From: Mark Rutland <mark.rutland@arm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>,
Will Deacon <will.deacon@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
Ingo Molnar <mingo@redhat.com>,
kasan-dev <kasan-dev@googlegroups.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
LKML <linux-kernel@vger.kernel.org>,
"x86@kernel.org" <x86@kernel.org>
Subject: Re: [PATCH] x86, kasan: add KASAN checks to atomic operations
Date: Tue, 14 Mar 2017 15:44:30 +0000 [thread overview]
Message-ID: <20170314154429.GB15740@leverpostej> (raw)
In-Reply-To: <20170314153230.GR5680@worktop>
On Tue, Mar 14, 2017 at 04:32:30PM +0100, Peter Zijlstra wrote:
> On Tue, Mar 14, 2017 at 04:22:52PM +0100, Dmitry Vyukov wrote:
> > -static __always_inline int atomic_read(const atomic_t *v)
> > +static __always_inline int arch_atomic_read(const atomic_t *v)
> > {
> > - return READ_ONCE((v)->counter);
> > + return READ_ONCE_NOCHECK((v)->counter);
>
> Should NOCHEKC come with a comment, because i've no idea why this is so.
I suspect the idea is that given the wrapper will have done the KASAN
check, duplicating it here is either sub-optimal, or results in
duplicate splats. READ_ONCE() has an implicit KASAN check,
READ_ONCE_NOCHECK() does not.
If this is to solve duplicate splats, it'd be worth having a
WRITE_ONCE_NOCHECK() for arch_atomic_set().
Agreed on the comment, regardless.
Thanks,
Mark.
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-03-14 15:44 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-06 12:42 [PATCH] x86, kasan: add KASAN checks to atomic operations Dmitry Vyukov
2017-03-06 12:50 ` Dmitry Vyukov
2017-03-06 12:58 ` Peter Zijlstra
2017-03-06 13:01 ` Peter Zijlstra
2017-03-06 14:24 ` Dmitry Vyukov
2017-03-06 15:20 ` Peter Zijlstra
2017-03-06 16:04 ` Mark Rutland
2017-03-06 15:33 ` Peter Zijlstra
2017-03-06 16:20 ` Mark Rutland
2017-03-06 16:27 ` Dmitry Vyukov
2017-03-06 17:25 ` Mark Rutland
2017-03-06 20:35 ` Peter Zijlstra
2017-03-08 13:42 ` Dmitry Vyukov
2017-03-08 15:20 ` Mark Rutland
2017-03-08 15:27 ` Dmitry Vyukov
2017-03-08 15:43 ` Mark Rutland
2017-03-08 15:45 ` Dmitry Vyukov
2017-03-08 15:48 ` Mark Rutland
2017-03-08 17:43 ` Will Deacon
2017-03-14 15:22 ` Dmitry Vyukov
2017-03-14 15:31 ` Peter Zijlstra
2017-03-14 15:32 ` Peter Zijlstra
2017-03-14 15:44 ` Mark Rutland [this message]
2017-03-14 19:25 ` Dmitry Vyukov
2017-03-06 16:48 ` Andrey Ryabinin
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=20170314154429.GB15740@leverpostej \
--to=mark.rutland@arm.com \
--cc=akpm@linux-foundation.org \
--cc=aryabinin@virtuozzo.com \
--cc=dvyukov@google.com \
--cc=kasan-dev@googlegroups.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=will.deacon@arm.com \
--cc=x86@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).