Date:	Sun, 7 Jan 2001 14:20:14 +0200 (IST)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	lauras AT softhome DOT net
cc:	djgpp-workers AT delorie DOT com, Richard Dawe <rich AT phekda DOT freeserve DOT co DOT uk>
Subject:	Re: Bug in lstat() - wrong arguments to FSEXT
In-Reply-To:	<20010107141016.A314@lauras.lt>
Message-ID:	<Pine.SUN.3.91.1010107141348.25836D-100000@is>
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Errors-To:	nobody AT delorie DOT com
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On Sun, 7 Jan 2001 lauras AT softhome DOT net wrote:

> On Sun, Jan 07, 2001 at 12:08:27PM +0200, Eli Zaretskii wrote:
> > I think this is a result of replacing `path' with `real_path' when 
> > symlink support was added to `stat': the former was on the stack, since 
> > it's the argument of `stat' (now `lstat'), and so passing a pointer to 
> > it does TRT, evebn though it is not declared as a va_list.
> 
> But the converted path is on the stack too, it's a local and
> not static variable, so shouldn't it work too?

Sorry, I wasn't being clear.

This will only work if `path' is on the stack with the other arguments 
passed to `stat', because the FSEXT hook expects to find the same 
argument list on its stack when it is called.  `path' satisfies this 
requirement, because it is `stat's argument.  But `real_path' is a local 
variable inside `stat' (now `lstat'), so it is further down the stack, 
far from the struct stat buffer which sits near `path' on the stack.

If this is still unclear, draw the stack layout upon call to `stat' and 
when the FSEXT hook is called, look at how va_arg walks the stack, and
I'm sure you will understand.

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