FreeBSD/src 991666a (r340408) — lib/libnv common_impl.h msgio.c, lib/libnv/tests nvlist_send_recv_test.c
Ensure that libnv can be used when kern.trap_enotcap=1.
libnv used fcntl(fd, F_GETFL) to test whether fd is a valid file
descriptor. Aside from being racy, this check requires CAP_FCNTL
rights on fd. Instead, use fcntl(fd, F_GETFD), which does not require
any capability rights.
Also remove some redundant fd_is_valid() checks to avoid extra system
calls; in many cases we were performing this check immediately before
dup()ing the descriptor.
Reviewed by: cem, oshogbo (previous version)
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D17963
UnifiedSplitRaw
