Messages in this thread | | | Date | Sun, 06 May 2001 23:54:16 -0400 | From | Brian Gerst <> | Subject | Re: [PATCH] x86 page fault handler not interrupt safe |
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Linus Torvalds wrote: > > On Sat, 5 May 2001, Brian Gerst wrote: > > > > Currently the page fault handler on the x86 can get a clobbered value > > for %cr2 if an interrupt occurs and causes another page fault (interrupt > > handler touches a vmalloced area for example) before %cr2 is read. > > That should be ok. > > Yes, we'll get a clobbered value, but we'll get a _valid_ clobbered value, > and we'll just end up doing the fixups twice (and returning to the user > process that didn't get the page it wanted, which will end up re-doing the > page fault). > > [ Looks closer.. ] > > Actually, the second time we'd do the fixup we'd be unhappy, because it > has already been done. That test should probably be removed. Hmm. > > Hmm.. The threading people wanted this same thing. Maybe we should just > make it so. > > Linus
I think it's better to be on the side of correctness. I designed the patch to have interrupts disabled for the minimum time possible, so there should be nearly no impact.
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