linux-mm.kvack.org archive mirror
 help / color / mirror / Atom feed
From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Abbott Liu <liuwenliang@huawei.com>,
	kstewart@linuxfoundation.org, tixy@linaro.org,
	grygorii.strashko@linaro.org, julien.thierry@arm.com,
	Catalin Marinas <catalin.marinas@arm.com>,
	linux@rasmusvillemoes.dk, dhowells@redhat.com,
	linux-mm@kvack.org, mark.rutland@arm.com,
	kvmarm@lists.cs.columbia.edu, f.fainelli@gmail.com,
	Jonathan Corbet <corbet@lwn.net>,
	linux-doc@vger.kernel.org, kasan-dev@googlegroups.com,
	geert@linux-m68k.org, linux-arm-kernel@lists.infradead.org,
	zhichao.huang@linaro.org, aryabinin@virtuozzo.com,
	labbott@redhat.com, vladimir.murzin@arm.com,
	keescook@chromium.org, Arnd Bergmann <arnd@arndb.de>,
	marc.zyngier@arm.com, philip@cog.systems, jinb.park7@gmail.com,
	opendmb@gmail.com, tglx@linutronix.de, dvyukov@google.com,
	ard.biesheuvel@linaro.org, gregkh@linuxfoundation.org,
	mawilcox@microsoft.com, linux-kernel@vger.kernel.org,
	alexander.levin@verizon.com, james.morse@arm.com,
	kirill.shutemov@linux.intel.com, pombredanne@nexb.com,
	Andrew Morton <akpm@linux-foundation.org>,
	thgarnie@google.com, christoffer.dall@linaro.org
Subject: Re: [PATCH v3 5/6] Initialize the mapping of KASan shadow memory
Date: Mon, 2 Apr 2018 19:15:37 +0100	[thread overview]
Message-ID: <20180402181536.GJ16141@n2100.armlinux.org.uk> (raw)
In-Reply-To: <nycvar.YSQ.7.76.1804021402521.28462@knanqh.ubzr>

On Mon, Apr 02, 2018 at 02:08:13PM -0400, Nicolas Pitre wrote:
> On Mon, 2 Apr 2018, Abbott Liu wrote:
> 
> > index c79b829..20161e2 100644
> > --- a/arch/arm/kernel/head-common.S
> > +++ b/arch/arm/kernel/head-common.S
> > @@ -115,6 +115,9 @@ __mmap_switched:
> >  	str	r8, [r2]			@ Save atags pointer
> >  	cmp	r3, #0
> >  	strne	r10, [r3]			@ Save control register values
> > +#ifdef CONFIG_KASAN
> > +	bl	kasan_early_init
> > +#endif
> >  	mov	lr, #0
> >  	b	start_kernel
> >  ENDPROC(__mmap_switched)
> 
> Would be better if lr was cleared before calling kasan_early_init.

No.  The code is correct - please remember that "bl" writes to LR.

The point of clearing LR here is to ensure that start_kernel is called
with a zero link register, which it won't be if kasan_early_init is
moved after it.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up

  reply	other threads:[~2018-04-02 18:16 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-02 12:04 [PATCH v3 0/6] KASan for arm Abbott Liu
2018-04-02 12:04 ` [PATCH v3 1/6] Add TTBR operator for kasan_init Abbott Liu
2018-04-02 12:04 ` [PATCH v3 2/6] Disable instrumentation for some code Abbott Liu
2018-04-03 11:30   ` Marc Zyngier
2018-04-03 11:38     ` Russell King - ARM Linux
2018-04-02 12:04 ` [PATCH v3 3/6] Replace memory function for kasan Abbott Liu
2018-04-02 12:04 ` [PATCH v3 4/6] Define the virtual space of KASan's shadow region Abbott Liu
2018-04-02 12:04 ` [PATCH v3 5/6] Initialize the mapping of KASan shadow memory Abbott Liu
2018-04-02 18:08   ` Nicolas Pitre
2018-04-02 18:15     ` Russell King - ARM Linux [this message]
2018-04-02 18:20       ` Nicolas Pitre
2018-04-02 12:04 ` [PATCH v3 6/6] Enable KASan for arm Abbott Liu

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=20180402181536.GJ16141@n2100.armlinux.org.uk \
    --to=linux@armlinux.org.uk \
    --cc=akpm@linux-foundation.org \
    --cc=alexander.levin@verizon.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=arnd@arndb.de \
    --cc=aryabinin@virtuozzo.com \
    --cc=catalin.marinas@arm.com \
    --cc=christoffer.dall@linaro.org \
    --cc=corbet@lwn.net \
    --cc=dhowells@redhat.com \
    --cc=dvyukov@google.com \
    --cc=f.fainelli@gmail.com \
    --cc=geert@linux-m68k.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=grygorii.strashko@linaro.org \
    --cc=james.morse@arm.com \
    --cc=jinb.park7@gmail.com \
    --cc=julien.thierry@arm.com \
    --cc=kasan-dev@googlegroups.com \
    --cc=keescook@chromium.org \
    --cc=kirill.shutemov@linux.intel.com \
    --cc=kstewart@linuxfoundation.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=labbott@redhat.com \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux@rasmusvillemoes.dk \
    --cc=liuwenliang@huawei.com \
    --cc=marc.zyngier@arm.com \
    --cc=mark.rutland@arm.com \
    --cc=mawilcox@microsoft.com \
    --cc=nicolas.pitre@linaro.org \
    --cc=opendmb@gmail.com \
    --cc=philip@cog.systems \
    --cc=pombredanne@nexb.com \
    --cc=tglx@linutronix.de \
    --cc=thgarnie@google.com \
    --cc=tixy@linaro.org \
    --cc=vladimir.murzin@arm.com \
    --cc=zhichao.huang@linaro.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).