[RFC PATCH 0/2] livepatch: Avoid possible race when releasing the patch

From: Petr Mladek
Date: Mon May 23 2016 - 11:54:24 EST


There was a long discussion about a possible race with sysfs, kobjects
when removing an unused livepatch, see
https://lkml.kernel.org/g/%3C1462190242-24731-1-git-send-email-mbenes@xxxxxxx%3E

This patch set tries to implement what looked the most preferred solution
from the discussion. I did my best to keep the patch definition simple.
But I am not super happy with the result.

I send the current state before I spent even more time on different
approaches.

I personally think that we might get better result if we declare
some limited structures, define them statically and then copy all
data into the final structures in a single call. I did not implement
this because it was weird on the first look but I am not sure now.

But even more I would prefer the solution with the completion.
It is already used by the module framework. It does not look
that hacky to me after all.

See the comments in the second patch for more details.


This patch set has been tested against linux-next.


Petr Mladek (2):
livepatch: Extend the livepatch-sample patch
livepatch: Use kobjects the right way

include/linux/livepatch.h | 70 +++++--
kernel/livepatch/core.c | 355 +++++++++++++++++++++++------------
samples/livepatch/livepatch-sample.c | 159 +++++++++++++---
3 files changed, 425 insertions(+), 159 deletions(-)

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1.8.5.6