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: Gabriel Krisman Bertazi <krisman@suse.de>
Link: https://lore.kernel.org/r/20240523214535.31890-1-krisman@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index edb9c5b..e89c5e2 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -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);
+ 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);
if (ret)
break;
- 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;
