Commit f4eaf8ed authored by Gabriel Krisman Bertazi's avatar Gabriel Krisman Bertazi Committed by Jens Axboe
Browse files

io_uring/rsrc: Drop io_copy_iov in favor of iovec API 



Instead of open coding an io_uring function to copy iovs from userspace,
rely on the existing iovec_from_user function.  While there, avoid
repeatedly zeroing the iov in the !arg case for io_sqe_buffer_register.

tested with liburing testsuite.

Signed-off-by: default avatarGabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240523214535.31890-1-krisman@suse.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 81cc927d

io_uring/rsrc.c

+21 −39
Original line number Diff line number Diff line
@@ -85,31 +85,6 @@ static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages) 
	return 0;

}



static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,

		       void __user *arg, unsigned index)

{

	struct iovec __user *src;



#ifdef CONFIG_COMPAT

	if (ctx->compat) {

		struct compat_iovec __user *ciovs;

		struct compat_iovec ciov;



		ciovs = (struct compat_iovec __user *) arg;

		if (copy_from_user(&ciov, &ciovs[index], sizeof(ciov)))

			return -EFAULT;



		dst->iov_base = u64_to_user_ptr((u64)ciov.iov_base);

		dst->iov_len = ciov.iov_len;

		return 0;

	}

#endif

	src = (struct iovec __user *) arg;

	if (copy_from_user(dst, &src[index], sizeof(*dst)))

		return -EFAULT;

	return 0;

}



static int io_buffer_validate(struct iovec *iov)

{

	unsigned long tmp, acct_len = iov->iov_len + (PAGE_SIZE - 1);
@@ -420,8 +395,9 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, 
				   struct io_uring_rsrc_update2 *up,

				   unsigned int nr_args)

{

	struct iovec __user *uvec = u64_to_user_ptr(up->data);

	u64 __user *tags = u64_to_user_ptr(up->tags);

	struct iovec iov, __user *iovs = u64_to_user_ptr(up->data);

	struct iovec fast_iov, *iov;

	struct page *last_hpage = NULL;

	__u32 done;

	int i, err;
@@ -435,21 +411,23 @@ static int __io_sqe_buffers_update(struct io_ring_ctx *ctx, 
		struct io_mapped_ubuf *imu;

		u64 tag = 0;



		err = io_copy_iov(ctx, &iov, iovs, done);

		if (err)

		iov = iovec_from_user(&uvec[done], 1, 1, &fast_iov, ctx->compat);

		if (IS_ERR(iov)) {

			err = PTR_ERR(iov);

			break;

		}

		if (tags && copy_from_user(&tag, &tags[done], sizeof(tag))) {

			err = -EFAULT;

			break;

		}

		err = io_buffer_validate(&iov);

		err = io_buffer_validate(iov);

		if (err)

			break;

		if (!iov.iov_base && tag) {

		if (!iov->iov_base && tag) {

			err = -EINVAL;

			break;

		}

		err = io_sqe_buffer_register(ctx, &iov, &imu, &last_hpage);

		err = io_sqe_buffer_register(ctx, iov, &imu, &last_hpage);

		if (err)

			break;
@@ -971,8 +949,9 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, 
{

	struct page *last_hpage = NULL;

	struct io_rsrc_data *data;

	struct iovec fast_iov, *iov = &fast_iov;

	const struct iovec __user *uvec = (struct iovec * __user) arg;

	int i, ret;

	struct iovec iov;



	BUILD_BUG_ON(IORING_MAX_REG_BUFFERS >= (1u << 16));
@@ -989,24 +968,27 @@ int io_sqe_buffers_register(struct io_ring_ctx *ctx, void __user *arg, 
		return ret;

	}



	if (!arg)

		memset(iov, 0, sizeof(*iov));



	for (i = 0; i < nr_args; i++, ctx->nr_user_bufs++) {

		if (arg) {

			ret = io_copy_iov(ctx, &iov, arg, i);

			if (ret)

			iov = iovec_from_user(&uvec[i], 1, 1, &fast_iov, ctx->compat);

			if (IS_ERR(iov)) {

				ret = PTR_ERR(iov);

				break;

			ret = io_buffer_validate(&iov);

			}

			ret = io_buffer_validate(iov);

			if (ret)

				break;

		} else {

			memset(&iov, 0, sizeof(iov));

		}



		if (!iov.iov_base && *io_get_tag_slot(data, i)) {

		if (!iov->iov_base && *io_get_tag_slot(data, i)) {

			ret = -EINVAL;

			break;

		}



		ret = io_sqe_buffer_register(ctx, &iov, &ctx->user_bufs[i],

		ret = io_sqe_buffer_register(ctx, iov, &ctx->user_bufs[i],

					     &last_hpage);

		if (ret)

			break;