linux-kernel - Re: [PATCH 3/3] s390/bitops: Remove volatile qualifier from flogr() inline assembly

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: <b326445d-0aec-44af-95f0-143dda6e635c-jchrist@linux.ibm.com>
Date: Thu, 11 Sep 2025 09:45:01 +0200
From: Juergen Christ <jchrist@...ux.ibm.com>
To: Heiko Carstens <hca@...ux.ibm.com>
Cc: Nathan Chancellor <nathan@...nel.org>, Miguel Ojeda <ojeda@...nel.org>,
        Vasily Gorbik <gor@...ux.ibm.com>,
        Alexander Gordeev <agordeev@...ux.ibm.com>,
        linux-kernel@...r.kernel.org, linux-s390@...r.kernel.org,
        Sven Schnelle <svens@...ux.ibm.com>,
        Christian Borntraeger <borntraeger@...ux.ibm.com>
Subject: Re: [PATCH 3/3] s390/bitops: Remove volatile qualifier from flogr()
 inline assembly

> The flogr() inline assembly has no side effects and generates the same
> output if the input does not change. Therefore remove the volatile
> qualifier to allow the compiler to optimize the inline assembly away,
> if possible.
> 
> This also removes the superfluous '\n' which makes the inline assembly
> appear larger than it is according to compiler heuristics (number of
> lines).
> 
> Suggested-by: Juergen Christ <jchrist@...ux.ibm.com>
> Signed-off-by: Heiko Carstens <hca@...ux.ibm.com>

Reviewed-by: Juergen Christ <jchrist@...ux.ibm.com>