PR/56979 CVS commit: src/libexec/ld.elf_so

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

The following reply was made to PR lib/56979; it has been noted by GNATS.

From: "Taylor R Campbell" <riastradh%netbsd.org@localhost>
To: gnats-bugs%gnats.NetBSD.org@localhost
Cc: 
Subject: PR/56979 CVS commit: src/libexec/ld.elf_so
Date: Tue, 13 Sep 2022 10:18:58 +0000

 Module Name:	src
 Committed By:	riastradh
 Date:		Tue Sep 13 10:18:58 UTC 2022
 
 Modified Files:
 	src/libexec/ld.elf_so: rtld.c
 
 Log Message:
 ld.elf_so(8): Make fork take a shared, not exclusive, lock.
 
 We only need to ensure that there are no concurrent modifications to
 the rtld data structures in flight, since the threads that began
 those modifications will not exist in the child and will therefore be
 unable to complete them in the child.
 
 A shared lock suffices to ensure there are no such concurrent
 modifications in flight; an exclusive lock is not necessary, and can
 cause deadlock if fork is executed from a signal handler, which is
 explicitly allowed by POSIX (and our own sigaction(2) man page) which
 marks fork as async-signal-safe.
 
 PR lib/56979
 
 
 To generate a diff of this commit:
 cvs rdiff -u -r1.211 -r1.212 src/libexec/ld.elf_so/rtld.c
 
 Please note that diffs are not public domain; they are subject to the
 copyright notices on the relevant files.