linux-kernel - Re: [PATCH 2/4] arm64: cpufeature: add feature for CRC32 instructions

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]

Date:   Tue, 4 Sep 2018 10:38:45 +0100
From:   Will Deacon <will.deacon@....com>
To:     Herbert Xu <herbert@...dor.apana.org.au>
Cc:     Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        linux-arm-kernel <linux-arm-kernel@...ts.infradead.org>,
        "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" 
        <linux-crypto@...r.kernel.org>,
        Catalin Marinas <catalin.marinas@....com>,
        Eric Biggers <ebiggers@...gle.com>,
        "Suzuki K. Poulose" <suzuki.poulose@....com>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/4] arm64: cpufeature: add feature for CRC32 instructions

On Tue, Sep 04, 2018 at 11:18:55AM +0800, Herbert Xu wrote:
> On Tue, Aug 28, 2018 at 08:43:35PM +0200, Ard Biesheuvel wrote:
> > On 28 August 2018 at 19:01, Will Deacon <will.deacon@....com> wrote:
> > > On Mon, Aug 27, 2018 at 01:02:43PM +0200, Ard Biesheuvel wrote:
> > >> Add a CRC32 feature bit and wire it up to the CPU id register so we
> > >> will be able to use alternatives patching for CRC32 operations.
> > >>
> > >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@...aro.org>
> > >> ---
> > >>  arch/arm64/include/asm/cpucaps.h | 3 ++-
> > >>  arch/arm64/kernel/cpufeature.c   | 9 +++++++++
> > >>  2 files changed, 11 insertions(+), 1 deletion(-)
> > >
> > > Acked-by: Will Deacon <will.deacon@....com>
> > >
> > > With the minor caveat below...
> > >
> > >> diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
> > >> index ae1f70450fb2..9932aca9704b 100644
> > >> --- a/arch/arm64/include/asm/cpucaps.h
> > >> +++ b/arch/arm64/include/asm/cpucaps.h
> > >> @@ -51,7 +51,8 @@
> > >>  #define ARM64_SSBD                           30
> > >>  #define ARM64_MISMATCHED_CACHE_TYPE          31
> > >>  #define ARM64_HAS_STAGE2_FWB                 32
> > >> +#define ARM64_HAS_CRC32                              33
> > >>
> > >> -#define ARM64_NCAPS                          33
> > >> +#define ARM64_NCAPS                          34
> > >
> > >
> > > ... if this goes via crypto, you'll almost certainly get a (trivial)
> > > conflict with arm64, since these numbers get bumped all the time.
> > >
> > 
> > I think the first three patches should go through the arm64 tree. The
> > last one just removes the now redundant crc32 SIMD driver, and Herbert
> > could pick that up separately, i.e., it should be totally independent.
> 
> Yes let's do that.

Okey doke! In which case, please can we have your Ack on the first patch?

Cheers,

Will