linux-kernel - Re: [PATCH] kexec: Replace kmap() with kmap_local

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] [day] [month] [year] [list]

Date:   Fri, 08 Jul 2022 01:50:35 +0200
From:   "Fabio M. De Francesco" <fmdefrancesco@...il.com>
To:     Eric Biederman <ebiederm@...ssion.com>, kexec@...ts.infradead.org,
        linux-kernel@...r.kernel.org
Cc:     Ira Weiny <ira.weiny@...el.com>
Subject: Re: [PATCH] kexec: Replace kmap() with kmap_local_page()

On venerdì 8 luglio 2022 01:14:12 CEST Fabio M. De Francesco wrote:
> The use of kmap() and kmap_atomic() are being deprecated in favor of
> kmap_local_page().
> 
> With kmap_local_page(), the mappings are per thread, CPU local and not
> globally visible. Furthermore, the mappings can be acquired from any
> context (including interrupts).
> 
> Therefore, use kmap_local_page() in kexec_core.c because these mappings 
are
> per thread, CPU local, and not globally visible.
> 
> Tested on a QEMU + KVM 32-bits VM booting a kernel with HIGHMEM64GB
> enabled.
> 
> Suggested-by: Ira Weiny <ira.weiny@...el.com>
> Signed-off-by: Fabio M. De Francesco <fmdefrancesco@...il.com>
> ---
> 
> v1->v2: A sentence of the commit message contained an error due to a
> mistake in copy-pasting from a previous patch. Replace "aio.c" with
> "kexec_core.c".
> 
>  kernel/kexec_core.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
Sorry, another error... Please discard this patch because the version 
number is missing in the subject.

The second version, hopefully final and correct, is at
https://lore.kernel.org/lkml/20220707231550.1484-1-fmdefrancesco@gmail.com/

Thank you,

Fabio