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Re: [RFC] Systemtap translator support for hardware breakpoints on

Hi -

On Thu, Jan 07, 2010 at 02:38:41PM -0800, Roland McGrath wrote:
> [...]
> On x86 at least, you can't distinguish different kinds of hits.

If that means that, at callback time, we can't tell the two cases
apart, then ...

> probe kernel.data(0x1234).write { one_thing() }
> probe kernel.data(0x1234).read { another_thing() }
> 
> you cannot consolidate these into one RW breakpoint, because you
> won't know which handler to run.

... this is a real problem.  Otherwise, if we had a usable access-type
flag available at the callback, we could dispatch to the handlers
(including setting custom pp()'s) based upon that.


- FChE
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