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freebsd-dev/sys/kern/subr_prf.c
Ed Schouten ca1d2f657a Make /dev/klog and kern.msgbuf* MPSAFE. 
Normally msgbufp is locked using Giant. Switch it to use the
msgbuf_lock. Instead of changing the tsleep() calls to msleep(), just
convert it to condvar(9).

In my opinion the locking around msgbuf_peekbytes() still remains
questionable. It looks like locks are dropped while performing copies of
multiple blocks to userspace, which may cause the msgbuf to be reset in
the mean time. At least getting it underneath from Giant should make it
a little easier for us to figure out how to solve that.

Reminded by:	rdivacky
2009-11-03 21:06:19 +00:00

1043 lines
22 KiB
C
Raw Blame History

/*-
* 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 "opt_ddb.h"
#include "opt_printf.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <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 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.");
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);
retval = 0;
goto out;
}
SESS_LOCK(p->p_session);
pca.tty = p->p_session->s_ttyp;
SESS_UNLOCK(p->p_session);
PROC_UNLOCK(p);
if (pca.tty == NULL) {
retval = 0;
goto out;
}
pca.flags = TOTTY;
va_start(ap, fmt);
tty_lock(pca.tty);
retval = kvprintf(fmt, putchar, &pca, 10, ap);
tty_unlock(pca.tty);
va_end(ap);
out:
sx_sunlock(&proctree_lock);
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;
va_start(ap, fmt);
if (pca.tty != NULL)
tty_lock(pca.tty);
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;
sx_sunlock(&proctree_lock);
}
/*
* 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;
struct putchar_arg pca;
pca.tty = NULL;
pca.pri = level;
pca.flags = log_open ? TOLOG : TOCONS;
pca.p_bufr = NULL;
va_start(ap, fmt);
kvprintf(fmt, putchar, &pca, 10, ap);
va_end(ap);
msgbuftrigger = 1;
}
#define CONSCHUNK 128
void
log_console(struct uio *uio)
{
int c, i, 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);
error = uiomove(consbuffer, c, uio);
if (error != 0)
break;
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(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)
{
struct putchar_arg pca;
int retval;
#ifdef PRINTF_BUFR_SIZE
char bufr[PRINTF_BUFR_SIZE];
#endif
pca.tty = NULL;
pca.flags = TOCONS | TOLOG;
pca.pri = -1;
#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 output: */
if (*pca.p_bufr != '\0')
cnputs(pca.p_bufr);
#endif
if (!panicstr)
msgbuftrigger = 1;
return (retval);
}
static void
putcons(int c, struct putchar_arg *ap)
{
/* Check if no console output buffer was provided. */
if (ap->p_bufr == NULL)
/* Output direct to the console. */
cnputc(c);
else {
/* Buffer the character: */
if (c == '\n') {
*ap->p_next++ = '\r';
ap->remain--;
}
*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 < 3 || c == '\n') {
cnputs(ap->p_bufr);
ap->p_next = ap->p_bufr;
ap->remain = ap->n_bufr;
*ap->p_next = '\0';
}
}
}
/*
* 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;
/* Don't use the tty code after a panic or while in ddb. */
if (kdb_active) {
if (c != '\0')
cnputc(c);
} else if (panicstr || ((flags & TOCONS) && constty == NULL)) {
if (c != '\0')
putcons(c, ap);
} else {
if ((flags & TOTTY) && tp != NULL)
tty_putchar(tp, c);
if (flags & TOCONS) {
if (constty != NULL)
msgbuf_addchar(&consmsgbuf, c);
if (always_console_output && c != '\0')
putcons(c, ap);
}
}
if ((flags & TOLOG))
msglogchar(c, ap->pri);
}
/*
* 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, &tmp, upper);
if (sharpflag && num != 0) {
if (base == 8)
tmp++;
else if (base == 16)
tmp += 2;
}
if (neg)
tmp++;
if (!ladjust && padc != '0' && width
&& (width -= tmp) > 0)
while (width--)
PCHAR(padc);
if (neg)
PCHAR('-');
if (sharpflag && num != 0) {
if (base == 8) {
PCHAR('0');
} else if (base == 16) {
PCHAR('0');
PCHAR('x');
}
}
if (!ladjust && width && (width -= tmp) > 0)
while (width--)
PCHAR(padc);
while (*p)
PCHAR(*p--);
if (ladjust && width && (width -= tmp) > 0)
while (width--)
PCHAR(padc);
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;
}
}
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");
}
}
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