;
+	unsigned			done_io;
+	unsigned			msg_flags;
+	unsigned			nr_multishot_loops;
+	u16				flags;
+	/* initialised and used only by !msg send variants */
+	u16				buf_group;
+	/* per-invocation mshot limit */
+	unsigned			mshot_len;
+	/* overall mshot byte limit */
+	unsigned			mshot_total_len;
+	void __user			*msg_control;
+	/* used only for send zerocopy */
+	struct io_kiocb 		*notif;
+};
+
+/*
+ * The UAPI flags are the lower 8 bits, as that's all sqe->ioprio will hold
+ * anyway. Use the upper 8 bits for internal uses.
+ */
+enum sr_retry_flags {
+	IORING_RECV_RETRY	= (1U << 15),
+	IORING_RECV_PARTIAL_MAP	= (1U << 14),
+	IORING_RECV_MSHOT_CAP	= (1U << 13),
+	IORING_RECV_MSHOT_LIM	= (1U << 12),
+	IORING_RECV_MSHOT_DONE	= (1U << 11),
+
+	IORING_RECV_RETRY_CLEAR	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
+	IORING_RECV_NO_RETRY	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP |
+				  IORING_RECV_MSHOT_CAP | IORING_RECV_MSHOT_DONE,
+};
+
+/*
+ * Number of times we'll try and do receives if there's more data. If we
+ * exceed this limit, then add us to the back of the queue and retry from
+ * there. This helps fairness between flooding clients.
+ */
+#define MULTISHOT_MAX_RETRY	32
+
+struct io_recvzc {
+	struct file			*file;
+	u16				flags;
+	u32				len;
+	struct io_zcrx_ifq		*ifq;
+};
+
+static int io_sg_from_iter_iovec(struct sk_buff *skb,
+				 struct iov_iter *from, size_t length);
+static int io_sg_from_iter(struct sk_buff *skb,
+			   struct iov_iter *from, size_t length);
+
+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);
+	req->flags |= REQ_F_FORCE_ASYNC;
+	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;
+
+	WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
+
+	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_COMPLETE;
+}
+
+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_iovec_free(struct io_async_msghdr *kmsg)
+{
+	if (kmsg->vec.iovec)
+		io_vec_free(&kmsg->vec);
+}
+
+static void io_netmsg_recycle(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_async_msghdr *hdr = req->async_data;
+
+	/* can't recycle, ensure we free the iovec if we have one */
+	if (unlikely(issue_flags & IO_URING_F_UNLOCKED)) {
+		io_netmsg_iovec_free(hdr);
+		return;
+	}
+
+	/* Let normal cleanup path reap it if we fail adding to the cache */
+	io_alloc_cache_vec_kasan(&hdr->vec);
+	if (hdr->vec.nr > IO_VEC_CACHE_SOFT_CAP)
+		io_vec_free(&hdr->vec);
+
+	if (io_alloc_cache_put(&req->ctx->netmsg_cache, hdr))
+		io_req_async_data_clear(req, REQ_F_NEED_CLEANUP);
+}
+
+static struct io_async_msghdr *io_msg_alloc_async(struct io_kiocb *req)
+{
+	struct io_ring_ctx *ctx = req->ctx;
+	struct io_async_msghdr *hdr;
+
+	hdr = io_uring_alloc_async_data(&ctx->netmsg_cache, req);
+	if (!hdr)
+		return NULL;
+
+	/* If the async data was cached, we might have an iov cached inside. */
+	if (hdr->vec.iovec)
+		req->flags |= REQ_F_NEED_CLEANUP;
+	return hdr;
+}
+
+static inline void io_mshot_prep_retry(struct io_kiocb *req,
+				       struct io_async_msghdr *kmsg)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+
+	req->flags &= ~REQ_F_BL_EMPTY;
+	sr->done_io = 0;
+	sr->flags &= ~IORING_RECV_RETRY_CLEAR;
+	sr->len = sr->mshot_len;
+}
+
+static int io_net_import_vec(struct io_kiocb *req, struct io_async_msghdr *iomsg,
+			     const struct iovec __user *uiov, unsigned uvec_seg,
+			     int ddir)
+{
+	struct iovec *iov;
+	int ret, nr_segs;
+
+	if (iomsg->vec.iovec) {
+		nr_segs = iomsg->vec.nr;
+		iov = iomsg->vec.iovec;
+	} else {
+		nr_segs = 1;
+		iov = &iomsg->fast_iov;
+	}
+
+	ret = __import_iovec(ddir, uiov, uvec_seg, nr_segs, &iov,
+			     &iomsg->msg.msg_iter, io_is_compat(req->ctx));
+	if (unlikely(ret < 0))
+		return ret;
+
+	if (iov) {
+		req->flags |= REQ_F_NEED_CLEANUP;
+		io_vec_reset_iovec(&iomsg->vec, iov, iomsg->msg.msg_iter.nr_segs);
+	}
+	return 0;
+}
+
+static int io_copy_msghdr_from_user(struct user_msghdr *msg,
+				    struct user_msghdr __user *umsg)
+{
+	if (!user_access_begin(umsg, sizeof(*umsg)))
+		return -EFAULT;
+	unsafe_get_user(msg->msg_name, &umsg->msg_name, ua_end);
+	unsafe_get_user(msg->msg_namelen, &umsg->msg_namelen, ua_end);
+	unsafe_get_user(msg->msg_iov, &umsg->msg_iov, ua_end);
+	unsafe_get_user(msg->msg_iovlen, &umsg->msg_iovlen, ua_end);
+	unsafe_get_user(msg->msg_control, &umsg->msg_control, ua_end);
+	unsafe_get_user(msg->msg_controllen, &umsg->msg_controllen, ua_end);
+	user_access_end();
+	return 0;
+ua_end:
+	user_access_end();
+	return -EFAULT;
+}
+
+static int io_msg_copy_hdr(struct io_kiocb *req, struct io_async_msghdr *iomsg,
+			   struct user_msghdr *msg,
+			   struct sockaddr __user **save_addr)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	int ret;
+
+	iomsg->msg.msg_name = &iomsg->addr;
+	iomsg->msg.msg_iter.nr_segs = 0;
+
+	if (io_is_compat(req->ctx)) {
+		struct compat_msghdr cmsg;
+
+		if (copy_from_user(&cmsg, sr->umsg_compat, sizeof(cmsg)))
+			return -EFAULT;
+
+		ret = __get_compat_msghdr(&iomsg->msg, &cmsg, save_addr);
+		if (ret)
+			return ret;
+
+		memset(msg, 0, sizeof(*msg));
+		msg->msg_namelen = cmsg.msg_namelen;
+		msg->msg_controllen = cmsg.msg_controllen;
+		msg->msg_iov = compat_ptr(cmsg.msg_iov);
+		msg->msg_iovlen = cmsg.msg_iovlen;
+	} else {
+		ret = io_copy_msghdr_from_user(msg, sr->umsg);
+		if (unlikely(ret))
+			return ret;
+
+		msg->msg_flags = 0;
+
+		ret = __copy_msghdr(&iomsg->msg, msg, save_addr);
+		if (ret)
+			return ret;
+	}
+
+	if (req->flags & REQ_F_BUFFER_SELECT) {
+		if (msg->msg_iovlen == 0) {
+			sr->len = 0;
+		} else if (msg->msg_iovlen > 1) {
+			return -EINVAL;
+		} else {
+			struct iovec fast_iov, *iov;
+
+			iov = iovec_from_user(msg->msg_iov, 1, 1, &fast_iov,
+					      io_is_compat(req->ctx));
+			if (IS_ERR(iov))
+				return PTR_ERR(iov);
+			sr->len = iov->iov_len;
+		}
+	}
+	return 0;
+}
+
+void io_sendmsg_recvmsg_cleanup(struct io_kiocb *req)
+{
+	struct io_async_msghdr *io = req->async_data;
+
+	io_netmsg_iovec_free(io);
+}
+
+static int io_send_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct io_async_msghdr *kmsg = req->async_data;
+	void __user *addr;
+	u16 addr_len;
+	int ret;
+
+	sr->buf = u64_to_user_ptr(READ_ONCE(sqe->addr));
+
+	if (READ_ONCE(sqe->__pad3[0]))
+		return -EINVAL;
+
+	kmsg->msg.msg_name = NULL;
+	kmsg->msg.msg_namelen = 0;
+	kmsg->msg.msg_control = NULL;
+	kmsg->msg.msg_controllen = 0;
+	kmsg->msg.msg_ubuf = NULL;
+
+	addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
+	addr_len = READ_ONCE(sqe->addr_len);
+	if (addr) {
+		ret = move_addr_to_kernel(addr, addr_len, &kmsg->addr);
+		if (unlikely(ret < 0))
+			return ret;
+		kmsg->msg.msg_name = &kmsg->addr;
+		kmsg->msg.msg_namelen = addr_len;
+	}
+	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+		if (!(sr->flags & IORING_SEND_VECTORIZED)) {
+			req->flags |= REQ_F_IMPORT_BUFFER;
+			return 0;
+		}
+
+		kmsg->msg.msg_iter.nr_segs = sr->len;
+		return io_prep_reg_iovec(req, &kmsg->vec, sr->buf, sr->len);
+	}
+	if (req->flags & REQ_F_BUFFER_SELECT)
+		return 0;
+
+	if (sr->flags & IORING_SEND_VECTORIZED)
+		return io_net_import_vec(req, kmsg, sr->buf, sr->len, ITER_SOURCE);
+
+	return import_ubuf(ITER_SOURCE, sr->buf, sr->len, &kmsg->msg.msg_iter);
+}
+
+static int io_sendmsg_setup(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct io_async_msghdr *kmsg = req->async_data;
+	struct user_msghdr msg;
+	int ret;
+
+	sr->flags |= IORING_SEND_VECTORIZED;
+	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	ret = io_msg_copy_hdr(req, kmsg, &msg, NULL);
+	if (unlikely(ret))
+		return ret;
+	/* save msg_control as sys_sendmsg() overwrites it */
+	sr->msg_control = kmsg->msg.msg_control_user;
+
+	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+		kmsg->msg.msg_iter.nr_segs = msg.msg_iovlen;
+		return io_prep_reg_iovec(req, &kmsg->vec, msg.msg_iov,
+					 msg.msg_iovlen);
+	}
+	if (req->flags & REQ_F_BUFFER_SELECT)
+		return 0;
+	return io_net_import_vec(req, kmsg, msg.msg_iov, msg.msg_iovlen, ITER_SOURCE);
+}
+
+#define SENDMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECVSEND_BUNDLE | \
+			IORING_SEND_VECTORIZED | IORING_RECVSEND_FIXED_BUF)
+
+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);
+
+	sr->done_io = 0;
+	sr->len = READ_ONCE(sqe->len);
+	if (unlikely(sr->len < 0))
+		return -EINVAL;
+	sr->flags = READ_ONCE(sqe->ioprio);
+	if (sr->flags & ~SENDMSG_FLAGS)
+		return -EINVAL;
+	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+		/* registered buffer send only supported for plain IORING_OP_SEND */
+		if (req->opcode != IORING_OP_SEND ||
+		    (req->flags & REQ_F_BUFFER_SELECT) ||
+		    (sr->flags & (IORING_RECVSEND_BUNDLE|IORING_SEND_VECTORIZED)))
+			return -EINVAL;
+		req->buf_index = READ_ONCE(sqe->buf_index);
+	}
+	sr->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL;
+	if (sr->msg_flags & MSG_DONTWAIT)
+		req->flags |= REQ_F_NOWAIT;
+	if (req->flags & REQ_F_BUFFER_SELECT)
+		sr->buf_group = req->buf_index;
+	sr->mshot_total_len = sr->mshot_len = 0;
+	if (sr->flags & IORING_RECVSEND_BUNDLE) {
+		if (req->opcode == IORING_OP_SENDMSG)
+			return -EINVAL;
+		sr->msg_flags |= MSG_WAITALL;
+		req->flags |= REQ_F_MULTISHOT;
+	}
+
+	if (io_is_compat(req->ctx))
+		sr->msg_flags |= MSG_CMSG_COMPAT;
+
+	if (unlikely(!io_msg_alloc_async(req)))
+		return -ENOMEM;
+	if (req->opcode != IORING_OP_SENDMSG)
+		return io_send_setup(req, sqe);
+	if (unlikely(sqe->addr2 || sqe->file_index))
+		return -EINVAL;
+	return io_sendmsg_setup(req, sqe);
+}
+
+static void io_req_msg_cleanup(struct io_kiocb *req,
+			       unsigned int issue_flags)
+{
+	io_netmsg_recycle(req, issue_flags);
+}
+
+/*
+ * For bundle completions, we need to figure out how many segments we consumed.
+ * A bundle could be using a single ITER_UBUF if that's all we mapped, or it
+ * could be using an ITER_IOVEC. If the latter, then if we consumed all of
+ * the segments, then it's a trivial questiont o answer. If we have residual
+ * data in the iter, then loop the segments to figure out how much we
+ * transferred.
+ */
+static int io_bundle_nbufs(struct io_async_msghdr *kmsg, int ret)
+{
+	struct iovec *iov;
+	int nbufs;
+
+	/* no data is always zero segments, and a ubuf is always 1 segment */
+	if (ret <= 0)
+		return 0;
+	if (iter_is_ubuf(&kmsg->msg.msg_iter))
+		return 1;
+
+	iov = kmsg->vec.iovec;
+	if (!iov)
+		iov = &kmsg->fast_iov;
+
+	/* if all data was transferred, it's basic pointer math */
+	if (!iov_iter_count(&kmsg->msg.msg_iter))
+		return iter_iov(&kmsg->msg.msg_iter) - iov;
+
+	/* short transfer, count segments */
+	nbufs = 0;
+	do {
+		int this_len = min_t(int, iov[nbufs].iov_len, ret);
+
+		nbufs++;
+		ret -= this_len;
+	} while (ret);
+
+	return nbufs;
+}
+
+static int io_net_kbuf_recyle(struct io_kiocb *req, struct io_buffer_list *bl,
+			      struct io_async_msghdr *kmsg, int len)
+{
+	req->flags |= REQ_F_BL_NO_RECYCLE;
+	if (req->flags & REQ_F_BUFFERS_COMMIT)
+		io_kbuf_commit(req, bl, len, io_bundle_nbufs(kmsg, len));
+	return IOU_RETRY;
+}
+
+static inline bool io_send_finish(struct io_kiocb *req,
+				  struct io_async_msghdr *kmsg,
+				  struct io_br_sel *sel)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	bool bundle_finished = sel->val <= 0;
+	unsigned int cflags;
+
+	if (!(sr->flags & IORING_RECVSEND_BUNDLE)) {
+		cflags = io_put_kbuf(req, sel->val, sel->buf_list);
+		goto finish;
+	}
+
+	cflags = io_put_kbufs(req, sel->val, sel->buf_list, io_bundle_nbufs(kmsg, sel->val));
+
+	/*
+	 * Don't start new bundles if the buffer list is empty, or if the
+	 * current operation needed to go through polling to complete.
+	 */
+	if (bundle_finished || req->flags & (REQ_F_BL_EMPTY | REQ_F_POLLED))
+		goto finish;
+
+	/*
+	 * Fill CQE for this receive and see if we should keep trying to
+	 * receive from this socket.
+	 */
+	if (io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
+		io_mshot_prep_retry(req, kmsg);
+		return false;
+	}
+
+	/* Otherwise stop bundle and use the current result. */
+finish:
+	io_req_set_res(req, sel->val, cflags);
+	sel->val = IOU_COMPLETE;
+	return true;
+}
+
+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 *kmsg = req->async_data;
+	struct socket *sock;
+	unsigned flags;
+	int min_ret = 0;
+	int ret;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	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);
+
+	kmsg->msg.msg_control_user = sr->msg_control;
+
+	ret = __sys_sendmsg_sock(sock, &kmsg->msg, flags);
+
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+			return -EAGAIN;
+		if (ret > 0 && io_net_retry(sock, flags)) {
+			kmsg->msg.msg_controllen = 0;
+			kmsg->msg.msg_control = NULL;
+			sr->done_io += ret;
+			return -EAGAIN;
+		}
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		req_set_fail(req);
+	}
+	io_req_msg_cleanup(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_COMPLETE;
+}
+
+static int io_send_select_buffer(struct io_kiocb *req, unsigned int issue_flags,
+				 struct io_br_sel *sel, struct io_async_msghdr *kmsg)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct buf_sel_arg arg = {
+		.iovs = &kmsg->fast_iov,
+		.max_len = min_not_zero(sr->len, INT_MAX),
+		.nr_iovs = 1,
+		.buf_group = sr->buf_group,
+	};
+	int ret;
+
+	if (kmsg->vec.iovec) {
+		arg.nr_iovs = kmsg->vec.nr;
+		arg.iovs = kmsg->vec.iovec;
+		arg.mode = KBUF_MODE_FREE;
+	}
+
+	if (!(sr->flags & IORING_RECVSEND_BUNDLE))
+		arg.nr_iovs = 1;
+	else
+		arg.mode |= KBUF_MODE_EXPAND;
+
+	ret = io_buffers_select(req, &arg, sel, issue_flags);
+	if (unlikely(ret < 0))
+		return ret;
+
+	if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
+		kmsg->vec.nr = ret;
+		kmsg->vec.iovec = arg.iovs;
+		req->flags |= REQ_F_NEED_CLEANUP;
+	}
+	sr->len = arg.out_len;
+
+	if (ret == 1) {
+		sr->buf = arg.iovs[0].iov_base;
+		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len,
+					&kmsg->msg.msg_iter);
+		if (unlikely(ret))
+			return ret;
+	} else {
+		iov_iter_init(&kmsg->msg.msg_iter, ITER_SOURCE,
+				arg.iovs, ret, arg.out_len);
+	}
+
+	return 0;
+}
+
+int io_send(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 *kmsg = req->async_data;
+	struct io_br_sel sel = { };
+	struct socket *sock;
+	unsigned flags;
+	int min_ret = 0;
+	int ret;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	if (req->flags & REQ_F_IMPORT_BUFFER) {
+		ret = io_import_reg_buf(req, &kmsg->msg.msg_iter,
+					(u64)(uintptr_t)sr->buf, sr->len,
+					ITER_SOURCE, issue_flags);
+		if (unlikely(ret))
+			return ret;
+		req->flags &= ~REQ_F_IMPORT_BUFFER;
+	}
+
+	flags = sr->msg_flags;
+	if (issue_flags & IO_URING_F_NONBLOCK)
+		flags |= MSG_DONTWAIT;
+
+retry_bundle:
+	sel.buf_list = NULL;
+	if (io_do_buffer_select(req)) {
+		ret = io_send_select_buffer(req, issue_flags, &sel, kmsg);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * If MSG_WAITALL is set, or this is a bundle send, then we need
+	 * the full amount. If just bundle is set, if we do a short send
+	 * then we complete the bundle sequence rather than continue on.
+	 */
+	if (flags & MSG_WAITALL || sr->flags & IORING_RECVSEND_BUNDLE)
+		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+	flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
+	kmsg->msg.msg_flags = flags;
+	ret = sock_sendmsg(sock, &kmsg->msg);
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+			return -EAGAIN;
+
+		if (ret > 0 && io_net_retry(sock, flags)) {
+			sr->len -= ret;
+			sr->buf += ret;
+			sr->done_io += ret;
+			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
+		}
+		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;
+
+	sel.val = ret;
+	if (!io_send_finish(req, kmsg, &sel))
+		goto retry_bundle;
+
+	io_req_msg_cleanup(req, issue_flags);
+	return sel.val;
+}
+
+static int io_recvmsg_mshot_prep(struct io_kiocb *req,
+				 struct io_async_msghdr *iomsg,
+				 int namelen, size_t controllen)
+{
+	if ((req->flags & (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) ==
+			  (REQ_F_APOLL_MULTISHOT|REQ_F_BUFFER_SELECT)) {
+		int hdr;
+
+		if (unlikely(namelen < 0))
+			return -EOVERFLOW;
+		if (check_add_overflow(sizeof(struct io_uring_recvmsg_out),
+					namelen, &hdr))
+			return -EOVERFLOW;
+		if (check_add_overflow(hdr, controllen, &hdr))
+			return -EOVERFLOW;
+
+		iomsg->namelen = namelen;
+		iomsg->controllen = controllen;
+		return 0;
+	}
+
+	return 0;
+}
+
+static int io_recvmsg_copy_hdr(struct io_kiocb *req,
+			       struct io_async_msghdr *iomsg)
+{
+	struct user_msghdr msg;
+	int ret;
+
+	ret = io_msg_copy_hdr(req, iomsg, &msg, &iomsg->uaddr);
+	if (unlikely(ret))
+		return ret;
+
+	if (!(req->flags & REQ_F_BUFFER_SELECT)) {
+		ret = io_net_import_vec(req, iomsg, msg.msg_iov, msg.msg_iovlen,
+					ITER_DEST);
+		if (unlikely(ret))
+			return ret;
+	}
+	return io_recvmsg_mshot_prep(req, iomsg, msg.msg_namelen,
+					msg.msg_controllen);
+}
+
+static int io_recvmsg_prep_setup(struct io_kiocb *req)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct io_async_msghdr *kmsg;
+
+	kmsg = io_msg_alloc_async(req);
+	if (unlikely(!kmsg))
+		return -ENOMEM;
+
+	if (req->opcode == IORING_OP_RECV) {
+		kmsg->msg.msg_name = NULL;
+		kmsg->msg.msg_namelen = 0;
+		kmsg->msg.msg_inq = 0;
+		kmsg->msg.msg_control = NULL;
+		kmsg->msg.msg_get_inq = 1;
+		kmsg->msg.msg_controllen = 0;
+		kmsg->msg.msg_ubuf = NULL;
+
+		if (req->flags & REQ_F_BUFFER_SELECT)
+			return 0;
+		if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+			req->flags |= REQ_F_IMPORT_BUFFER;
+			return 0;
+		}
+		return import_ubuf(ITER_DEST, sr->buf, sr->len,
+				   &kmsg->msg.msg_iter);
+	}
+
+	return io_recvmsg_copy_hdr(req, kmsg);
+}
+
+#define RECVMSG_FLAGS (IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT | \
+			IORING_RECVSEND_BUNDLE | IORING_RECVSEND_FIXED_BUF)
+
+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);
+
+	sr->done_io = 0;
+
+	if (unlikely(sqe->addr2))
+		return -EINVAL;
+
+	sr->umsg = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	sr->len = READ_ONCE(sqe->len);
+	if (unlikely(sr->len < 0))
+		return -EINVAL;
+	sr->flags = READ_ONCE(sqe->ioprio);
+	if (sr->flags & ~RECVMSG_FLAGS)
+		return -EINVAL;
+	if (sr->flags & IORING_RECVSEND_FIXED_BUF) {
+		/* registered buffer recv only for plain IORING_OP_RECV */
+		if (req->opcode != IORING_OP_RECV ||
+		    (req->flags & REQ_F_BUFFER_SELECT) ||
+		    (sr->flags & (IORING_RECV_MULTISHOT | IORING_RECVSEND_BUNDLE)))
+			return -EINVAL;
+		req->buf_index = READ_ONCE(sqe->buf_index);
+	}
+	sr->msg_flags = READ_ONCE(sqe->msg_flags);
+	if (sr->msg_flags & MSG_DONTWAIT)
+		req->flags |= REQ_F_NOWAIT;
+	if (sr->msg_flags & MSG_ERRQUEUE)
+		req->flags |= REQ_F_CLEAR_POLLIN;
+	if (req->flags & REQ_F_BUFFER_SELECT)
+		sr->buf_group = req->buf_index;
+	sr->mshot_total_len = sr->mshot_len = 0;
+	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->mshot_len = sr->len;
+			sr->mshot_total_len = READ_ONCE(sqe->optlen);
+			if (sr->mshot_total_len)
+				sr->flags |= IORING_RECV_MSHOT_LIM;
+		} else if (sqe->optlen) {
+			return -EINVAL;
+		}
+		req->flags |= REQ_F_APOLL_MULTISHOT;
+	} else if (sqe->optlen) {
+		return -EINVAL;
+	}
+
+	if (sr->flags & IORING_RECVSEND_BUNDLE) {
+		if (req->opcode == IORING_OP_RECVMSG)
+			return -EINVAL;
+	}
+
+	if (io_is_compat(req->ctx))
+		sr->msg_flags |= MSG_CMSG_COMPAT;
+
+	sr->nr_multishot_loops = 0;
+	return io_recvmsg_prep_setup(req);
+}
+
+/* bits to clear in old and inherit in new cflags on bundle retry */
+#define CQE_F_MASK	(IORING_CQE_F_SOCK_NONEMPTY|IORING_CQE_F_MORE|\
+			 IORING_CQE_F_BUF_MORE)
+
+/*
+ * 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,
+				  struct io_async_msghdr *kmsg,
+				  struct io_br_sel *sel, bool mshot_finished,
+				  unsigned issue_flags, int consumed)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	unsigned int cflags = 0;
+
+	if (kmsg->msg.msg_inq > 0)
+		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
+
+	if (sel->val > 0 && sr->flags & IORING_RECV_MSHOT_LIM) {
+		/*
+		 * If sr->len hits zero, the limit has been reached. Mark
+		 * mshot as finished, and flag MSHOT_DONE as well to prevent
+		 * a potential bundle from being retried.
+		 */
+		sr->mshot_total_len -= min_t(int, sel->val, sr->mshot_total_len);
+		if (!sr->mshot_total_len) {
+			sr->flags |= IORING_RECV_MSHOT_DONE;
+			mshot_finished = true;
+		}
+	}
+
+	if (sr->flags & IORING_RECVSEND_BUNDLE) {
+		size_t this_ret = sel->val - sr->done_io;
+
+		cflags |= io_put_kbufs(req, consumed, sel->buf_list, io_bundle_nbufs(kmsg, consumed));
+		if (sr->flags & IORING_RECV_RETRY)
+			cflags = req->cqe.flags | (cflags & CQE_F_MASK);
+		if (sr->mshot_len && sel->val >= sr->mshot_len)
+			sr->flags |= IORING_RECV_MSHOT_CAP;
+		/* bundle with no more immediate buffers, we're done */
+		if (req->flags & REQ_F_BL_EMPTY)
+			goto finish;
+		/*
+		 * If more is available AND it was a full transfer, retry and
+		 * append to this one
+		 */
+		if (!(sr->flags & IORING_RECV_NO_RETRY) &&
+		    kmsg->msg.msg_inq > 1 && this_ret > 0 &&
+		    !iov_iter_count(&kmsg->msg.msg_iter)) {
+			req->cqe.flags = cflags & ~CQE_F_MASK;
+			sr->len = kmsg->msg.msg_inq;
+			sr->done_io += this_ret;
+			sr->flags |= IORING_RECV_RETRY;
+			return false;
+		}
+	} else {
+		cflags |= io_put_kbuf(req, consumed, sel->buf_list);
+	}
+
+	/*
+	 * Fill CQE for this receive and see if we should keep trying to
+	 * receive from this socket.
+	 */
+	if ((req->flags & REQ_F_APOLL_MULTISHOT) && !mshot_finished &&
+	    io_req_post_cqe(req, sel->val, cflags | IORING_CQE_F_MORE)) {
+		sel->val = IOU_RETRY;
+		io_mshot_prep_retry(req, kmsg);
+		/* Known not-empty or unknown state, retry */
+		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || kmsg->msg.msg_inq < 0) {
+			if (sr->nr_multishot_loops++ < MULTISHOT_MAX_RETRY &&
+			    !(sr->flags & IORING_RECV_MSHOT_CAP)) {
+				return false;
+			}
+			/* mshot retries exceeded, force a requeue */
+			sr->nr_multishot_loops = 0;
+			sr->flags &= ~IORING_RECV_MSHOT_CAP;
+			if (issue_flags & IO_URING_F_MULTISHOT)
+				sel->val = IOU_REQUEUE;
+		}
+		return true;
+	}
+
+	/* Finish the request / stop multishot. */
+finish:
+	io_req_set_res(req, sel->val, cflags);
+	sel->val = IOU_COMPLETE;
+	io_req_msg_cleanup(req, issue_flags);
+	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 *kmsg = req->async_data;
+	struct io_br_sel sel = { };
+	struct socket *sock;
+	unsigned flags;
+	int ret, min_ret = 0;
+	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+	bool mshot_finished = true;
+	int consumed = 0;
+	size_t len;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	flags = sr->msg_flags;
+	if (force_nonblock)
+		flags |= MSG_DONTWAIT;
+
+retry_multishot:
+	sel.buf_list = NULL;
+	len = sr->len;
+	if (io_do_buffer_select(req)) {
+		sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
+		if (!sel.addr)
+			return -ENOBUFS;
+
+		if (req->flags & REQ_F_APOLL_MULTISHOT) {
+			ret = io_recvmsg_prep_multishot(kmsg, sr, &sel.addr, &len);
+			if (ret) {
+				io_kbuf_recycle(req, sel.buf_list, issue_flags);
+				return ret;
+			}
+		}
+
+		iov_iter_ubuf(&kmsg->msg.msg_iter, ITER_DEST, sel.addr, len);
+	}
+
+	kmsg->msg.msg_get_inq = 1;
+	kmsg->msg.msg_inq = -1;
+	if (req->flags & REQ_F_APOLL_MULTISHOT) {
+		ret = io_recvmsg_multishot(sock, sr, kmsg, flags,
+					   &mshot_finished);
+		consumed = ret;
+	} else {
+		/* disable partial retry for recvmsg with cmsg attached */
+		if (flags & MSG_WAITALL && !kmsg->msg.msg_controllen)
+			min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+		ret = __sys_recvmsg_sock(sock, &kmsg->msg, sr->umsg,
+					 kmsg->uaddr, flags);
+		/*
+		 * With MSG_TRUNC, the net layer will return the full size of
+		 * the packet, even if we only filled part of it in the buffers.
+		 * Adjust the returned size to consume only the real part of the
+		 * buffer.
+		 */
+		consumed = ret;
+		if (ret > 0)
+			consumed = min_t(size_t, ret, len);
+	}
+
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && force_nonblock) {
+			io_kbuf_recycle(req, sel.buf_list, issue_flags);
+			return IOU_RETRY;
+		}
+		if (ret > 0 && io_net_retry(sock, flags)) {
+			sr->done_io += ret;
+			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
+		}
+		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, sel.buf_list, issue_flags);
+
+	sel.val = ret;
+	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags, consumed))
+		goto retry_multishot;
+
+	return sel.val;
+}
+
+static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg,
+			      struct io_br_sel *sel, unsigned int issue_flags)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	size_t len;
+	int ret;
+
+	/*
+	 * If the ring isn't locked, then don't use the peek interface
+	 * to grab multiple buffers as we will lock/unlock between
+	 * this selection and posting the buffers.
+	 */
+	if (!(issue_flags & IO_URING_F_UNLOCKED) &&
+	    sr->flags & IORING_RECVSEND_BUNDLE) {
+		struct buf_sel_arg arg = {
+			.iovs = &kmsg->fast_iov,
+			.nr_iovs = 1,
+			.mode = KBUF_MODE_EXPAND,
+			.buf_group = sr->buf_group,
+		};
+
+		if (kmsg->vec.iovec) {
+			arg.nr_iovs = kmsg->vec.nr;
+			arg.iovs = kmsg->vec.iovec;
+			arg.mode |= KBUF_MODE_FREE;
+		}
+
+		if (sel->val)
+			arg.max_len = sel->val;
+		else if (kmsg->msg.msg_inq > 1)
+			arg.max_len = min_not_zero(sel->val, (ssize_t) kmsg->msg.msg_inq);
+
+		/* if mshot limited, ensure we don't go over */
+		if (sr->flags & IORING_RECV_MSHOT_LIM)
+			arg.max_len = min_not_zero(arg.max_len, sr->mshot_total_len);
+		ret = io_buffers_peek(req, &arg, sel);
+		if (unlikely(ret < 0))
+			return ret;
+
+		if (arg.iovs != &kmsg->fast_iov && arg.iovs != kmsg->vec.iovec) {
+			kmsg->vec.nr = ret;
+			kmsg->vec.iovec = arg.iovs;
+			req->flags |= REQ_F_NEED_CLEANUP;
+		}
+		if (arg.partial_map)
+			sr->flags |= IORING_RECV_PARTIAL_MAP;
+
+		/* special case 1 vec, can be a fast path */
+		if (ret == 1) {
+			sr->buf = arg.iovs[0].iov_base;
+			len = sr->len = arg.iovs[0].iov_len;
+			goto map_ubuf;
+		}
+		iov_iter_init(&kmsg->msg.msg_iter, ITER_DEST, arg.iovs, ret,
+			      arg.out_len);
+		len = arg.out_len;
+	} else {
+		len = sel->val;
+
+		*sel = io_buffer_select(req, &len, sr->buf_group, issue_flags);
+		if (!sel->addr)
+			return -ENOBUFS;
+		sr->buf = sel->addr;
+		sr->len = len;
+map_ubuf:
+		ret = import_ubuf(ITER_DEST, sr->buf, sr->len,
+				  &kmsg->msg.msg_iter);
+		if (unlikely(ret))
+			return ret;
+	}
+
+	return len;
+}
+
+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 io_async_msghdr *kmsg = req->async_data;
+	struct io_br_sel sel;
+	struct socket *sock;
+	unsigned flags;
+	int ret, min_ret = 0, consumed = 0;
+	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+	bool mshot_finished;
+	size_t len = 0;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	flags = sr->msg_flags;
+	if (force_nonblock)
+		flags |= MSG_DONTWAIT;
+
+	if (req->flags & REQ_F_IMPORT_BUFFER) {
+		ret = io_import_reg_buf(req, &kmsg->msg.msg_iter,
+					(u64)(uintptr_t)sr->buf, sr->len,
+					ITER_DEST, issue_flags);
+		if (unlikely(ret)) {
+			kmsg->msg.msg_inq = -1;
+			sel.buf_list = NULL;
+			goto out_free;
+		}
+		req->flags &= ~REQ_F_IMPORT_BUFFER;
+	}
+
+retry_multishot:
+	sel.buf_list = NULL;
+	len = sr->len;
+	if (io_do_buffer_select(req)) {
+		sel.val = sr->len;
+		ret = io_recv_buf_select(req, kmsg, &sel, issue_flags);
+		if (unlikely(ret < 0)) {
+			kmsg->msg.msg_inq = -1;
+			goto out_free;
+		}
+		len = ret;
+		sr->buf = NULL;
+	}
+
+	kmsg->msg.msg_flags = 0;
+	kmsg->msg.msg_inq = -1;
+
+	if (flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+	ret = sock_recvmsg(sock, &kmsg->msg, flags);
+	if (ret < min_ret) {
+		if (ret == -EAGAIN && force_nonblock) {
+			io_kbuf_recycle(req, sel.buf_list, issue_flags);
+			return IOU_RETRY;
+		}
+		if (ret > 0 && io_net_retry(sock, flags)) {
+			sr->len -= ret;
+			sr->buf += ret;
+			sr->done_io += ret;
+			return io_net_kbuf_recyle(req, sel.buf_list, kmsg, ret);
+		}
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		req_set_fail(req);
+	} else if ((flags & MSG_WAITALL) && (kmsg->msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC))) {
+out_free:
+		req_set_fail(req);
+	}
+
+	mshot_finished = ret <= 0;
+
+	/*
+	 * With MSG_TRUNC, the net layer will return the full size of
+	 * the packet, even if we only filled part of it in the buffers.
+	 * Adjust the returned size to consume only the real part of the
+	 * buffer.
+	 */
+	consumed = ret;
+	if (ret > 0)
+		consumed = min_t(size_t, ret, len);
+
+	if (ret > 0)
+		ret += sr->done_io;
+	else if (sr->done_io)
+		ret = sr->done_io;
+	else
+		io_kbuf_recycle(req, sel.buf_list, issue_flags);
+
+	sel.val = ret;
+	if (!io_recv_finish(req, kmsg, &sel, mshot_finished, issue_flags, consumed))
+		goto retry_multishot;
+
+	return sel.val;
+}
+
+int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
+	unsigned ifq_idx;
+
+	if (unlikely(sqe->addr2 || sqe->addr || sqe->addr3))
+		return -EINVAL;
+
+	ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx);
+	zc->ifq = xa_load(&req->ctx->zcrx_ctxs, ifq_idx);
+	if (!zc->ifq)
+		return -EINVAL;
+
+	zc->len = READ_ONCE(sqe->len);
+	zc->flags = READ_ONCE(sqe->ioprio);
+	if (READ_ONCE(sqe->msg_flags))
+		return -EINVAL;
+	if (zc->flags & ~(IORING_RECVSEND_POLL_FIRST | IORING_RECV_MULTISHOT))
+		return -EINVAL;
+	/* multishot required */
+	if (!(zc->flags & IORING_RECV_MULTISHOT))
+		return -EINVAL;
+	/* All data completions are posted as aux CQEs. */
+	req->flags |= REQ_F_APOLL_MULTISHOT;
+
+	return 0;
+}
+
+int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
+	struct socket *sock;
+	unsigned int len;
+	int ret;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (zc->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	len = zc->len;
+	ret = io_zcrx_recv(req, zc->ifq, sock, 0, issue_flags, &zc->len);
+	if (len && zc->len == 0) {
+		io_req_set_res(req, 0, 0);
+
+		return IOU_COMPLETE;
+	}
+	if (unlikely(ret <= 0) && ret != -EAGAIN) {
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+		if (ret == IOU_REQUEUE)
+			return IOU_REQUEUE;
+
+		req_set_fail(req);
+		io_req_set_res(req, ret, 0);
+		return IOU_COMPLETE;
+	}
+	return IOU_RETRY;
+}
+
+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 = req->async_data;
+
+	if (req_has_async_data(req))
+		io_netmsg_iovec_free(io);
+	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 | \
+				IORING_SEND_VECTORIZED)
+
+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_async_msghdr *iomsg;
+	struct io_kiocb *notif;
+	u64 user_data;
+	int ret;
+
+	zc->done_io = 0;
+
+	if (unlikely(READ_ONCE(sqe->__pad2[0])))
+		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;
+	user_data = READ_ONCE(sqe->addr3);
+	if (!user_data)
+		user_data = req->cqe.user_data;
+
+	notif->cqe.user_data = user_data;
+	notif->cqe.res = 0;
+	notif->cqe.flags = IORING_CQE_F_NOTIF;
+	req->flags |= REQ_F_NEED_CLEANUP | REQ_F_POLL_NO_LAZY;
+
+	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) {
+			struct io_notif_data *nd = io_notif_to_data(notif);
+
+			nd->zc_report = true;
+			nd->zc_used = false;
+			nd->zc_copied = false;
+		}
+	}
+
+	zc->len = READ_ONCE(sqe->len);
+	zc->msg_flags = READ_ONCE(sqe->msg_flags) | MSG_NOSIGNAL | MSG_ZEROCOPY;
+	req->buf_index = READ_ONCE(sqe->buf_index);
+	if (zc->msg_flags & MSG_DONTWAIT)
+		req->flags |= REQ_F_NOWAIT;
+
+	if (io_is_compat(ctx))
+		zc->msg_flags |= MSG_CMSG_COMPAT;
+
+	iomsg = io_msg_alloc_async(req);
+	if (unlikely(!iomsg))
+		return -ENOMEM;
+
+	if (req->opcode == IORING_OP_SEND_ZC) {
+		ret = io_send_setup(req, sqe);
+	} else {
+		if (unlikely(sqe->addr2 || sqe->file_index))
+			return -EINVAL;
+		ret = io_sendmsg_setup(req, sqe);
+	}
+	if (unlikely(ret))
+		return ret;
+
+	if (!(zc->flags & IORING_RECVSEND_FIXED_BUF)) {
+		iomsg->msg.sg_from_iter = io_sg_from_iter_iovec;
+		return io_notif_account_mem(zc->notif, iomsg->msg.msg_iter.count);
+	}
+	iomsg->msg.sg_from_iter = io_sg_from_iter;
+	return 0;
+}
+
+static int io_sg_from_iter_iovec(struct sk_buff *skb,
+				 struct iov_iter *from, size_t length)
+{
+	skb_zcopy_downgrade_managed(skb);
+	return zerocopy_fill_skb_from_iter(skb, from, length);
+}
+
+static int io_sg_from_iter(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_fill_skb_from_iter(skb, from, length);
+
+	bi.bi_size = min(from->count, length);
+	bi.bi_offset = 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_offset;
+
+	skb->data_len += copied;
+	skb->len += copied;
+	skb->truesize += truesize;
+	return ret;
+}
+
+static int io_send_zc_import(struct io_kiocb *req,
+			     struct io_async_msghdr *kmsg,
+			     unsigned int issue_flags)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+	struct io_kiocb *notif = sr->notif;
+	int ret;
+
+	WARN_ON_ONCE(!(sr->flags & IORING_RECVSEND_FIXED_BUF));
+
+	notif->buf_index = req->buf_index;
+
+	if (!(sr->flags & IORING_SEND_VECTORIZED)) {
+		ret = io_import_reg_buf(notif, &kmsg->msg.msg_iter,
+					(u64)(uintptr_t)sr->buf, sr->len,
+					ITER_SOURCE, issue_flags);
+	} else {
+		unsigned uvec_segs = kmsg->msg.msg_iter.nr_segs;
+
+		ret = io_import_reg_vec(ITER_SOURCE, &kmsg->msg.msg_iter,
+					notif, &kmsg->vec, uvec_segs,
+					issue_flags);
+	}
+
+	if (unlikely(ret))
+		return ret;
+	req->flags &= ~REQ_F_IMPORT_BUFFER;
+	return 0;
+}
+
+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 *kmsg = req->async_data;
+	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;
+	if (!(req->flags & REQ_F_POLLED) &&
+	    (sr->flags & IORING_RECVSEND_POLL_FIRST))
+		return -EAGAIN;
+
+	if (req->flags & REQ_F_IMPORT_BUFFER) {
+		ret = io_send_zc_import(req, kmsg, issue_flags);
+		if (unlikely(ret))
+			return ret;
+	}
+
+	msg_flags = sr->msg_flags;
+	if (issue_flags & IO_URING_F_NONBLOCK)
+		msg_flags |= MSG_DONTWAIT;
+	if (msg_flags & MSG_WAITALL)
+		min_ret = iov_iter_count(&kmsg->msg.msg_iter);
+
+	kmsg->msg.msg_ubuf = &io_notif_to_data(sr->notif)->uarg;
+
+	if (req->opcode == IORING_OP_SEND_ZC) {
+		msg_flags &= ~MSG_INTERNAL_SENDMSG_FLAGS;
+		kmsg->msg.msg_flags = msg_flags;
+		ret = sock_sendmsg(sock, &kmsg->msg);
+	} else {
+		kmsg->msg.msg_control_user = sr->msg_control;
+		ret = __sys_sendmsg_sock(sock, &kmsg->msg, msg_flags);
+	}
+
+	if (unlikely(ret < min_ret)) {
+		if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
+			return -EAGAIN;
+
+		if (ret > 0 && io_net_retry(sock, sr->msg_flags)) {
+			sr->done_io += ret;
+			return -EAGAIN;
+		}
+		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;
+
+	/*
+	 * 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);
+		sr->notif = NULL;
+		io_req_msg_cleanup(req, 0);
+	}
+	io_req_set_res(req, ret, IORING_CQE_F_MORE);
+	return IOU_COMPLETE;
+}
+
+void io_sendrecv_fail(struct io_kiocb *req)
+{
+	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
+
+	if (sr->done_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;
+}
+
+#define ACCEPT_FLAGS	(IORING_ACCEPT_MULTISHOT | IORING_ACCEPT_DONTWAIT | \
+			 IORING_ACCEPT_POLL_FIRST)
+
+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);
+
+	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);
+	accept->iou_flags = READ_ONCE(sqe->ioprio);
+	if (accept->iou_flags & ~ACCEPT_FLAGS)
+		return -EINVAL;
+
+	accept->file_slot = READ_ONCE(sqe->file_index);
+	if (accept->file_slot) {
+		if (accept->flags & SOCK_CLOEXEC)
+			return -EINVAL;
+		if (accept->iou_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 (accept->iou_flags & IORING_ACCEPT_MULTISHOT)
+		req->flags |= REQ_F_APOLL_MULTISHOT;
+	if (accept->iou_flags & IORING_ACCEPT_DONTWAIT)
+		req->flags |= REQ_F_NOWAIT;
+	return 0;
+}
+
+int io_accept(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_accept *accept = io_kiocb_to_cmd(req, struct io_accept);
+	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+	bool fixed = !!accept->file_slot;
+	struct proto_accept_arg arg = {
+		.flags = force_nonblock ? O_NONBLOCK : 0,
+	};
+	struct file *file;
+	unsigned cflags;
+	int ret, fd;
+
+	if (!(req->flags & REQ_F_POLLED) &&
+	    accept->iou_flags & IORING_ACCEPT_POLL_FIRST)
+		return -EAGAIN;
+
+retry:
+	if (!fixed) {
+		fd = __get_unused_fd_flags(accept->flags, accept->nofile);
+		if (unlikely(fd < 0))
+			return fd;
+	}
+	arg.err = 0;
+	arg.is_empty = -1;
+	file = do_accept(req->file, &arg, 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 &&
+		    !(accept->iou_flags & IORING_ACCEPT_DONTWAIT))
+			return IOU_RETRY;
+
+		if (ret == -ERESTARTSYS)
+			ret = -EINTR;
+	} else if (!fixed) {
+		fd_install(fd, file);
+		ret = fd;
+	} else {
+		ret = io_fixed_fd_install(req, issue_flags, file,
+						accept->file_slot);
+	}
+
+	cflags = 0;
+	if (!arg.is_empty)
+		cflags |= IORING_CQE_F_SOCK_NONEMPTY;
+
+	if (ret >= 0 && (req->flags & REQ_F_APOLL_MULTISHOT) &&
+	    io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
+		if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
+			goto retry;
+		return IOU_RETRY;
+	}
+
+	io_req_set_res(req, ret, cflags);
+	if (ret < 0)
+		req_set_fail(req);
+	return IOU_COMPLETE;
+}
+
+void io_socket_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
+{
+	struct io_socket *sock = io_kiocb_to_cmd(req, struct io_socket);
+
+	bctx->socket.family = sock->domain;
+	bctx->socket.type = sock->type;
+	bctx->socket.protocol = sock->protocol;
+}
+
+void io_connect_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
+{
+	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
+	struct sockaddr_storage *ss = req->async_data;
+
+	/*
+	 * move_addr_to_kernel() skips the copy for addr_len == 0, so
+	 * iomsg->addr may hold stale data from a prior CONNECT. Bail
+	 * unless addr_len covers the family discriminator.
+	 */
+	if (conn->addr_len < (int)sizeof(sa_family_t))
+		return;
+
+	bctx->connect.family = ss->ss_family;
+	switch (ss->ss_family) {
+	case AF_INET: {
+		struct sockaddr_in *sin = (struct sockaddr_in *)ss;
+
+		if (conn->addr_len < (int)sizeof(*sin))
+			break;
+		bctx->connect.port = sin->sin_port;
+		bctx->connect.v4_addr = sin->sin_addr.s_addr;
+		break;
+	}
+	case AF_INET6: {
+		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ss;
+
+		if (conn->addr_len < (int)sizeof(*sin6))
+			break;
+		bctx->connect.port = sin6->sin6_port;
+		memcpy(bctx->connect.v6_addr, &sin6->sin6_addr,
+		       sizeof(bctx->connect.v6_addr));
+		break;
+	}
+	default:
+		/* family is set; per-family fields stay zero - family-only filtering */
+		break;
+	}
+}
+
+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_COMPLETE;
+}
+
+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);
+	struct sockaddr_storage *addr;
+
+	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 = conn->seen_econnaborted = false;
+
+	addr = io_uring_alloc_async_data(NULL, req);
+	if (unlikely(!addr))
+		return -ENOMEM;
+
+	return move_addr_to_kernel(conn->addr, conn->addr_len, addr);
+}
+
+int io_connect(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
+	struct sockaddr_storage *addr = req->async_data;
+	unsigned file_flags;
+	int ret;
+	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+
+	if (connect->in_progress) {
+		struct poll_table_struct pt = { ._key = EPOLLERR };
+
+		if (vfs_poll(req->file, &pt) & EPOLLERR)
+			goto get_sock_err;
+	}
+
+	file_flags = force_nonblock ? O_NONBLOCK : 0;
+
+	ret = __sys_connect_file(req->file, addr, connect->addr_len, file_flags);
+	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
+	    && force_nonblock) {
+		if (ret == -EINPROGRESS) {
+			connect->in_progress = true;
+		} else if (ret == -ECONNABORTED) {
+			if (connect->seen_econnaborted)
+				goto out;
+			connect->seen_econnaborted = true;
+		}
+		return -EAGAIN;
+	}
+	if (connect->in_progress) {
+		/*
+		 * At least bluetooth will return -EBADFD on a re-connect
+		 * attempt, and it's (supposedly) also valid to get -EISCONN
+		 * which means the previous result is good. For both of these,
+		 * grab the sock_error() and use that for the completion.
+		 */
+		if (ret == -EBADFD || ret == -EISCONN) {
+get_sock_err:
+			ret = sock_error(sock_from_file(req->file)->sk);
+		}
+	}
+	if (ret == -ERESTARTSYS)
+		ret = -EINTR;
+out:
+	if (ret < 0)
+		req_set_fail(req);
+	io_req_set_res(req, ret, 0);
+	return IOU_COMPLETE;
+}
+
+/*
+ * Check if bind request would potentially end up with filename_create(),
+ * which in turn end up in mnt_want_write() which will grab the fs
+ * percpu start write sem. This can trigger a lockdep warning.
+ */
+static int io_bind_file_create(const struct sockaddr_storage *addr, int addr_len)
+{
+	const struct sockaddr_un *sun;
+
+	if (addr->ss_family != AF_UNIX)
+		return 0;
+	if (addr_len <= offsetof(struct sockaddr_un, sun_path))
+		return 0;
+	sun = (const struct sockaddr_un *) addr;
+	return sun->sun_path[0] != '\0';
+}
+
+int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
+	struct sockaddr __user *uaddr;
+	struct sockaddr_storage *addr;
+	int ret;
+
+	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
+		return -EINVAL;
+
+	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
+	bind->addr_len =  READ_ONCE(sqe->addr2);
+
+	addr = io_uring_alloc_async_data(NULL, req);
+	if (unlikely(!addr))
+		return -ENOMEM;
+	ret = move_addr_to_kernel(uaddr, bind->addr_len, addr);
+	if (unlikely(ret))
+		return ret;
+	if (io_bind_file_create(addr, bind->addr_len))
+		req->flags |= REQ_F_FORCE_ASYNC;
+	return 0;
+}
+
+
+int io_bind(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
+	struct sockaddr_storage *addr = req->async_data;
+	struct socket *sock;
+	int ret;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	ret = __sys_bind_socket(sock, addr, bind->addr_len);
+	if (ret < 0)
+		req_set_fail(req);
+	io_req_set_res(req, ret, 0);
+	return 0;
+}
+
+int io_listen_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
+
+	if (sqe->addr || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in || sqe->addr2)
+		return -EINVAL;
+
+	listen->backlog = READ_ONCE(sqe->len);
+	return 0;
+}
+
+int io_listen(struct io_kiocb *req, unsigned int issue_flags)
+{
+	struct io_listen *listen = io_kiocb_to_cmd(req, struct io_listen);
+	struct socket *sock;
+	int ret;
+
+	sock = sock_from_file(req->file);
+	if (unlikely(!sock))
+		return -ENOTSOCK;
+
+	ret = __sys_listen_socket(sock, listen->backlog);
+	if (ret < 0)
+		req_set_fail(req);
+	io_req_set_res(req, ret, 0);
+	return 0;
+}
+
+void io_netmsg_cache_free(const void *entry)
+{
+	struct io_async_msghdr *kmsg = (struct io_async_msghdr *) entry;
+
+	io_vec_free(&kmsg->vec);
+	kfree(kmsg);
+}