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Subject: Re: [PATCH v8 8/8] livepatch: Detect offset for the ftrace location
 during build
To: Torsten Duwe <duwe@lst.de>
References: <20160212164517.GO12548@pathway.suse.cz>
 <20160216054701.GA20570@linux.vnet.ibm.com> <20160216082302.GA20522@lst.de>
 <20160216103028.GA10730@linux.vnet.ibm.com> <20160216103907.GB25103@lst.de>
 <20160216135742.GT12548@pathway.suse.cz>
 <1455678521.2956.4.camel@ellerman.id.au> <20160223170017.GB21932@lst.de>
 <56CD4FA0.4090109@gmail.com> <56CD53E7.3010108@gmail.com>
 <20160224092318.GA24232@lst.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>, Petr Mladek <pmladek@suse.com>,
 Jessica Yu <jeyu@redhat.com>, Jiri Kosina <jkosina@suse.cz>,
 linux-kernel@vger.kernel.org, Steven Rostedt <rostedt@goodmis.org>,
 Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>,
 live-patching@vger.kernel.org, Miroslav Benes <mbenes@suse.cz>,
 linuxppc-dev@lists.ozlabs.org
From: Balbir Singh <bsingharora@gmail.com>
Message-ID: <56CD925E.4060000@gmail.com>
Date: Wed, 24 Feb 2016 22:22:06 +1100
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On 24/02/16 20:23, Torsten Duwe wrote:
> On Wed, Feb 24, 2016 at 05:55:35PM +1100, Balbir Singh wrote:
>> <snip>
>>
>> We need to remove the SQUASH_TOC_SAVE_INSNS bits as well, now that the ppc64_profile_stub_insns does not save r2
> Sure -- this was meant to _replace_ the changes from patch 2/8, not on top.
> And yes, it exposes duplicate definitions, but does not cause them AFAICS.
> The two unasked questions about it were: Is Michael's solution on a similar
> basis? Is this worth any further effort e.g. put into v9?
>
>
My bad you did mention _replace_, but I think 2/8 and 6/8 of tightly bound
together, so the replacement is not straight forward. Yes, it is heading in
a similar direction, but it focuses mostly on ftrace. I think v9 makes sense,
but I'll let Michael comment on this as well]

Personally, I think your v8 or v9 + Michael's changes - RECORD_C_MCOUNT +
some changes (yet to code them based on v8/v9/ftrace stability) should get
the full live patching working.

Balbir Singh.