linux - Torvalds' mirror for benchmark reasons

Age	Commit message (Collapse)	Author
2024-10-19	crypto: jitter - output full sample from test interface	Joachim Vandersmissen
	The Jitter RNG time delta is computed based on the difference of two high-resolution, 64-bit time stamps. However, the test interface added in 69f1c387ba only outputs the lower 32 bits of those time stamps. To ensure all information is available during the evaluation process of the Jitter RNG, output the full 64-bit time stamps. Any clients collecting data from the test interface will need to be updated to take this change into account. Additionally, the size of the temporary buffer that holds the data for user space has been clarified. Previously, this buffer was JENT_TEST_RINGBUFFER_SIZE (= 1000) bytes in size, however that value represents the number of samples held in the kernel space ring buffer, with each sample taking 8 (previously 4) bytes. Rather than increasing the size to allow for all 1000 samples to be output, we keep it at 1000 bytes, but clarify that this means at most 125 64-bit samples will be output every time this interface is called. Reviewed-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Joachim Vandersmissen <git@jvdsn.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-05-12	crypto: jitter - add interface for gathering of raw entropy	Stephan Müller
	The test interface allows a privileged process to capture the raw unconditioned noise that is collected by the Jitter RNG for statistical analysis. Such testing allows the analysis how much entropy the Jitter RNG noise source provides on a given platform. The obtained data is the time stamp sampled by the Jitter RNG. Considering that the Jitter RNG inserts the delta of this time stamp compared to the immediately preceding time stamp, the obtained data needs to be post-processed accordingly to obtain the data the Jitter RNG inserts into its entropy pool. The raw entropy collection is provided to obtain the raw unmodified time stamps that are about to be added to the Jitter RNG entropy pool and are credited with entropy. Thus, this patch adds an interface which renders the Jitter RNG insecure. This patch is NOT INTENDED FOR PRODUCTION SYSTEMS, but solely for development/test systems to verify the available entropy rate. Access to the data is given through the jent_raw_hires debugfs file. The data buffer should be multiples of sizeof(u32) to fill the entire buffer. Using the option jitterentropy_testing.boot_raw_hires_test=1 the raw noise of the first 1000 entropy events since boot can be sampled. This test interface allows generating the data required for analysis whether the Jitter RNG is in compliance with SP800-90B sections 3.1.3 and 3.1.4. If the test interface is not compiled, its code is a noop which has no impact on the performance. Signed-off-by: Stephan Mueller <smueller@chronox.de> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>