Date: Wed, 11 Nov 2015 16:46:48 +0800
From: Minfei Huang <mnfhuang@gmail.com>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Zhou Chengming <zhouchengming1@huawei.com>, sjenning@redhat.com,
        jkosina@suse.cz, vojtech@suse.cz, live-patching@vger.kernel.org,
        linux-kernel@vger.kernel.org, guohanjun@huawei.com,
        huawei.libin@huawei.com, xiexiuqi@huawei.com, cbay@alwaysdata.com
Subject: Re: [PATCH v2] livepatch: x86: bugfix about kASLR
Message-ID: <20151111084648.GA26302@dhcp-129-10.nay.redhat.com>
References: <1446791100-41585-1-git-send-email-zhouchengming1@huawei.com>
 <20151110140721.GC3163@treble.redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20151110140721.GC3163@treble.redhat.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1370
Lines: 39

On 11/10/15 at 08:07am, Josh Poimboeuf wrote:
> On Fri, Nov 06, 2015 at 02:25:00PM +0800, Zhou Chengming wrote:
> > When enable KASLR, livepatch will adjust old_addr of changed
> > function accordingly. So do the same thing for reloc.
> > 
> > +
> > +#if defined(CONFIG_RANDOMIZE_BASE)
> > +			/* If KASLR has been enabled, adjust old value accordingly */
> > +			if (kaslr_enabled())
> > +				reloc->val += kaslr_offset();
> > +#endif
> >  			ret = klp_verify_vmlinux_symbol(reloc->name,
> >  							reloc->val);
> >  			if (ret)
> 
> Zhou, thanks a lot for this fix.
> 
> Generally I think this patch is fine.  However, Chris J Arges is working
> on another patch[*] which may get rid of reloc->val as an input and make
> this patch obsolete.
> 
> So, assuming Chris's patch eventually gets accepted, I don't see a need
> for this one unless anybody wants it as a bug fix for 4.4.
> 
> [*] https://lkml.kernel.org/r/1447085770-11729-1-git-send-email-chris.j.arges@canonical.com
> 

Hi, Josh.

I think Jessica Yu is working on the relative patchset which will
offload relocation logical to the module loader.

Thanks
Minfei
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/