On Wed, Oct 24, 2018 at 12:35:01AM +0300, Igor Stoppa wrote:

In some cases, all the data needing protection can be allocated from a pool
in one go, as directly writable, then initialized and protected.
The sequence is relatively short and it's acceptable to leave the entire
data set unprotected.

In other cases, this is not possible, because the data will trickle over
a relatively long period of time, in a non predictable way, possibly for
the entire duration of the operations.

For these cases, the safe approach is to have the memory already write
protected, when allocated. However, this will require replacing any
direct assignment with calls to functions that can perform write rare.

Since lists are one of the most commonly used data structures in kernel,
they are a the first candidate for receiving write rare extensions.

This patch implements basic functionality for altering said lists.

Signed-off-by: Igor Stoppa <redacted>
CC: Thomas Gleixner <redacted>
CC: Kate Stewart <redacted>
CC: "David S. Miller" <davem@davemloft.net>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
CC: Philippe Ombredanne <redacted>
CC: "Paul E. McKenney" <redacted>
CC: Josh Triplett <josh@joshtriplett.org>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
CC: Lai Jiangshan <jiangshanlai@gmail.com>
CC: linux-kernel@vger.kernel.org
---
 MAINTAINERS            |   1 +
 include/linux/prlist.h | 934 +++++++++++++++++++++++++++++++++++++++++

I'm not at all sure I understand the Changelog, or how it justifies
duplicating almost 1k lines of code.

Sure lists aren't the most complicated thing we have, but duplicating
that much is still very _very_ bad form. Why are we doing this?