From: Jens Axboe <axboe@kernel.dk>
To: Kees Cook <keescook@chromium.org>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>,
linux-next@vger.kernel.org
Subject: Re: Coverity: io_wqe_worker(): Program hangs
Date: Mon, 28 Oct 2019 17:35:15 -0600 [thread overview]
Message-ID: <7fdaef1a-6c7a-46df-f84b-4d05cca16fca@kernel.dk> (raw)
In-Reply-To: <201910281629.5F6B1D038@keescook>
On 10/28/19 5:30 PM, Kees Cook wrote:
> On Mon, Oct 28, 2019 at 05:27:59PM -0600, Jens Axboe wrote:
>> On 10/28/19 5:05 PM, coverity-bot wrote:
>>> Hello!
>>>
>>> This is an experimental automated report about issues detected by Coverity
>>> from a scan of next-20191025 as part of the linux-next weekly scan project:
>>> https://scan.coverity.com/projects/linux-next-weekly-scan
>>>
>>> You're getting this email because you were associated with the identified
>>> lines of code (noted below) that were touched by recent commits:
>>>
>>> 46134db8fdc5 ("io-wq: small threadpool implementation for io_uring")
>>>
>>> Coverity reported the following:
>>>
>>> *** CID 1487365: Program hangs (LOCK)
>>> /fs/io-wq.c: 349 in io_wqe_worker()
>>> 343 io_worker_handle_work(worker);
>>> 344 else
>>> 345 spin_unlock(&wqe->lock);
>>> 346 }
>>> 347
>>> 348 io_worker_exit(worker);
>>> vvv CID 1487365: Program hangs (LOCK)
>>> vvv Returning without unlocking "(*wqe).lock".
>>> 349 return 0;
>>> 350 }
>>> 351
>>> 352 /*
>>> 353 * Check head of free list for an available worker. If one isn't available,
>>> 354 * caller must wake up the wq manager to create one.
>>>
>>> If this is a false positive, please let us know so we can mark it as
>>> such, or teach the Coverity rules to be smarter. If not, please make
>>> sure fixes get into linux-next. :) For patches fixing this, please
>>> include:
>>
>> It's a false positive, lock is dropped on non-zero return.
>
> Does that happen in the caller side? I'll see if I can figure out how to
> teach coverity about that... Hmmm
I was trying to use the right incantations of __release() etc to shut up
the checker as well. So if there are things I could be improving on that
side, do let me know.
As mentioned in other emails, the linux-next version is somewhat outdated
at this point. My for-next branch has the latest version.
--
Jens Axboe
next prev parent reply other threads:[~2019-10-28 23:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 23:05 Coverity: io_wqe_worker(): Program hangs coverity-bot
2019-10-28 23:27 ` Jens Axboe
2019-10-28 23:30 ` Kees Cook
2019-10-28 23:35 ` Jens Axboe [this message]
2019-10-29 16:11 ` Kees Cook
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 \
--in-reply-to=7fdaef1a-6c7a-46df-f84b-4d05cca16fca@kernel.dk \
--to=axboe@kernel.dk \
--cc=gustavo@embeddedor.com \
--cc=keescook@chromium.org \
--cc=linux-next@vger.kernel.org \
/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;
as well as URLs for NNTP newsgroup(s).