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Date: Tue, 7 Aug 2007 12:20:08 -0700
From: Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [patch 3/3] mm: variable length argument support
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To: Olaf Hering <olaf@aepfle.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-kernel@vger.kernel.org, parisc-linux@lists.parisc-linux.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, Ollie Wild <aaw@google.com>, Ingo Molnar <mingo@elte.hu>, Andi Kleen <ak@suse.de>
List-ID: <linux-arch.vger.kernel.org>

On Tue, 7 Aug 2007 21:03:57 +0200
Olaf Hering <olaf@aepfle.de> wrote:

> On Wed, Jun 13, Peter Zijlstra wrote:
> 
> > From: Ollie Wild <aaw@google.com>
> > 
> > Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly
> > from the old mm into the new mm.
> 
> > +++ linux-2.6-2/include/linux/binfmts.h	2007-06-13 11:52:46.000000000 +0200
> > @@ -6,11 +6,13 @@
> >  struct pt_regs;
> >  
> >  /*
> > - * MAX_ARG_PAGES defines the number of pages allocated for arguments
> > - * and envelope for the new program. 32 should suffice, this gives
> > - * a maximum env+arg of 128kB w/4KB pages!
> > + * These are the maximum length and maximum number of strings passed to the
> > + * execve() system call.  MAX_ARG_STRLEN is essentially random but serves to
> > + * prevent the kernel from being unduly impacted by misaddressed pointers.
> > + * MAX_ARG_STRINGS is chosen to fit in a signed 32-bit integer.
> >   */
> > -#define MAX_ARG_PAGES 32
> > +#define MAX_ARG_STRLEN (PAGE_SIZE * 32)
> > +#define MAX_ARG_STRINGS 0x7FFFFFFF
> 
> This adds a new usage of PAGE_SIZE to an exported header.
> How can this be fixed for 2.6.23?

Put #ifdef __KERNEL__ around it?