• Stephan Müller's avatar
    crypto: jitter - reuse allocated entropy collector · 8405ec8e
    Stephan Müller authored
    In case a health test error occurs during runtime, the power-up health
    tests are rerun to verify that the noise source is still good and
    that the reported health test error was an outlier. For performing this
    power-up health test, the already existing entropy collector instance
    is used instead of allocating a new one. This change has the following
    implications:
    
    * The noise that is collected as part of the newly run health tests is
      inserted into the entropy collector and thus stirs the existing
      data present in there further. Thus, the entropy collected during
      the health test is not wasted. This is also allowed by SP800-90B.
    
    * The power-on health test is not affected by the state of the entropy
      collector, because it resets the APT / RCT state. The remainder of
      the state is unrelated to the health test as it is only applied to
      newly obtained time stamps.
    
    This change also fixes a bug report about an allocation while in an
    atomic lock (the lock is taken in jent_kcapi_random, jent_read_entropy
    is called and this can call jent_entropy_init).
    
    Fixes: 04597c8d ("jitter - add RCT/APT support for different OSRs")
    Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
    Signed-off-by: default avatarStephan Mueller <smueller@chronox.de>
    Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
    8405ec8e
jitterentropy-kcapi.c 11 KB