2 * Copyright (c) 1986, 1988, 1991, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
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11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
35 * $FreeBSD: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/msgbuf.h>
44 #include <sys/malloc.h>
48 #include <sys/tprintf.h>
49 #include <sys/stdint.h>
50 #include <sys/syslog.h>
53 #include <sys/sysctl.h>
55 #include <sys/ctype.h>
56 #include <sys/eventhandler.h>
57 #include <sys/kthread.h>
59 #include <sys/thread2.h>
60 #include <sys/spinlock2.h>
67 * Note that stdarg.h and the ANSI style va_start macro is used for both
68 * ANSI and traditional C compilers. We use the __ machine version to stay
69 * within the kernel header file set.
71 #include <machine/stdarg.h>
78 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
79 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
94 struct tty *constty; /* pointer to console "window" tty */
96 static void msglogchar(int c, int pri);
97 static void msgaddchar(int c, void *dummy);
98 static void kputchar (int ch, void *arg);
99 static char *ksprintn (char *nbuf, uintmax_t num, int base, int *lenp,
101 static void snprintf_func (int ch, void *arg);
103 static int consintr = 1; /* Ok to handle console interrupts? */
104 static int msgbufmapped; /* Set when safe to use msgbuf */
105 static struct spinlock cons_spin = SPINLOCK_INITIALIZER(cons_spin);
106 static thread_t constty_td = NULL;
110 static int log_console_output = 1;
111 TUNABLE_INT("kern.log_console_output", &log_console_output);
112 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
113 &log_console_output, 0, "");
115 static int unprivileged_read_msgbuf = 1;
116 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW,
117 &unprivileged_read_msgbuf, 0,
118 "Unprivileged processes may read the kernel message buffer");
121 * Warn that a system table is full.
124 tablefull(const char *tab)
127 log(LOG_ERR, "%s: table is full\n", tab);
131 * Uprintf prints to the controlling terminal for the current process.
134 uprintf(const char *fmt, ...)
136 struct proc *p = curproc;
138 struct putchar_arg pca;
141 if (p && (p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
143 pca.tty = p->p_session->s_ttyp;
146 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
153 tprintf_open(struct proc *p)
155 if ((p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
156 sess_hold(p->p_session);
157 return ((tpr_t) p->p_session);
163 tprintf_close(tpr_t sess)
166 sess_rele((struct session *) sess);
170 * tprintf prints on the controlling terminal associated
171 * with the given session.
174 tprintf(tpr_t tpr, const char *fmt, ...)
176 struct session *sess = (struct session *)tpr;
177 struct tty *tp = NULL;
180 struct putchar_arg pca;
183 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
191 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
198 * Ttyprintf displays a message on a tty; it should be used only by
199 * the tty driver, or anything that knows the underlying tty will not
200 * be revoke(2)'d away. Other callers should use tprintf.
203 ttyprintf(struct tty *tp, const char *fmt, ...)
206 struct putchar_arg pca;
212 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
218 * Log writes to the log buffer, and guarantees not to sleep (so can be
219 * called by interrupt routines). If there is no process reading the
220 * log yet, it writes to the console also.
223 log(int level, const char *fmt, ...)
227 struct putchar_arg pca;
231 pca.flags = log_open ? TOLOG : TOCONS;
234 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
241 #define CONSCHUNK 128
244 log_console(struct uio *uio)
246 int c, i, error, iovlen, nl;
248 struct iovec *miov = NULL;
252 if (!log_console_output)
255 pri = LOG_INFO | LOG_CONSOLE;
257 iovlen = uio->uio_iovcnt * sizeof (struct iovec);
258 miov = kmalloc(iovlen, M_TEMP, M_WAITOK);
259 consbuffer = kmalloc(CONSCHUNK, M_TEMP, M_WAITOK);
260 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
265 while (uio->uio_resid > 0) {
266 c = (int)szmin(uio->uio_resid, CONSCHUNK);
267 error = uiomove(consbuffer, (size_t)c, uio);
270 for (i = 0; i < c; i++) {
271 msglogchar(consbuffer[i], pri);
272 if (consbuffer[i] == '\n')
279 msglogchar('\n', pri);
282 kfree(consbuffer, M_TEMP);
287 * Output to the console.
290 kprintf(const char *fmt, ...)
294 struct putchar_arg pca;
297 savintr = consintr; /* disable interrupts */
301 pca.flags = TOCONS | TOLOG;
303 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
307 consintr = savintr; /* reenable interrupts */
312 kvprintf(const char *fmt, __va_list ap)
315 struct putchar_arg pca;
318 savintr = consintr; /* disable interrupts */
321 pca.flags = TOCONS | TOLOG;
323 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
326 consintr = savintr; /* reenable interrupts */
331 * Limited rate kprintf. The passed rate structure must be initialized
332 * with the desired reporting frequency. A frequency of 0 will result in
335 * count may be initialized to a negative number to allow an initial
339 krateprintf(struct krate *rate, const char *fmt, ...)
343 if (rate->ticks != (int)time_uptime) {
344 rate->ticks = (int)time_uptime;
348 if (rate->count < rate->freq) {
357 * Print a character to the dmesg log, the console, and/or the user's
360 * NOTE: TOTTY does not require nonblocking operation, but TOCONS
361 * and TOLOG do. When we have a constty we still output to
362 * the real console but we have a monitoring thread which
363 * we wakeup which tracks the log.
366 kputchar(int c, void *arg)
368 struct putchar_arg *ap = (struct putchar_arg*) arg;
369 int flags = ap->flags;
370 struct tty *tp = ap->tty;
374 if ((flags & TOCONS) && tp == NULL && constty)
375 flags |= TOLOG | TOWAKEUP;
376 if ((flags & TOTTY) && tputchar(c, tp) < 0)
379 msglogchar(c, ap->pri);
380 if ((flags & TOCONS) && c)
382 if (flags & TOWAKEUP)
387 * Scaled down version of sprintf(3).
390 ksprintf(char *buf, const char *cfmt, ...)
395 __va_start(ap, cfmt);
396 retval = kvcprintf(cfmt, NULL, buf, 10, ap);
403 * Scaled down version of vsprintf(3).
406 kvsprintf(char *buf, const char *cfmt, __va_list ap)
410 retval = kvcprintf(cfmt, NULL, buf, 10, ap);
416 * Scaled down version of snprintf(3).
419 ksnprintf(char *str, size_t size, const char *format, ...)
424 __va_start(ap, format);
425 retval = kvsnprintf(str, size, format, ap);
431 * Scaled down version of vsnprintf(3).
434 kvsnprintf(char *str, size_t size, const char *format, __va_list ap)
436 struct snprintf_arg info;
441 retval = kvcprintf(format, snprintf_func, &info, 10, ap);
442 if (info.remain >= 1)
448 ksnrprintf(char *str, size_t size, int radix, const char *format, ...)
453 __va_start(ap, format);
454 retval = kvsnrprintf(str, size, radix, format, ap);
460 kvsnrprintf(char *str, size_t size, int radix, const char *format, __va_list ap)
462 struct snprintf_arg info;
467 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
468 if (info.remain >= 1)
474 kvasnrprintf(char **strp, size_t size, int radix,
475 const char *format, __va_list ap)
477 struct snprintf_arg info;
480 *strp = kmalloc(size, M_TEMP, M_WAITOK);
483 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
484 if (info.remain >= 1)
490 kvasfree(char **strp)
493 kfree(*strp, M_TEMP);
499 snprintf_func(int ch, void *arg)
501 struct snprintf_arg *const info = arg;
503 if (info->remain >= 2) {
510 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
511 * order; return an optional length and a pointer to the last character
512 * written in the buffer (i.e., the first character of the string).
513 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
516 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
523 c = hex2ascii(num % base);
524 *++p = upper ? toupper(c) : c;
525 } while (num /= base);
532 * Scaled down version of printf(3).
534 * Two additional formats:
536 * The format %b is supported to decode error registers.
539 * kprintf("reg=%b\n", regval, "<base><arg>*");
541 * where <base> is the output base expressed as a control character, e.g.
542 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
543 * the first of which gives the bit number to be inspected (origin 1), and
544 * the next characters (up to a control character, i.e. a character <= 32),
545 * give the name of the register. Thus:
547 * kvcprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
549 * would produce output:
551 * reg=3<BITTWO,BITONE>
554 #define PCHAR(c) {int cc=(c); if(func) (*func)(cc,arg); else *d++=cc; retval++;}
557 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg,
558 int radix, __va_list ap)
562 const char *p, *percent, *q;
565 int base, tmp, width, ladjust, sharpflag, neg, sign, dot;
566 int cflag, hflag, jflag, lflag, qflag, tflag, zflag;
569 int retval = 0, stop = 0;
573 * Make a supreme effort to avoid reentrant panics or deadlocks.
575 * NOTE! Do nothing that would access mycpu/gd/fs unless the
576 * function is the normal kputchar(), which allows us to
577 * use this function for very early debugging with a special
580 if (func == kputchar) {
581 if (mycpu->gd_flags & GDF_KPRINTF)
583 atomic_set_long(&mycpu->gd_flags, GDF_KPRINTF);
593 fmt = "(fmt null)\n";
595 if (radix < 2 || radix > 36)
598 usespin = (func == kputchar &&
599 panic_cpu_gd != mycpu &&
600 (((struct putchar_arg *)arg)->flags & TOTTY) == 0);
603 spin_lock(&cons_spin);
609 while ((ch = (u_char)*fmt++) != '%' || stop) {
615 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0;
616 cflag = hflag = jflag = lflag = qflag = tflag = zflag = 0;
619 switch (ch = (u_char)*fmt++) {
637 width = __va_arg(ap, int);
643 dwidth = __va_arg(ap, int);
651 case '1': case '2': case '3': case '4':
652 case '5': case '6': case '7': case '8': case '9':
653 for (n = 0;; ++fmt) {
654 n = n * 10 + ch - '0';
656 if (ch < '0' || ch > '9')
665 num = (u_int)__va_arg(ap, int);
666 p = __va_arg(ap, char *);
667 for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
675 if (num & (1 << (n - 1))) {
676 PCHAR(tmp ? ',' : '<');
677 for (; (n = *p) > ' '; ++p)
681 for (; *p > ' '; ++p)
688 PCHAR(__va_arg(ap, int));
714 *(__va_arg(ap, char *)) = retval;
716 *(__va_arg(ap, short *)) = retval;
718 *(__va_arg(ap, intmax_t *)) = retval;
720 *(__va_arg(ap, long *)) = retval;
722 *(__va_arg(ap, quad_t *)) = retval;
724 *(__va_arg(ap, int *)) = retval;
731 sharpflag = (width == 0);
733 num = (uintptr_t)__va_arg(ap, void *);
744 p = __va_arg(ap, char *);
750 for (n = 0; n < dwidth && p[n]; n++)
755 if (!ladjust && width > 0)
760 if (ladjust && width > 0)
782 num = (u_char)__va_arg(ap, int);
784 num = (u_short)__va_arg(ap, int);
786 num = __va_arg(ap, uintmax_t);
788 num = __va_arg(ap, u_long);
790 num = __va_arg(ap, u_quad_t);
792 num = __va_arg(ap, ptrdiff_t);
794 num = __va_arg(ap, size_t);
796 num = __va_arg(ap, u_int);
800 num = (char)__va_arg(ap, int);
802 num = (short)__va_arg(ap, int);
804 num = __va_arg(ap, intmax_t);
806 num = __va_arg(ap, long);
808 num = __va_arg(ap, quad_t);
810 num = __va_arg(ap, ptrdiff_t);
812 num = __va_arg(ap, ssize_t);
814 num = __va_arg(ap, int);
816 if (sign && (intmax_t)num < 0) {
818 num = -(intmax_t)num;
820 p = ksprintn(nbuf, num, base, &n, upper);
822 if (sharpflag && num != 0) {
831 if (!ladjust && padc == '0')
832 dwidth = width - tmp;
833 width -= tmp + imax(dwidth, n);
840 if (sharpflag && num != 0) {
843 } else if (base == 16) {
860 while (percent < fmt)
863 * Since we ignore an formatting argument it is no
864 * longer safe to obey the remaining formatting
865 * arguments as the arguments will no longer match
874 * Cleanup reentrancy issues.
876 if (func == kputchar)
877 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
879 spin_unlock(&cons_spin);
888 * Called from the panic code to try to get the console working
889 * again in case we paniced inside a kprintf().
894 spin_init(&cons_spin);
895 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
899 * Console support thread for constty intercepts. This is needed because
900 * console tty intercepts can block. Instead of having kputchar() attempt
901 * to directly write to the console intercept we just force it to log
902 * and wakeup this baby to track and dump the log to constty.
912 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc,
913 constty_td, SHUTDOWN_PRI_FIRST);
914 constty_td->td_flags |= TDF_SYSTHREAD;
917 kproc_suspend_loop();
921 if (mbp == NULL || msgbufmapped == 0 ||
922 windex == mbp->msg_bufx) {
923 tsleep(constty_td, 0, "waiting", hz*60);
927 windex = mbp->msg_bufx;
931 * Get message buf FIFO indices. rindex is tracking.
933 if ((tp = constty) == NULL) {
934 rindex = mbp->msg_bufx;
939 * Don't blow up if the message buffer is broken
941 if (windex < 0 || windex >= mbp->msg_size)
943 if (rindex < 0 || rindex >= mbp->msg_size)
947 * And dump it. If constty gets stuck will give up.
949 while (rindex != windex) {
950 if (tputchar((uint8_t)mbp->msg_ptr[rindex], tp) < 0) {
952 rindex = mbp->msg_bufx;
955 if (++rindex >= mbp->msg_size)
957 if (tp->t_outq.c_cc >= tp->t_ohiwat) {
958 tsleep(constty_daemon, 0, "blocked", hz / 10);
959 if (tp->t_outq.c_cc >= tp->t_ohiwat) {
968 static struct kproc_desc constty_kp = {
973 SYSINIT(bufdaemon, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY,
974 kproc_start, &constty_kp)
977 * Put character in log buffer with a particular priority.
982 msglogchar(int c, int pri)
984 static int lastpri = -1;
991 if (c == '\0' || c == '\r')
993 if (pri != -1 && pri != lastpri) {
995 msgaddchar('\n', NULL);
998 msgaddchar('<', NULL);
999 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
1000 msgaddchar(*p--, NULL);
1001 msgaddchar('>', NULL);
1004 msgaddchar(c, NULL);
1014 * Put char in log buffer. Make sure nothing blows up beyond repair if
1015 * we have an MP race.
1020 msgaddchar(int c, void *dummy)
1029 windex = mbp->msg_bufx;
1030 mbp->msg_ptr[windex] = c;
1031 if (++windex >= mbp->msg_size)
1033 rindex = mbp->msg_bufr;
1034 if (windex == rindex) {
1036 if (rindex >= mbp->msg_size)
1037 rindex -= mbp->msg_size;
1038 mbp->msg_bufr = rindex;
1040 mbp->msg_bufx = windex;
1044 msgbufcopy(struct msgbuf *oldp)
1048 pos = oldp->msg_bufr;
1049 while (pos != oldp->msg_bufx) {
1050 msglogchar(oldp->msg_ptr[pos], -1);
1051 if (++pos >= oldp->msg_size)
1057 msgbufinit(void *ptr, size_t size)
1060 static struct msgbuf *oldp = NULL;
1062 size -= sizeof(*msgbufp);
1064 msgbufp = (struct msgbuf *) (cp + size);
1065 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
1066 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
1068 bzero(msgbufp, sizeof(*msgbufp));
1069 msgbufp->msg_magic = MSG_MAGIC;
1070 msgbufp->msg_size = (char *)msgbufp - cp;
1072 msgbufp->msg_ptr = cp;
1073 if (msgbufmapped && oldp != msgbufp)
1079 /* Sysctls for accessing/clearing the msgbuf */
1082 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1088 * Only wheel or root can access the message log.
1090 if (unprivileged_read_msgbuf == 0) {
1091 KKASSERT(req->td->td_proc);
1092 cred = req->td->td_proc->p_ucred;
1094 if ((cred->cr_prison || groupmember(0, cred) == 0) &&
1095 priv_check(req->td, PRIV_ROOT) != 0
1102 * Unwind the buffer, so that it's linear (possibly starting with
1103 * some initial nulls).
1105 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
1106 msgbufp->msg_size - msgbufp->msg_bufx, req);
1109 if (msgbufp->msg_bufx > 0) {
1110 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
1111 msgbufp->msg_bufx, req);
1116 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
1117 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1119 static int msgbuf_clear;
1122 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1125 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1126 if (!error && req->newptr) {
1127 /* Clear the buffer and reset write pointer */
1128 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
1129 msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
1135 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1136 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
1137 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
1141 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1145 if (!msgbufmapped) {
1146 db_printf("msgbuf not mapped yet\n");
1149 db_printf("msgbufp = %p\n", msgbufp);
1150 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
1151 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
1152 msgbufp->msg_bufx, msgbufp->msg_ptr);
1153 for (i = 0; i < msgbufp->msg_size; i++) {
1154 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
1155 db_printf("%c", msgbufp->msg_ptr[j]);
1164 hexdump(const void *ptr, int length, const char *hdr, int flags)
1168 const unsigned char *cp;
1171 if ((flags & HD_DELIM_MASK) != 0)
1172 delim = (flags & HD_DELIM_MASK) >> 8;
1176 if ((flags & HD_COLUMN_MASK) != 0)
1177 cols = flags & HD_COLUMN_MASK;
1182 for (i = 0; i < length; i+= cols) {
1186 if ((flags & HD_OMIT_COUNT) == 0)
1187 kprintf("%04x ", i);
1189 if ((flags & HD_OMIT_HEX) == 0) {
1190 for (j = 0; j < cols; j++) {
1193 kprintf("%c%02x", delim, cp[k]);
1199 if ((flags & HD_OMIT_CHARS) == 0) {
1201 for (j = 0; j < cols; j++) {
1205 else if (cp[k] >= ' ' && cp[k] <= '~')
1206 kprintf("%c", cp[k]);