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| author | Dave Hansen <dave.hansen@linux.intel.com> | 2016-02-12 13:02:29 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-02-18 19:46:30 +0100 |
| commit | 0697694564c84f4c9320e5d103d0191297a20023 (patch) | |
| tree | ad51052f77274436c9ac89a0ca86b551b4503884 /Documentation/kernel-parameters.txt | |
| parent | 284244a9876225eb73102aff41d4492f65cb2868 (diff) | |
| download | linux-0697694564c84f4c9320e5d103d0191297a20023.tar.gz | |
x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
This sets the bit in 'cr4' to actually enable the protection
keys feature. We also include a boot-time disable for the
feature "nopku".
Seting X86_CR4_PKE will cause the X86_FEATURE_OSPKE cpuid
bit to appear set. At this point in boot, identify_cpu()
has already run the actual CPUID instructions and populated
the "cpu features" structures. We need to go back and
re-run identify_cpu() to make sure it gets updated values.
We *could* simply re-populate the 11th word of the cpuid
data, but this is probably quick enough.
Also note that with the cpu_has() check and X86_FEATURE_PKU
present in disabled-features.h, we do not need an #ifdef
for setup_pku().
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210229.6708027C@viggo.jf.intel.com
[ Small readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a37b5bb03e517..acf467d44e39b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -976,6 +976,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/x86/intel_mpx.txt for more information about the feature. + nopku [X86] Disable Memory Protection Keys CPU feature found + in some Intel CPUs. + eagerfpu= [X86] on enable eager fpu restore off disable eager fpu restore |