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Message-ID: <24fedc0f503527ef847a4f534277856388fb6a6a.camel@linux.intel.com>
Subject: Re: [PATCH v4 00/10] Function Granular KASLR
From:   Kristen Carlson Accardi <kristen@linux.intel.com>
To:     Joe Lawrence <joe.lawrence@redhat.com>,
        Kees Cook <keescook@chromium.org>,
        Miroslav Benes <mbenes@suse.cz>
Cc:     tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        arjan@linux.intel.com, x86@kernel.org,
        linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com,
        rick.p.edgecombe@intel.com, live-patching@vger.kernel.org
Date:   Wed, 22 Jul 2020 11:24:46 -0700
In-Reply-To: <b5bc7a92-a11e-d75d-eefb-fc640c87490d@redhat.com>
References: <20200717170008.5949-1-kristen@linux.intel.com>
         <alpine.LSU.2.21.2007221122110.10163@pobox.suse.cz>
         <202007220738.72F26D2480@keescook>
         <aa51eb26-e2a9-c448-a3b8-e9e68deeb468@redhat.com>
         <b5bc7a92-a11e-d75d-eefb-fc640c87490d@redhat.com>
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On Wed, 2020-07-22 at 10:56 -0400, Joe Lawrence wrote:
> On 7/22/20 10:51 AM, Joe Lawrence wrote:
> > On 7/22/20 10:39 AM, Kees Cook wrote:
> > > On Wed, Jul 22, 2020 at 11:27:30AM +0200, Miroslav Benes wrote:
> > > > Let me CC live-patching ML, because from a quick glance this is
> > > > something
> > > > which could impact live patching code. At least it invalidates
> > > > assumptions
> > > > which "sympos" is based on.
> > > 
> > > In a quick skim, it looks like the symbol resolution is using
> > > kallsyms_on_each_symbol(), so I think this is safe? What's a good
> > > selftest for live-patching?
> > > 
> > 
> > Hi Kees,
> > 
> > I don't think any of the in-tree tests currently exercise the
> > kallsyms/sympos end of livepatching.
> > 
> 
> On second thought, I mispoke.. The general livepatch code does use
> it:
> 
> klp_init_object
>    klp_init_object_loaded
>      klp_find_object_symbol
> 
> in which case any of the current kselftests should exercise that.
> 
>    % make -C tools/testing/selftests/livepatch run_tests
> 
> -- Joe
> 

Thanks, it looks like this should work for helping me exercise the live
patch code paths. I will take a look and get back to you all.