Subject: [PATCH 9/9] ARM: add uprobes support

From: [email-masked] (Rabin Vincent)
Date: Sun, 21 Oct 2012 20:43:30 +0200

On Wed, Oct 17, 2012 at 03:50:48PM +0100, Jon Medhurst (Tixy) wrote:
> I just been looking at the decoding changes in patch 8 and had similar
> thoughts. The patch as it stands looks rather bolted on the side and
> makes the resulting code rather messy.

I agree.

> a) uprobes is similar enough to kprobes that the existing code can be
> morphed into something that cleanly supports both, or
> 
> b) the similarities aren't close enough and that we should factor out
> the similarities into a more generalised decoding base, which the
> {u,k}probe code can then build on.
> 
> c) some mix of a) and b)
> 
> I can't help but think of the various calls over the past year or so for
> a general ARM/Thumb instruction decoding framework (the last one only a
> few weeks ago on the linux-arm-kernel list). Perhaps b) would be a small
> step towards that.
> 
> I hope to find some time to understand the uprobe patches in more
> detail, so I can try and come up with some sensible suggestions on a
> cleaner solution; because I feel that as they stand they aren't really
> suitable for inclusion in the kernel.

I contemplated sending the decoding patch with [RFC] but finally went
with [PATCH] since they mostly mean the same thing :-).

Suggestions welcome.  For one thing, the creation of a fake struct
kprobe from within the uprobes and the dependency on kprobes because of
that is not very nice, we probably need a "struct probe" of some sort
perhaps.

> Rabin, what tree/commit are your patches based on? (They don't seem to
> apply cleanly to 3.6 or 3.7-rc1.) I want to apply them locally so I can
> use my favourite visualisation tool and to play with them.

The patches are based on next-20121012.  The uprobes core is seeing
quite a few changes in linux-next so the series will probably not apply
on later linux-next trees.