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SubjectRe: [PATCH] 2.4.0 i386 watchpoint problems
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> Actually, even simpler approach:
>
> - always clear db7 after sending signal - don't test for pending or for
> kernel mode at all at that point.
> - re-load %db7 at the top of the for(;;) loop in do_signal().
>
> That should mean that you will actually get a debug signal for ALL
> triggers of the debug registers, except you'll only get one for kernel
> mode.

This is obviously much better (getting a signal for ALL debug register
triggers is a _good_ thing), but is it safe to call force_sig_info
from the debug trap handler if it was entered from kernel mode ?

Since the debug trap handler can (potentially) be entered as a result
of _any_ store instruction in the kernel, it's certainly not clear to me
that I wouldn't be violating locking assumptions by calling
force_sig_info from here...

-- Jim

James Cownie <jcownie@etnus.com>
Etnus, LLC. +44 117 9071438
http://www.etnus.com


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