linux-kernel - Re: [PATCH] scripts: Add script to extract built-in firmware blobs

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]

Message-Id: <20250124150756.b8b9b9ac9aaff778a9edcbf0@linux-foundation.org>
Date: Fri, 24 Jan 2025 15:07:56 -0800
From: Andrew Morton <akpm@...ux-foundation.org>
To: "Guilherme G. Piccoli" <gpiccoli@...lia.com>
Cc: linux-kernel@...r.kernel.org, mcgrof@...nel.org, russ.weight@...ux.dev,
 dakr@...nel.org, gregkh@...uxfoundation.org, rafael@...nel.org,
 masahiroy@...nel.org, nathan@...nel.org, nicolas@...sle.eu,
 kernel-dev@...lia.com, kernel@...ccoli.net, Thadeu Lima de Souza Cascardo
 <cascardo@...lia.com>
Subject: Re: [PATCH] scripts: Add script to extract built-in firmware blobs

On Fri, 24 Jan 2025 09:31:07 -0300 "Guilherme G. Piccoli" <gpiccoli@...lia.com> wrote:

> On 24/01/2025 03:38, Andrew Morton wrote:
> > On Mon, 20 Jan 2025 16:04:26 -0300 "Guilherme G. Piccoli" <gpiccoli@...lia.com> wrote:
> > 
> >> Through the options CONFIG_EXTRA_FIRMWARE{_DIR} one is able to build
> >> a kernel including firmware blobs in a built-in fashion. This is
> >> usually the case of built-in drivers that require some blobs in
> >> order to work properly, for example, like in non-initrd based systems.
> >>
> >> Add hereby a script to extract these blobs from a non-stripped vmlinux,
> >> similar to the idea of "extract-ikconfig". The firmware loader interface
> >> saves such built-in blobs as rodata entries, having a field for the FW
> >> name as "_fw_<module_name>_<firmware_name>_bin"; the tool extracts files
> >> named "<module_name>_<firmware_name>" for each rodata firmware entry
> >> detected. It makes use of awk, bash, dd and readelf, pretty standard
> >> tooling for Linux development.
> > 
> > Please describe the use case(s) for this.  ie, why are you suggesting
> > this be added to Linux?
> > 
> 
> Hi Andrew, there is currently no tool to extract a firmware blob that is
> built-in on vmlinux to the best of my knowledge. So if we have a kernel
> image containing the blobs, and we want to rebuild the kernel with some
> debug patches for example (and given that the image also has
> IKCONFIG=y), we currently can't do that for the same versions for all
> the firmware blobs, _unless_ we have exact commits of linux-firmware for
> the specific versions for each firmware included.
> 
> With this tool, we can blindly extract the FWs and easily re-add them in
> the new debug kernel build, allowing a more deterministic testing
> without the burden of "hunting down" the proper version of each firmware
> binary.
> 
> Makes sense to you?

OK, thanks.  I (badly) pasted the above into the changelog.