From: Johannes Berg <johannes@sipsolutions.net>
To: Thomas Gleixner <tglx@linutronix.de>,
Mukesh Ojha <quic_mojha@quicinc.com>,
linux-kernel@vger.kernel.org
Cc: sboyd@kernel.org, rafael@kernel.org, gregkh@linuxfoundation.org
Subject: Re: [PATCH v2 ] devcoredump : Serialize devcd_del work
Date: Mon, 25 Apr 2022 19:19:58 +0200 [thread overview]
Message-ID: <8186de033c87f0cdec296ae272a72c5b9a2880a3.camel@sipsolutions.net> (raw)
In-Reply-To: <87levt14kn.ffs@tglx>
On Mon, 2022-04-25 at 19:00 +0200, Thomas Gleixner wrote:
>
> Johannes, can you please explain whether this immediate flush in
> disabled_store() is really required and if so, why?
>
I don't really know, as I remember that requirement (or maybe even code,
not sure) came from Kees, who needed the lockdown.
Given the use case (ChromeOS?) I'm not sure I see a need to flush all of
them, since I guess a typical system would set the lockdown early in
boot and hopefully not have a crash-dump around already.
That said, I don't think the diagram you made works - fn() during the
iteration is guaranteed to be invoked with a reference of its own, so
the put_device() there can't be the last reference, only as fn() returns
you'd put the last reference *there*, freeing it.
johannes
next prev parent reply other threads:[~2022-04-25 17:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-25 13:09 Mukesh Ojha
2022-04-25 14:06 ` Greg KH
2022-04-25 17:00 ` Thomas Gleixner
2022-04-25 17:19 ` Johannes Berg [this message]
2022-04-25 19:37 ` Thomas Gleixner
2022-04-26 14:04 ` Mukesh Ojha
2022-04-26 21:25 ` Kees Cook
2022-04-27 11:58 ` Johannes Berg
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=8186de033c87f0cdec296ae272a72c5b9a2880a3.camel@sipsolutions.net \
--to=johannes@sipsolutions.net \
--cc=gregkh@linuxfoundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=quic_mojha@quicinc.com \
--cc=rafael@kernel.org \
--cc=sboyd@kernel.org \
--cc=tglx@linutronix.de \
/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
all inboxes | Powered by JetHome®