path: root/io_uring/rw.c

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/blk-mq.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/fsnotify.h>
#include <linux/poll.h>
#include <linux/nospec.h>
#include <linux/compat.h>
#include <linux/io_uring/cmd.h>
#include <linux/indirect_call_wrapper.h>

#include <uapi/linux/io_uring.h>

#include "io_uring.h"
#include "opdef.h"
#include "kbuf.h"
#include "alloc_cache.h"
#include "rsrc.h"
#include "poll.h"
#include "rw.h"

static void io_complete_rw(struct kiocb *kiocb, long res);
static void io_complete_rw_iopoll(struct kiocb *kiocb, long res);

struct io_rw {
	/* NOTE: kiocb has the file as the first member, so don't do it here */
	struct kiocb			kiocb;
	u64				addr;
	u32				len;
	rwf_t				flags;
};

static bool io_file_supports_nowait(struct io_kiocb *req, __poll_t mask)
{
	/* If FMODE_NOWAIT is set for a file, we're golden */
	if (req->flags & REQ_F_SUPPORT_NOWAIT)
		return true;
	/* No FMODE_NOWAIT, if we can poll, check the status */
	if (io_file_can_poll(req)) {
		struct poll_table_struct pt = { ._key = mask };

		return vfs_poll(req->file, &pt) & mask;
	}
	/* No FMODE_NOWAIT support, and file isn't pollable. Tough luck. */
	return false;
}

static int io_iov_compat_buffer_select_prep(struct io_rw *rw)
{
	struct compat_iovec __user *uiov = u64_to_user_ptr(rw->addr);
	struct compat_iovec iov;

	if (copy_from_user(&iov, uiov, sizeof(iov)))
		return -EFAULT;
	rw->len = iov.iov_len;
	return 0;
}

static int io_iov_buffer_select_prep(struct io_kiocb *req)
{
	struct iovec __user *uiov;
	struct iovec iov;
	struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);

	if (rw->len != 1)
		return -EINVAL;

	if (io_is_compat(req->ctx))
		return io_iov_compat_buffer_select_prep(rw);

	uiov = u64_to_user_ptr(rw->addr);
	if (copy_from_user(&iov,