linux-kernel - Re: [PATCH 08/16] mm: add remap_pfn_range_prepare(), remap_pfn_range

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: <20250908133538.GF616306@nvidia.com>
Date: Mon, 8 Sep 2025 10:35:38 -0300
From: Jason Gunthorpe <jgg@...dia.com>
To: Lorenzo Stoakes <lorenzo.stoakes@...cle.com>
Cc: Andrew Morton <akpm@...ux-foundation.org>,
	Jonathan Corbet <corbet@....net>,
	Matthew Wilcox <willy@...radead.org>, Guo Ren <guoren@...nel.org>,
	Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
	Heiko Carstens <hca@...ux.ibm.com>,
	Vasily Gorbik <gor@...ux.ibm.com>,
	Alexander Gordeev <agordeev@...ux.ibm.com>,
	Christian Borntraeger <borntraeger@...ux.ibm.com>,
	Sven Schnelle <svens@...ux.ibm.com>,
	"David S . Miller" <davem@...emloft.net>,
	Andreas Larsson <andreas@...sler.com>,
	Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Dan Williams <dan.j.williams@...el.com>,
	Vishal Verma <vishal.l.verma@...el.com>,
	Dave Jiang <dave.jiang@...el.com>, Nicolas Pitre <nico@...xnic.net>,
	Muchun Song <muchun.song@...ux.dev>,
	Oscar Salvador <osalvador@...e.de>,
	David Hildenbrand <david@...hat.com>,
	Konstantin Komarov <almaz.alexandrovich@...agon-software.com>,
	Baoquan He <bhe@...hat.com>, Vivek Goyal <vgoyal@...hat.com>,
	Dave Young <dyoung@...hat.com>, Tony Luck <tony.luck@...el.com>,
	Reinette Chatre <reinette.chatre@...el.com>,
	Dave Martin <Dave.Martin@....com>,
	James Morse <james.morse@....com>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Christian Brauner <brauner@...nel.org>, Jan Kara <jack@...e.cz>,
	"Liam R . Howlett" <Liam.Howlett@...cle.com>,
	Vlastimil Babka <vbabka@...e.cz>, Mike Rapoport <rppt@...nel.org>,
	Suren Baghdasaryan <surenb@...gle.com>,
	Michal Hocko <mhocko@...e.com>, Hugh Dickins <hughd@...gle.com>,
	Baolin Wang <baolin.wang@...ux.alibaba.com>,
	Uladzislau Rezki <urezki@...il.com>,
	Dmitry Vyukov <dvyukov@...gle.com>,
	Andrey Konovalov <andreyknvl@...il.com>,
	Jann Horn <jannh@...gle.com>, Pedro Falcato <pfalcato@...e.de>,
	linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, linux-csky@...r.kernel.org,
	linux-mips@...r.kernel.org, linux-s390@...r.kernel.org,
	sparclinux@...r.kernel.org, nvdimm@...ts.linux.dev,
	linux-cxl@...r.kernel.org, linux-mm@...ck.org,
	ntfs3@...ts.linux.dev, kexec@...ts.infradead.org,
	kasan-dev@...glegroups.com
Subject: Re: [PATCH 08/16] mm: add remap_pfn_range_prepare(),
 remap_pfn_range_complete()

On Mon, Sep 08, 2025 at 02:27:12PM +0100, Lorenzo Stoakes wrote:

> It's not only remap that is a concern here, people do all kinds of weird
> and wonderful things in .mmap(), sometimes in combination with remap.

So it should really not be split this way, complete is a badly name
prepopulate and it should only fill the PTEs, which shouldn't need
more locking.

The only example in this series didn't actually need to hold the lock.

Jason