linux-kernel - Re: [VDSO]: vdso_test failing on arm 32 bit

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]

Date:   Thu, 8 Feb 2018 16:11:07 +0000
From:   "Lynch, Nathan" <Nathan_Lynch@...tor.com>
To:     Pintu Kumar <pintu.ping@...il.com>
CC:     Russell King - ARM Linux <linux@...linux.org.uk>,
        "david.brown@...aro.org" <david.brown@...aro.org>,
        open list <linux-kernel@...r.kernel.org>,
        "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [VDSO]: vdso_test failing on arm 32 bit

> I commented the device tree reading property:
> arm,cpu-registers-not-fw-configured , from the arch/arm/kernel/vdso.c

Don't do that, please. The presence of that property indicates that the counter is not suitable for use by the OS. There is nothing we can do in Linux to make the VDSO useful on this system; that is why it gets disabled at runtime.

The timing measurements you get are likely tainted by garbage results from the VDSO itself.