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
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20 * This product includes software developed by the University of
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22 * 4. Neither the name of the University nor the names of its contributors
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35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * @(#)subr_prf.c 8.3 (Berkeley) 1/21/94
39 * $FreeBSD: src/sys/kern/subr_prf.c,v 1.61.2.5 2002/08/31 18:22:08 dwmalone Exp $
40 * $DragonFly: src/sys/kern/subr_prf.c,v 1.21 2008/07/17 23:56:23 dillon Exp $
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/kernel.h>
48 #include <sys/msgbuf.h>
49 #include <sys/malloc.h>
53 #include <sys/tprintf.h>
54 #include <sys/stdint.h>
55 #include <sys/syslog.h>
58 #include <sys/sysctl.h>
60 #include <sys/ctype.h>
61 #include <sys/eventhandler.h>
62 #include <sys/kthread.h>
64 #include <sys/thread2.h>
65 #include <sys/spinlock2.h>
72 * Note that stdarg.h and the ANSI style va_start macro is used for both
73 * ANSI and traditional C compilers. We use the __ machine version to stay
74 * within the kernel header file set.
76 #include <machine/stdarg.h>
83 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
84 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
99 struct tty *constty; /* pointer to console "window" tty */
101 static void msglogchar(int c, int pri);
102 static void msgaddchar(int c, void *dummy);
103 static void kputchar (int ch, void *arg);
104 static char *ksprintn (char *nbuf, uintmax_t num, int base, int *lenp,
106 static void snprintf_func (int ch, void *arg);
108 static int consintr = 1; /* Ok to handle console interrupts? */
109 static int msgbufmapped; /* Set when safe to use msgbuf */
110 static struct spinlock cons_spin = SPINLOCK_INITIALIZER(cons_spin);
111 static thread_t constty_td = NULL;
115 static int log_console_output = 1;
116 TUNABLE_INT("kern.log_console_output", &log_console_output);
117 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
118 &log_console_output, 0, "");
120 static int unprivileged_read_msgbuf = 1;
121 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW,
122 &unprivileged_read_msgbuf, 0,
123 "Unprivileged processes may read the kernel message buffer");
126 * Warn that a system table is full.
129 tablefull(const char *tab)
132 log(LOG_ERR, "%s: table is full\n", tab);
136 * Uprintf prints to the controlling terminal for the current process.
139 uprintf(const char *fmt, ...)
141 struct proc *p = curproc;
143 struct putchar_arg pca;
146 if (p && (p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
148 pca.tty = p->p_session->s_ttyp;
151 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
158 tprintf_open(struct proc *p)
160 if ((p->p_flags & P_CONTROLT) && p->p_session->s_ttyvp) {
161 sess_hold(p->p_session);
162 return ((tpr_t) p->p_session);
164 return ((tpr_t) NULL);
168 tprintf_close(tpr_t sess)
171 sess_rele((struct session *) sess);
175 * tprintf prints on the controlling terminal associated
176 * with the given session.
179 tprintf(tpr_t tpr, const char *fmt, ...)
181 struct session *sess = (struct session *)tpr;
182 struct tty *tp = NULL;
185 struct putchar_arg pca;
188 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
196 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
203 * Ttyprintf displays a message on a tty; it should be used only by
204 * the tty driver, or anything that knows the underlying tty will not
205 * be revoke(2)'d away. Other callers should use tprintf.
208 ttyprintf(struct tty *tp, const char *fmt, ...)
211 struct putchar_arg pca;
217 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
223 * Log writes to the log buffer, and guarantees not to sleep (so can be
224 * called by interrupt routines). If there is no process reading the
225 * log yet, it writes to the console also.
228 log(int level, const char *fmt, ...)
232 struct putchar_arg pca;
236 pca.flags = log_open ? TOLOG : TOCONS;
239 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
246 #define CONSCHUNK 128
249 log_console(struct uio *uio)
251 int c, i, error, iovlen, nl;
253 struct iovec *miov = NULL;
257 if (!log_console_output)
260 pri = LOG_INFO | LOG_CONSOLE;
262 iovlen = uio->uio_iovcnt * sizeof (struct iovec);
263 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
264 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
265 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
270 while (uio->uio_resid > 0) {
271 c = (int)szmin(uio->uio_resid, CONSCHUNK);
272 error = uiomove(consbuffer, (size_t)c, uio);
275 for (i = 0; i < c; i++) {
276 msglogchar(consbuffer[i], pri);
277 if (consbuffer[i] == '\n')
284 msglogchar('\n', pri);
287 FREE(consbuffer, M_TEMP);
292 * Output to the console.
295 kprintf(const char *fmt, ...)
299 struct putchar_arg pca;
302 savintr = consintr; /* disable interrupts */
306 pca.flags = TOCONS | TOLOG;
308 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
312 consintr = savintr; /* reenable interrupts */
317 kvprintf(const char *fmt, __va_list ap)
320 struct putchar_arg pca;
323 savintr = consintr; /* disable interrupts */
326 pca.flags = TOCONS | TOLOG;
328 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
331 consintr = savintr; /* reenable interrupts */
336 * Limited rate kprintf. The passed rate structure must be initialized
337 * with the desired reporting frequency. A frequency of 0 will result in
340 * count may be initialized to a negative number to allow an initial
344 krateprintf(struct krate *rate, const char *fmt, ...)
348 if (rate->ticks != (int)time_second) {
349 rate->ticks = (int)time_second;
353 if (rate->count < rate->freq) {
362 * Print a character to the dmesg log, the console, and/or the user's
365 * NOTE: TOTTY does not require nonblocking operation, but TOCONS
366 * and TOLOG do. When we have a constty we still output to
367 * the real console but we have a monitoring thread which
368 * we wakeup which tracks the log.
371 kputchar(int c, void *arg)
373 struct putchar_arg *ap = (struct putchar_arg*) arg;
374 int flags = ap->flags;
375 struct tty *tp = ap->tty;
379 if ((flags & TOCONS) && tp == NULL && constty)
380 flags |= TOLOG | TOWAKEUP;
381 if ((flags & TOTTY) && tputchar(c, tp) < 0)
384 msglogchar(c, ap->pri);
385 if ((flags & TOCONS) && c)
387 if (flags & TOWAKEUP)
392 * Scaled down version of sprintf(3).
395 ksprintf(char *buf, const char *cfmt, ...)
400 __va_start(ap, cfmt);
401 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap);
408 * Scaled down version of vsprintf(3).
411 kvsprintf(char *buf, const char *cfmt, __va_list ap)
415 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap);
421 * Scaled down version of snprintf(3).
424 ksnprintf(char *str, size_t size, const char *format, ...)
429 __va_start(ap, format);
430 retval = kvsnprintf(str, size, format, ap);
436 * Scaled down version of vsnprintf(3).
439 kvsnprintf(char *str, size_t size, const char *format, __va_list ap)
441 struct snprintf_arg info;
446 retval = kvcprintf(format, snprintf_func, &info, 10, ap);
447 if (info.remain >= 1)
453 ksnrprintf(char *str, size_t size, int radix, const char *format, ...)
458 __va_start(ap, format);
459 retval = kvsnrprintf(str, size, radix, format, ap);
465 kvsnrprintf(char *str, size_t size, int radix, const char *format, __va_list ap)
467 struct snprintf_arg info;
472 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
473 if (info.remain >= 1)
479 kvasnrprintf(char **strp, size_t size, int radix,
480 const char *format, __va_list ap)
482 struct snprintf_arg info;
485 *strp = kmalloc(size, M_TEMP, M_WAITOK);
488 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
489 if (info.remain >= 1)
495 kvasfree(char **strp)
498 kfree(*strp, M_TEMP);
504 snprintf_func(int ch, void *arg)
506 struct snprintf_arg *const info = arg;
508 if (info->remain >= 2) {
515 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
516 * order; return an optional length and a pointer to the last character
517 * written in the buffer (i.e., the first character of the string).
518 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
521 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
528 c = hex2ascii(num % base);
529 *++p = upper ? toupper(c) : c;
530 } while (num /= base);
537 * Scaled down version of printf(3).
539 * Two additional formats:
541 * The format %b is supported to decode error registers.
544 * kprintf("reg=%b\n", regval, "<base><arg>*");
546 * where <base> is the output base expressed as a control character, e.g.
547 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
548 * the first of which gives the bit number to be inspected (origin 1), and
549 * the next characters (up to a control character, i.e. a character <= 32),
550 * give the name of the register. Thus:
552 * kvcprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
554 * would produce output:
556 * reg=3<BITTWO,BITONE>
558 * XXX: %D -- Hexdump, takes pointer and separator string:
559 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX
560 * ("%*D", len, ptr, " " -> XX XX XX XX ...
563 #define PCHAR(c) {int cc=(c); if(func) (*func)(cc,arg); else *d++=cc; retval++;}
566 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg,
567 int radix, __va_list ap)
571 const char *p, *percent, *q;
575 int base, tmp, width, ladjust, sharpflag, neg, sign, dot;
576 int cflag, hflag, jflag, lflag, qflag, tflag, zflag;
579 int retval = 0, stop = 0;
583 * Make a supreme effort to avoid reentrant panics or deadlocks.
585 * NOTE! Do nothing that would access mycpu/gd/fs unless the
586 * function is the normal kputchar(), which allows us to
587 * use this function for very early debugging with a special
590 if (func == kputchar) {
591 if (mycpu->gd_flags & GDF_KPRINTF)
593 atomic_set_long(&mycpu->gd_flags, GDF_KPRINTF);
603 fmt = "(fmt null)\n";
605 if (radix < 2 || radix > 36)
608 usespin = (func == kputchar &&
609 panic_cpu_gd != mycpu &&
610 (((struct putchar_arg *)arg)->flags & TOTTY) == 0);
613 spin_lock(&cons_spin);
619 while ((ch = (u_char)*fmt++) != '%' || stop) {
625 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0;
626 cflag = hflag = jflag = lflag = qflag = tflag = zflag = 0;
629 switch (ch = (u_char)*fmt++) {
647 width = __va_arg(ap, int);
653 dwidth = __va_arg(ap, int);
661 case '1': case '2': case '3': case '4':
662 case '5': case '6': case '7': case '8': case '9':
663 for (n = 0;; ++fmt) {
664 n = n * 10 + ch - '0';
666 if (ch < '0' || ch > '9')
675 num = (u_int)__va_arg(ap, int);
676 p = __va_arg(ap, char *);
677 for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
685 if (num & (1 << (n - 1))) {
686 PCHAR(tmp ? ',' : '<');
687 for (; (n = *p) > ' '; ++p)
691 for (; *p > ' '; ++p)
698 PCHAR(__va_arg(ap, int));
701 up = __va_arg(ap, u_char *);
702 p = __va_arg(ap, char *);
706 PCHAR(hex2ascii(*up >> 4));
707 PCHAR(hex2ascii(*up & 0x0f));
738 *(__va_arg(ap, char *)) = retval;
740 *(__va_arg(ap, short *)) = retval;
742 *(__va_arg(ap, intmax_t *)) = retval;
744 *(__va_arg(ap, long *)) = retval;
746 *(__va_arg(ap, quad_t *)) = retval;
748 *(__va_arg(ap, int *)) = retval;
755 sharpflag = (width == 0);
757 num = (uintptr_t)__va_arg(ap, void *);
768 p = __va_arg(ap, char *);
774 for (n = 0; n < dwidth && p[n]; n++)
779 if (!ladjust && width > 0)
784 if (ladjust && width > 0)
806 num = (u_char)__va_arg(ap, int);
808 num = (u_short)__va_arg(ap, int);
810 num = __va_arg(ap, uintmax_t);
812 num = __va_arg(ap, u_long);
814 num = __va_arg(ap, u_quad_t);
816 num = __va_arg(ap, ptrdiff_t);
818 num = __va_arg(ap, size_t);
820 num = __va_arg(ap, u_int);
824 num = (char)__va_arg(ap, int);
826 num = (short)__va_arg(ap, int);
828 num = __va_arg(ap, intmax_t);
830 num = __va_arg(ap, long);
832 num = __va_arg(ap, quad_t);
834 num = __va_arg(ap, ptrdiff_t);
836 num = __va_arg(ap, ssize_t);
838 num = __va_arg(ap, int);
840 if (sign && (intmax_t)num < 0) {
842 num = -(intmax_t)num;
844 p = ksprintn(nbuf, num, base, &tmp, upper);
845 if (sharpflag && num != 0) {
854 if (!ladjust && padc != '0' && width &&
855 (width -= tmp) > 0) {
861 if (sharpflag && num != 0) {
864 } else if (base == 16) {
869 if (!ladjust && width && (width -= tmp) > 0)
876 if (ladjust && width && (width -= tmp) > 0)
882 while (percent < fmt)
885 * Since we ignore an formatting argument it is no
886 * longer safe to obey the remaining formatting
887 * arguments as the arguments will no longer match
896 * Cleanup reentrancy issues.
898 if (func == kputchar)
899 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
901 spin_unlock(&cons_spin);
910 * Called from the panic code to try to get the console working
911 * again in case we paniced inside a kprintf().
916 spin_init(&cons_spin);
917 atomic_clear_long(&mycpu->gd_flags, GDF_KPRINTF);
921 * Console support thread for constty intercepts. This is needed because
922 * console tty intercepts can block. Instead of having kputchar() attempt
923 * to directly write to the console intercept we just force it to log
924 * and wakeup this baby to track and dump the log to constty.
934 EVENTHANDLER_REGISTER(shutdown_pre_sync, shutdown_kproc,
935 constty_td, SHUTDOWN_PRI_FIRST);
936 constty_td->td_flags |= TDF_SYSTHREAD;
939 kproc_suspend_loop();
943 if (mbp == NULL || msgbufmapped == 0 ||
944 windex == mbp->msg_bufx) {
945 tsleep(constty_td, 0, "waiting", hz*60);
949 windex = mbp->msg_bufx;
953 * Get message buf FIFO indices. rindex is tracking.
955 if ((tp = constty) == NULL) {
956 rindex = mbp->msg_bufx;
961 * Don't blow up if the message buffer is broken
963 if (windex < 0 || windex >= mbp->msg_size)
965 if (rindex < 0 || rindex >= mbp->msg_size)
969 * And dump it. If constty gets stuck will give up.
971 while (rindex != windex) {
972 if (tputchar((uint8_t)mbp->msg_ptr[rindex], tp) < 0) {
974 rindex = mbp->msg_bufx;
977 if (++rindex >= mbp->msg_size)
979 if (tp->t_outq.c_cc >= tp->t_ohiwat) {
980 tsleep(constty_daemon, 0, "blocked", hz / 10);
981 if (tp->t_outq.c_cc >= tp->t_ohiwat) {
990 static struct kproc_desc constty_kp = {
995 SYSINIT(bufdaemon, SI_SUB_KTHREAD_UPDATE, SI_ORDER_ANY,
996 kproc_start, &constty_kp)
999 * Put character in log buffer with a particular priority.
1004 msglogchar(int c, int pri)
1006 static int lastpri = -1;
1007 static int dangling;
1013 if (c == '\0' || c == '\r')
1015 if (pri != -1 && pri != lastpri) {
1017 msgaddchar('\n', NULL);
1020 msgaddchar('<', NULL);
1021 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
1022 msgaddchar(*p--, NULL);
1023 msgaddchar('>', NULL);
1026 msgaddchar(c, NULL);
1036 * Put char in log buffer. Make sure nothing blows up beyond repair if
1037 * we have an MP race.
1042 msgaddchar(int c, void *dummy)
1051 windex = mbp->msg_bufx;
1052 mbp->msg_ptr[windex] = c;
1053 if (++windex >= mbp->msg_size)
1055 rindex = mbp->msg_bufr;
1056 if (windex == rindex) {
1058 if (rindex >= mbp->msg_size)
1059 rindex -= mbp->msg_size;
1060 mbp->msg_bufr = rindex;
1062 mbp->msg_bufx = windex;
1066 msgbufcopy(struct msgbuf *oldp)
1070 pos = oldp->msg_bufr;
1071 while (pos != oldp->msg_bufx) {
1072 msglogchar(oldp->msg_ptr[pos], -1);
1073 if (++pos >= oldp->msg_size)
1079 msgbufinit(void *ptr, size_t size)
1082 static struct msgbuf *oldp = NULL;
1084 size -= sizeof(*msgbufp);
1086 msgbufp = (struct msgbuf *) (cp + size);
1087 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
1088 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
1090 bzero(msgbufp, sizeof(*msgbufp));
1091 msgbufp->msg_magic = MSG_MAGIC;
1092 msgbufp->msg_size = (char *)msgbufp - cp;
1094 msgbufp->msg_ptr = cp;
1095 if (msgbufmapped && oldp != msgbufp)
1101 /* Sysctls for accessing/clearing the msgbuf */
1104 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
1110 * Only wheel or root can access the message log.
1112 if (unprivileged_read_msgbuf == 0) {
1113 KKASSERT(req->td->td_proc);
1114 cred = req->td->td_proc->p_ucred;
1116 if ((cred->cr_prison || groupmember(0, cred) == 0) &&
1117 priv_check(req->td, PRIV_ROOT) != 0
1124 * Unwind the buffer, so that it's linear (possibly starting with
1125 * some initial nulls).
1127 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
1128 msgbufp->msg_size - msgbufp->msg_bufx, req);
1131 if (msgbufp->msg_bufx > 0) {
1132 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
1133 msgbufp->msg_bufx, req);
1138 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
1139 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1141 static int msgbuf_clear;
1144 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1147 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1148 if (!error && req->newptr) {
1149 /* Clear the buffer and reset write pointer */
1150 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
1151 msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
1157 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1158 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
1159 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
1163 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1167 if (!msgbufmapped) {
1168 db_printf("msgbuf not mapped yet\n");
1171 db_printf("msgbufp = %p\n", msgbufp);
1172 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
1173 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
1174 msgbufp->msg_bufx, msgbufp->msg_ptr);
1175 for (i = 0; i < msgbufp->msg_size; i++) {
1176 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
1177 db_printf("%c", msgbufp->msg_ptr[j]);
1186 hexdump(const void *ptr, int length, const char *hdr, int flags)
1190 const unsigned char *cp;
1193 if ((flags & HD_DELIM_MASK) != 0)
1194 delim = (flags & HD_DELIM_MASK) >> 8;
1198 if ((flags & HD_COLUMN_MASK) != 0)
1199 cols = flags & HD_COLUMN_MASK;
1204 for (i = 0; i < length; i+= cols) {
1208 if ((flags & HD_OMIT_COUNT) == 0)
1209 kprintf("%04x ", i);
1211 if ((flags & HD_OMIT_HEX) == 0) {
1212 for (j = 0; j < cols; j++) {
1215 kprintf("%c%02x", delim, cp[k]);
1221 if ((flags & HD_OMIT_CHARS) == 0) {
1223 for (j = 0; j < cols; j++) {
1227 else if (cp[k] >= ' ' && cp[k] <= '~')
1228 kprintf("%c", cp[k]);