Re: [PATCH] x86: Add a list for custom page fault handlers.

From: Arjan van de Ven
Date: Wed Jan 30 2008 - 13:21:29 EST


On Sun, 27 Jan 2008 18:52:38 +0200
Pekka Paalanen <pq@xxxxxx> wrote:

> From: Pekka Paalanen <pq@xxxxxx>
>
> Provides kernel modules a way to register custom page fault handlers.
> On every page fault, except those handled in vmalloc_fault(), this
> will call a list of registered functions. The functions may handle
> the fault and force do_page_fault() to return immediately.
>
> This functionality is similar to the now removed page fault notifiers.
> Custom page fault handlers are used by debugging and reverse
> engineering tools. Mmio-trace is one such tool and a patch to add it
> into the tree will follow.
>
> The custom page fault handlers are called from the exact same points
> in do_page_fault() as the page fault notifiers were.

to be honest I don't like this approach.
I fully would like to see mmio tracing in the kernel, but please
make the hook explicit and direct (eg call the mmio tracing function,
not some list) instead...


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