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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 1.10 2005/11/21 21:56:14 dillon Exp $
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/kernel.h>
46 #include <sys/msgbuf.h>
47 #include <sys/malloc.h>
50 #include <sys/tprintf.h>
51 #include <sys/syslog.h>
54 #include <sys/sysctl.h>
58 * Note that stdarg.h and the ANSI style va_start macro is used for both
59 * ANSI and traditional C compilers. We use the __ machine version to stay
60 * within the kernel header file set.
62 #include <machine/stdarg.h>
68 /* Max number conversion buffer length: a u_quad_t in base 2, plus NUL byte. */
69 #define MAXNBUF (sizeof(quad_t) * NBBY + 1)
84 struct tty *constty; /* pointer to console "window" tty */
86 static void (*v_putc)(int) = cnputc; /* routine to putc on virtual console */
87 static void msglogchar(int c, int pri);
88 static void msgaddchar(int c, void *dummy);
89 static void putchar (int ch, void *arg);
90 static char *ksprintn (char *nbuf, u_long num, int base, int *len);
91 static char *ksprintqn (char *nbuf, u_quad_t num, int base, int *len);
92 static void snprintf_func (int ch, void *arg);
94 static int consintr = 1; /* Ok to handle console interrupts? */
95 static int msgbufmapped; /* Set when safe to use msgbuf */
98 static int log_console_output = 1;
99 TUNABLE_INT("kern.log_console_output", &log_console_output);
100 SYSCTL_INT(_kern, OID_AUTO, log_console_output, CTLFLAG_RW,
101 &log_console_output, 0, "");
103 static int unprivileged_read_msgbuf = 1;
104 SYSCTL_INT(_kern, OID_AUTO, unprivileged_read_msgbuf, CTLFLAG_RW,
105 &unprivileged_read_msgbuf, 0,
106 "Unprivileged processes may read the kernel message buffer");
109 * Warn that a system table is full.
112 tablefull(const char *tab)
115 log(LOG_ERR, "%s: table is full\n", tab);
119 * Uprintf prints to the controlling terminal for the current process.
120 * It may block if the tty queue is overfull. No message is printed if
121 * the queue does not clear in a reasonable time.
124 uprintf(const char *fmt, ...)
126 struct proc *p = curproc;
128 struct putchar_arg pca;
131 if (p && p->p_flag & P_CONTROLT &&
132 p->p_session->s_ttyvp) {
134 pca.tty = p->p_session->s_ttyp;
137 retval = kvprintf(fmt, putchar, &pca, 10, ap);
144 tprintf_open(struct proc *p)
147 if ((p->p_flag & P_CONTROLT) && p->p_session->s_ttyvp) {
148 sess_hold(p->p_session);
149 return ((tpr_t) p->p_session);
151 return ((tpr_t) NULL);
155 tprintf_close(tpr_t sess)
158 sess_rele((struct session *) sess);
162 * tprintf prints on the controlling terminal associated
163 * with the given session.
166 tprintf(tpr_t tpr, const char *fmt, ...)
168 struct session *sess = (struct session *)tpr;
169 struct tty *tp = NULL;
172 struct putchar_arg pca;
175 if (sess && sess->s_ttyvp && ttycheckoutq(sess->s_ttyp, 0)) {
183 retval = kvprintf(fmt, putchar, &pca, 10, ap);
190 * Ttyprintf displays a message on a tty; it should be used only by
191 * the tty driver, or anything that knows the underlying tty will not
192 * be revoke(2)'d away. Other callers should use tprintf.
195 ttyprintf(struct tty *tp, const char *fmt, ...)
198 struct putchar_arg pca;
204 retval = kvprintf(fmt, putchar, &pca, 10, ap);
210 * Log writes to the log buffer, and guarantees not to sleep (so can be
211 * called by interrupt routines). If there is no process reading the
212 * log yet, it writes to the console also.
215 log(int level, const char *fmt, ...)
219 struct putchar_arg pca;
223 pca.flags = log_open ? TOLOG : TOCONS;
226 retval = kvprintf(fmt, putchar, &pca, 10, ap);
234 addlog(const char *fmt, ...)
238 struct putchar_arg pca;
242 pca.flags = log_open ? TOLOG : TOCONS;
245 retval = kvprintf(fmt, putchar, &pca, 10, ap);
252 #define CONSCHUNK 128
255 log_console(struct uio *uio)
257 int c, i, error, iovlen, nl;
259 struct iovec *miov = NULL;
263 if (!log_console_output)
266 pri = LOG_INFO | LOG_CONSOLE;
268 iovlen = uio->uio_iovcnt * sizeof (struct iovec);
269 MALLOC(miov, struct iovec *, iovlen, M_TEMP, M_WAITOK);
270 MALLOC(consbuffer, char *, CONSCHUNK, M_TEMP, M_WAITOK);
271 bcopy((caddr_t)muio.uio_iov, (caddr_t)miov, iovlen);
276 while (uio->uio_resid > 0) {
277 c = imin(uio->uio_resid, CONSCHUNK);
278 error = uiomove(consbuffer, c, uio);
281 for (i = 0; i < c; i++) {
282 msglogchar(consbuffer[i], pri);
283 if (consbuffer[i] == '\n')
290 msglogchar('\n', pri);
293 FREE(consbuffer, M_TEMP);
298 * Output to the console.
300 * NOT YET ENTIRELY MPSAFE
303 printf(const char *fmt, ...)
307 struct putchar_arg pca;
310 savintr = consintr; /* disable interrupts */
314 pca.flags = TOCONS | TOLOG;
317 retval = kvprintf(fmt, putchar, &pca, 10, ap);
322 consintr = savintr; /* reenable interrupts */
327 vprintf(const char *fmt, __va_list ap)
330 struct putchar_arg pca;
333 savintr = consintr; /* disable interrupts */
336 pca.flags = TOCONS | TOLOG;
339 retval = kvprintf(fmt, putchar, &pca, 10, ap);
343 consintr = savintr; /* reenable interrupts */
348 * Print a character on console or users terminal. If destination is
349 * the console then the last bunch of characters are saved in msgbuf for
352 * NOT YET ENTIRELY MPSAFE, EVEN WHEN LOGGING JUST TO THE SYSCONSOLE.
355 putchar(int c, void *arg)
357 struct putchar_arg *ap = (struct putchar_arg*) arg;
358 int flags = ap->flags;
359 struct tty *tp = ap->tty;
362 if ((flags & TOCONS) && tp == NULL && constty) {
366 if ((flags & TOTTY) && tp && tputchar(c, tp) < 0 &&
367 (flags & TOCONS) && tp == constty)
370 msglogchar(c, ap->pri);
371 if ((flags & TOCONS) && constty == NULL && c != '\0')
376 * Scaled down version of sprintf(3).
379 sprintf(char *buf, const char *cfmt, ...)
384 __va_start(ap, cfmt);
385 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
392 * Scaled down version of vsprintf(3).
395 vsprintf(char *buf, const char *cfmt, __va_list ap)
399 retval = kvprintf(cfmt, NULL, (void *)buf, 10, ap);
405 * Scaled down version of snprintf(3).
408 snprintf(char *str, size_t size, const char *format, ...)
413 __va_start(ap, format);
414 retval = vsnprintf(str, size, format, ap);
420 * Scaled down version of vsnprintf(3).
423 vsnprintf(char *str, size_t size, const char *format, __va_list ap)
425 struct snprintf_arg info;
430 retval = kvprintf(format, snprintf_func, &info, 10, ap);
431 if (info.remain >= 1)
437 snprintf_func(int ch, void *arg)
439 struct snprintf_arg *const info = arg;
441 if (info->remain >= 2) {
448 * Put a NUL-terminated ASCII number (base <= 36) in a buffer in reverse
449 * order; return an optional length and a pointer to the last character
450 * written in the buffer (i.e., the first character of the string).
451 * The buffer pointed to by `nbuf' must have length >= MAXNBUF.
454 ksprintn(nbuf, ul, base, lenp)
464 *++p = hex2ascii(ul % base);
465 } while (ul /= base);
470 /* ksprintn, but for a quad_t. */
472 ksprintqn(nbuf, uq, base, lenp)
482 *++p = hex2ascii(uq % base);
483 } while (uq /= base);
490 * Scaled down version of printf(3).
492 * Two additional formats:
494 * The format %b is supported to decode error registers.
497 * printf("reg=%b\n", regval, "<base><arg>*");
499 * where <base> is the output base expressed as a control character, e.g.
500 * \10 gives octal; \20 gives hex. Each arg is a sequence of characters,
501 * the first of which gives the bit number to be inspected (origin 1), and
502 * the next characters (up to a control character, i.e. a character <= 32),
503 * give the name of the register. Thus:
505 * kvprintf("reg=%b\n", 3, "\10\2BITTWO\1BITONE\n");
507 * would produce output:
509 * reg=3<BITTWO,BITONE>
511 * XXX: %D -- Hexdump, takes pointer and separator string:
512 * ("%6D", ptr, ":") -> XX:XX:XX:XX:XX:XX
513 * ("%*D", len, ptr, " " -> XX XX XX XX ...
516 kvprintf(char const *fmt, void (*func)(int, void*), void *arg, int radix, __va_list ap)
518 #define PCHAR(c) {int cc=(c); if (func) (*func)(cc,arg); else *d++ = cc; retval++; }
525 int base, lflag, qflag, tmp, width, ladjust, sharpflag, neg, sign, dot;
538 fmt = "(fmt null)\n";
540 if (radix < 2 || radix > 36)
546 while ((ch = (u_char)*fmt++) != '%') {
551 qflag = 0; lflag = 0; ladjust = 0; sharpflag = 0; neg = 0;
552 sign = 0; dot = 0; dwidth = 0;
553 reswitch: switch (ch = (u_char)*fmt++) {
571 width = __va_arg(ap, int);
577 dwidth = __va_arg(ap, int);
585 case '1': case '2': case '3': case '4':
586 case '5': case '6': case '7': case '8': case '9':
587 for (n = 0;; ++fmt) {
588 n = n * 10 + ch - '0';
590 if (ch < '0' || ch > '9')
599 ul = __va_arg(ap, int);
600 p = __va_arg(ap, char *);
601 for (q = ksprintn(nbuf, ul, *p++, NULL); *q;)
609 if (ul & (1 << (n - 1))) {
610 PCHAR(tmp ? ',' : '<');
611 for (; (n = *p) > ' '; ++p)
615 for (; *p > ' '; ++p)
622 PCHAR(__va_arg(ap, int));
625 up = __va_arg(ap, u_char *);
626 p = __va_arg(ap, char *);
630 PCHAR(hex2ascii(*up >> 4));
631 PCHAR(hex2ascii(*up & 0x0f));
640 uq = __va_arg(ap, quad_t);
642 ul = __va_arg(ap, long);
644 ul = __va_arg(ap, int);
657 uq = __va_arg(ap, u_quad_t);
659 ul = __va_arg(ap, u_long);
661 ul = __va_arg(ap, u_int);
665 ul = (uintptr_t)__va_arg(ap, void *);
667 sharpflag = (width == 0);
675 uq = __va_arg(ap, u_quad_t);
677 ul = __va_arg(ap, u_long);
680 (u_long)__va_arg(ap, int) : __va_arg(ap, u_int);
684 p = __va_arg(ap, char *);
690 for (n = 0; n < dwidth && p[n]; n++)
695 if (!ladjust && width > 0)
700 if (ladjust && width > 0)
706 uq = __va_arg(ap, u_quad_t);
708 ul = __va_arg(ap, u_long);
710 ul = __va_arg(ap, u_int);
716 uq = __va_arg(ap, u_quad_t);
718 ul = __va_arg(ap, u_long);
720 ul = __va_arg(ap, u_int);
725 uq = __va_arg(ap, u_quad_t);
727 ul = __va_arg(ap, u_long);
730 (u_long)__va_arg(ap, int) : __va_arg(ap, u_int);
736 if (sign && (quad_t)uq < 0) {
740 p = ksprintqn(nbuf, uq, base, &tmp);
742 if (sign && (long)ul < 0) {
746 p = ksprintn(nbuf, ul, base, &tmp);
748 if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
757 if (!ladjust && width && (width -= tmp) > 0)
762 if (sharpflag && (qflag ? uq != 0 : ul != 0)) {
765 } else if (base == 16) {
774 if (ladjust && width && (width -= tmp) > 0)
791 * Put character in log buffer with a particular priority.
796 msglogchar(int c, int pri)
798 static int lastpri = -1;
805 if (c == '\0' || c == '\r')
807 if (pri != -1 && pri != lastpri) {
809 msgaddchar('\n', NULL);
812 msgaddchar('<', NULL);
813 for (p = ksprintn(nbuf, (u_long)pri, 10, NULL); *p;)
814 msgaddchar(*p--, NULL);
815 msgaddchar('>', NULL);
828 * Put char in log buffer. Make sure nothing blows up beyond repair if
829 * we have an MP race.
834 msgaddchar(int c, void *dummy)
843 windex = mbp->msg_bufx;
844 mbp->msg_ptr[windex] = c;
845 if (++windex >= mbp->msg_size)
847 rindex = mbp->msg_bufr;
848 if (windex == rindex) {
850 if (rindex >= mbp->msg_size)
851 rindex -= mbp->msg_size;
852 mbp->msg_bufr = rindex;
854 mbp->msg_bufx = windex;
858 msgbufcopy(struct msgbuf *oldp)
862 pos = oldp->msg_bufr;
863 while (pos != oldp->msg_bufx) {
864 msglogchar(oldp->msg_ptr[pos], -1);
865 if (++pos >= oldp->msg_size)
871 msgbufinit(void *ptr, size_t size)
874 static struct msgbuf *oldp = NULL;
876 size -= sizeof(*msgbufp);
878 msgbufp = (struct msgbuf *) (cp + size);
879 if (msgbufp->msg_magic != MSG_MAGIC || msgbufp->msg_size != size ||
880 msgbufp->msg_bufx >= size || msgbufp->msg_bufr >= size) {
882 bzero(msgbufp, sizeof(*msgbufp));
883 msgbufp->msg_magic = MSG_MAGIC;
884 msgbufp->msg_size = (char *)msgbufp - cp;
886 msgbufp->msg_ptr = cp;
887 if (msgbufmapped && oldp != msgbufp)
893 /* Sysctls for accessing/clearing the msgbuf */
896 sysctl_kern_msgbuf(SYSCTL_HANDLER_ARGS)
902 * Only wheel or root can access the message log.
904 if (unprivileged_read_msgbuf == 0) {
905 KKASSERT(req->td->td_proc);
906 cred = req->td->td_proc->p_ucred;
908 if ((cred->cr_prison || groupmember(0, cred) == 0) &&
916 * Unwind the buffer, so that it's linear (possibly starting with
917 * some initial nulls).
919 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr + msgbufp->msg_bufx,
920 msgbufp->msg_size - msgbufp->msg_bufx, req);
923 if (msgbufp->msg_bufx > 0) {
924 error = sysctl_handle_opaque(oidp, msgbufp->msg_ptr,
925 msgbufp->msg_bufx, req);
930 SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_STRING | CTLFLAG_RD,
931 0, 0, sysctl_kern_msgbuf, "A", "Contents of kernel message buffer");
933 static int msgbuf_clear;
936 sysctl_kern_msgbuf_clear(SYSCTL_HANDLER_ARGS)
939 error = sysctl_handle_int(oidp, oidp->oid_arg1, oidp->oid_arg2, req);
940 if (!error && req->newptr) {
941 /* Clear the buffer and reset write pointer */
942 bzero(msgbufp->msg_ptr, msgbufp->msg_size);
943 msgbufp->msg_bufr = msgbufp->msg_bufx = 0;
949 SYSCTL_PROC(_kern, OID_AUTO, msgbuf_clear,
950 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_SECURE, &msgbuf_clear, 0,
951 sysctl_kern_msgbuf_clear, "I", "Clear kernel message buffer");
957 DB_SHOW_COMMAND(msgbuf, db_show_msgbuf)
962 db_printf("msgbuf not mapped yet\n");
965 db_printf("msgbufp = %p\n", msgbufp);
966 db_printf("magic = %x, size = %d, r= %d, w = %d, ptr = %p\n",
967 msgbufp->msg_magic, msgbufp->msg_size, msgbufp->msg_bufr,
968 msgbufp->msg_bufx, msgbufp->msg_ptr);
969 for (i = 0; i < msgbufp->msg_size; i++) {
970 j = (i + msgbufp->msg_bufr) % msgbufp->msg_size;
971 db_printf("%c", msgbufp->msg_ptr[j]);