linux-kernel - Re: [PATCHv3 5/6] arm64: Use __pa

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20161118164602.GD1197@leverpostej>
Date:   Fri, 18 Nov 2016 16:46:02 +0000
From:   Mark Rutland <mark.rutland@....com>
To:     Laura Abbott <labbott@...hat.com>, lorenzo.pieralisi@....com
Cc:     Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Catalin Marinas <catalin.marinas@....com>, x86@...nel.org,
        Will Deacon <will.deacon@....com>,
        linux-kernel@...r.kernel.org, linux-mm@...ck.org,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Joonsoo Kim <iamjoonsoo.kim@....com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Andrew Morton <akpm@...ux-foundation.org>,
        linux-arm-kernel@...ts.infradead.org,
        Marek Szyprowski <m.szyprowski@...sung.com>
Subject: Re: [PATCHv3 5/6] arm64: Use __pa_symbol for kernel symbols

On Fri, Nov 18, 2016 at 02:35:44PM +0000, Mark Rutland wrote:
> Hi Laura,
> 
> On Thu, Nov 17, 2016 at 05:16:55PM -0800, Laura Abbott wrote:
> > 
> > __pa_symbol is technically the marco that should be used for kernel
> > symbols. Switch to this as a pre-requisite for DEBUG_VIRTUAL which
> > will do bounds checking.
> > 
> > Signed-off-by: Laura Abbott <labbott@...hat.com>
> > ---
> > v3: Conversion of more sites besides just _end. Addition of __lm_sym_addr
> > macro to take care of the _va(__pa_symbol(..)) idiom.
> > 
> > Note that a copy of __pa_symbol was added to avoid a mess of headers
> > since the #ifndef __pa_symbol case is defined in linux/mm.h
> 
> I think we also need to fix up virt_to_phys(__cpu_soft_restart) in
> arch/arm64/kernel/cpu-reset.h. Otherwise, this looks complete for uses
> falling under arch/arm64/.

I think I spoke too soon. :(

In the kasan code, use of tmp_pg_dir, kasan_zero_{page,pte,pmd,pud} all
need to be vetted, as those are in the image, but get passed directly to
functions which will end up doing a virt_to_phys behind the scenes (e.g.
cpu_replace_ttbr1(), pmd_populate_kernel()).

There's also some virt_to_pfn(<symbol>) usage that needs to be fixed up
in arch/arm64/kernel/hibernate.c.

... there's also more of that in common kernel code. :(

Thanks,
Mark.