From: Torsten Duwe <duwe@lst.de>
To: Petr Mladek <pmladek@suse.com>
Cc: linuxppc-dev@ozlabs.org, Balbir Singh <bsingharora@gmail.com>,
linux-kernel@vger.kernel.org, rostedt@goodmis.org,
kamalesh@linux.vnet.ibm.com, jeyu@redhat.com, jkosina@suse.cz,
live-patching@vger.kernel.org, mbenes@suse.cz
Subject: Re: [PATCH][v4] livepatch/ppc: Enable livepatching on powerpc
Date: Fri, 4 Mar 2016 19:16:57 +0100 [thread overview]
Message-ID: <20160304181657.GA30434@lst.de> (raw)
In-Reply-To: <20160304130137.GC3166@pathway.suse.cz>
On Fri, Mar 04, 2016 at 02:01:37PM +0100, Petr Mladek wrote:
>
> Do I understand it correctly that we could not patch functions that
> pass arguments on the stack with this implementation? If yes, how hard
> would be to get it working, please? At least, it would be great to
> catch this problem and handle it with grace. Otherwise, it might
> be hard to debug.
No, those functions only require special attention.
I needed _any_ location to store the caller's TOC;
and the stack is thread-safe and recursion-safe.
The current caller's frame is already full so I had
to create a new one.
A patch function could e.g. grab that TOC value in a
prologue and then pop that stack frame. Or it could
add those 32 bytes to the assumed arguments' stack offsets.
>
> > Where shall we put this warning?
>
> Sadly, we do not have any Documentation/livepatch/ yet/.
> I still hope that we could handle it somehow in the code.
I really think some documentation would be good, a live patch
howto for a start...
Torsten
next prev parent reply other threads:[~2016-03-04 18:17 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-03 16:52 [PATCH][v4] livepatch/ppc: Enable livepatching on powerpc Petr Mladek
2016-03-03 20:43 ` Balbir Singh
2016-03-04 6:08 ` Kamalesh Babulal
2016-03-04 7:58 ` Michael Ellerman
2016-03-04 9:31 ` Miroslav Benes
2016-03-07 3:29 ` Michael Ellerman
2016-03-04 8:06 ` How to merge? (was Re: [PATCH][v4] livepatch/ppc: Enable livepatching on powerpc) Michael Ellerman
2016-03-04 8:56 ` Jiri Kosina
2016-03-07 10:06 ` Michael Ellerman
2016-03-07 22:52 ` Jiri Kosina
2016-03-07 23:20 ` Michael Ellerman
2016-03-08 1:53 ` Steven Rostedt
2016-03-07 23:22 ` Josh Poimboeuf
2016-03-04 12:42 ` [PATCH][v4] livepatch/ppc: Enable livepatching on powerpc Torsten Duwe
2016-03-04 13:01 ` Petr Mladek
2016-03-04 18:16 ` Torsten Duwe [this message]
2016-03-04 19:22 ` Torsten Duwe
2016-03-08 11:14 ` Torsten Duwe
2016-03-06 23:55 ` Balbir Singh
2016-03-04 21:56 ` Josh Poimboeuf
2016-03-08 21:42 ` Steven Rostedt
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