As part of the Y2038 development, __getnstimeofday is not supposed to be
used any more. It is now replaced with ktime_get_ns. The Jitter RNG uses
the time stamp to measure the execution time of a given code path and
tries to detect variations in the execution time. Therefore, the only
requirement the Jitter RNG has, is a sufficient high resolution to
detect these variations.
The change was tested on x86 to show an identical behavior as RDTSC. The
used test code simply measures the execution time of the heart of the
RNG:
jent_get_nstime(&time);
jent_memaccess(ec, min);
jent_fold_time(NULL, time, &folded, min);
jent_get_nstime(&time2);
return ((time2 - time));
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The clocksource does not provide clocksource_register() function since
f893598 commit (clocksource: Mostly kill clocksource_register()), so
let's remove unnecessary information about this function from a comment.
Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com>
Suggested-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Since the API for jent_panic() does not include format string parameters,
adjust the call to panic() to use a literal string to avoid any future
callers from leaking format strings into the panic message.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The core of the Jitter RNG is intended to be compiled with -O0. To
ensure that the Jitter RNG can be compiled on all architectures,
separate out the RNG core into a stand-alone C file that can be compiled
with -O0 which does not depend on any kernel include file.
As no kernel includes can be used in the C file implementing the core
RNG, any dependencies on kernel code must be extracted.
A second file provides the link to the kernel and the kernel crypto API
that can be compiled with the regular compile options of the kernel.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stephan Mueller