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freebsd-nq/sys/kern/subr_prf.c
John Baldwin 44731cab3b Change the suser() API to take advantage of td_ucred as well as do a 
general cleanup of the API.  The entire API now consists of two functions
similar to the pre-KSE API.  The suser() function takes a thread pointer
as its only argument.  The td_ucred member of this thread must be valid
so the only valid thread pointers are curthread and a few kernel threads
such as thread0.  The suser_cred() function takes a pointer to a struct
ucred as its first argument and an integer flag as its second argument.
The flag is currently only used for the PRISON_ROOT flag.

Discussed on:	smp@
2002-04-01 21:31:13 +00:00

931 lines
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/*-
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/sx.h>
#include <sys/kernel.h>
#include <sys/msgbuf.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/sysctl.h>
#include <sys/tty.h>
#include <sys/syslog.h>
#include <sys/cons.h>
#include <sys/uio.h>
/*
* 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(quad_t) * NBBY + 1)
struct putchar_arg {
int flags;
int pri;
struct tty *tty;
};
struct snprintf_arg {
char *str;
size_t remain;
};
extern int log_open;
struct tty *constty; /* pointer to console "window" tty */
static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */
static void msglogchar(int c, int pri);
static void msgaddchar(int c, void *dummy);
static void putchar(int ch, void *arg);
static char *ksprintn(char *nbuf, u_long num, int base, int *len);
static char *ksprintqn(char *nbuf, u_quad_t num, int base, int *len);
static void snprintf_func(int ch, void *arg);
static int consintr = 1; /* Ok to handle console interrupts? */
static int msgbufmapped; /* Set when safe to use msgbuf */
int msgbuftrigger;
/*
* 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.
* It may block if the tty queue is overfull. No message is printed if
* the queue does not clear in a reasonable time.
*/
int
uprintf(const char *fmt, ...)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
va_list ap;
struct putchar_arg pca;
int retval;
if (td == NULL || td == PCPU_GET(idlethread))
return (0);
p = td->td_proc;
PROC_LOCK(p);
if ((p->p_flag & P_CONTROLT) == 0) {
PROC_UNLOCK(p);
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)
return (0);
pca.flags = TOTTY;
va_start(ap, fmt);
retval = kvprintf(fmt, putchar, &pca, 10, ap);
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, shld = 0;
va_list ap;
struct putchar_arg pca;
int retval;
if (pri != -1)
flags |= TOLOG;
if (p != NULL) {
PROC_LOCK(p);
if (p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
SESS_LOCK(p->p_session);
SESSHOLD(p->p_session);
tp = p->p_session->s_ttyp;
SESS_UNLOCK(p->p_session);
PROC_UNLOCK(p);
shld++;
if (ttycheckoutq(tp, 0))
flags |= TOTTY;
else
tp = NULL;
} else
PROC_UNLOCK(p);
}
pca.pri = pri;
pca.tty = tp;
pca.flags = flags;
va_start(ap, fmt);
retval = kvprintf(fmt, putchar, &pca, 10, ap);
va_end(ap);
if (shld) {
PROC_LOCK(p);
SESS_LOCK(p->p_session);
SESSRELE(p->p_session);
SESS_UNLOCK(p->p_session);
PROC_UNLOCK(p);
}
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;
retval = kvprintf(fmt, putchar, &pca, 10, ap);
va_end(ap);
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;
int retval;
struct putchar_arg pca;
pca.tty = NULL;
pca.pri = level;
pca.flags = log_open ? TOLOG : TOCONS;
va_start(ap, fmt);
retval = kvprintf(fmt, putchar, &pca, 10, ap);
va_end(ap);
msgbuftrigger = 1;
}
#define CONSCHUNK 128
void
log_console(struct uio *uio)
{
int c, i, error, iovlen, nl;
struct uio muio;
struct iovec *miov = NULL;
char *consbuffer;
int pri;
pri = LOG_INFO | LOG_CONSOLE;
muio = *uio;
iovlen = uio->uio_iovcnt * sizeof (struct iovec);
MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
muio.uio_iov = miov;
uio = &muio;
nl = 0;
while (uio->uio_resid > 0) {
c = imin(uio->uio_resid, CONSCHUNK);
error = uiomove(consbuffer, c, uio);
if (error != 0)
return;
for (i = 0; i < c; i++) {
msglogchar(consbuffer[i], pri);
if (consbuffer[i] == '\n')
nl = 1;
else
nl = 0;
}
}
if (!nl)
msglogchar('\n', pri);
msgbuftrigger = 1;
FREE(miov, M_TEMP);
FREE(consbuffer, M_TEMP);
return;
}
int
printf(const char *fmt, ...)
{
va_list ap;
int savintr;
struct putchar_arg pca;
int retval;
savintr = consintr; /* disable interrupts */
consintr = 0;
va_start(ap, fmt);
pca.tty = NULL;
pca.flags = TOCONS | TOLOG;
pca.pri = -1;
retval = kvprintf(fmt, putchar, &pca, 10, ap);
va_end(ap);
if (!panicstr)
msgbuftrigger = 1;
consintr = savintr; /* reenable interrupts */
return (retval);
}
int
vprintf(const char *fmt, va_list ap)
{
int savintr;
struct putchar_arg pca;
int retval;
savintr = consintr; /* disable interrupts */
consintr = 0;
pca.tty = NULL;
pca.flags = TOCONS | TOLOG;
pca.pri = -1;
retval = kvprintf(fmt, putchar, &pca, 10, ap);
if (!panicstr)
msgbuftrigger = 1;
consintr = savintr; /* reenable interrupts */
return (retval);
}
/*
* 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;
int flags = ap->flags;
struct tty *tp = ap->tty;
if (panicstr)
constty = NULL;
if ((flags & TOCONS) && tp == NULL && constty) {
tp = constty;
flags |= TOTTY;
}
if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
(flags & TOCONS) && tp == constty)
constty = NULL;
if ((flags & TOLOG))
msglogchar(c, ap->pri);
if ((flags & TOCONS) && constty == NULL && c != '\0')
(*v_putc)(c);
}
/*
* 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);
}
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(nbuf, ul, base, lenp)
char *nbuf;
u_long ul;
int base, *lenp;
{
char *p;
p = nbuf;
*p = '\0';
do {
*++p = hex2ascii(ul % base);
} while (ul /= base);
if (lenp)
*lenp = p - nbuf;
return (p);
}
/* ksprintn, but for a quad_t. */
static char *
ksprintqn(nbuf, uq, base, lenp)
char *nbuf;
u_quad_t uq;
int base, *lenp;
{
char *p;
p = nbuf;
*p = '\0';
do {
*++p = hex2ascii(uq % base);
} while (uq /= 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 *p, *q, *d;
u_char *up;
int ch, n;
u_long ul;
u_quad_t uq;
int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
int dwidth;
char padc;
int retval = 0;
ul = 0;
uq = 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++) != '%') {
if (ch == '\0')
return (retval);
PCHAR(ch);
}
qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
sign = 0; dot = 0; dwidth = 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':
ul = va_arg(ap, int);
p = va_arg(ap, char *);
for (q = ksprintn(nbuf, ul, *p++, NULL); *q;)
PCHAR(*q--);
if (!ul)
break;
for (tmp = 0; *p;) {
n = *p++;
if (ul & (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':
if (qflag)
uq = va_arg(ap, quad_t);
else if (lflag)
ul = va_arg(ap, long);
else
ul = va_arg(ap, int);
sign = 1;
base = 10;
goto number;
case 'l':
if (lflag) {
lflag = 0;
qflag = 1;
} else
lflag = 1;
goto reswitch;
case 'o':
if (qflag)
uq = va_arg(ap, u_quad_t);
else if (lflag)
ul = va_arg(ap, u_long);
else
ul = va_arg(ap, u_int);
base = 8;
goto nosign;
case 'p':
ul = (uintptr_t)va_arg(ap, void *);
base = 16;
sharpflag = (width == 0);
goto nosign;
case 'q':
qflag = 1;
goto reswitch;
case 'n':
case 'r':
if (qflag)
uq = va_arg(ap, u_quad_t);
else if (lflag)
ul = va_arg(ap, u_long);
else
ul = sign ?
(u_long)va_arg(ap, int) : va_arg(ap, u_int);
base = radix;
goto number;
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 'u':
if (qflag)
uq = va_arg(ap, u_quad_t);
else if (lflag)
ul = va_arg(ap, u_long);
else
ul = va_arg(ap, u_int);
base = 10;
goto nosign;
case 'x':
case 'X':
if (qflag)
uq = va_arg(ap, u_quad_t);
else if (lflag)
ul = va_arg(ap, u_long);
else
ul = va_arg(ap, u_int);
base = 16;
goto nosign;
case 'z':
if (qflag)
uq = va_arg(ap, u_quad_t);
else if (lflag)
ul = va_arg(ap, u_long);
else
ul = sign ?
(u_long)va_arg(ap, int) : va_arg(ap, u_int);
base = 16;
goto number;
nosign: sign = 0;
number:
if (qflag) {
if (sign && (quad_t)uq < 0) {
neg = 1;
uq = -(quad_t)uq;
}
p = ksprintqn(nbuf, uq, base, &tmp);
} else {
if (sign && (long)ul < 0) {
neg = 1;
ul = -(long)ul;
}
p = ksprintn(nbuf, ul, base, &tmp);
}
if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
if (base == 8)
tmp++;
else if (base == 16)
tmp += 2;
}
if (neg)
tmp++;
if (!ladjust && width && (width -= tmp) > 0)
while (width--)
PCHAR(padc);
if (neg)
PCHAR('-');
if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
if (base == 8) {
PCHAR('0');
} else if (base == 16) {
PCHAR('0');
PCHAR('x');
}
}
while (*p)
PCHAR(*p--);
if (ladjust && width && (width -= tmp) > 0)
while (width--)
PCHAR(padc);
break;
default:
PCHAR('%');
if (lflag)
PCHAR('l');
PCHAR(ch);
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) {
msgaddchar('\n', NULL);
dangling = 0;
}
msgaddchar('<', NULL);
for (p = ksprintn(nbuf, (u_long)pri, 10, NULL); *p;)
msgaddchar(*p--, NULL);
msgaddchar('>', NULL);
lastpri = pri;
}
msgaddchar(c, NULL);
if (c == '\n') {
dangling = 0;
lastpri = -1;
} else {
dangling = 1;
}
}
/*
* Put char in log buffer
*/
static void
msgaddchar(int c, void *dummy)
{
struct msgbuf *mbp;
if (!msgbufmapped)
return;
mbp = msgbufp;
mbp->msg_ptr[mbp->msg_bufx++] = c;
if (mbp->msg_bufx >= mbp->msg_size)
mbp->msg_bufx = 0;
/* If the buffer is full, keep the most recent data. */
if (mbp->msg_bufr == mbp->msg_bufx) {
if (++mbp->msg_bufr >= mbp->msg_size)
mbp->msg_bufr = 0;
}
}
static void
msgbufcopy(struct msgbuf *oldp)
{
int pos;
pos = oldp->msg_bufr;
while (pos != oldp->msg_bufx) {
msglogchar(oldp->msg_ptr[pos], -1);
if (++pos >= oldp->msg_size)
pos = 0;
}
}
void
msgbufinit(void *ptr, size_t size)
{
char *cp;
static struct msgbuf *oldp = NULL;
size -= sizeof(*msgbufp);
cp = (char *)ptr;
msgbufp = (struct msgbuf *) (cp + size);
if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
bzero(cp, size);
bzero(msgbufp, sizeof(*msgbufp));
msgbufp->msg_magic = MSG_MAGIC;
msgbufp->msg_size = (char *)msgbufp - cp;
}
msgbufp->msg_ptr = cp;
if (msgbufmapped && oldp != msgbufp)
msgbufcopy(oldp);
msgbufmapped = 1;
oldp = msgbufp;
}
SYSCTL_DECL(_security_bsd);
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)
{
int error;
if (!unprivileged_read_msgbuf) {
error = suser(req->td);
if (error)
return (error);
}
/*
* Unwind the buffer, so that it's linear (possibly starting with
* some initial nulls).
*/
error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
msgbufp->msg_size - msgbufp->msg_bufx, req);
if (error)
return (error);
if (msgbufp->msg_bufx > 0) {
error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
msgbufp->msg_bufx, req);
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
static int msgbuf_clear;
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) {
/* Clear the buffer and reset write pointer */
bzero(msgbufp->msg_ptr, msgbufp->msg_size);
msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
msgbuf_clear = 0;
}
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
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= %d, w = %d, ptr = %p\n",
msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
msgbufp->msg_bufx, msgbufp->msg_ptr);
for (i = 0; i < msgbufp->msg_size; i++) {
j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
db_printf("%c", msgbufp->msg_ptr[j]);
}
db_printf("\n");
}
#endif /* DDB */
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