[lkml]   [2011]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH RFC 0/5] uprobes: kill xol vma
On Mon, 2011-11-28 at 20:06 +0100, Oleg Nesterov wrote:
> On top of this series, not for inclusion yet, just to explain what
> I mean. May be someone can test it ;)
> This series kills xol_vma. Instead we use the per_cpu-like xol slots.
> This is much more simple and efficient. And this of course solves
> many problems we currently have with xol_vma.
> For example, we simply can not trust it. We do not know what actually
> we are going to execute in UTASK_SSTEP mode. An application can unmap
> this area and then do mmap(PROT_EXEC|PROT_WRITE, MAP_FIXED) to fool
> uprobes.
> The only disadvantage is that this adds a bit more arch-dependant
> code.
> The main question, can this work? I know very little in this area.
> And I am not sure if this can be ported to other architectures.

I very much like this approach! I think the provided implementation
might have some issues, but yeah, using fixmaps and a __switch_to_xtra
hook to provide per task slots seems very nice indeed!

 \ /
  Last update: 2011-11-28 21:01    [W:0.272 / U:5.212 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site