linux-kernel - Re: [PATCH v2 1/7] timekeeping: introduce __current_kernel

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:	Tue, 10 Nov 2015 07:26:01 -0800
From:	John Stultz <john.stultz@...aro.org>
To:	Stefano Stabellini <stefano.stabellini@...citrix.com>
Cc:	Arnd Bergmann <arnd@...db.de>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	xen-devel@...ts.xensource.com, Ian.Campbell@...rix.com,
	Peter Zijlstra <peterz@...radead.org>,
	lkml <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...nel.org>
Subject: Re: [PATCH v2 1/7] timekeeping: introduce __current_kernel_time64

On Tue, Nov 10, 2015 at 7:10 AM, Stefano Stabellini
<stefano.stabellini@...citrix.com> wrote:
> On Tue, 10 Nov 2015, Arnd Bergmann wrote:
>> On Tuesday 10 November 2015 11:57:49 Stefano Stabellini wrote:
>> > __current_kernel_time64 returns a struct timespec64, without taking the
>> > xtime lock. Mirrors __current_kernel_time/current_kernel_time.
>> >
>>
>> Actually it doesn't mirror __current_kernel_time/current_kernel_time
>>
>> > diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
>> > index ec89d84..b5802bf 100644
>> > --- a/include/linux/timekeeping.h
>> > +++ b/include/linux/timekeeping.h
>> > @@ -19,7 +19,8 @@ extern int do_sys_settimeofday(const struct timespec *tv,
>> >   */
>> >  unsigned long get_seconds(void);
>> >  struct timespec64 current_kernel_time64(void);
>> > -/* does not take xtime_lock */
>> > +/* do not take xtime_lock */
>> > +struct timespec64 __current_kernel_time64(void);
>> >  struct timespec __current_kernel_time(void);
>>
>> Please change __current_kernel_time into a static inline function
>> while you are introducing the new one, to match the patch description ;-)
>
> The implementation is:
>
>         struct timekeeper *tk = &tk_core.timekeeper;
>
>         return timespec64_to_timespec(tk_xtime(tk));
>
> which cannot be easily made into a static inline, unless we start
> exporting tk_core.

So the timekeeper is passed to the notifier. So you probably want something like

struct timespec64 __current_kernel_time64(struct timekeeper *tk)
{
 return timespec64_to_timespec(tk_xtime(tk));
}

Then you can cast the priv pointer in the notifier to a timekeeper and
use it that way?

thanks
-john
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/