From: Kees Cook Date: Wed, 10 Apr 2013 19:24:22 +0000 (-0700) Subject: x86: Use a read-only IDT alias on all CPUs X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~111^2~5 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4eefbe792baedb474e256d35370849992fcf1c79;p=pandora-kernel.git x86: Use a read-only IDT alias on all CPUs Make a copy of the IDT (as seen via the "sidt" instruction) read-only. This primarily removes the IDT from being a target for arbitrary memory write attacks, and has the added benefit of also not leaking the kernel base offset, if it has been relocated. We already did this on vendor == Intel and family == 5 because of the F0 0F bug -- regardless of if a particular CPU had the F0 0F bug or not. Since the workaround was so cheap, there simply was no reason to be very specific. This patch extends the readonly alias to all CPUs, but does not activate the #PF to #UD conversion code needed to deliver the proper exception in the F0 0F case except on Intel family 5 processors. Signed-off-by: Kees Cook Link: http://lkml.kernel.org/r/20130410192422.GA17344@www.outflux.net Cc: Eric Northup Signed-off-by: H. Peter Anvin --- Reading git-diff-tree failed