CVS commit: src/sys/kern

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Sun May 10 00:08:12 UTC 2020

Modified Files:
        src/sys/kern: kern_entropy.c

Log Message:
Use a temporary pool to consolidate entropy atomically.

There was a low-probability race with the entropy consolidation
logic: calls to entropy_extract at the same time as consolidation is
happening might witness partial contributions from the CPUs when
needed=256, say 64 bits at a time.

To avoid this, feed everything from the per-CPU pools into a
temporary pool, and then feed the temporary pool into the global pool
under the lock at the same time as we update needed.


To generate a diff of this commit:
cvs rdiff -u -r1.18 -r1.19 src/sys/kern/kern_entropy.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.