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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34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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>
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>
77 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
78 #define MAXNBUF (sizeof(intmax_t) * NBBY + 1)
93 struct tty *constty; /* pointer to console "window" tty */
95 static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */
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 */
107 static int log_console_output = 1;
108 TUNABLE_INT("kern.log_console_output", &log_console_output);
109 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
110 &log_console_output, 0, "");
112 static int unprivileged_read_msgbuf = 1;
113 SYSCTL_INT(_security, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW,
114 &unprivileged_read_msgbuf, 0,
115 "Unprivileged processes may read the kernel message buffer");
118 * Warn that a system table is full.
121 tablefull(const char *tab)
124 log(LOG_ERR, "%s: table is full\n", tab);
128 * Uprintf prints to the controlling terminal for the current process.
131 uprintf(const char *fmt, ...)
133 struct proc *p = curproc;
135 struct putchar_arg pca;
138 if (p && p->p_flag & P_CONTROLT &&
139 p->p_session->s_ttyvp) {
141 pca.tty = p->p_session->s_ttyp;
144 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
151 tprintf_open(struct proc *p)
154 if ((p->p_flag & P_CONTROLT) && p->p_session->s_ttyvp) {
155 sess_hold(p->p_session);
156 return ((tpr_t) p->p_session);
158 return ((tpr_t) NULL);
162 tprintf_close(tpr_t sess)
165 sess_rele((struct session *) sess);
169 * tprintf prints on the controlling terminal associated
170 * with the given session.
173 tprintf(tpr_t tpr, const char *fmt, ...)
175 struct session *sess = (struct session *)tpr;
176 struct tty *tp = NULL;
179 struct putchar_arg pca;
182 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
190 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
197 * Ttyprintf displays a message on a tty; it should be used only by
198 * the tty driver, or anything that knows the underlying tty will not
199 * be revoke(2)'d away. Other callers should use tprintf.
202 ttyprintf(struct tty *tp, const char *fmt, ...)
205 struct putchar_arg pca;
211 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
217 * Log writes to the log buffer, and guarantees not to sleep (so can be
218 * called by interrupt routines). If there is no process reading the
219 * log yet, it writes to the console also.
222 log(int level, const char *fmt, ...)
226 struct putchar_arg pca;
230 pca.flags = log_open ? TOLOG : TOCONS;
233 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
240 #define CONSCHUNK 128
243 log_console(struct uio *uio)
245 int c, i, error, iovlen, nl;
247 struct iovec *miov = NULL;
251 if (!log_console_output)
254 pri = LOG_INFO | LOG_CONSOLE;
256 iovlen = uio->uio_iovcnt * sizeof (struct iovec);
257 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
258 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
259 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
264 while (uio->uio_resid > 0) {
265 c = (int)szmin(uio->uio_resid, CONSCHUNK);
266 error = uiomove(consbuffer, (size_t)c, uio);
269 for (i = 0; i < c; i++) {
270 msglogchar(consbuffer[i], pri);
271 if (consbuffer[i] == '\n')
278 msglogchar('\n', pri);
281 FREE(consbuffer, M_TEMP);
286 * Output to the console.
288 * NOT YET ENTIRELY MPSAFE
291 kprintf(const char *fmt, ...)
295 struct putchar_arg pca;
298 savintr = consintr; /* disable interrupts */
302 pca.flags = TOCONS | TOLOG;
305 retval = kvcprintf(fmt, kputchar, &pca, 10, ap);
310 consintr = savintr; /* reenable interrupts */
315 kvprintf(const char *fmt, __va_list ap)
318 struct putchar_arg pca;
321 savintr = consintr; /* disable interrupts */
324 pca.flags = TOCONS | TOLOG;
327 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 on console or users terminal. If destination is
363 * the console then the last bunch of characters are saved in msgbuf for
366 * NOT YET ENTIRELY MPSAFE, EVEN WHEN LOGGING JUST TO THE SYSCONSOLE.
369 kputchar(int c, void *arg)
371 struct putchar_arg *ap = (struct putchar_arg*) arg;
372 int flags = ap->flags;
373 struct tty *tp = ap->tty;
376 if ((flags & TOCONS) && tp == NULL && constty) {
380 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
381 (flags & TOCONS) && tp == constty)
384 msglogchar(c, ap->pri);
385 if ((flags & TOCONS) && constty == NULL && c != '\0')
390 * Scaled down version of sprintf(3).
393 ksprintf(char *buf, const char *cfmt, ...)
398 __va_start(ap, cfmt);
399 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap);
406 * Scaled down version of vsprintf(3).
409 kvsprintf(char *buf, const char *cfmt, __va_list ap)
413 retval = kvcprintf(cfmt, NULL, (void *)buf, 10, ap);
419 * Scaled down version of snprintf(3).
422 ksnprintf(char *str, size_t size, const char *format, ...)
427 __va_start(ap, format);
428 retval = kvsnprintf(str, size, format, ap);
434 * Scaled down version of vsnprintf(3).
437 kvsnprintf(char *str, size_t size, const char *format, __va_list ap)
439 struct snprintf_arg info;
444 retval = kvcprintf(format, snprintf_func, &info, 10, ap);
445 if (info.remain >= 1)
451 ksnrprintf(char *str, size_t size, int radix, const char *format, ...)
456 __va_start(ap, format);
457 retval = kvsnrprintf(str, size, radix, format, ap);
463 kvsnrprintf(char *str, size_t size, int radix, const char *format, __va_list ap)
465 struct snprintf_arg info;
470 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
471 if (info.remain >= 1)
477 kvasnrprintf(char **strp, size_t size, int radix,
478 const char *format, __va_list ap)
480 struct snprintf_arg info;
483 *strp = kmalloc(size, M_TEMP, M_WAITOK);
486 retval = kvcprintf(format, snprintf_func, &info, radix, ap);
487 if (info.remain >= 1)
493 kvasfree(char **strp)
496 kfree(*strp, M_TEMP);
502 snprintf_func(int ch, void *arg)
504 struct snprintf_arg *const info = arg;
506 if (info->remain >= 2) {
513 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
514 * order; return an optional length and a pointer to the last character
515 * written in the buffer (i.e., the first character of the string).
516 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
519 ksprintn(char *nbuf, uintmax_t num, int base, int *lenp, int upper)
526 c = hex2ascii(num % base);
527 *++p = upper ? toupper(c) : c;
528 } while (num /= base);
535 * Scaled down version of printf(3).
537 * Two additional formats:
539 * The format %b is supported to decode error registers.
542 * kprintf("reg=%b\n", regval, "<base><arg>*");
544 * where <base> is the output base expressed as a control character, e.g.
545 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
546 * the first of which gives the bit number to be inspected (origin 1), and
547 * the next characters (up to a control character, i.e. a character <= 32),
548 * give the name of the register. Thus:
550 * kvcprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
552 * would produce output:
554 * reg=3<BITTWO,BITONE>
556 * XXX: %D -- Hexdump, takes pointer and separator string:
557 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX
558 * ("%*D", len, ptr, " " -> XX XX XX XX ...
561 kvcprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, __va_list ap)
563 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
566 const char *p, *percent, *q;
570 int base, tmp, width, ladjust, sharpflag, neg, sign, dot;
571 int cflag, hflag, jflag, lflag, qflag, tflag, zflag;
574 int retval = 0, stop = 0;
583 fmt = "(fmt null)\n";
585 if (radix < 2 || radix > 36)
591 while ((ch = (u_char)*fmt++) != '%' || stop) {
597 dot = dwidth = ladjust = neg = sharpflag = sign = upper = 0;
598 cflag = hflag = jflag = lflag = qflag = tflag = zflag = 0;
601 switch (ch = (u_char)*fmt++) {
619 width = __va_arg(ap, int);
625 dwidth = __va_arg(ap, int);
633 case '1': case '2': case '3': case '4':
634 case '5': case '6': case '7': case '8': case '9':
635 for (n = 0;; ++fmt) {
636 n = n * 10 + ch - '0';
638 if (ch < '0' || ch > '9')
647 num = (u_int)__va_arg(ap, int);
648 p = __va_arg(ap, char *);
649 for (q = ksprintn(nbuf, num, *p++, NULL, 0); *q;)
657 if (num & (1 << (n - 1))) {
658 PCHAR(tmp ? ',' : '<');
659 for (; (n = *p) > ' '; ++p)
663 for (; *p > ' '; ++p)
670 PCHAR(__va_arg(ap, int));
673 up = __va_arg(ap, u_char *);
674 p = __va_arg(ap, char *);
678 PCHAR(hex2ascii(*up >> 4));
679 PCHAR(hex2ascii(*up & 0x0f));
710 *(__va_arg(ap, char *)) = retval;
712 *(__va_arg(ap, short *)) = retval;
714 *(__va_arg(ap, intmax_t *)) = retval;
716 *(__va_arg(ap, long *)) = retval;
718 *(__va_arg(ap, quad_t *)) = retval;
720 *(__va_arg(ap, int *)) = retval;
727 sharpflag = (width == 0);
729 num = (uintptr_t)__va_arg(ap, void *);
740 p = __va_arg(ap, char *);
746 for (n = 0; n < dwidth && p[n]; n++)
751 if (!ladjust && width > 0)
756 if (ladjust && width > 0)
778 num = (u_char)__va_arg(ap, int);
780 num = (u_short)__va_arg(ap, int);
782 num = __va_arg(ap, uintmax_t);
784 num = __va_arg(ap, u_long);
786 num = __va_arg(ap, u_quad_t);
788 num = __va_arg(ap, ptrdiff_t);
790 num = __va_arg(ap, size_t);
792 num = __va_arg(ap, u_int);
796 num = (char)__va_arg(ap, int);
798 num = (short)__va_arg(ap, int);
800 num = __va_arg(ap, intmax_t);
802 num = __va_arg(ap, long);
804 num = __va_arg(ap, quad_t);
806 num = __va_arg(ap, ptrdiff_t);
808 num = __va_arg(ap, ssize_t);
810 num = __va_arg(ap, int);
812 if (sign && (intmax_t)num < 0) {
814 num = -(intmax_t)num;
816 p = ksprintn(nbuf, num, base, &tmp, upper);
817 if (sharpflag && num != 0) {
826 if (!ladjust && padc != '0' && width &&
827 (width -= tmp) > 0) {
833 if (sharpflag && num != 0) {
836 } else if (base == 16) {
841 if (!ladjust && width && (width -= tmp) > 0)
848 if (ladjust && width && (width -= tmp) > 0)
854 while (percent < fmt)
857 * Since we ignore an formatting argument it is no
858 * longer safe to obey the remaining formatting
859 * arguments as the arguments will no longer match
870 * Put character in log buffer with a particular priority.
875 msglogchar(int c, int pri)
877 static int lastpri = -1;
884 if (c == '\0' || c == '\r')
886 if (pri != -1 && pri != lastpri) {
888 msgaddchar('\n', NULL);
891 msgaddchar('<', NULL);
892 for (p = ksprintn(nbuf, (uintmax_t)pri, 10, NULL, 0); *p;)
893 msgaddchar(*p--, NULL);
894 msgaddchar('>', NULL);
907 * Put char in log buffer. Make sure nothing blows up beyond repair if
908 * we have an MP race.
913 msgaddchar(int c, void *dummy)
922 windex = mbp->msg_bufx;
923 mbp->msg_ptr[windex] = c;
924 if (++windex >= mbp->msg_size)
926 rindex = mbp->msg_bufr;
927 if (windex == rindex) {
929 if (rindex >= mbp->msg_size)
930 rindex -= mbp->msg_size;
931 mbp->msg_bufr = rindex;
933 mbp->msg_bufx = windex;
937 msgbufcopy(struct msgbuf *oldp)
941 pos = oldp->msg_bufr;
942 while (pos != oldp->msg_bufx) {
943 msglogchar(oldp->msg_ptr[pos], -1);
944 if (++pos >= oldp->msg_size)
950 msgbufinit(void *ptr, size_t size)
953 static struct msgbuf *oldp = NULL;
955 size -= sizeof(*msgbufp);
957 msgbufp = (struct msgbuf *) (cp + size);
958 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
959 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
961 bzero(msgbufp, sizeof(*msgbufp));
962 msgbufp->msg_magic = MSG_MAGIC;
963 msgbufp->msg_size = (char *)msgbufp - cp;
965 msgbufp->msg_ptr = cp;
966 if (msgbufmapped && oldp != msgbufp)
972 /* Sysctls for accessing/clearing the msgbuf */
975 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
981 * Only wheel or root can access the message log.
983 if (unprivileged_read_msgbuf == 0) {
984 KKASSERT(req->td->td_proc);
985 cred = req->td->td_proc->p_ucred;
987 if ((cred->cr_prison || groupmember(0, cred) == 0) &&
988 priv_check(req->td, PRIV_ROOT) != 0
995 * Unwind the buffer, so that it's linear (possibly starting with
996 * some initial nulls).
998 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
999 msgbufp->msg_size - msgbufp->msg_bufx, req);
1002 if (msgbufp->msg_bufx > 0) {
1003 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
1004 msgbufp->msg_bufx, req);
1009 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
1010 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
1012 static int msgbuf_clear;
1015 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
1018 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
1019 if (!error && req->newptr) {
1020 /* Clear the buffer and reset write pointer */
1021 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
1022 msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
1028 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
1029 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
1030 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
1034 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
1038 if (!msgbufmapped) {
1039 db_printf("msgbuf not mapped yet\n");
1042 db_printf("msgbufp = %p\n", msgbufp);
1043 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
1044 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
1045 msgbufp->msg_bufx, msgbufp->msg_ptr);
1046 for (i = 0; i < msgbufp->msg_size; i++) {
1047 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
1048 db_printf("%c", msgbufp->msg_ptr[j]);