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From: Roger Larsson <roger.larsson@skelleftea.mail.telia.com>
To: linux-kernel@vger.kernel.org
Subject: Re: [CHECKER] 37 stack variables >= 1K in 2.4.17
Date: Thu, 13 Jun 2002 15:24:14 +0200
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On Thursday 13 June 2002 10.30, Helge Hafting wrote:
> Alexander Viro wrote:
> > 
> > On Wed, 12 Jun 2002, Benjamin LaHaise wrote:
> > 
> > > On Wed, Jun 12, 2002 at 06:26:55PM -0400, Alexander Viro wrote:
> > > > Not realistic - we have a recursion through the ->follow_link(), and
> > > > a lot of stuff can be called from ->follow_link().  We _do_ have a
> > > > limit on depth of recursion here, but it won't be fun to deal with.
> > >
> > > Perfection isn't what I'm looking for, rather just an approximation.
> > > Any tool would have to give up on non-trivial recursion, or have
> > 
> > ... in which case it will be useless - anything callable from path_walk()
> > will be out of its scope and that's a fairly large part of VFS, 
filesystems,
> > VM and upper halves of block devices.
> 
> The automated checker may use hard-coded limits for recursions with
> limited depth.  If follow_link stops after n iterations, tell
> the checker about it and it will use that in its computations.

Alexander Viro <viro@math.psu.edu> wrote:
> (link_path_walk->do_follow_link->foofs_follow_link->
> vfs_follow_link->link_path_walk)

It would not need to follow the recursion at all.

A simple warning "vfs_follow_link makes a recursive call back
to link_path_walk, stack space needed for each recursion is N bytes"

/RogerL

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