PR/59117 CVS commit: src/lib/libc/gen

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

The following reply was made to PR lib/59117; it has been noted by GNATS.

From: "Taylor R Campbell" <riastradh%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/59117 CVS commit: src/lib/libc/gen
Date: Sun, 2 Mar 2025 22:46:24 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Sun Mar  2 22:46:24 UTC 2025
 
 Modified Files:
 	src/lib/libc/gen: arc4random.c pthread_atfork.c
 
 Log Message:
 libc: New __libc_atfork.
 
 This uses caller-provided storage for the callback queues.
 
 Use it in arc4random(3) in order to avoid possible failure modes.
 
 This is a private symbol, not designed for use outside NetBSD, and
 the API is not intended to be stable (yet) -- I just took the
 existing purely internal structure (struct atfork_callback) and
 reused it for this API without changing any of the calling-side
 logic.  We could change it, e.g. to use a single structure per call,
 to make the API a little less unwieldy, at the cost of
 microscopically more storage and runtime for the users that don't use
 all three callbacks; to be considered in a future change.
 
 We might reasonably use __libc_atfork in libpthread for use in the
 pthread_tsd_init constructor, in order to be confident it never
 attempts malloc(3), but let's do that in a separate commit just in
 case anything goes awry with that plan.
 
 PR lib/59112: libpthread constructors use malloc
 PR lib/59117: arc4random has some failure modes it shouldn't
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.39 -r1.40 src/lib/libc/gen/arc4random.c
 cvs rdiff -u -r1.23 -r1.24 src/lib/libc/gen/pthread_atfork.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.