CVS commit: src/sys/kern

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

Module Name:    src
Committed By:   riastradh
Date:           Sat Aug  5 11:21:24 UTC 2023

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

Log Message:
cprng(9): Drop and retake percpu reference across entropy_extract.

entropy_extract may sleep on an adaptive lock, which invalidates
percpu(9) references.

Add a note in the comment over entropy_extract about this.

Discovered by stumbling upon this panic during a test run:

[   1.0200050] panic: kernel diagnostic assertion "(cprng == percpu_getref(cprng_fast_percpu)) && (percpu_putref(cprng_fast_percpu), true)" failed: file 
"/home/riastradh/netbsd/current/src/sys/rump/librump/rumpkern/../../../crypto/cprng_fast/cprng_fast.c", line 117

XXX pullup-10


To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/sys/kern/kern_entropy.c
cvs rdiff -u -r1.43 -r1.44 src/sys/kern/subr_cprng.c

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