Re: [RFC][PATCH] procfs: Add /proc/<pid>/mapped_files

From: Kirill A. Shutemov
Date: Fri Jan 16 2015 - 06:01:18 EST


On Thu, Jan 15, 2015 at 05:15:43PM -0800, Andrew Morton wrote:
> On Thu, 15 Jan 2015 00:51:50 +0100 Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx> wrote:
>
> > > There are still several flags unused in vma.vm_flags btw.
> > >
> > > I'm not sure that we can repurpose vm_pgoff (or vm_private_data) for
> > > this: a badly behaved thread could make its sp point at a random vma
> > > then trick the kernel into scribbling on that vma's vm_proff?
> >
> > Well, we could still check vm_file for being NULL before writing to
> > vm_pgoff/vm_stack_tid.
>
> Yes, I guess that would work. We'd need to check that nobody else
> is already playing similar games with vm_pgoff.

Well, we do use ->vm_pgoff in anonymous VMAs. For rmap in particular --
vma_address().

--
Kirill A. Shutemov
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