K 10
svn:author
V 5
markj
K 8
svn:date
V 27
2018-11-13T20:07:55.282604Z
K 7
svn:log
V 608
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

END