All of lore.kernel.org
 help / color / mirror / Atom feed
From: Vincent Whitchurch <vincent.whitchurch@axis.com>
To: David Gow <davidgow@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	Patricia Alfonso <trishalfonso@google.com>,
	Jeff Dike <jdike@addtoit.com>,
	Richard Weinberger <richard@nod.at>,
	"anton.ivanov@cambridgegreys.com"
	<anton.ivanov@cambridgegreys.com>,
	Brendan Higgins <brendanhiggins@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	kasan-dev <kasan-dev@googlegroups.com>,
	"linux-um@lists.infradead.org" <linux-um@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Daniel Latypov <dlatypov@google.com>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"kunit-dev@googlegroups.com" <kunit-dev@googlegroups.com>
Subject: Re: [PATCH v4 2/2] UML: add support for KASAN under x86_64
Date: Fri, 1 Jul 2022 11:16:53 +0200	[thread overview]
Message-ID: <20220701091653.GA7009@axis.com> (raw)
In-Reply-To: <CABVgOSmxnTc31C-gbmbns+8YOkpppK77sdXLzASZ-hspFYDwfA@mail.gmail.com>

On Fri, Jul 01, 2022 at 11:08:27AM +0200, David Gow wrote:
> On Thu, Jun 30, 2022 at 9:29 PM Andrey Konovalov <andreyknvl@gmail.com> wrote:
> > Stack trace collection code might trigger KASAN splats when walking
> > stack frames, but this can be resolved by using unchecked accesses.
> > The main reason to disable instrumentation here is for performance
> > reasons, see the upcoming patch for arm64 [1] for some details.
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?id=802b91118d11
> 
> Ah -- that does it! Using READ_ONCE_NOCHECK() in dump_trace() gets rid
> of the nasty recursive KASAN failures we were getting in the tests.
> 
> I'll send out v5 with those files instrumented again.

Hmm, do we really want that?  In the patch Andrey linked to above he
removed the READ_ONCE_NOCHECK() and added the KASAN_SANITIZE on the
corresponding files for arm64, just like it's already the case in this
patch for UML.

_______________________________________________
linux-um mailing list
linux-um@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-um


WARNING: multiple messages have this Message-ID (diff)
From: Vincent Whitchurch <vincent.whitchurch@axis.com>
To: David Gow <davidgow@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>,
	Dmitry Vyukov <dvyukov@google.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	Patricia Alfonso <trishalfonso@google.com>,
	Jeff Dike <jdike@addtoit.com>,
	Richard Weinberger <richard@nod.at>,
	"anton.ivanov@cambridgegreys.com"
	<anton.ivanov@cambridgegreys.com>,
	Brendan Higgins <brendanhiggins@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andrey Ryabinin <ryabinin.a.a@gmail.com>,
	kasan-dev <kasan-dev@googlegroups.com>,
	"linux-um@lists.infradead.org" <linux-um@lists.infradead.org>,
	LKML <linux-kernel@vger.kernel.org>,
	Daniel Latypov <dlatypov@google.com>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	"kunit-dev@googlegroups.com" <kunit-dev@googlegroups.com>
Subject: Re: [PATCH v4 2/2] UML: add support for KASAN under x86_64
Date: Fri, 1 Jul 2022 11:16:53 +0200	[thread overview]
Message-ID: <20220701091653.GA7009@axis.com> (raw)
In-Reply-To: <CABVgOSmxnTc31C-gbmbns+8YOkpppK77sdXLzASZ-hspFYDwfA@mail.gmail.com>

On Fri, Jul 01, 2022 at 11:08:27AM +0200, David Gow wrote:
> On Thu, Jun 30, 2022 at 9:29 PM Andrey Konovalov <andreyknvl@gmail.com> wrote:
> > Stack trace collection code might trigger KASAN splats when walking
> > stack frames, but this can be resolved by using unchecked accesses.
> > The main reason to disable instrumentation here is for performance
> > reasons, see the upcoming patch for arm64 [1] for some details.
> >
> > [1] https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?id=802b91118d11
> 
> Ah -- that does it! Using READ_ONCE_NOCHECK() in dump_trace() gets rid
> of the nasty recursive KASAN failures we were getting in the tests.
> 
> I'll send out v5 with those files instrumented again.

Hmm, do we really want that?  In the patch Andrey linked to above he
removed the READ_ONCE_NOCHECK() and added the KASAN_SANITIZE on the
corresponding files for arm64, just like it's already the case in this
patch for UML.


  reply	other threads:[~2022-07-01  9:17 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-06-30  8:08 [PATCH v4 1/2] mm: Add PAGE_ALIGN_DOWN macro David Gow
2022-06-30  8:08 ` David Gow
2022-06-30  8:08 ` [PATCH v4 2/2] UML: add support for KASAN under x86_64 David Gow
2022-06-30  8:08   ` David Gow
2022-06-30  9:41   ` Dmitry Vyukov
2022-06-30  9:41     ` Dmitry Vyukov
2022-06-30 12:54     ` Vincent Whitchurch
2022-06-30 12:54       ` Vincent Whitchurch
2022-06-30 13:28       ` Andrey Konovalov
2022-06-30 13:28         ` Andrey Konovalov
2022-07-01  9:08         ` David Gow
2022-07-01  9:08           ` David Gow
2022-07-01  9:16           ` Vincent Whitchurch [this message]
2022-07-01  9:16             ` Vincent Whitchurch
2022-07-01  9:43             ` David Gow
2022-07-01  9:43               ` David Gow
2022-07-01 10:04               ` Vincent Whitchurch
2022-07-01 10:04                 ` Vincent Whitchurch
2022-07-01 10:34                 ` Dmitry Vyukov
2022-07-01 10:34                   ` Dmitry Vyukov

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=20220701091653.GA7009@axis.com \
    --to=vincent.whitchurch@axis.com \
    --cc=akpm@linux-foundation.org \
    --cc=andreyknvl@gmail.com \
    --cc=anton.ivanov@cambridgegreys.com \
    --cc=brendanhiggins@google.com \
    --cc=davidgow@google.com \
    --cc=dlatypov@google.com \
    --cc=dvyukov@google.com \
    --cc=jdike@addtoit.com \
    --cc=johannes@sipsolutions.net \
    --cc=kasan-dev@googlegroups.com \
    --cc=kunit-dev@googlegroups.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-um@lists.infradead.org \
    --cc=richard@nod.at \
    --cc=ryabinin.a.a@gmail.com \
    --cc=trishalfonso@google.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.