Messages in this thread | | | Date | Thu, 17 Nov 2016 07:52:13 +0100 | From | Ingo Molnar <> | Subject | Re: [PATCH] x86: add UMIP support |
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* Jan Beulich <JBeulich@suse.com> wrote:
> This is a small aid to security, hiding in particular the kernel address > information otherwise available through SGDT/SIDT. > > Signed-off-by: Jan Beulich <jbeulich@suse.com> > --- > Main question here is whether to limit this to 64-bit (or at least > !CONFIG_VM86) for the time being, or to disable it while running VM86 > mode code: Such code isn't unlikely to use SMSW (and one of SGDT/SIDT) > to figure out whether it's running on an i286 or i386, as the EFLAGS > based method recommended by Intel's SDM can't be relied upon there. > --- > Documentation/kernel-parameters.txt | 4 ++++ > arch/x86/include/asm/cpufeatures.h | 1 + > arch/x86/include/uapi/asm/processor-flags.h | 2 ++ > arch/x86/kernel/cpu/common.c | 16 +++++++++++++++- > 4 files changed, 22 insertions(+), 1 deletion(-)
Note that similar patches have been submitted a week ago:
https://lkml.org/lkml/2016/11/8/68
Thanks,
Ingo
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