summaryrefslogtreecommitdiff
path: root/Documentation/kernel-parameters.txt
diff options
context:
space:
mode:
authorDave Hansen <dave.hansen@linux.intel.com>2016-02-13 00:02:29 +0300
committerIngo Molnar <mingo@kernel.org>2016-02-18 21:46:30 +0300
commit0697694564c84f4c9320e5d103d0191297a20023 (patch)
treead51052f77274436c9ac89a0ca86b551b4503884 /Documentation/kernel-parameters.txt
parent284244a9876225eb73102aff41d4492f65cb2868 (diff)
downloadlinux-0697694564c84f4c9320e5d103d0191297a20023.tar.xz
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.txt3
1 files changed, 3 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a37b5bb03e51..acf467d44e39 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