From: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
To: Linus Torvalds <torvalds@osdl.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
Lukasz Trabinski <lukasz@wsisiz.edu.pl>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: uselib() & 2.6.X?
Date: Sat, 8 Jan 2005 16:28:41 -0200 [thread overview]
Message-ID: <20050108182841.GD2701@logos.cnet> (raw)
In-Reply-To: <Pine.LNX.4.58.0501081042040.2386@ppc970.osdl.org>
On Sat, Jan 08, 2005 at 10:46:19AM -0800, Linus Torvalds wrote:
>
>
> On Fri, 7 Jan 2005, Marcelo Tosatti wrote:
> >
> > Only problem is that current do_brk() callers dont take the lock - you would
> > need a version of do_brk() that doesnt warn for them?
>
> No, I'd just fix them up.
What do you mean by "fix them up" ? With your minimal fix the other do_brk() callers
do not have the lock, you dont mean "fix" by grabbing the lock?
> They mostly don't _need_ the lock (at least not the binary loader ones),
> since at executable loading time you're guaranteed to be the only user
> anyway,
OK - the old mappings have been unmapped at this point, correct? There are no
mappings at all?
I think you also need to fix some cases in arch/sparc{64},arch/mips? as Alan said.
> but hey, we get the lock for do_mmap() there for the same reason:
> to just keep things consistent (and I think we used to have a warning in
> do_mmap() a long time ago when we were chasing down some other bug, so
> doign the same thing for do_brk() is just very consistent).
I think the rule "always have mmap_sem locked when calling do_brk()" is simpler and
easier to understand, but hey, you prefer the minimal fix.
I was also not sure if it was safe to NOT have the lock except for execve() as
you mention.
> Another issue is likely that we should make the whole "uselib()"
> interfaces configurable. I don't think modern binaries use it (where
> "modern" probably means "compiled within the last 8 years" ;).
next prev parent reply other threads:[~2005-01-09 1:30 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-07 15:59 uselib() & 2.6.X? Lukasz Trabinski
2005-01-07 17:07 ` Marcelo Tosatti
2005-01-07 20:27 ` linux-os
2005-01-07 22:29 ` Athanasius
2005-01-07 22:49 ` Alan Cox
2005-01-08 0:15 ` Linus Torvalds
2005-01-07 22:12 ` Marcelo Tosatti
2005-01-08 18:46 ` Linus Torvalds
2005-01-08 18:28 ` Marcelo Tosatti [this message]
2005-01-09 1:38 ` Linus Torvalds
2005-01-09 11:06 ` Marcelo Tosatti
2005-01-10 8:34 ` Frank Steiner
2005-01-10 16:51 ` Marcelo Tosatti
2005-01-10 18:28 ` Alan Cox
2005-01-11 7:49 ` Frank Steiner
2005-01-08 21:07 ` Andreas Schwab
2005-01-08 22:30 ` Barry K. Nathan
2005-01-08 23:21 ` Andi Kleen
2005-01-08 23:30 ` Alan Cox
2005-01-09 0:57 ` Andi Kleen
2005-01-09 0:49 ` Andries Brouwer
2005-01-09 2:21 ` Jesper Juhl
2005-01-09 2:17 ` Andries Brouwer
2005-01-08 21:47 ` Alan Cox
2005-01-11 22:51 ` [PATCH] make uselib configurable (was Re: uselib() & 2.6.X?) Barry K. Nathan
2005-01-11 23:42 ` Jesper Juhl
2005-01-11 23:59 ` Andries Brouwer
2005-01-12 1:06 ` Jesper Juhl
2005-01-12 1:18 ` David Lang
2005-01-11 22:36 ` Marcelo Tosatti
2005-01-12 2:32 ` Barry K. Nathan
2005-01-12 0:56 ` Marcelo Tosatti
2005-01-12 6:10 ` Barry K. Nathan
2005-01-12 16:47 ` Adrian Bunk
2005-01-12 17:10 ` Barry K. Nathan
2005-01-12 20:16 ` Matt Mackall
2005-01-12 2:12 ` Barry K. Nathan
2005-01-12 2:23 ` David Lang
2005-01-12 2:30 ` Adrian Bunk
2005-01-12 5:11 ` Stephen Pollei
2005-01-12 16:54 ` Adrian Bunk
2005-01-12 7:58 ` Christoph Hellwig
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