public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Stephan Mueller <smueller@chronox.de>
To: John Stultz <john.stultz@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Herbert Xu <herbert@gondor.apana.org.au>,
	Alexander Kuleshov <kuleshovmail@gmail.com>,
	y2038 Mailman List <y2038@lists.linaro.org>,
	lkml <linux-kernel@vger.kernel.org>,
	linux-crypto@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Kees Cook <keescook@chromium.org>
Subject: Re: [Y2038] [PATCH] crypto: use timespec64 for jent_get_nstime
Date: Tue, 21 Jun 2016 19:16:15 +0200	[thread overview]
Message-ID: <2228716.yrSLSS60Ke@tauon.atsec.com> (raw)
In-Reply-To: <CALAqxLV4qmY8hhzYjQ8+Mx-Tb5WKP1RUQd4JLUnoZRndKTM9og@mail.gmail.com>

Am Dienstag, 21. Juni 2016, 10:12:24 schrieb John Stultz:

Hi John,
> 
> So this is definitely more clear then what was described earlier, and
> worries me because on many x86 machines (though fewer I guess these
> days then in the past) the clocksource will often not be the TSC (and
> have lower resolution).

Please note, the use of the ktime_get_raw_ns() is *only* used as a fallback on 
architectures where random_get_entropy / get_cycles is not implemented.

So, on X86 and on many other arches, this function call will never be 
triggered.

...
> 
> But please just make sure the reason why you're using that specific
> interface is clearly documented in the code so we don't have to later
> reverse engineer the intent.

Will do.

@Arnd: I would prepare a patch then using ktime_get_raw_ns and providing a 
good documentation in the code.

Ciao
Stephan

      reply	other threads:[~2016-06-21 17:17 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-17 15:59 [PATCH] crypto: use timespec64 for jent_get_nstime Arnd Bergmann
2016-06-18  8:16 ` Stephan Mueller
2016-06-21  6:20 ` Stephan Mueller
2016-06-21  8:32   ` Arnd Bergmann
2016-06-21  8:39     ` Stephan Mueller
2016-06-21 16:22     ` [Y2038] " John Stultz
2016-06-21 16:34       ` Stephan Mueller
2016-06-21 16:47         ` John Stultz
2016-06-21 16:51           ` Stephan Mueller
2016-06-21 17:07             ` Stephan Mueller
2016-06-21 17:12             ` John Stultz
2016-06-21 17:16               ` Stephan Mueller [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=2228716.yrSLSS60Ke@tauon.atsec.com \
    --to=smueller@chronox.de \
    --cc=arnd@arndb.de \
    --cc=davem@davemloft.net \
    --cc=herbert@gondor.apana.org.au \
    --cc=john.stultz@linaro.org \
    --cc=keescook@chromium.org \
    --cc=kuleshovmail@gmail.com \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=y2038@lists.linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox