linux-kernel - Re: [patch 1/2] ufd v1 - unsequential O(1) fdmap core

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.4.64.0706041051090.30836@alien.or.mcafeemobile.com>
Date:	Mon, 4 Jun 2007 10:57:31 -0700 (PDT)
From:	Davide Libenzi <davidel@...ilserver.org>
To:	Andrew Morton <akpm@...ux-foundation.org>
cc:	Ingo Molnar <mingo@...e.hu>, Eric Dumazet <dada1@...mosbay.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ulrich Drepper <drepper@...hat.com>
Subject: Re: [patch 1/2] ufd v1 - unsequential O(1) fdmap core

On Mon, 4 Jun 2007, Andrew Morton wrote:

> > must be RCU friendly (proper barriers) since it's used in 
> > lockless code,
> 
> Haven't looked at that.
> 
> > and must have flags associated to an allocation.
> 
> Don't understand that.

It needs to be able to store flags (like close-on-exec, and maybe more) 
together with a file*.

> > And I'm 
> > leaving out the O(1) part, that for something like this, is just silly not 
> > to have it. This is really an array.
> 
> Having to walk down a tree in fget_light() would kinda suck.
> 
> What about my b)?

Right now, I'm working on a patch that uses fdmap even for legacy 
(sequential) fd allocations. With a cleaner interface, w/out having code 
all around the kernel that access fdtable members directly. This should 
cut some code WRT using two different allocators (code in fs/file.c will 
almost zip-away), and maybe it'll look even better and have some new 
comments too ;)
It can be, in theory, completely abstracted and moved into lib/. I'll look 
into it once I completed the first cleanup, assuming the whole thing won't 
look worse than before :)

- 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/