linux-kernel - Re: [PATCH v2 6/6] alloc_tag: config to store page allocation tag refs in page flags

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: <ZtiMZWqht_8Bse-5@casper.infradead.org>
Date: Wed, 4 Sep 2024 17:35:49 +0100
From: Matthew Wilcox <willy@...radead.org>
To: Suren Baghdasaryan <surenb@...gle.com>
Cc: John Hubbard <jhubbard@...dia.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	kent.overstreet@...ux.dev, corbet@....net, arnd@...db.de,
	mcgrof@...nel.org, rppt@...nel.org, paulmck@...nel.org,
	thuth@...hat.com, tglx@...utronix.de, bp@...en8.de,
	xiongwei.song@...driver.com, ardb@...nel.org, david@...hat.com,
	vbabka@...e.cz, mhocko@...e.com, hannes@...xchg.org,
	roman.gushchin@...ux.dev, dave@...olabs.net,
	liam.howlett@...cle.com, pasha.tatashin@...een.com,
	souravpanda@...gle.com, keescook@...omium.org, dennis@...nel.org,
	yuzhao@...gle.com, vvvvvv@...gle.com, rostedt@...dmis.org,
	iamjoonsoo.kim@....com, rientjes@...gle.com, minchan@...gle.com,
	kaleshsingh@...gle.com, linux-doc@...r.kernel.org,
	linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
	linux-mm@...ck.org, linux-modules@...r.kernel.org,
	kernel-team@...roid.com
Subject: Re: [PATCH v2 6/6] alloc_tag: config to store page allocation tag
 refs in page flags

On Wed, Sep 04, 2024 at 09:18:01AM -0700, Suren Baghdasaryan wrote:
> I'm not sure I understand your suggestion, Matthew. We allocate a
> folio and need to store a reference to the tag associated with the
> code that allocated that folio. We are not operating with ranges here.
> Are you suggesting to use a maple tree instead of page_ext to store
> this reference?

I'm saying that a folio has a physical address.  So you can use a physical
address as an index into a maple tree to store additional information
instead of using page_ext or trying to hammer the additional information
into struct page somewhere.