linux-kernel - Re: Apparent backward time travel in timestamps on file creation

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <23410.1490902528@warthog.procyon.org.uk>
Date:   Thu, 30 Mar 2017 20:35:28 +0100
From:   David Howells <dhowells@...hat.com>
To:     Linus Torvalds <torvalds@...ux-foundation.org>
Cc:     dhowells@...hat.com, Thomas Gleixner <tglx@...utronix.de>,
        John Stultz <john.stultz@...aro.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        linux-fsdevel <linux-fsdevel@...r.kernel.org>
Subject: Re: Apparent backward time travel in timestamps on file creation

Linus Torvalds <torvalds@...ux-foundation.org> wrote:

> The difference can be quite noticeable - basically the
> "gettimeofday()" time will interpolate within timer ticks, while
> "xtime" is just the truncated "time at timer tick" value _without_ the
> correction.

Is there any way to determine the error bar, do you know?  Or do I just make
up a fudge factor?

Obviously the filesystem truncation would need to be taken into account (and
this can be different for different timestamps within the same filesystem).

David