linux-kernel - Re: [PATCH v1 11/13] arm64: mm: More flags for __flush_tlb

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: <aV3RMohRCvzWnuwI@a079125.arm.com>
Date: Wed, 7 Jan 2026 08:51:22 +0530
From: Linu Cherian <linu.cherian@....com>
To: Ryan Roberts <ryan.roberts@....com>
Cc: Will Deacon <will@...nel.org>, Ard Biesheuvel <ardb@...nel.org>,
	Catalin Marinas <catalin.marinas@....com>,
	Mark Rutland <mark.rutland@....com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Oliver Upton <oliver.upton@...ux.dev>,
	Marc Zyngier <maz@...nel.org>, Dev Jain <dev.jain@....com>,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 11/13] arm64: mm: More flags for __flush_tlb_range()

Ryan,

On Tue, Dec 16, 2025 at 02:45:56PM +0000, Ryan Roberts wrote:
> Refactor function variants with "_nosync", "_local" and "_nonotify" into
> a single __always_inline implementation that takes flags and rely on
> constant folding to select the parts that are actually needed at any
> given callsite, based on the provided flags.
> 
> Flags all live in the tlbf_t (TLB flags) type; TLBF_NONE (0) continues
> to provide the strongest semantics (i.e. evict from walk cache,
> broadcast, synchronise and notify). Each flag reduces the strength in
> some way; TLBF_NONOTIFY, TLBF_NOSYNC and TLBF_NOBROADCAST are added to
> complement the existing TLBF_NOWALKCACHE.

It would be nice to have some notes added on the below for better clarity 
* What a walk cache is and why we bother about them ?
* Why and how should we invalidate the walk caches ?

--
Linu Cherian.