CVS commit: src/sys/kern

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

Module Name:    src
Committed By:   riastradh
Date:           Sun Mar 20 14:30:57 UTC 2022

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

Log Message:
entropy(9): Fix premature optimization deadlock in entropy_request.

- For synchronous queries from /dev/random, which are waiting for
  entropy to be ready, wait for concurrent access -- e.g., concurrent
  rnd_detach_source -- to finish, and make sure to request entropy
  from all sources (unless we're interrupted by a signal).

- When invoked through softint context (e.g., cprng_fast_intr ->
  cprng_strong -> entropy_extract), don't wait, because we're
  forbidden from waiting anyway.

- For entropy_bootrequest, wait but don't bother failing on signal
  because this only happens in kthread context, not in userland
  process context, so there can't be signals.

Nix rnd_trylock_sources; use the same entropy_extract flags
(ENTROPY_WAIT, ENTROPY_SIG) for rnd_lock_sources.


To generate a diff of this commit:
cvs rdiff -u -r1.48 -r1.49 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.