linux-kernel - Re: [PATCH v2 RESEND 1/2] arm64: avoid flushing icache multiple times on contiguous HugeTLB

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] [day] [month] [year] [list]

Message-Id: <164668935493.3276132.12110588269320094587.b4-ty@kernel.org>
Date:   Mon,  7 Mar 2022 22:03:36 +0000
From:   Will Deacon <will@...nel.org>
To:     mike.kravetz@...cle.com, osalvador@...e.de, rientjes@...gle.com,
        mark.rutland@....com, Muchun Song <songmuchun@...edance.com>,
        akpm@...ux-foundation.org, james.morse@....com,
        bodeddub@...zon.com, david@...hat.com, catalin.marinas@....com,
        song.bao.hua@...ilicon.com
Cc:     kernel-team@...roid.com, Will Deacon <will@...nel.org>,
        smuchun@...il.com, linux-kernel@...r.kernel.org,
        duanxiongchun@...edance.com, linux-mm@...ck.org,
        linux-arm-kernel@...ts.infradead.org, fam.zheng@...edance.com
Subject: Re: [PATCH v2 RESEND 1/2] arm64: avoid flushing icache multiple times on contiguous HugeTLB

On Wed, 2 Mar 2022 16:46:23 +0800, Muchun Song wrote:
> When a contiguous HugeTLB page is mapped, set_pte_at() will be called
> CONT_PTES/CONT_PMDS times.  Therefore, __sync_icache_dcache() will
> flush cache multiple times if the page is executable (to ensure
> the I-D cache coherency).  However, the first flushing cache already
> covers subsequent cache flush operations.  So only flusing cache
> for the head page if it is a HugeTLB page to avoid redundant cache
> flushing.  In the next patch, it is also depends on this change
> since the tail vmemmap pages of HugeTLB is mapped with read-only
> meanning only head page struct can be modified.
> 
> [...]

Applied first patch only to arm64 (for-next/mm), thanks!

[1/2] arm64: avoid flushing icache multiple times on contiguous HugeTLB
      https://git.kernel.org/arm64/c/cf5a501d985b

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev