Re: [RFC PATCH 02/12] On Tue, 23 Sep 2008, David Miller wrote:

From: Arjan van de Ven
Date: Sun Oct 05 2008 - 11:10:32 EST


Thomas Gleixner wrote:
On Sat, 4 Oct 2008, Jesse Brandeburg wrote:
Exactly. The access to a ro region results in a fault. I have nowhere
seen that trigger, but I can reproduce the trylock() WARN_ON, which
confirms that there is concurrent access to the NVRAM registers. The
backtrace pattern is similar to the one you have seen.
are you still getting WARN_ON *with* all the mutex based fixes already applied?

The WARN_ON triggers with current mainline. Is there any fixlet in
Linus tree missing ?

with the mutex patches in place (without protection patch) we are
still reproducing the issue, until we apply the set_memory_ro patch.

That does not make sense to me. If the memory_ro patch is providing
_real_ protection then you _must_ run into an access violation. If not,
then the patch just papers over the real problem in some mysterious
way.


not if the bad code is doing copy_to_user .... (or similar)
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