diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2011-07-31 14:02:19 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-21 09:17:12 -0700 |
| commit | 8b9b3bf4e79b8f41fa910932885526c2d1083af9 (patch) | |
| tree | 13ccd050915a838b801c99aaf5a06a4a6c89bdc6 /Documentation | |
| parent | 5faf9fc361bac926a2f9efe6018fdc16c0e7dad8 (diff) | |
x86, random: Verify RDRAND functionality and allow it to be disabled
commit 49d859d78c5aeb998b6936fcb5f288f78d713489 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index aa47be71df4..397ee05132a 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. |