Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/hardening
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/segvguard
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/log
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/chacha
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/pie
Allocate buffer for READ BUFFER/WRITE BUFFER commands on demand.

These commands are rare, but consume additional 256KB RAM per LUN.

MFC after:	1 week
Simplify memrw().

MFC after:	10 days
Merge branch 'hardened/current/master' into hardened/current/ptrace

Conflicts:
	sys/kern/kern_pax.c
	sys/kern/kern_pax_hardening.c
getgrouplist(3) was reimplemented in terms of getgrent_r(3) in r174547, so
this bug is no longer valid.

MFC after:	3 days
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/hardening
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/segvguard
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/ptrace
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/log
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/userlandenhanced
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/chacha
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/pie
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/unstable
Merge remote-tracking branch 'origin/hardened/current/hardening' into hardened/current/unstable