f4f7c153a6
For two reasons, current_quality may become zero within the rngd kernel thread: (1) The user lowers current_quality to 0 by writing to the sysfs module parameter file (note that increasing the quality from zero is without effect at the moment), or (2) there are two or more hwrng devices registered, and those which provide quality>0 are unregistered, but one with quality==0 remains. If current_quality is 0, the randomness is not trusted and cannot help to increase the entropy count. That will lead to continuous calls to the hwrngd thread and continuous stirring of the input pool with untrusted bits. Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jason A. Donenfeld <Jason@zx2c4.com> Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.