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io_uring/rsrc: Drop io_copy_iov in favor of iovec API

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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>
This commit is contained in:
Gabriel Krisman Bertazi 2024-05-23 17:45:35 -04:00 committed by Jens Axboe
parent 81cc927d9c
commit f4eaf8eda8
1 changed files with 22 additions and 40 deletions
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62
io_uring/rsrc.c
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@ -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;