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| author | Kees Cook <keescook@chromium.org> | 2013-10-10 17:18:15 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-10-13 03:12:12 -0700 |
| commit | 5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3 (patch) | |
| tree | ead4a5281554b6f2e0a334cc7e1d83dccf35e15c /arch/x86/kernel/cpu | |
| parent | 8ab3820fd5b2896d66da7bb2a906bc382e63e7bc (diff) | |
| download | linux-stable-5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3.tar.gz linux-stable-5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3.tar.bz2 linux-stable-5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3.zip | |
x86, kaslr: Provide randomness functions
Adds potential sources of randomness: RDRAND, RDTSC, or the i8254.
This moves the pre-alternatives inline rdrand function into the header so
both pieces of code can use it. Availability of RDRAND is then controlled
by CONFIG_ARCH_RANDOM, if someone wants to disable it even for kASLR.
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-4-git-send-email-keescook@chromium.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/cpu')
| -rw-r--r-- | arch/x86/kernel/cpu/rdrand.c | 14 |
1 files changed, 0 insertions, 14 deletions
diff --git a/arch/x86/kernel/cpu/rdrand.c b/arch/x86/kernel/cpu/rdrand.c index 88db010845cb..384df5105fbc 100644 --- a/arch/x86/kernel/cpu/rdrand.c +++ b/arch/x86/kernel/cpu/rdrand.c @@ -31,20 +31,6 @@ static int __init x86_rdrand_setup(char *s) } __setup("nordrand", x86_rdrand_setup); -/* We can't use arch_get_random_long() here since alternatives haven't run */ -static inline int rdrand_long(unsigned long *v) -{ - int ok; - asm volatile("1: " RDRAND_LONG "\n\t" - "jc 2f\n\t" - "decl %0\n\t" - "jnz 1b\n\t" - "2:" - : "=r" (ok), "=a" (*v) - : "0" (RDRAND_RETRY_LOOPS)); - return ok; -} - /* * Force a reseed cycle; we are architecturally guaranteed a reseed * after no more than 512 128-bit chunks of random data. This also |