linux-kernel - Re: [PATCH] RTC: Add mmap method to rtc character driver

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: <44C67E1A.7050105@zytor.com>
Date:	Tue, 25 Jul 2006 13:24:58 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	Dave Airlie <airlied@...il.com>
CC:	Neil Horman <nhorman@...driver.com>,
	Segher Boessenkool <segher@...nel.crashing.org>,
	linux-kernel@...r.kernel.org, a.zummo@...ertech.it,
	jg@...edesktop.org
Subject: Re: [PATCH] RTC: Add mmap method to rtc character driver

Dave Airlie wrote:
> 
> So far the requirements are pretty much not high resolution but is
> accurate and increasing. so like 10ms is fine, the current X timer is
> in the 20ms range.
> 
> I think an mmap'ed page with whatever cgt(CLOCK_MONOTONIC) returns
> would be very good, but it might be nice to implement some sort of new
> generic /dev that X can mmap and each arch can do what they want in
> it,
> 
> I'm wondering why x86 doesn't have gettimeofday vDSO (does x86 have
> proper vDSO support at all apart from sysenter?),
> 

The i386 vdso right now has only two entry points, as far as I can tell: 
system call and signal return.

There is no reason it couldn't have more than that.  A low-resolution 
and a high-resolution gettimeofday might be a good idea.

	-hpa

-
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/