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

[Bruce Ashfield]

On 12-11-13 11:20 PM, Tom Zanussi wrote:
> 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?

Agreed. Something went off the rails and the best way to fix it right
now is to restore them. I'll merge this on Wednesday.

Cheers,

Bruce

>
> 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(+)
>>>
>>
>
>