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path: root/arch/x86/kernel/verify_cpu.S
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2011-03-18x86: Fix common misspellingsLucas De Marchi
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>
2010-11-18x86: Fix included-by file reference commentsKees Cook
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>
2010-11-10x86, cpu: Call verify_cpu during 32bit CPU startupKees Cook
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>
2010-11-10x86, cpu: Clear XD_DISABLED flag on Intel to regain NXKees Cook
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>
2010-11-10x86, cpu: Rename verify_cpu_64.S to verify_cpu.SKees Cook
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>