Commit graph

5 commits

Author SHA1 Message Date
Lucas De Marchi
0d2eb44f63 x86: Fix common misspellings
They were generated by 'codespell' and then manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: trivial@kernel.org
LKML-Reference: <1300389856-1099-3-git-send-email-lucas.demarchi@profusion.mobi>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-03-18 10:39:30 +01:00
Kees Cook
79250af2d5 x86: Fix included-by file reference comments
Adjust the paths for files that are including verify_cpu.S.

Reported-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
LKML-Reference: <1289931004-16066-1-git-send-email-kees.cook@canonical.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-11-18 09:58:54 +01:00
Kees Cook
ebba638ae7 x86, cpu: Call verify_cpu during 32bit CPU startup
The XD_DISABLE-clearing side-effect needs to happen for both 32bit
and 64bit, but the 32bit init routines were not calling verify_cpu()
yet. This adds that call to gain the side-effect.

The longmode/SSE tests being performed in verify_cpu() need to happen very
early for 64bit but not for 32bit. Instead of including it in two places
for 32bit, we can just include it once in arch/x86/kernel/head_32.S.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
LKML-Reference: <1289414154-7829-4-git-send-email-kees.cook@canonical.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-11-10 15:43:09 -08:00
Kees Cook
ae84739c27 x86, cpu: Clear XD_DISABLED flag on Intel to regain NX
Intel CPUs have an additional MSR bit to indicate if the BIOS was
configured to disable the NX cpu feature. This bit was traditionally
used for operating systems that did not understand how to handle the
NX bit. Since Linux understands this, this BIOS flag should be ignored
by default.

In a review[1] of reported hardware being used by Ubuntu bug reporters,
almost 10% of systems had an incorrectly configured BIOS, leaving their
systems unable to use the NX features of their CPU.

This change will clear the MSR_IA32_MISC_ENABLE_XD_DISABLE bit so that NX
cannot be inappropriately controlled by the BIOS on Intel CPUs. If, under
very strange hardware configurations, NX actually needs to be disabled,
"noexec=off" can be used to restore the prior behavior.

[1] http://www.outflux.net/blog/archives/2010/02/18/data-mining-for-nx-bit/

Signed-off-by: Kees Cook <kees.cook@canonical.com>
LKML-Reference: <1289414154-7829-3-git-send-email-kees.cook@canonical.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-11-10 15:42:54 -08:00
Kees Cook
c5cbac6942 x86, cpu: Rename verify_cpu_64.S to verify_cpu.S
The code is 32bit already, and can be used in 32bit routines.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
LKML-Reference: <1289414154-7829-2-git-send-email-kees.cook@canonical.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-11-10 15:42:42 -08:00
Renamed from arch/x86/kernel/verify_cpu_64.S (Browse further)