Messages in this thread | | | Date | Sun, 14 Sep 2008 17:21:36 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] kmemcheck: lazy checking for MOVS instructions |
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* Vegard Nossum <vegard.nossum@gmail.com> wrote:
> On Fri, Sep 12, 2008 at 11:06 AM, Ingo Molnar <mingo@elte.hu> wrote: > >> From: Vegard Nossum <vegard.nossum@gmail.com> > >> Date: Thu, 11 Sep 2008 17:31:07 +0200 > >> Subject: [PATCH] kmemcheck: lazy checking for MOVS instructions > >> > >> This patch adds the support for lazy (as opposed to eager) checking > >> for [REP] MOVS instructions (mostly used in memcpy()). This means that > >> if both the source and destination addresses are tracked by kmemcheck, > >> we copy the shadow memory instead of checking that it is initialized. > >> > >> In this way, we get rid of a few more false positives. > > > > looks good to me. I've applied it to tip/kmemcheck - but can zap it and > > pull your for-tip branch as well. > > Please zap, I believe it contains an error :-) > > In short, when reading/writing the shadow memory of the second page in > a page-boundary-crossing memory access, the offsets into the second > shadow page will be wrong (off by up to 8 bytes). It's a pretty > obscure case, but it would be nice to have it fixed. Will send a pull > request later.
ok, zapped it.
Ingo
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