. new kernel call sysctl for generic unprivileged system operations;

now used for printing diagnostic messages through the kernel message
   buffer. this lets processes print diagnostics without sending messages
   to tty and log directly, simplifying the message protocol a lot and
   reducing difficulties with deadlocks and other situations in which
   diagnostics are blackholed (e.g. grants don't work). this makes
   DIAGNOSTICS(_S), ASYN_DIAGNOSTICS and DIAG_REPL obsolete, although tty
   and log still accept the codes for 'old' binaries. This also simplifies
   diagnostics in several servers and drivers - only tty needs its own
   kputc() now.
 . simplifications in vfs, and some effort to get the vnode references
   right (consistent) even during shutdown. m_mounted_on is now NULL
   for root filesystems (!) (the original and new root), a less awkward
   special case than 'm_mounted_on == m_root_node'. root now has exactly
   one reference, to root, if no files are open, just like all other
   filesystems. m_driver_e is unused.

servers/rs/manager.c

@@ -1024,10 +1024,6 @@ struct rproc *rp;
 	case 0:
 		execle(rp->r_script, rp->r_script, rp->r_label, reason,
 			incarnation_str, NULL, NULL);
-		{
-			extern int kputc_use_private_grants;
-			kputc_use_private_grants= 1;
-		}
 		printf("RS: run_script: execl '%s' failed: %s\n",
 			rp->r_script, strerror(errno));
 		exit(1);

servers/rs/service.c

@@ -692,6 +692,7 @@ struct
 	{ "MAPDMA",		SYS_MAPDMA },
 	{ "VMCTL",		SYS_VMCTL },
 	{ "PROFBUF",		SYS_PROFBUF },
+	{ "SYSCTL",		SYS_SYSCTL },
 	{ NULL,		0 }
 };