[PATCH] add hook to read_from_oldmem() to check for non-ram pages

Andrew Morton akpm at linux-foundation.org
Fri May 6 15:55:46 EDT 2011

On Fri, 6 May 2011 21:39:16 +0200
Olaf Hering <olaf at aepfle.de> wrote:

> On Fri, May 06, Andrew Morton wrote:
> > So as your module will have a reference to vmcore.c's register and unregister
> > functions, nothing needs to be done: the presence of the client module alone
> > will pin the vmcore.c module.
> I meant the other way around. Keep /proc/vmcore open and read from it,
> then try to rmmod foo.ko which provides fn().

The client foo.ko will need to prevent itself from being unloaded while
it's actively doing stuff, yes.  Typically that would be done in its
module_exit() function - wait for current activity to complete and
block new activity.  The "block new activity" thing should be automatic
because nobody has any more references to anything in the module.

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