Messages in this thread | | | Date | Sun, 5 Oct 2008 19:15:55 +0100 | From | Alan Cox <> | Subject | Re: [PATCH -tip] kmemcheck: fix crash in PnP BIOS calls |
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> It turns out that BIOS calls are made with a different code segment. So > when kmemcheck tries to dereference the EIP/RIP (using the kernel data > segment register), we get the unhandled page fault. > > I think we can solve this by verifying (in the page fault handler) that > the faulting code is using the kernel CS.
That isn't an entirely safe assumption and some services such as BIOS32 are 32bit. Would it be better wrap BIOS calls with a kmemcheck wrapper which changes the way kmemcheck works/dumps stuff and also gives you a hook after BIOS calls to do stuff like corruption scans or change detection on kernel pages ?
Alan
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