linux-kernel - Re: [PATCH 4/5] mm: shmem: Convert shmem_enabled_show to use sysfs_emit

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: <20201102140836.GJ27442@casper.infradead.org>
Date:   Mon, 2 Nov 2020 14:08:36 +0000
From:   Matthew Wilcox <willy@...radead.org>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Joe Perches <joe@...ches.com>, Hugh Dickins <hughd@...gle.com>,
        Andrew Morton <akpm@...ux-foundation.org>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 4/5] mm: shmem: Convert shmem_enabled_show to use
 sysfs_emit_at

On Mon, Nov 02, 2020 at 02:33:43PM +0100, Greg Kroah-Hartman wrote:
> > Oh, ugh, sysfs_emit() should be able to work on a buffer that isn't
> > page aligned.  Greg, how about this?
> 
> How can sysfs_emit() be called on a non-page-aligned buffer?  It's being
> used on the buffer that was passed to the sysfs call.
> 
> And if you are writing multiple values to a single sysfs file output,
> well, not good...

See shmem_enabled_show() in mm/shmem.c (output at
/sys/kernel/mm/transparent_hugepage/shmem_enabled on your machine).

I don't claim it's a good interface, but it exists.