Messages in this thread | | | Date | Tue, 13 Oct 2009 11:34:26 -0400 | Subject | Re: [PATCH V5] x86: NX protection for kernel data | From | Siarhei Liakh <> |
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>> I'd be surprised if anything ever did; this is the *kernel* mapping of >> the first megabyte, not some userspace mapping.... > > APM, BIOS32, EDD, PnPBIOS .. > > However except for APM (which isn't generally needed on NX capable > devices or found on them) none of them are usually on critical paths > because EDD is just grovelling around sort of stuff, and BIOS32 isn't > generally used by the kernel anyway so could probably cope with flipping > the permissions on the low 1 MB each call.
Actually, I have posted a patch to fix RW+X problem with BIOS32 some time ago. See my submission to LKML (and subsequent discussion) on Jul 19 2009 "[PATCH] x86: Reducing footprint of BIOS32 service mappings".
Nevertheless, that 1MB area is on my "to do" list, and I will be patching it sooner or later (assuming I get my patches tested well enough to get them accepted).
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