[linux-yocto] [PATCH 0/1] fix broken uprobe config

[Tom Zanussi]

On Tue, 2012-11-13 at 21:23 -0500, Bruce Ashfield wrote:
> On 12-11-13 4:35 PM, tom.zanussi at intel.com wrote:
> > From: Tom Zanussi<tom.zanussi at intel.com>
> >
> > I just noticed while testing some tracing tools that uprobes was broken
> > from changes made by commit 17ec51adfff (meta: cleanup invalid/obselete
> > 3.4 CONFIG options).
> >
> > The rest of the changes in that commit should also probably be audited
> > to see if it broke anything else.
> 
> It's long since been audited, none of the Kconfig exist in a mainline
> kernel, which is what the commit was intended to address.
> 
> The uprobes config was supposed to have been re-introduced via an
> optional tracing feature, but I don't see any evidence of where that
> went.
> 
> I can pull these back in, and make that global tracing feature use
> the uprobes fragment directly.
> 

Yeah, there seems to have been a lot of churn for this, and at this
point I'm not sure what it should be, other than at the end of it all,
we no longer have the CONFIG_UPROBES and CONFIG_UPROBE_EVENT options
anywhere but should have...

Originally, there was the feature but no config options to actually turn
it on, so I added them, along with another patch to uprobe.scc to use
them:

  commit a69d1dbbb7a05e5c7e1b4dd9ac78ad876d6c1061 
  Author: Tom Zanussi <tom.zanussi at intel.com>
  Date:   Mon Sep 10 12:02:25 2012 -0500

    meta: add uprobe.cfg

commit d40ed99c6273682c339351c4b623210d6e717c78
Author: Tom Zanussi <tom.zanussi at intel.com>
Date:   Mon Sep 10 12:02:26 2012 -0500

    meta: have uprobe feature use uprobe.cfg

That added these options along with the .cfg:
 
 +CONFIG_UPROBES=y 
 +CONFIG_UPROBE_EVENT=y

+kconf non-hardware uprobe.cfg

Then I discovered that it actually also requires:

 +CONFIG_PERF_EVENTS=y

Added by:

  commit 7c50e572635d356f0b66d9ab90823f127f835744 
  Author: Tom Zanussi <tom.zanussi at intel.com>
  Date:   Thu Sep 13 20:56:09 2012 -0500

    meta: add PERF_EVENTS config to uprobes feature

Then later on, which somehow I missed, were these two:

commit 17ec51adfff17e6ce81d0be64cc42968a614d97e
Author: Bruce Ashfield <bruce.ashfield at windriver.com>
Date:   Wed Sep 26 15:42:28 2012 -0400

    meta: cleanup invalid/obselete 3.4 CONFIG options
 
which removes them again but leaves CONFIG_PERF_EVENTS:

-CONFIG_UPROBES=y
-CONFIG_UPROBE_EVENT=y

and this, which I'm not sure of what it's meant to do, but doesn't
restore the missing options either...

commit 3da11722e36591bafab908141876c89d1dfb229d
Author: Bruce Ashfield <bruce.ashfield at windriver.com>
Date:   Tue Oct 2 16:48:50 2012 -0400

    uprobes: split into enable and patch fragments

It looks like it should be adding the config options in somewhere again,
but doesn't?

Tom

> Cheers,
> 
> Bruce
> 
> >
> > Please pull into linux-yocto-3.4/meta.
> >
> > Thanks,
> >
> > Tom
> >
> > The following changes since commit 3905e74f5e14f73c7d9aefc856a493ceb811b33a:
> >
> >    meta: rangeley: Enable Zlib Compression (2012-11-04 13:26:06 -0500)
> >
> > are available in the git repository at:
> >
> >    git://git.yoctoproject.org/linux-yocto-2.6.37-contrib.git tzanussi/reinstate-uprobes-3.4
> >    http://git.yoctoproject.org/cgit/cgit.cgi/linux-yocto-2.6.37-contrib/log/?h=tzanussi/reinstate-uprobes-3.4
> >
> > Tom Zanussi (1):
> >    uprobes: reinstate config options for 'uprobe' feature
> >
> >   meta/cfg/kernel-cache/features/uprobe/uprobe.cfg | 2 ++
> >   1 file changed, 2 insertions(+)
> >
>