From: Pavel Begunkov <[email protected]>
To: Jens Axboe <[email protected]>,
Xiaoguang Wang <[email protected]>,
[email protected]
Subject: Re: [PATCH] io_uring: add io_uring_enter(2) fixed file support
Date: Fri, 4 Mar 2022 02:39:55 +0000 [thread overview]
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
On 3/4/22 02:19, Jens Axboe wrote:
> On 3/3/22 6:52 PM, Pavel Begunkov wrote:
>> On 3/3/22 16:31, Jens Axboe wrote:
>>> On 3/3/22 7:40 AM, Jens Axboe wrote:
>>>> On 3/3/22 7:36 AM, Jens Axboe wrote:
[...]
>>>
>>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>>> index ad3e0b0ab3b9..8a1f97054b71 100644
>>> --- a/fs/io_uring.c
>>> +++ b/fs/io_uring.c
>> [...]
>>> static void *io_uring_validate_mmap_request(struct file *file,
>>> loff_t pgoff, size_t sz)
>>> {
>>> @@ -10191,12 +10266,23 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
>>> io_run_task_work();
>>> if (unlikely(flags & ~(IORING_ENTER_GETEVENTS | IORING_ENTER_SQ_WAKEUP |
>>> - IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG)))
>>> + IORING_ENTER_SQ_WAIT | IORING_ENTER_EXT_ARG |
>>> + IORING_ENTER_REGISTERED_RING)))
>>> return -EINVAL;
>>> - f = fdget(fd);
>>> - if (unlikely(!f.file))
>>> - return -EBADF;
>>> + if (flags & IORING_ENTER_REGISTERED_RING) {
>>> + struct io_uring_task *tctx = current->io_uring;
>>> +
>>> + if (fd >= IO_RINGFD_REG_MAX || !tctx)
>>> + return -EINVAL;
>>> + f.file = tctx->registered_rings[fd];
>>
>> btw, array_index_nospec(), possibly not only here.
>
> Yeah, was thinking that earlier too in fact but forgot about it. Might
> as well, though I don't think it's strictly required as it isn't a user
> table.
I may have missed in what cases it's used, but shouldn't it be
in all cases when we use a user passed index for array addressing?
e.g. to protect from pre-caching a chunk of memory computed from
an out-of-array malevolent index
I just don't see any relevant difference from normal file tables
--
Pavel Begunkov
next prev parent reply other threads:[~2022-03-04 2:44 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-03 5:28 [PATCH] io_uring: add io_uring_enter(2) fixed file support Xiaoguang Wang
2022-03-03 8:56 ` Hao Xu
2022-03-03 13:38 ` Jens Axboe
2022-03-03 14:36 ` Jens Axboe
2022-03-03 14:40 ` Jens Axboe
2022-03-03 16:31 ` Jens Axboe
2022-03-03 17:18 ` Jens Axboe
2022-03-03 20:41 ` Jens Axboe
2022-03-03 21:19 ` Jens Axboe
2022-03-04 0:07 ` Jens Axboe
2022-03-04 13:39 ` Xiaoguang Wang
2022-03-04 13:44 ` Jens Axboe
2022-03-04 15:16 ` Xiaoguang Wang
2022-03-04 15:22 ` Jens Axboe
2022-03-08 8:38 ` Xiaoguang Wang
2022-03-08 13:10 ` Jens Axboe
2022-03-03 22:24 ` Vito Caputo
2022-03-03 22:26 ` Jens Axboe
2022-03-04 1:49 ` Pavel Begunkov
2022-03-04 2:18 ` Jens Axboe
2022-03-04 2:28 ` Pavel Begunkov
2022-03-04 2:35 ` Pavel Begunkov
2022-03-04 2:43 ` Jens Axboe
2022-03-04 1:52 ` Pavel Begunkov
2022-03-04 2:19 ` Jens Axboe
2022-03-04 2:39 ` Pavel Begunkov [this message]
2022-03-04 3:03 ` Jens Axboe
2022-04-21 14:16 ` Hao Xu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
[email protected] \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox