linux-kernel - Re: [PATCH] Revised timerfd() interface

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: <Pine.LNX.4.64.0709050901420.11426@alien.or.mcafeemobile.com>
Date:	Wed, 5 Sep 2007 09:14:12 -0700 (PDT)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Michael Kerrisk <mtk-manpages@....net>
cc:	rdunlap@...otime.net, tglx@...utronix.de,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ulrich Drepper <drepper@...hat.com>, stable@...nel.org,
	hch@....de, jengelh@...putergmbh.de, corbet@....net,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] Revised timerfd() interface

On Wed, 5 Sep 2007, Michael Kerrisk wrote:

> Davide,

A Michael!


> > > As I think about this more, I see more problems with
> > > your argument.  timerfd needs the ability to get and 
> > > get-while-setting just as much as the earlier APIs.
> > > Consider a library that creates a timerfd file descriptor that
> > > is handed off to an application: that library may want
> > > to modify the timer settings without having to create a
> > > new file descriptor (the app mey not be able to be told about
> > > the new fd).  Your argument just doesn't hold, AFAICS.
> > 
> > Such hypotethical library, in case it really wanted to offer such 
> > functionality, could simply return an handle instead of the raw fd, and 
> > take care of all that stuff in userspace.
> 
> Did I miss something?  Is it not the case that as soon as the
> library returns a handle, rather than an fd, then the whole
> advantage of timerfd() (being able to select/poll/epoll on 
> the timer as well as other fds) is lost?  

Why? The handle would simply be a little struct where the timerfd fd is 
stored, and a XXX_getfd() would return it.
So my point is, I doubt such functionalities are really needed, and I also 
argue that the kernel is the best place for such wrapper code to go.



- Davide


-
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/