From 5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 10 Oct 2013 17:18:15 -0700 Subject: 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 Link: http://lkml.kernel.org/r/1381450698-28710-4-git-send-email-keescook@chromium.org Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/rdrand.c | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'arch/x86/kernel/cpu') 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 -- cgit v1.2.3