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authorKees Cook <keescook@chromium.org>2013-10-11 02:18:15 +0200
committerH. Peter Anvin <hpa@linux.intel.com>2013-10-13 12:12:12 +0200
commit5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3 (patch)
treeead4a5281554b6f2e0a334cc7e1d83dccf35e15c /arch/x86/kernel/cpu/rdrand.c
parentx86, kaslr: Return location from decompress_kernel (diff)
downloadlinux-5bfce5ef55cbe78ee2ee6e97f2e26a8a582008f3.tar.xz
linux-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/rdrand.c')
-rw-r--r--arch/x86/kernel/cpu/rdrand.c14
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