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author | H. Peter Anvin <hpa@zytor.com> | 2011-07-31 14:02:19 -0700 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-10-21 09:17:12 -0700 |
commit | 8b9b3bf4e79b8f41fa910932885526c2d1083af9 (patch) | |
tree | 13ccd050915a838b801c99aaf5a06a4a6c89bdc6 /arch/x86/include | |
parent | 5faf9fc361bac926a2f9efe6018fdc16c0e7dad8 (diff) | |
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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 'arch/x86/include')
-rw-r--r-- | arch/x86/include/asm/archrandom.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/archrandom.h b/arch/x86/include/asm/archrandom.h index b7b5bc0..0d9ec77 100644 --- a/arch/x86/include/asm/archrandom.h +++ b/arch/x86/include/asm/archrandom.h @@ -70,4 +70,6 @@ GET_RANDOM(arch_get_random_int, unsigned int, RDRAND_INT, ASM_NOP3); #endif /* CONFIG_ARCH_RANDOM */ +extern void x86_init_rdrand(struct cpuinfo_x86 *c); + #endif /* ASM_X86_ARCHRANDOM_H */ |