subr_prf.c: Import from FreeBSD

1 files changed, 1126 insertions, 0 deletions

diff --git a/freebsd/sys/kern/subr_prf.c b/freebsd/sys/kern/subr_prf.c
new file mode 100644
index 00000000..0df816ee
--- /dev/null
+++ b/freebsd/sys/kern/subr_prf.c
@@ -0,0 +1,1126 @@
+#include <machine/rtems-bsd-kernel-space.h>
+
+/*-
+ * Copyright (c) 1986, 1988, 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ * (c) UNIX System Laboratories, Inc.
+ * All or some portions of this file are derived from material licensed
+ * to the University of California by American Telephone and Telegraph
+ * Co. or Unix System Laboratories, Inc. and are reproduced herein with
+ * the permission of UNIX System Laboratories, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)subr_prf.c	8.3 (Berkeley) 1/21/94
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <rtems/bsd/local/opt_ddb.h>
+#include <rtems/bsd/local/opt_printf.h>
+
+#include <rtems/bsd/sys/param.h>
+#include <sys/systm.h>
+#include <rtems/bsd/sys/lock.h>
+#include <sys/kdb.h>
+#include <sys/mutex.h>
+#include <sys/sx.h>
+#include <sys/kernel.h>
+#include <sys/msgbuf.h>
+#include <sys/malloc.h>
+#include <sys/priv.h>
+#include <sys/proc.h>
+#include <sys/stddef.h>
+#include <sys/sysctl.h>
+#include <sys/tty.h>
+#include <sys/syslog.h>
+#include <sys/cons.h>
+#include <sys/uio.h>
+#include <sys/ctype.h>
+
+#ifdef DDB
+#include <ddb/ddb.h>
+#endif
+
+/*
+ * Note that stdarg.h and the ANSI style va_start macro is used for both
+ * ANSI and traditional C compilers.
+ */
+#include <machine/stdarg.h>
+
+#define TOCONS	0x01
+#define TOTTY	0x02
+#define TOLOG	0x04
+
+/* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
+#define MAXNBUF	(sizeof(intmax_t) * NBBY + 1)
+
+struct putchar_arg {
+	int	flags;
+	int	pri;
+	struct	tty *tty;
+	char	*p_bufr;
+	size_t	n_bufr;
+	char	*p_next;
+	size_t	remain;
+};
+
+struct snprintf_arg {
+	char	*str;
+	size_t	remain;
+};
+
+extern	int log_open;
+
+static void  msglogchar(int c, int pri);
+static void  msglogstr(char *str, int pri, int filter_cr);
+static void  putchar(int ch, void *arg);
+static char *ksprintn(char *nbuf, uintmax_t num, int base, int *len, int upper);
+static void  snprintf_func(int ch, void *arg);
+
+static int msgbufmapped;		/* Set when safe to use msgbuf */
+int msgbuftrigger;
+
+static int      log_console_output = 1;
+TUNABLE_INT("kern.log_console_output", &log_console_output);
+SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
+    &log_console_output, 0, "Duplicate console output to the syslog.");
+
+/*
+ * See the comment in log_console() below for more explanation of this.
+ */
+static int log_console_add_linefeed = 0;
+TUNABLE_INT("kern.log_console_add_linefeed", &log_console_add_linefeed);
+SYSCTL_INT(_kern, OID_AUTO, log_console_add_linefeed, CTLFLAG_RW,
+    &log_console_add_linefeed, 0, "log_console() adds extra newlines.");
+
+static int	always_console_output = 0;
+TUNABLE_INT("kern.always_console_output", &always_console_output);
+SYSCTL_INT(_kern, OID_AUTO, always_console_output, CTLFLAG_RW,
+    &always_console_output, 0, "Always output to console despite TIOCCONS.");
+
+/*
+ * Warn that a system table is full.
+ */
+void
+tablefull(const char *tab)
+{
+
+	log(LOG_ERR, "%s: table is full\n", tab);
+}
+
+/*
+ * Uprintf prints to the controlling terminal for the current process.
+ */
+int
+uprintf(const char *fmt, ...)
+{
+	va_list ap;
+	struct putchar_arg pca;
+	struct proc *p;
+	struct thread *td;
+	int retval;
+
+	td = curthread;
+	if (TD_IS_IDLETHREAD(td))
+		return (0);
+
+	sx_slock(&proctree_lock);
+	p = td->td_proc;
+	PROC_LOCK(p);
+	if ((p->p_flag & P_CONTROLT) == 0) {
+		PROC_UNLOCK(p);
+		sx_sunlock(&proctree_lock);
+		return (0);
+	}
+	SESS_LOCK(p->p_session);
+	pca.tty = p->p_session->s_ttyp;
+	SESS_UNLOCK(p->p_session);
+	PROC_UNLOCK(p);
+	if (pca.tty == NULL) {
+		sx_sunlock(&proctree_lock);
+		return (0);
+	}
+	pca.flags = TOTTY;
+	pca.p_bufr = NULL;
+	va_start(ap, fmt);
+	tty_lock(pca.tty);
+	sx_sunlock(&proctree_lock);
+	retval = kvprintf(fmt, putchar, &pca, 10, ap);
+	tty_unlock(pca.tty);
+	va_end(ap);
+	return (retval);
+}
+
+/*
+ * tprintf prints on the controlling terminal associated with the given
+ * session, possibly to the log as well.
+ */
+void
+tprintf(struct proc *p, int pri, const char *fmt, ...)
+{
+	struct tty *tp = NULL;
+	int flags = 0;
+	va_list ap;
+	struct putchar_arg pca;
+	struct session *sess = NULL;
+
+	sx_slock(&proctree_lock);
+	if (pri != -1)
+		flags |= TOLOG;
+	if (p != NULL) {
+		PROC_LOCK(p);
+		if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
+			sess = p->p_session;
+			sess_hold(sess);
+			PROC_UNLOCK(p);
+			tp = sess->s_ttyp;
+			if (tp != NULL && tty_checkoutq(tp))
+				flags |= TOTTY;
+			else
+				tp = NULL;
+		} else
+			PROC_UNLOCK(p);
+	}
+	pca.pri = pri;
+	pca.tty = tp;
+	pca.flags = flags;
+	pca.p_bufr = NULL;
+	va_start(ap, fmt);
+	if (pca.tty != NULL)
+		tty_lock(pca.tty);
+	sx_sunlock(&proctree_lock);
+	kvprintf(fmt, putchar, &pca, 10, ap);
+	if (pca.tty != NULL)
+		tty_unlock(pca.tty);
+	va_end(ap);
+	if (sess != NULL)
+		sess_release(sess);
+	msgbuftrigger = 1;
+}
+
+/*
+ * Ttyprintf displays a message on a tty; it should be used only by
+ * the tty driver, or anything that knows the underlying tty will not
+ * be revoke(2)'d away.  Other callers should use tprintf.
+ */
+int
+ttyprintf(struct tty *tp, const char *fmt, ...)
+{
+	va_list ap;
+	struct putchar_arg pca;
+	int retval;
+
+	va_start(ap, fmt);
+	pca.tty = tp;
+	pca.flags = TOTTY;
+	pca.p_bufr = NULL;
+	retval = kvprintf(fmt, putchar, &pca, 10, ap);
+	va_end(ap);
+	return (retval);
+}
+
+static int
+_vprintf(int level, int flags, const char *fmt, va_list ap)
+{
+	struct putchar_arg pca;
+	int retval;
+#ifdef PRINTF_BUFR_SIZE
+	char bufr[PRINTF_BUFR_SIZE];
+#endif
+
+	pca.tty = NULL;
+	pca.pri = level;
+	pca.flags = flags;
+#ifdef PRINTF_BUFR_SIZE
+	pca.p_bufr = bufr;
+	pca.p_next = pca.p_bufr;
+	pca.n_bufr = sizeof(bufr);
+	pca.remain = sizeof(bufr);
+	*pca.p_next = '\0';
+#else
+	/* Don't buffer console output. */
+	pca.p_bufr = NULL;
+#endif
+
+	retval = kvprintf(fmt, putchar, &pca, 10, ap);
+
+#ifdef PRINTF_BUFR_SIZE
+	/* Write any buffered console/log output: */
+	if (*pca.p_bufr != '\0') {
+		if (pca.flags & TOLOG)
+			msglogstr(pca.p_bufr, level, /*filter_cr*/1);
+
+		if (pca.flags & TOCONS)
+			cnputs(pca.p_bufr);
+	}
+#endif
+
+	return (retval);
+}
+
+/*
+ * Log writes to the log buffer, and guarantees not to sleep (so can be
+ * called by interrupt routines).  If there is no process reading the
+ * log yet, it writes to the console also.
+ */
+void
+log(int level, const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	(void)_vprintf(level, log_open ? TOLOG : TOCONS, fmt, ap);
+	va_end(ap);
+
+	msgbuftrigger = 1;
+}
+
+#define CONSCHUNK 128
+
+void
+log_console(struct uio *uio)
+{
+	int c, error, nl;
+	char *consbuffer;
+	int pri;
+
+	if (!log_console_output)
+		return;
+
+	pri = LOG_INFO | LOG_CONSOLE;
+	uio = cloneuio(uio);
+	consbuffer = malloc(CONSCHUNK, M_TEMP, M_WAITOK);
+
+	nl = 0;
+	while (uio->uio_resid > 0) {
+		c = imin(uio->uio_resid, CONSCHUNK - 1);
+		error = uiomove(consbuffer, c, uio);
+		if (error != 0)
+			break;
+		/* Make sure we're NUL-terminated */
+		consbuffer[c] = '\0';
+		if (consbuffer[c - 1] == '\n')
+			nl = 1;
+		else
+			nl = 0;
+		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
+	}
+	/*
+	 * The previous behavior in log_console() is preserved when
+	 * log_console_add_linefeed is non-zero.  For that behavior, if an
+	 * individual console write came in that was not terminated with a
+	 * line feed, it would add a line feed.
+	 *
+	 * This results in different data in the message buffer than
+	 * appears on the system console (which doesn't add extra line feed
+	 * characters).
+	 *
+	 * A number of programs and rc scripts write a line feed, or a period
+	 * and a line feed when they have completed their operation.  On
+	 * the console, this looks seamless, but when displayed with
+	 * 'dmesg -a', you wind up with output that looks like this:
+	 *
+	 * Updating motd:
+	 * .
+	 *
+	 * On the console, it looks like this:
+	 * Updating motd:.
+	 *
+	 * We could add logic to detect that situation, or just not insert
+	 * the extra newlines.  Set the kern.log_console_add_linefeed
+	 * sysctl/tunable variable to get the old behavior.
+	 */
+	if (!nl && log_console_add_linefeed) {
+		consbuffer[0] = '\n';
+		consbuffer[1] = '\0';
+		msglogstr(consbuffer, pri, /*filter_cr*/ 1);
+	}
+	msgbuftrigger = 1;
+	free(uio, M_IOV);
+	free(consbuffer, M_TEMP);
+	return;
+}
+
+int
+printf(const char *fmt, ...)
+{
+	va_list ap;
+	int retval;
+
+	va_start(ap, fmt);
+	retval = vprintf(fmt, ap);
+	va_end(ap);
+
+	return (retval);
+}
+
+int
+vprintf(const char *fmt, va_list ap)
+{
+	int retval;
+
+	retval = _vprintf(-1, TOCONS | TOLOG, fmt, ap);
+
+	if (!panicstr)
+		msgbuftrigger = 1;
+
+	return (retval);
+}
+
+static void
+putbuf(int c, struct putchar_arg *ap)
+{
+	/* Check if no console output buffer was provided. */
+	if (ap->p_bufr == NULL) {
+		/* Output direct to the console. */
+		if (ap->flags & TOCONS)
+			cnputc(c);
+
+		if (ap->flags & TOLOG)
+			msglogchar(c, ap->pri);
+	} else {
+		/* Buffer the character: */
+		*ap->p_next++ = c;
+		ap->remain--;
+
+		/* Always leave the buffer zero terminated. */
+		*ap->p_next = '\0';
+
+		/* Check if the buffer needs to be flushed. */
+		if (ap->remain == 2 || c == '\n') {
+
+			if (ap->flags & TOLOG)
+				msglogstr(ap->p_bufr, ap->pri, /*filter_cr*/1);
+
+			if (ap->flags & TOCONS) {
+				if ((panicstr == NULL) && (constty != NULL))
+					msgbuf_addstr(&consmsgbuf, -1,
+					    ap->p_bufr, /*filter_cr*/ 0);
+
+				if ((constty == NULL) ||(always_console_output))
+					cnputs(ap->p_bufr);
+			}
+
+			ap->p_next = ap->p_bufr;
+			ap->remain = ap->n_bufr;
+			*ap->p_next = '\0';
+		}
+
+		/*
+		 * Since we fill the buffer up one character at a time,
+		 * this should not happen.  We should always catch it when
+		 * ap->remain == 2 (if not sooner due to a newline), flush
+		 * the buffer and move on.  One way this could happen is
+		 * if someone sets PRINTF_BUFR_SIZE to 1 or something
+		 * similarly silly.
+		 */
+		KASSERT(ap->remain > 2, ("Bad buffer logic, remain = %zd",
+		    ap->remain));
+	}
+}
+
+/*
+ * Print a character on console or users terminal.  If destination is
+ * the console then the last bunch of characters are saved in msgbuf for
+ * inspection later.
+ */
+static void
+putchar(int c, void *arg)
+{
+	struct putchar_arg *ap = (struct putchar_arg*) arg;
+	struct tty *tp = ap->tty;
+	int flags = ap->flags;
+	int putbuf_done = 0;
+
+	/* Don't use the tty code after a panic or while in ddb. */
+	if (kdb_active) {
+		if (c != '\0')
+			cnputc(c);
+	} else {
+		if ((panicstr == NULL) && (flags & TOTTY) && (tp != NULL))
+			tty_putchar(tp, c);
+
+		if (flags & TOCONS) {
+			putbuf(c, ap);
+			putbuf_done = 1;
+		}
+	}
+	if ((flags & TOLOG) && (putbuf_done == 0)) {
+		if (c != '\0')
+			putbuf(c, ap);
+	}
+}
+
+/*
+ * Scaled down version of sprintf(3).
+ */
+int
+sprintf(char *buf, const char *cfmt, ...)
+{
+	int retval;
+	va_list ap;
+
+	va_start(ap, cfmt);
+	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
+	buf[retval] = '\0';
+	va_end(ap);
+	return (retval);
+}
+
+/*
+ * Scaled down version of vsprintf(3).
+ */
+int
+vsprintf(char *buf, const char *cfmt, va_list ap)
+{
+	int retval;
+
+	retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
+	buf[retval] = '\0';
+	return (retval);
+}
+
+/*
+ * Scaled down version of snprintf(3).
+ */
+int
+snprintf(char *str, size_t size, const char *format, ...)
+{
+	int retval;
+	va_list ap;
+
+	va_start(ap, format);
+	retval = vsnprintf(str, size, format, ap);
+	va_end(ap);
+	return(retval);
+}
+
+/*
+ * Scaled down version of vsnprintf(3).
+ */
+int
+vsnprintf(char *str, size_t size, const char *format, va_list ap)
+{
+	struct snprintf_arg info;
+	int retval;
+
+	info.str = str;
+	info.remain = size;
+	retval = kvprintf(format, snprintf_func, &info, 10, ap);
+	if (info.remain >= 1)
+		*info.str++ = '\0';
+	return (retval);
+}
+
+/*
+ * Kernel version which takes radix argument vsnprintf(3).
+ */
+int
+vsnrprintf(char *str, size_t size, int radix, const char *format, va_list ap)
+{
+	struct snprintf_arg info;
+	int retval;
+
+	info.str = str;
+	info.remain = size;
+	retval = kvprintf(format, snprintf_func, &info, radix, ap);
+	if (info.remain >= 1)
+		*info.str++ = '\0';
+	return (retval);
+}
+
+static void
+snprintf_func(int ch, void *arg)
+{
+	struct snprintf_arg *const info = arg;
+
+	if (info->remain >= 2) {
+		*info->str++ = ch;
+		info->remain--;
+	}
+}
+
+/*
+ * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
+ * order; return an optional length and a pointer to the last character
+ * written in the buffer (i.e., the first character of the string).
+ * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
+ */
+static char *
+ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
+{
+	char *p, c;
+
+	p = nbuf;
+	*p = '\0';
+	do {
+		c = hex2ascii(num % base);
+		*++p = upper ? toupper(c) : c;
+	} while (num /= base);
+	if (lenp)
+		*lenp = p - nbuf;
+	return (p);
+}
+
+/*
+ * Scaled down version of printf(3).
+ *
+ * Two additional formats:
+ *
+ * The format %b is supported to decode error registers.
+ * Its usage is:
+ *
+ *	printf("reg=%b\n", regval, "<base><arg>*");
+ *
+ * where <base> is the output base expressed as a control character, e.g.
+ * \10 gives octal; \20 gives hex.  Each arg is a sequence of characters,
+ * the first of which gives the bit number to be inspected (origin 1), and
+ * the next characters (up to a control character, i.e. a character <= 32),
+ * give the name of the register.  Thus:
+ *
+ *	kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
+ *
+ * would produce output:
+ *
+ *	reg=3<BITTWO,BITONE>
+ *
+ * XXX:  %D  -- Hexdump, takes pointer and separator string:
+ *		("%6D", ptr, ":")   -> XX:XX:XX:XX:XX:XX
+ *		("%*D", len, ptr, " " -> XX XX XX XX ...
+ */
+int
+kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, va_list ap)
+{
+#define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
+	char nbuf[MAXNBUF];
+	char *d;
+	const char *p, *percent, *q;
+	u_char *up;
+	int ch, n;
+	uintmax_t num;
+	int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
+	int cflag, hflag, jflag, tflag, zflag;
+	int dwidth, upper;
+	char padc;
+	int stop = 0, retval = 0;
+
+	num = 0;
+	if (!func)
+		d = (char *) arg;
+	else
+		d = NULL;
+
+	if (fmt == NULL)
+		fmt = "(fmt null)\n";
+
+	if (radix < 2 || radix > 36)
+		radix = 10;
+
+	for (;;) {
+		padc = ' ';
+		width = 0;
+		while ((ch = (u_char)*fmt++) != '%' || stop) {
+			if (ch == '\0')
+				return (retval);
+			PCHAR(ch);
+		}
+		percent = fmt - 1;
+		qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
+		sign = 0; dot = 0; dwidth = 0; upper = 0;
+		cflag = 0; hflag = 0; jflag = 0; tflag = 0; zflag = 0;
+reswitch:	switch (ch = (u_char)*fmt++) {
+		case '.':
+			dot = 1;
+			goto reswitch;
+		case '#':
+			sharpflag = 1;
+			goto reswitch;
+		case '+':
+			sign = 1;
+			goto reswitch;
+		case '-':
+			ladjust = 1;
+			goto reswitch;
+		case '%':
+			PCHAR(ch);
+			break;
+		case '*':
+			if (!dot) {
+				width = va_arg(ap, int);
+				if (width < 0) {
+					ladjust = !ladjust;
+					width = -width;
+				}
+			} else {
+				dwidth = va_arg(ap, int);
+			}
+			goto reswitch;
+		case '0':
+			if (!dot) {
+				padc = '0';
+				goto reswitch;
+			}
+		case '1': case '2': case '3': case '4':
+		case '5': case '6': case '7': case '8': case '9':
+				for (n = 0;; ++fmt) {
+					n = n * 10 + ch - '0';
+					ch = *fmt;
+					if (ch < '0' || ch > '9')
+						break;
+				}
+			if (dot)
+				dwidth = n;
+			else
+				width = n;
+			goto reswitch;
+		case 'b':
+			num = (u_int)va_arg(ap, int);
+			p = va_arg(ap, char *);
+			for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
+				PCHAR(*q--);
+
+			if (num == 0)
+				break;
+
+			for (tmp = 0; *p;) {
+				n = *p++;
+				if (num & (1 << (n - 1))) {
+					PCHAR(tmp ? ',' : '<');
+					for (; (n = *p) > ' '; ++p)
+						PCHAR(n);
+					tmp = 1;
+				} else
+					for (; *p > ' '; ++p)
+						continue;
+			}
+			if (tmp)
+				PCHAR('>');
+			break;
+		case 'c':
+			PCHAR(va_arg(ap, int));
+			break;
+		case 'D':
+			up = va_arg(ap, u_char *);
+			p = va_arg(ap, char *);
+			if (!width)
+				width = 16;
+			while(width--) {
+				PCHAR(hex2ascii(*up >> 4));
+				PCHAR(hex2ascii(*up & 0x0f));
+				up++;
+				if (width)
+					for (q=p;*q;q++)
+						PCHAR(*q);
+			}
+			break;
+		case 'd':
+		case 'i':
+			base = 10;
+			sign = 1;
+			goto handle_sign;
+		case 'h':
+			if (hflag) {
+				hflag = 0;
+				cflag = 1;
+			} else
+				hflag = 1;
+			goto reswitch;
+		case 'j':
+			jflag = 1;
+			goto reswitch;
+		case 'l':
+			if (lflag) {
+				lflag = 0;
+				qflag = 1;
+			} else
+				lflag = 1;
+			goto reswitch;
+		case 'n':
+			if (jflag)
+				*(va_arg(ap, intmax_t *)) = retval;
+			else if (qflag)
+				*(va_arg(ap, quad_t *)) = retval;
+			else if (lflag)
+				*(va_arg(ap, long *)) = retval;
+			else if (zflag)
+				*(va_arg(ap, size_t *)) = retval;
+			else if (hflag)
+				*(va_arg(ap, short *)) = retval;
+			else if (cflag)
+				*(va_arg(ap, char *)) = retval;
+			else
+				*(va_arg(ap, int *)) = retval;
+			break;
+		case 'o':
+			base = 8;
+			goto handle_nosign;
+		case 'p':
+			base = 16;
+			sharpflag = (width == 0);
+			sign = 0;
+			num = (uintptr_t)va_arg(ap, void *);
+			goto number;
+		case 'q':
+			qflag = 1;
+			goto reswitch;
+		case 'r':
+			base = radix;
+			if (sign)
+				goto handle_sign;
+			goto handle_nosign;
+		case 's':
+			p = va_arg(ap, char *);
+			if (p == NULL)
+				p = "(null)";
+			if (!dot)
+				n = strlen (p);
+			else
+				for (n = 0; n < dwidth && p[n]; n++)
+					continue;
+
+			width -= n;
+
+			if (!ladjust && width > 0)
+				while (width--)
+					PCHAR(padc);
+			while (n--)
+				PCHAR(*p++);
+			if (ladjust && width > 0)
+				while (width--)
+					PCHAR(padc);
+			break;
+		case 't':
+			tflag = 1;
+			goto reswitch;
+		case 'u':
+			base = 10;
+			goto handle_nosign;
+		case 'X':
+			upper = 1;
+		case 'x':
+			base = 16;
+			goto handle_nosign;
+		case 'y':
+			base = 16;
+			sign = 1;
+			goto handle_sign;
+		case 'z':
+			zflag = 1;
+			goto reswitch;
+handle_nosign:
+			sign = 0;
+			if (jflag)
+				num = va_arg(ap, uintmax_t);
+			else if (qflag)
+				num = va_arg(ap, u_quad_t);
+			else if (tflag)
+				num = va_arg(ap, ptrdiff_t);
+			else if (lflag)
+				num = va_arg(ap, u_long);
+			else if (zflag)
+				num = va_arg(ap, size_t);
+			else if (hflag)
+				num = (u_short)va_arg(ap, int);
+			else if (cflag)
+				num = (u_char)va_arg(ap, int);
+			else
+				num = va_arg(ap, u_int);
+			goto number;
+handle_sign:
+			if (jflag)
+				num = va_arg(ap, intmax_t);
+			else if (qflag)
+				num = va_arg(ap, quad_t);
+			else if (tflag)
+				num = va_arg(ap, ptrdiff_t);
+			else if (lflag)
+				num = va_arg(ap, long);
+			else if (zflag)
+				num = va_arg(ap, ssize_t);
+			else if (hflag)
+				num = (short)va_arg(ap, int);
+			else if (cflag)
+				num = (char)va_arg(ap, int);
+			else
+				num = va_arg(ap, int);
+number:
+			if (sign && (intmax_t)num < 0) {
+				neg = 1;
+				num = -(intmax_t)num;
+			}
+			p = ksprintn(nbuf, num, base, &n, upper);
+			tmp = 0;
+			if (sharpflag && num != 0) {
+				if (base == 8)
+					tmp++;
+				else if (base == 16)
+					tmp += 2;
+			}
+			if (neg)
+				tmp++;
+
+			if (!ladjust && padc == '0')
+				dwidth = width - tmp;
+			width -= tmp + imax(dwidth, n);
+			dwidth -= n;
+			if (!ladjust)
+				while (width-- > 0)
+					PCHAR(' ');
+			if (neg)
+				PCHAR('-');
+			if (sharpflag && num != 0) {
+				if (base == 8) {
+					PCHAR('0');
+				} else if (base == 16) {
+					PCHAR('0');
+					PCHAR('x');
+				}
+			}
+			while (dwidth-- > 0)
+				PCHAR('0');
+
+			while (*p)
+				PCHAR(*p--);
+
+			if (ladjust)
+				while (width-- > 0)
+					PCHAR(' ');
+
+			break;
+		default:
+			while (percent < fmt)
+				PCHAR(*percent++);
+			/*
+			 * Since we ignore an formatting argument it is no 
+			 * longer safe to obey the remaining formatting
+			 * arguments as the arguments will no longer match
+			 * the format specs.
+			 */
+			stop = 1;
+			break;
+		}
+	}
+#undef PCHAR
+}
+
+/*
+ * Put character in log buffer with a particular priority.
+ */
+static void
+msglogchar(int c, int pri)
+{
+	static int lastpri = -1;
+	static int dangling;
+	char nbuf[MAXNBUF];
+	char *p;
+
+	if (!msgbufmapped)
+		return;
+	if (c == '\0' || c == '\r')
+		return;
+	if (pri != -1 && pri != lastpri) {
+		if (dangling) {
+			msgbuf_addchar(msgbufp, '\n');
+			dangling = 0;
+		}
+		msgbuf_addchar(msgbufp, '<');
+		for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
+			msgbuf_addchar(msgbufp, *p--);
+		msgbuf_addchar(msgbufp, '>');
+		lastpri = pri;
+	}
+	msgbuf_addchar(msgbufp, c);
+	if (c == '\n') {
+		dangling = 0;
+		lastpri = -1;
+	} else {
+		dangling = 1;
+	}
+}
+
+static void
+msglogstr(char *str, int pri, int filter_cr)
+{
+	if (!msgbufmapped)
+		return;
+
+	msgbuf_addstr(msgbufp, pri, str, filter_cr);
+}
+
+void
+msgbufinit(void *ptr, int size)
+{
+	char *cp;
+	static struct msgbuf *oldp = NULL;
+
+	size -= sizeof(*msgbufp);
+	cp = (char *)ptr;
+	msgbufp = (struct msgbuf *)(cp + size);
+	msgbuf_reinit(msgbufp, cp, size);
+	if (msgbufmapped && oldp != msgbufp)
+		msgbuf_copy(oldp, msgbufp);
+	msgbufmapped = 1;
+	oldp = msgbufp;
+}
+
+static int unprivileged_read_msgbuf = 1;
+SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_read_msgbuf,
+    CTLFLAG_RW, &unprivileged_read_msgbuf, 0,
+    "Unprivileged processes may read the kernel message buffer");
+
+/* Sysctls for accessing/clearing the msgbuf */
+static int
+sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
+{
+	char buf[128];
+	u_int seq;
+	int error, len;
+
+	if (!unprivileged_read_msgbuf) {
+		error = priv_check(req->td, PRIV_MSGBUF);
+		if (error)
+			return (error);
+	}
+
+	/* Read the whole buffer, one chunk at a time. */
+	mtx_lock(&msgbuf_lock);
+	msgbuf_peekbytes(msgbufp, NULL, 0, &seq);
+	for (;;) {
+		len = msgbuf_peekbytes(msgbufp, buf, sizeof(buf), &seq);
+		mtx_unlock(&msgbuf_lock);
+		if (len == 0)
+			return (0);
+
+		error = sysctl_handle_opaque(oidp, buf, len, req);
+		if (error)
+			return (error);
+
+		mtx_lock(&msgbuf_lock);
+	}
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, msgbuf,
+    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
+    NULL, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
+
+static int msgbuf_clearflag;
+
+static int
+sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
+{
+	int error;
+	error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
+	if (!error && req->newptr) {
+		mtx_lock(&msgbuf_lock);
+		msgbuf_clear(msgbufp);
+		mtx_unlock(&msgbuf_lock);
+		msgbuf_clearflag = 0;
+	}
+	return (error);
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
+    CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE | CTLFLAG_MPSAFE,
+    &msgbuf_clearflag, 0, sysctl_kern_msgbuf_clear, "I",
+    "Clear kernel message buffer");
+
+#ifdef DDB
+
+DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
+{
+	int i, j;
+
+	if (!msgbufmapped) {
+		db_printf("msgbuf not mapped yet\n");
+		return;
+	}
+	db_printf("msgbufp = %p\n", msgbufp);
+	db_printf("magic = %x, size = %d, r= %u, w = %u, ptr = %p, cksum= %u\n",
+	    msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_rseq,
+	    msgbufp->msg_wseq, msgbufp->msg_ptr, msgbufp->msg_cksum);
+	for (i = 0; i < msgbufp->msg_size && !db_pager_quit; i++) {
+		j = MSGBUF_SEQ_TO_POS(msgbufp, i + msgbufp->msg_rseq);
+		db_printf("%c", msgbufp->msg_ptr[j]);
+	}
+	db_printf("\n");
+}
+
+#endif /* DDB */
+
+void
+hexdump(const void *ptr, int length, const char *hdr, int flags)
+{
+	int i, j, k;
+	int cols;
+	const unsigned char *cp;
+	char delim;
+
+	if ((flags & HD_DELIM_MASK) != 0)
+		delim = (flags & HD_DELIM_MASK) >> 8;
+	else
+		delim = ' ';
+
+	if ((flags & HD_COLUMN_MASK) != 0)
+		cols = flags & HD_COLUMN_MASK;
+	else
+		cols = 16;
+
+	cp = ptr;
+	for (i = 0; i < length; i+= cols) {
+		if (hdr != NULL)
+			printf("%s", hdr);
+
+		if ((flags & HD_OMIT_COUNT) == 0)
+			printf("%04x  ", i);
+
+		if ((flags & HD_OMIT_HEX) == 0) {
+			for (j = 0; j < cols; j++) {
+				k = i + j;
+				if (k < length)
+					printf("%c%02x", delim, cp[k]);
+				else
+					printf("   ");
+			}
+		}
+
+		if ((flags & HD_OMIT_CHARS) == 0) {
+			printf("  |");
+			for (j = 0; j < cols; j++) {
+				k = i + j;
+				if (k >= length)
+					printf(" ");
+				else if (cp[k] >= ' ' && cp[k] <= '~')
+					printf("%c", cp[k]);
+				else
+					printf(".");
+			}
+			printf("|");
+		}
+		printf("\n");
+	}
+}
+