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freebsd-dev/sys/kern/subr_prf.c
Ian Dowse cca8f9808b Properly sanity-check the old msgbuf structure before we accept it 
as being valid. Previously only the magic number and the virtual
address were checked, but it makes little sense to require that
the virtual address is the same (the message buffer is located at
the end of physical memory), and checks on the msg_bufx and msg_bufr
indices were missing.

Submitted by:	Bodo Rueskamp <br@clabsms.de>
Tripped over during a kernel debugging tutorial given by: grog
Reviewed by:	grog, dwmalone
MFC after:	1 week
2001-11-09 23:58:07 +00:00

890 lines
19 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.
* 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/kernel.h>
#include <sys/msgbuf.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/syslog.h>
#include <sys/cons.h>
#include <sys/uio.h>
#include <sys/sysctl.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 __P((int ch, void *arg));
static char *ksprintn __P((char *nbuf, u_long num, int base, int *len));
static char *ksprintqn __P((char *nbuf, u_quad_t num, int base, int *len));
static void snprintf_func __P((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 = 0;
if (td && td != PCPU_GET(idlethread) && p->p_flag & P_CONTROLT &&
p->p_session->s_ttyvp) {
va_start(ap, fmt);
pca.tty = p->p_session->s_ttyp;
pca.flags = TOTTY;
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 && p->p_flag & P_CONTROLT && p->p_session->s_ttyvp) {
SESSHOLD(p->p_session);
shld++;
if (ttycheckoutq(p->p_session->s_ttyp, 0)) {
flags |= TOTTY;
tp = p->p_session->s_ttyp;
}
}
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)
SESSRELE(p->p_session);
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;
}
/* Sysctls for accessing/clearing the msgbuf */
static int
sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
{
int 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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