linux-kernel - Re: [PATCH v2] selftests/x86: add "ffff8" -- kernel memory scanner

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: <Y2DAk9zKYG9hT/Ov@p183>
Date:   Tue, 1 Nov 2022 09:45:39 +0300
From:   Alexey Dobriyan <adobriyan@...il.com>
To:     Dave Hansen <dave.hansen@...el.com>
Cc:     "H. Peter Anvin" <hpa@...or.com>, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH v2] selftests/x86: add "ffff8" -- kernel memory scanner

On Mon, Oct 31, 2022 at 02:37:43PM -0700, Dave Hansen wrote:
> On 10/29/22 10:25, Alexey Dobriyan wrote:
> > 
> > 	$ ./ffff8_64 -h
> > 	usage: ./ffff8_64 [-f] [-r] [-n N] [-s S]
> > 	        -f: sequential scan
> > 	        -r: random scan (default)
> > 	        -n: use N threads (default: $(nproc))
> > 	        -s: lowest address shift (default: 47)
> > 	        -t: time to run (default: 256 seconds)
> 
> Does this mean that if someone is just running all kernel selftests,
> they need to wait for 256 seconds for this to finish?

Yes. But low time will cover negligible amount of address space.

Is there some kind of policy to not do this? LTP surely has similar
tests for races.