From: David Laight <David.Laight@ACULAB.COM>
To: 'Petko Manolov' <petko.manolov@konsulko.com>,
"Paul E. McKenney" <paulmck@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: RE: [RFC] WRITE_ONCE_INC() and friends
Date: Tue, 21 Apr 2020 08:00:48 +0000 [thread overview]
Message-ID: <3a6f974efad4453e9af7a3152ca0bbce@AcuMS.aculab.com> (raw)
In-Reply-To: <20200420163215.GA43378@carbon>
From: Petko Manolov
> Sent: 20 April 2020 17:32
...
> > But one downside of declaring variables volatile is that it can prevent KCSAN
> > from spotting violations of the concurrency design for those variables.
>
> Which would be unfortunate.
>
> I just wish there was C type declaration that would force the compiler to do
> what READ/WRITE_ONCE() does now, but i also know this is too naive... :)
It does, it is called 'volatile'.
All READ_ONCE() does is force the access through a volatile pointer.
The thing to do is mark the structure elements 'volatile'
rather than using a 'pointer to volatile structure'.
I'm sure KASAN could be taught about volatile structure members.
David.
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-04-21 8:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-19 9:44 Petko Manolov
2020-04-19 18:02 ` David Laight
2020-04-19 18:29 ` Petko Manolov
2020-04-19 21:37 ` David Laight
2020-04-20 15:05 ` Paul E. McKenney
2020-04-20 16:32 ` Petko Manolov
2020-04-21 8:00 ` David Laight [this message]
2020-04-21 9:30 ` Petko Manolov
2020-04-20 22:57 ` Marco Elver
2020-04-20 23:12 ` Paul E. McKenney
2020-04-21 9:33 ` Marco Elver
2020-04-21 13:19 ` Paul E. McKenney
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=3a6f974efad4453e9af7a3152ca0bbce@AcuMS.aculab.com \
--to=david.laight@aculab.com \
--cc=linux-kernel@vger.kernel.org \
--cc=paulmck@kernel.org \
--cc=petko.manolov@konsulko.com \
/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
Powered by JetHome