[src/trunk]: src Add a new kern.messages sysctl to allow kernel message verbo...

[pgoyette <pgoyette%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/bd4f9bb20e8b
branches:  trunk
changeset: 345525:bd4f9bb20e8b
user:      pgoyette <pgoyette%NetBSD.org@localhost>
date:      Tue May 31 05:44:19 2016 +0000

description:
Add a new kern.messages sysctl to allow kernel message verbosity to be
altered after boot.

Fixes PR kern/46539 using patch submitted by Nat Sloss.

diffstat:

 share/man/man7/sysctl.7 |  17 +++++++++-
 sys/kern/init_sysctl.c  |  78 +++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 91 insertions(+), 4 deletions(-)

diffs (165 lines):

diff -r 583b74ff0081 -r bd4f9bb20e8b share/man/man7/sysctl.7
--- a/share/man/man7/sysctl.7   Tue May 31 04:14:12 2016 +0000
+++ b/share/man/man7/sysctl.7   Tue May 31 05:44:19 2016 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: sysctl.7,v 1.101 2016/05/25 20:47:57 wiz Exp $
+.\"    $NetBSD: sysctl.7,v 1.102 2016/05/31 05:44:19 pgoyette Exp $
 .\"
 .\" Copyright (c) 1993
 .\"    The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"    @(#)sysctl.3    8.4 (Berkeley) 5/9/95
 .\"
-.Dd May 25, 2016
+.Dd May 31, 2016
 .Dt SYSCTL 7
 .Os
 .Sh NAME
@@ -315,6 +315,7 @@
 .It kern.maxproc       integer yes
 .It kern.maxptys       integer yes
 .It kern.maxvnodes     integer yes
+.It kern.messages      integer yes
 .It kern.mbuf  node    not applicable
 .It kern.memlock       integer no
 .It kern.memlock_range integer no
@@ -739,6 +740,18 @@
 .St -p1003.1b-93
 Memory Protection Option is available on this system,
 otherwise\ 0.
+.It Li kern.messages
+Kernel console message verbosity.
+See
+.Sy \<sys/reboot.h\>
+.Bl -column "verbosity" "setting" -offset indent
+.It Sy Verbosity       Setting
+.It \ \ \ \ 0  Silent Sy AB_SILENT
+.It \ \ \ \ 1  Quiet Sy AB_QUIET
+.It \ \ \ \ 2  Normal Sy AB_NORMAL
+.It \ \ \ \ 3  Verbose Sy AB_VERBOSE
+.It \ \ \ \ 4  Debug Sy AB_DEBUG
+.El
 .It Li kern.module
 Settings related to kernel modules.
 The third level names for the settings are described below.
diff -r 583b74ff0081 -r bd4f9bb20e8b sys/kern/init_sysctl.c
--- a/sys/kern/init_sysctl.c    Tue May 31 04:14:12 2016 +0000
+++ b/sys/kern/init_sysctl.c    Tue May 31 05:44:19 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: init_sysctl.c,v 1.210 2015/11/09 01:21:18 pgoyette Exp $ */
+/*     $NetBSD: init_sysctl.c,v 1.211 2016/05/31 05:44:19 pgoyette Exp $ */
 
 /*-
  * Copyright (c) 2003, 2007, 2008, 2009 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: init_sysctl.c,v 1.210 2015/11/09 01:21:18 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: init_sysctl.c,v 1.211 2016/05/31 05:44:19 pgoyette Exp $");
 
 #include "opt_sysv.h"
 #include "opt_compat_netbsd.h"
@@ -56,6 +56,7 @@
 #include <sys/filedesc.h>
 #include <sys/tty.h>
 #include <sys/kmem.h>
+#include <sys/reboot.h>
 #include <sys/resource.h>
 #include <sys/resourcevar.h>
 #include <sys/exec.h>
@@ -110,6 +111,7 @@
 static int sysctl_kern_trigger_panic(SYSCTLFN_PROTO);
 #endif
 static int sysctl_kern_maxvnodes(SYSCTLFN_PROTO);
+static int sysctl_kern_messages(SYSCTLFN_PROTO);
 static int sysctl_kern_rtc_offset(SYSCTLFN_PROTO);
 static int sysctl_kern_maxproc(SYSCTLFN_PROTO);
 static int sysctl_kern_hostid(SYSCTLFN_PROTO);
@@ -590,6 +592,12 @@
                        SYSCTL_DESCR("Information from build environment"),
                        NULL, 0, __UNCONST(buildinfo), 0,
                        CTL_KERN, CTL_CREATE, CTL_EOL);
+       sysctl_createv(clog, 0, NULL, NULL,
+                       CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
+                       CTLTYPE_INT, "messages",
+                       SYSCTL_DESCR("Kernel message verbosity"),
+                       sysctl_kern_messages, 0, NULL, 0,
+                       CTL_KERN, CTL_CREATE, CTL_EOL);
 }
 
 SYSCTL_SETUP(sysctl_hw_misc_setup, "sysctl hw subtree misc setup")
@@ -760,6 +768,72 @@
 }
 
 /*
+ * sysctl helper routine for kern.messages.
+ * Alters boothowto to display kernel messages in increasing verbosity
+ * from 0 to 4.
+ */
+
+#define MAXMESSAGES            4
+static int
+sysctl_kern_messages(SYSCTLFN_ARGS)
+{
+       int error, messageverbose, messagemask, newboothowto;
+       struct sysctlnode node;
+
+       messagemask = (AB_NORMAL|AB_QUIET|AB_SILENT|AB_VERBOSE|AB_DEBUG);
+       switch (boothowto & messagemask) {
+       case AB_SILENT:
+               messageverbose = 0;
+               break;
+       case AB_QUIET:
+               messageverbose = 1;
+               break;
+       case AB_VERBOSE:
+               messageverbose = 3;
+               break;
+       case AB_DEBUG:
+               messageverbose = 4;
+               break;
+       case AB_NORMAL:
+       default:
+               messageverbose = 2;
+}
+
+       node = *rnode;
+       node.sysctl_data = &messageverbose;
+       error = sysctl_lookup(SYSCTLFN_CALL(&node));
+       if (error || newp == NULL)
+               return (error);
+       if (messageverbose < 0 || messageverbose > MAXMESSAGES)
+               return EINVAL;
+
+       /* Set boothowto */
+       newboothowto = boothowto & ~messagemask;
+
+       switch (messageverbose) {
+       case 0:
+               newboothowto |= AB_SILENT;
+               break;
+       case 1:
+               newboothowto |= AB_QUIET;
+               break;
+       case 3:
+               newboothowto |= AB_VERBOSE;
+               break;
+       case 4:
+               newboothowto |= AB_DEBUG;
+               break;
+       case 2:
+       default:                /* Messages default to normal. */
+               break;
+       }
+
+       boothowto = newboothowto;
+
+       return (0);
+}
+
+/*
  * sysctl helper routine for rtc_offset - set time after changes
  */
 static int