linux-kernel - Re: [PATCH v4 1/3] kernfs: remove page_mkwrite() from vm_operations

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: <2024070927-expand-carless-0680@gregkh>
Date: Tue, 9 Jul 2024 07:24:36 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: Martin Oliveira <martin.oliveira@...eticom.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	linux-rdma@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	Artemy Kovalyov <artemyko@...dia.com>,
	Jason Gunthorpe <jgg@...pe.ca>, Leon Romanovsky <leon@...nel.org>,
	Logan Gunthorpe <logang@...tatee.com>,
	Michael Guralnik <michaelgur@...dia.com>,
	Mike Marciniszyn <mike.marciniszyn@...el.com>,
	Shiraz Saleem <shiraz.saleem@...el.com>, Tejun Heo <tj@...nel.org>,
	John Hubbard <jhubbard@...dia.com>,
	Dan Williams <dan.j.williams@...el.com>,
	David Sloan <david.sloan@...eticom.com>
Subject: Re: [PATCH v4 1/3] kernfs: remove page_mkwrite() from
 vm_operations_struct

On Mon, Jul 08, 2024 at 10:57:12AM -0600, Martin Oliveira wrote:
> The .page_mkwrite operator of kernfs just calls file_update_time().
> This is the same behaviour that the fault code does if .page_mkwrite is
> not set.
> 
> Furthermore, having the page_mkwrite() operator causes
> writable_file_mapping_allowed() to fail due to
> vma_needs_dirty_tracking() on the gup flow, which is a pre-requisite for
> enabling P2PDMA over RDMA.
> 
> There are no users of .page_mkwrite and no known valid use cases, so
> just remove the .page_mkwrite from kernfs_ops and WARN if an mmap()
> implementation sets .page_mkwrite.
> 
> Co-developed-by: Logan Gunthorpe <logang@...tatee.com>
> Signed-off-by: Logan Gunthorpe <logang@...tatee.com>
> Signed-off-by: Martin Oliveira <martin.oliveira@...eticom.com>
> ---
>  fs/kernfs/file.c | 40 +++++++++++-----------------------------
>  1 file changed, 11 insertions(+), 29 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>