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authorH. Peter Anvin <hpa@zytor.com>2011-07-31 23:02:19 +0200
committerH. Peter Anvin <hpa@zytor.com>2011-07-31 23:02:19 +0200
commit49d859d78c5aeb998b6936fcb5f288f78d713489 (patch)
tree04b7746d1b79ab12bf94ff1eaf9ab91e74db37ef /Documentation
parentx86, random: Architectural inlines to get random integers with RDRAND (diff)
downloadlinux-49d859d78c5aeb998b6936fcb5f288f78d713489.tar.xz
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x86, random: Verify RDRAND functionality and allow it to be disabled
If the CPU declares that RDRAND is available, go through a guranteed reseed sequence, and make sure that it is actually working (producing data.) If it does not, disable the CPU feature flag. Allow RDRAND to be disabled on the command line (as opposed to at compile time) for a user who has special requirements with regards to random numbers. Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/kernel-parameters.txt5
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index aa47be71df4c..397ee05132a3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1764,6 +1764,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
noresidual [PPC] Don't use residual data on PReP machines.
+ nordrand [X86] Disable the direct use of the RDRAND
+ instruction even if it is supported by the
+ processor. RDRAND is still available to user
+ space applications.
+
noresume [SWSUSP] Disables resume and restores original swap
space.