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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #include <sys/sysmacros.h>
     28 
     29 #include <strings.h>
     30 #include <unistd.h>
     31 #include <stdarg.h>
     32 #include <stddef.h>
     33 #include <stdlib.h>
     34 #include <stdio.h>
     35 #include <errno.h>
     36 #include <ctype.h>
     37 #include <alloca.h>
     38 #include <assert.h>
     39 #include <libgen.h>
     40 #include <limits.h>
     41 
     42 #include <dt_impl.h>
     43 
     44 static const struct {
     45 	size_t dtps_offset;
     46 	size_t dtps_len;
     47 } dtrace_probespecs[] = {
     48 	{ offsetof(dtrace_probedesc_t, dtpd_provider),	DTRACE_PROVNAMELEN },
     49 	{ offsetof(dtrace_probedesc_t, dtpd_mod),	DTRACE_MODNAMELEN },
     50 	{ offsetof(dtrace_probedesc_t, dtpd_func),	DTRACE_FUNCNAMELEN },
     51 	{ offsetof(dtrace_probedesc_t, dtpd_name),	DTRACE_NAMELEN }
     52 };
     53 
     54 int
     55 dtrace_xstr2desc(dtrace_hdl_t *dtp, dtrace_probespec_t spec,
     56     const char *s, int argc, char *const argv[], dtrace_probedesc_t *pdp)
     57 {
     58 	size_t off, len, vlen, wlen;
     59 	const char *p, *q, *v, *w;
     60 
     61 	char buf[32]; /* for id_t as %d (see below) */
     62 
     63 	if (spec < DTRACE_PROBESPEC_NONE || spec > DTRACE_PROBESPEC_NAME)
     64 		return (dt_set_errno(dtp, EINVAL));
     65 
     66 	bzero(pdp, sizeof (dtrace_probedesc_t));
     67 	p = s + strlen(s) - 1;
     68 
     69 	do {
     70 		for (len = 0; p >= s && *p != ':'; len++)
     71 			p--; /* move backward until we find a delimiter */
     72 
     73 		q = p + 1;
     74 		vlen = 0;
     75 		w = NULL;
     76 		wlen = 0;
     77 
     78 		if ((v = strchr(q, '$')) != NULL && v < q + len) {
     79 			/*
     80 			 * Set vlen to the length of the variable name and then
     81 			 * reset len to the length of the text prior to '$'. If
     82 			 * the name begins with a digit, interpret it using the
     83 			 * the argv[] array.  Otherwise we look in dt_macros.
     84 			 * For the moment, all dt_macros variables are of type
     85 			 * id_t (see dtrace_update() for more details on that).
     86 			 */
     87 			vlen = (size_t)(q + len - v);
     88 			len = (size_t)(v - q);
     89 
     90 			/*
     91 			 * If the variable string begins with $$, skip past the
     92 			 * leading dollar sign since $ and $$ are equivalent
     93 			 * macro reference operators in a probe description.
     94 			 */
     95 			if (vlen > 2 && v[1] == '$') {
     96 				vlen--;
     97 				v++;
     98 			}
     99 
    100 			if (isdigit(v[1])) {
    101 				long i;
    102 
    103 				errno = 0;
    104 				i = strtol(v + 1, (char **)&w, 10);
    105 
    106 				wlen = vlen - (w - v);
    107 
    108 				if (i < 0 || i >= argc || errno != 0)
    109 					return (dt_set_errno(dtp, EDT_BADSPCV));
    110 
    111 				v = argv[i];
    112 				vlen = strlen(v);
    113 
    114 				if (yypcb != NULL && yypcb->pcb_sargv == argv)
    115 					yypcb->pcb_sflagv[i] |= DT_IDFLG_REF;
    116 
    117 			} else if (vlen > 1) {
    118 				char *vstr = alloca(vlen);
    119 				dt_ident_t *idp;
    120 
    121 				(void) strncpy(vstr, v + 1, vlen - 1);
    122 				vstr[vlen - 1] = '\0';
    123 				idp = dt_idhash_lookup(dtp->dt_macros, vstr);
    124 
    125 				if (idp == NULL)
    126 					return (dt_set_errno(dtp, EDT_BADSPCV));
    127 
    128 				v = buf;
    129 				vlen = snprintf(buf, 32, "%d", idp->di_id);
    130 
    131 			} else
    132 				return (dt_set_errno(dtp, EDT_BADSPCV));
    133 		}
    134 
    135 		if (spec == DTRACE_PROBESPEC_NONE)
    136 			return (dt_set_errno(dtp, EDT_BADSPEC));
    137 
    138 		if (len + vlen >= dtrace_probespecs[spec].dtps_len)
    139 			return (dt_set_errno(dtp, ENAMETOOLONG));
    140 
    141 		off = dtrace_probespecs[spec--].dtps_offset;
    142 		bcopy(q, (char *)pdp + off, len);
    143 		bcopy(v, (char *)pdp + off + len, vlen);
    144 		bcopy(w, (char *)pdp + off + len + vlen, wlen);
    145 	} while (--p >= s);
    146 
    147 	pdp->dtpd_id = DTRACE_IDNONE;
    148 	return (0);
    149 }
    150 
    151 int
    152 dtrace_str2desc(dtrace_hdl_t *dtp, dtrace_probespec_t spec,
    153     const char *s, dtrace_probedesc_t *pdp)
    154 {
    155 	return (dtrace_xstr2desc(dtp, spec, s, 0, NULL, pdp));
    156 }
    157 
    158 int
    159 dtrace_id2desc(dtrace_hdl_t *dtp, dtrace_id_t id, dtrace_probedesc_t *pdp)
    160 {
    161 	bzero(pdp, sizeof (dtrace_probedesc_t));
    162 	pdp->dtpd_id = id;
    163 
    164 	if (dt_ioctl(dtp, DTRACEIOC_PROBES, pdp) == -1 ||
    165 	    pdp->dtpd_id != id)
    166 		return (dt_set_errno(dtp, EDT_BADID));
    167 
    168 	return (0);
    169 }
    170 
    171 char *
    172 dtrace_desc2str(const dtrace_probedesc_t *pdp, char *buf, size_t len)
    173 {
    174 	if (pdp->dtpd_id == 0) {
    175 		(void) snprintf(buf, len, "%s:%s:%s:%s", pdp->dtpd_provider,
    176 		    pdp->dtpd_mod, pdp->dtpd_func, pdp->dtpd_name);
    177 	} else
    178 		(void) snprintf(buf, len, "%u", pdp->dtpd_id);
    179 
    180 	return (buf);
    181 }
    182 
    183 char *
    184 dtrace_attr2str(dtrace_attribute_t attr, char *buf, size_t len)
    185 {
    186 	const char *name = dtrace_stability_name(attr.dtat_name);
    187 	const char *data = dtrace_stability_name(attr.dtat_data);
    188 	const char *class = dtrace_class_name(attr.dtat_class);
    189 
    190 	if (name == NULL || data == NULL || class == NULL)
    191 		return (NULL); /* one or more invalid attributes */
    192 
    193 	(void) snprintf(buf, len, "%s/%s/%s", name, data, class);
    194 	return (buf);
    195 }
    196 
    197 static char *
    198 dt_getstrattr(char *p, char **qp)
    199 {
    200 	char *q;
    201 
    202 	if (*p == '\0')
    203 		return (NULL);
    204 
    205 	if ((q = strchr(p, '/')) == NULL)
    206 		q = p + strlen(p);
    207 	else
    208 		*q++ = '\0';
    209 
    210 	*qp = q;
    211 	return (p);
    212 }
    213 
    214 int
    215 dtrace_str2attr(const char *str, dtrace_attribute_t *attr)
    216 {
    217 	dtrace_stability_t s;
    218 	dtrace_class_t c;
    219 	char *p, *q;
    220 
    221 	if (str == NULL || attr == NULL)
    222 		return (-1); /* invalid function arguments */
    223 
    224 	*attr = _dtrace_maxattr;
    225 	p = alloca(strlen(str) + 1);
    226 	(void) strcpy(p, str);
    227 
    228 	if ((p = dt_getstrattr(p, &q)) == NULL)
    229 		return (0);
    230 
    231 	for (s = 0; s <= DTRACE_STABILITY_MAX; s++) {
    232 		if (strcasecmp(p, dtrace_stability_name(s)) == 0) {
    233 			attr->dtat_name = s;
    234 			break;
    235 		}
    236 	}
    237 
    238 	if (s > DTRACE_STABILITY_MAX)
    239 		return (-1);
    240 
    241 	if ((p = dt_getstrattr(q, &q)) == NULL)
    242 		return (0);
    243 
    244 	for (s = 0; s <= DTRACE_STABILITY_MAX; s++) {
    245 		if (strcasecmp(p, dtrace_stability_name(s)) == 0) {
    246 			attr->dtat_data = s;
    247 			break;
    248 		}
    249 	}
    250 
    251 	if (s > DTRACE_STABILITY_MAX)
    252 		return (-1);
    253 
    254 	if ((p = dt_getstrattr(q, &q)) == NULL)
    255 		return (0);
    256 
    257 	for (c = 0; c <= DTRACE_CLASS_MAX; c++) {
    258 		if (strcasecmp(p, dtrace_class_name(c)) == 0) {
    259 			attr->dtat_class = c;
    260 			break;
    261 		}
    262 	}
    263 
    264 	if (c > DTRACE_CLASS_MAX || (p = dt_getstrattr(q, &q)) != NULL)
    265 		return (-1);
    266 
    267 	return (0);
    268 }
    269 
    270 const char *
    271 dtrace_stability_name(dtrace_stability_t s)
    272 {
    273 	switch (s) {
    274 	case DTRACE_STABILITY_INTERNAL:	return ("Internal");
    275 	case DTRACE_STABILITY_PRIVATE:	return ("Private");
    276 	case DTRACE_STABILITY_OBSOLETE:	return ("Obsolete");
    277 	case DTRACE_STABILITY_EXTERNAL:	return ("External");
    278 	case DTRACE_STABILITY_UNSTABLE:	return ("Unstable");
    279 	case DTRACE_STABILITY_EVOLVING:	return ("Evolving");
    280 	case DTRACE_STABILITY_STABLE:	return ("Stable");
    281 	case DTRACE_STABILITY_STANDARD:	return ("Standard");
    282 	default:			return (NULL);
    283 	}
    284 }
    285 
    286 const char *
    287 dtrace_class_name(dtrace_class_t c)
    288 {
    289 	switch (c) {
    290 	case DTRACE_CLASS_UNKNOWN:	return ("Unknown");
    291 	case DTRACE_CLASS_CPU:		return ("CPU");
    292 	case DTRACE_CLASS_PLATFORM:	return ("Platform");
    293 	case DTRACE_CLASS_GROUP:	return ("Group");
    294 	case DTRACE_CLASS_ISA:		return ("ISA");
    295 	case DTRACE_CLASS_COMMON:	return ("Common");
    296 	default:			return (NULL);
    297 	}
    298 }
    299 
    300 dtrace_attribute_t
    301 dt_attr_min(dtrace_attribute_t a1, dtrace_attribute_t a2)
    302 {
    303 	dtrace_attribute_t am;
    304 
    305 	am.dtat_name = MIN(a1.dtat_name, a2.dtat_name);
    306 	am.dtat_data = MIN(a1.dtat_data, a2.dtat_data);
    307 	am.dtat_class = MIN(a1.dtat_class, a2.dtat_class);
    308 
    309 	return (am);
    310 }
    311 
    312 dtrace_attribute_t
    313 dt_attr_max(dtrace_attribute_t a1, dtrace_attribute_t a2)
    314 {
    315 	dtrace_attribute_t am;
    316 
    317 	am.dtat_name = MAX(a1.dtat_name, a2.dtat_name);
    318 	am.dtat_data = MAX(a1.dtat_data, a2.dtat_data);
    319 	am.dtat_class = MAX(a1.dtat_class, a2.dtat_class);
    320 
    321 	return (am);
    322 }
    323 
    324 /*
    325  * Compare two attributes and return an integer value in the following ranges:
    326  *
    327  * <0 if any of a1's attributes are less than a2's attributes
    328  * =0 if all of a1's attributes are equal to a2's attributes
    329  * >0 if all of a1's attributes are greater than or equal to a2's attributes
    330  *
    331  * To implement this function efficiently, we subtract a2's attributes from
    332  * a1's to obtain a negative result if an a1 attribute is less than its a2
    333  * counterpart.  We then OR the intermediate results together, relying on the
    334  * twos-complement property that if any result is negative, the bitwise union
    335  * will also be negative since the highest bit will be set in the result.
    336  */
    337 int
    338 dt_attr_cmp(dtrace_attribute_t a1, dtrace_attribute_t a2)
    339 {
    340 	return (((int)a1.dtat_name - a2.dtat_name) |
    341 	    ((int)a1.dtat_data - a2.dtat_data) |
    342 	    ((int)a1.dtat_class - a2.dtat_class));
    343 }
    344 
    345 char *
    346 dt_attr_str(dtrace_attribute_t a, char *buf, size_t len)
    347 {
    348 	static const char stability[] = "ipoxuesS";
    349 	static const char class[] = "uCpgIc";
    350 
    351 	if (a.dtat_name < sizeof (stability) &&
    352 	    a.dtat_data < sizeof (stability) && a.dtat_class < sizeof (class)) {
    353 		(void) snprintf(buf, len, "[%c/%c/%c]", stability[a.dtat_name],
    354 		    stability[a.dtat_data], class[a.dtat_class]);
    355 	} else {
    356 		(void) snprintf(buf, len, "[%u/%u/%u]",
    357 		    a.dtat_name, a.dtat_data, a.dtat_class);
    358 	}
    359 
    360 	return (buf);
    361 }
    362 
    363 char *
    364 dt_version_num2str(dt_version_t v, char *buf, size_t len)
    365 {
    366 	uint_t M = DT_VERSION_MAJOR(v);
    367 	uint_t m = DT_VERSION_MINOR(v);
    368 	uint_t u = DT_VERSION_MICRO(v);
    369 
    370 	if (u == 0)
    371 		(void) snprintf(buf, len, "%u.%u", M, m);
    372 	else
    373 		(void) snprintf(buf, len, "%u.%u.%u", M, m, u);
    374 
    375 	return (buf);
    376 }
    377 
    378 int
    379 dt_version_str2num(const char *s, dt_version_t *vp)
    380 {
    381 	int i = 0, n[3] = { 0, 0, 0 };
    382 	char c;
    383 
    384 	while ((c = *s++) != '\0') {
    385 		if (isdigit(c))
    386 			n[i] = n[i] * 10 + c - '0';
    387 		else if (c != '.' || i++ >= sizeof (n) / sizeof (n[0]) - 1)
    388 			return (-1);
    389 	}
    390 
    391 	if (n[0] > DT_VERSION_MAJMAX ||
    392 	    n[1] > DT_VERSION_MINMAX ||
    393 	    n[2] > DT_VERSION_MICMAX)
    394 		return (-1);
    395 
    396 	if (vp != NULL)
    397 		*vp = DT_VERSION_NUMBER(n[0], n[1], n[2]);
    398 
    399 	return (0);
    400 }
    401 
    402 int
    403 dt_version_defined(dt_version_t v)
    404 {
    405 	int i;
    406 
    407 	for (i = 0; _dtrace_versions[i] != 0; i++) {
    408 		if (_dtrace_versions[i] == v)
    409 			return (1);
    410 	}
    411 
    412 	return (0);
    413 }
    414 
    415 char *
    416 dt_cpp_add_arg(dtrace_hdl_t *dtp, const char *str)
    417 {
    418 	char *arg;
    419 
    420 	if (dtp->dt_cpp_argc == dtp->dt_cpp_args) {
    421 		int olds = dtp->dt_cpp_args;
    422 		int news = olds * 2;
    423 		char **argv = realloc(dtp->dt_cpp_argv, sizeof (char *) * news);
    424 
    425 		if (argv == NULL)
    426 			return (NULL);
    427 
    428 		bzero(&argv[olds], sizeof (char *) * olds);
    429 		dtp->dt_cpp_argv = argv;
    430 		dtp->dt_cpp_args = news;
    431 	}
    432 
    433 	if ((arg = strdup(str)) == NULL)
    434 		return (NULL);
    435 
    436 	assert(dtp->dt_cpp_argc < dtp->dt_cpp_args);
    437 	dtp->dt_cpp_argv[dtp->dt_cpp_argc++] = arg;
    438 	return (arg);
    439 }
    440 
    441 char *
    442 dt_cpp_pop_arg(dtrace_hdl_t *dtp)
    443 {
    444 	char *arg;
    445 
    446 	if (dtp->dt_cpp_argc <= 1)
    447 		return (NULL); /* dt_cpp_argv[0] cannot be popped */
    448 
    449 	arg = dtp->dt_cpp_argv[--dtp->dt_cpp_argc];
    450 	dtp->dt_cpp_argv[dtp->dt_cpp_argc] = NULL;
    451 
    452 	return (arg);
    453 }
    454 
    455 /*PRINTFLIKE1*/
    456 void
    457 dt_dprintf(const char *format, ...)
    458 {
    459 	if (_dtrace_debug) {
    460 		va_list alist;
    461 
    462 		va_start(alist, format);
    463 		(void) fputs("libdtrace DEBUG: ", stderr);
    464 		(void) vfprintf(stderr, format, alist);
    465 		va_end(alist);
    466 	}
    467 }
    468 
    469 int
    470 dt_ioctl(dtrace_hdl_t *dtp, int val, void *arg)
    471 {
    472 	const dtrace_vector_t *v = dtp->dt_vector;
    473 
    474 	if (v != NULL)
    475 		return (v->dtv_ioctl(dtp->dt_varg, val, arg));
    476 
    477 	if (dtp->dt_fd >= 0)
    478 		return (ioctl(dtp->dt_fd, val, arg));
    479 
    480 	errno = EBADF;
    481 	return (-1);
    482 }
    483 
    484 int
    485 dt_status(dtrace_hdl_t *dtp, processorid_t cpu)
    486 {
    487 	const dtrace_vector_t *v = dtp->dt_vector;
    488 
    489 	if (v == NULL)
    490 		return (p_online(cpu, P_STATUS));
    491 
    492 	return (v->dtv_status(dtp->dt_varg, cpu));
    493 }
    494 
    495 long
    496 dt_sysconf(dtrace_hdl_t *dtp, int name)
    497 {
    498 	const dtrace_vector_t *v = dtp->dt_vector;
    499 
    500 	if (v == NULL)
    501 		return (sysconf(name));
    502 
    503 	return (v->dtv_sysconf(dtp->dt_varg, name));
    504 }
    505 
    506 /*
    507  * Wrapper around write(2) to handle partial writes.  For maximum safety of
    508  * output files and proper error reporting, we continuing writing in the
    509  * face of partial writes until write(2) fails or 'buf' is completely written.
    510  * We also record any errno in the specified dtrace_hdl_t as well as 'errno'.
    511  */
    512 ssize_t
    513 dt_write(dtrace_hdl_t *dtp, int fd, const void *buf, size_t n)
    514 {
    515 	ssize_t resid = n;
    516 	ssize_t len;
    517 
    518 	while (resid != 0) {
    519 		if ((len = write(fd, buf, resid)) <= 0)
    520 			break;
    521 
    522 		resid -= len;
    523 		buf = (char *)buf + len;
    524 	}
    525 
    526 	if (resid == n && n != 0)
    527 		return (dt_set_errno(dtp, errno));
    528 
    529 	return (n - resid);
    530 }
    531 
    532 /*
    533  * This function handles all output from libdtrace, as well as the
    534  * dtrace_sprintf() case.  If we're here due to dtrace_sprintf(), then
    535  * dt_sprintf_buflen will be non-zero; in this case, we sprintf into the
    536  * specified buffer and return.  Otherwise, if output is buffered (denoted by
    537  * a NULL fp), we sprintf the desired output into the buffered buffer
    538  * (expanding the buffer if required).  If we don't satisfy either of these
    539  * conditions (that is, if we are to actually generate output), then we call
    540  * fprintf with the specified fp.  In this case, we need to deal with one of
    541  * the more annoying peculiarities of libc's printf routines:  any failed
    542  * write persistently sets an error flag inside the FILE causing every
    543  * subsequent write to fail, but only the caller that initiated the error gets
    544  * the errno.  Since libdtrace clients often intercept SIGINT, this case is
    545  * particularly frustrating since we don't want the EINTR on one attempt to
    546  * write to the output file to preclude later attempts to write.  This
    547  * function therefore does a clearerr() if any error occurred, and saves the
    548  * errno for the caller inside the specified dtrace_hdl_t.
    549  */
    550 /*PRINTFLIKE3*/
    551 int
    552 dt_printf(dtrace_hdl_t *dtp, FILE *fp, const char *format, ...)
    553 {
    554 	va_list ap;
    555 	int n;
    556 
    557 	va_start(ap, format);
    558 
    559 	if (dtp->dt_sprintf_buflen != 0) {
    560 		int len;
    561 		char *buf;
    562 
    563 		assert(dtp->dt_sprintf_buf != NULL);
    564 
    565 		buf = &dtp->dt_sprintf_buf[len = strlen(dtp->dt_sprintf_buf)];
    566 		len = dtp->dt_sprintf_buflen - len;
    567 		assert(len >= 0);
    568 
    569 		if ((n = vsnprintf(buf, len, format, ap)) < 0)
    570 			n = dt_set_errno(dtp, errno);
    571 
    572 		va_end(ap);
    573 
    574 		return (n);
    575 	}
    576 
    577 	if (fp == NULL) {
    578 		int needed, rval;
    579 		size_t avail;
    580 
    581 		/*
    582 		 * It's not legal to use buffered ouput if there is not a
    583 		 * handler for buffered output.
    584 		 */
    585 		if (dtp->dt_bufhdlr == NULL) {
    586 			va_end(ap);
    587 			return (dt_set_errno(dtp, EDT_NOBUFFERED));
    588 		}
    589 
    590 		if (dtp->dt_buffered_buf == NULL) {
    591 			assert(dtp->dt_buffered_size == 0);
    592 			dtp->dt_buffered_size = 1;
    593 			dtp->dt_buffered_buf = malloc(dtp->dt_buffered_size);
    594 
    595 			if (dtp->dt_buffered_buf == NULL) {
    596 				va_end(ap);
    597 				return (dt_set_errno(dtp, EDT_NOMEM));
    598 			}
    599 
    600 			dtp->dt_buffered_offs = 0;
    601 			dtp->dt_buffered_buf[0] = '\0';
    602 		}
    603 
    604 		if ((needed = vsnprintf(NULL, 0, format, ap)) < 0) {
    605 			rval = dt_set_errno(dtp, errno);
    606 			va_end(ap);
    607 			return (rval);
    608 		}
    609 
    610 		if (needed == 0) {
    611 			va_end(ap);
    612 			return (0);
    613 		}
    614 
    615 		for (;;) {
    616 			char *newbuf;
    617 
    618 			assert(dtp->dt_buffered_offs < dtp->dt_buffered_size);
    619 			avail = dtp->dt_buffered_size - dtp->dt_buffered_offs;
    620 
    621 			if (needed + 1 < avail)
    622 				break;
    623 
    624 			if ((newbuf = realloc(dtp->dt_buffered_buf,
    625 			    dtp->dt_buffered_size << 1)) == NULL) {
    626 				va_end(ap);
    627 				return (dt_set_errno(dtp, EDT_NOMEM));
    628 			}
    629 
    630 			dtp->dt_buffered_buf = newbuf;
    631 			dtp->dt_buffered_size <<= 1;
    632 		}
    633 
    634 		if (vsnprintf(&dtp->dt_buffered_buf[dtp->dt_buffered_offs],
    635 		    avail, format, ap) < 0) {
    636 			rval = dt_set_errno(dtp, errno);
    637 			va_end(ap);
    638 			return (rval);
    639 		}
    640 
    641 		dtp->dt_buffered_offs += needed;
    642 		assert(dtp->dt_buffered_buf[dtp->dt_buffered_offs] == '\0');
    643 		return (0);
    644 	}
    645 
    646 	n = vfprintf(fp, format, ap);
    647 	va_end(ap);
    648 
    649 	if (n < 0) {
    650 		clearerr(fp);
    651 		return (dt_set_errno(dtp, errno));
    652 	}
    653 
    654 	return (n);
    655 }
    656 
    657 int
    658 dt_buffered_flush(dtrace_hdl_t *dtp, dtrace_probedata_t *pdata,
    659     const dtrace_recdesc_t *rec, const dtrace_aggdata_t *agg, uint32_t flags)
    660 {
    661 	dtrace_bufdata_t data;
    662 
    663 	if (dtp->dt_buffered_offs == 0)
    664 		return (0);
    665 
    666 	data.dtbda_handle = dtp;
    667 	data.dtbda_buffered = dtp->dt_buffered_buf;
    668 	data.dtbda_probe = pdata;
    669 	data.dtbda_recdesc = rec;
    670 	data.dtbda_aggdata = agg;
    671 	data.dtbda_flags = flags;
    672 
    673 	if ((*dtp->dt_bufhdlr)(&data, dtp->dt_bufarg) == DTRACE_HANDLE_ABORT)
    674 		return (dt_set_errno(dtp, EDT_DIRABORT));
    675 
    676 	dtp->dt_buffered_offs = 0;
    677 	dtp->dt_buffered_buf[0] = '\0';
    678 
    679 	return (0);
    680 }
    681 
    682 void
    683 dt_buffered_destroy(dtrace_hdl_t *dtp)
    684 {
    685 	free(dtp->dt_buffered_buf);
    686 	dtp->dt_buffered_buf = NULL;
    687 	dtp->dt_buffered_offs = 0;
    688 	dtp->dt_buffered_size = 0;
    689 }
    690 
    691 void *
    692 dt_zalloc(dtrace_hdl_t *dtp, size_t size)
    693 {
    694 	void *data;
    695 
    696 	if ((data = malloc(size)) == NULL)
    697 		(void) dt_set_errno(dtp, EDT_NOMEM);
    698 	else
    699 		bzero(data, size);
    700 
    701 	return (data);
    702 }
    703 
    704 void *
    705 dt_alloc(dtrace_hdl_t *dtp, size_t size)
    706 {
    707 	void *data;
    708 
    709 	if ((data = malloc(size)) == NULL)
    710 		(void) dt_set_errno(dtp, EDT_NOMEM);
    711 
    712 	return (data);
    713 }
    714 
    715 void
    716 dt_free(dtrace_hdl_t *dtp, void *data)
    717 {
    718 	assert(dtp != NULL); /* ensure sane use of this interface */
    719 	free(data);
    720 }
    721 
    722 void
    723 dt_difo_free(dtrace_hdl_t *dtp, dtrace_difo_t *dp)
    724 {
    725 	if (dp == NULL)
    726 		return; /* simplify caller code */
    727 
    728 	dt_free(dtp, dp->dtdo_buf);
    729 	dt_free(dtp, dp->dtdo_inttab);
    730 	dt_free(dtp, dp->dtdo_strtab);
    731 	dt_free(dtp, dp->dtdo_vartab);
    732 	dt_free(dtp, dp->dtdo_kreltab);
    733 	dt_free(dtp, dp->dtdo_ureltab);
    734 	dt_free(dtp, dp->dtdo_xlmtab);
    735 
    736 	dt_free(dtp, dp);
    737 }
    738 
    739 /*
    740  * dt_gmatch() is similar to gmatch(3GEN) and dtrace(7D) globbing, but also
    741  * implements the behavior that an empty pattern matches any string.
    742  */
    743 int
    744 dt_gmatch(const char *s, const char *p)
    745 {
    746 	return (p == NULL || *p == '\0' || gmatch(s, p));
    747 }
    748 
    749 char *
    750 dt_basename(char *str)
    751 {
    752 	char *last = strrchr(str, '/');
    753 
    754 	if (last == NULL)
    755 		return (str);
    756 
    757 	return (last + 1);
    758 }
    759 
    760 /*
    761  * dt_popc() is a fast implementation of population count.  The algorithm is
    762  * from "Hacker's Delight" by Henry Warren, Jr with a 64-bit equivalent added.
    763  */
    764 ulong_t
    765 dt_popc(ulong_t x)
    766 {
    767 #ifdef _ILP32
    768 	x = x - ((x >> 1) & 0x55555555UL);
    769 	x = (x & 0x33333333UL) + ((x >> 2) & 0x33333333UL);
    770 	x = (x + (x >> 4)) & 0x0F0F0F0FUL;
    771 	x = x + (x >> 8);
    772 	x = x + (x >> 16);
    773 	return (x & 0x3F);
    774 #endif
    775 #ifdef _LP64
    776 	x = x - ((x >> 1) & 0x5555555555555555ULL);
    777 	x = (x & 0x3333333333333333ULL) + ((x >> 2) & 0x3333333333333333ULL);
    778 	x = (x + (x >> 4)) & 0x0F0F0F0F0F0F0F0FULL;
    779 	x = x + (x >> 8);
    780 	x = x + (x >> 16);
    781 	x = x + (x >> 32);
    782 	return (x & 0x7F);
    783 #endif
    784 }
    785 
    786 /*
    787  * dt_popcb() is a bitmap-based version of population count that returns the
    788  * number of one bits in the specified bitmap 'bp' at bit positions below 'n'.
    789  */
    790 ulong_t
    791 dt_popcb(const ulong_t *bp, ulong_t n)
    792 {
    793 	ulong_t maxb = n & BT_ULMASK;
    794 	ulong_t maxw = n >> BT_ULSHIFT;
    795 	ulong_t w, popc = 0;
    796 
    797 	if (n == 0)
    798 		return (0);
    799 
    800 	for (w = 0; w < maxw; w++)
    801 		popc += dt_popc(bp[w]);
    802 
    803 	return (popc + dt_popc(bp[maxw] & ((1UL << maxb) - 1)));
    804 }
    805 
    806 static int
    807 dt_string2str(char *s, char *str, int nbytes)
    808 {
    809 	int len = strlen(s);
    810 
    811 	if (nbytes == 0) {
    812 		/*
    813 		 * Like snprintf(3C), we don't check the value of str if the
    814 		 * number of bytes is 0.
    815 		 */
    816 		return (len);
    817 	}
    818 
    819 	if (nbytes <= len) {
    820 		(void) strncpy(str, s, nbytes - 1);
    821 		/*
    822 		 * Like snprintf(3C) (and unlike strncpy(3C)), we guarantee
    823 		 * that the string is null-terminated.
    824 		 */
    825 		str[nbytes - 1] = '\0';
    826 	} else {
    827 		(void) strcpy(str, s);
    828 	}
    829 
    830 	return (len);
    831 }
    832 
    833 int
    834 dtrace_addr2str(dtrace_hdl_t *dtp, uint64_t addr, char *str, int nbytes)
    835 {
    836 	dtrace_syminfo_t dts;
    837 	GElf_Sym sym;
    838 
    839 	size_t n = 20; /* for 0x%llx\0 */
    840 	char *s;
    841 	int err;
    842 
    843 	if ((err = dtrace_lookup_by_addr(dtp, addr, &sym, &dts)) == 0)
    844 		n += strlen(dts.dts_object) + strlen(dts.dts_name) + 2; /* +` */
    845 
    846 	s = alloca(n);
    847 
    848 	if (err == 0 && addr != sym.st_value) {
    849 		(void) snprintf(s, n, "%s`%s+0x%llx", dts.dts_object,
    850 		    dts.dts_name, (u_longlong_t)addr - sym.st_value);
    851 	} else if (err == 0) {
    852 		(void) snprintf(s, n, "%s`%s",
    853 		    dts.dts_object, dts.dts_name);
    854 	} else {
    855 		/*
    856 		 * We'll repeat the lookup, but this time we'll specify a NULL
    857 		 * GElf_Sym -- indicating that we're only interested in the
    858 		 * containing module.
    859 		 */
    860 		if (dtrace_lookup_by_addr(dtp, addr, NULL, &dts) == 0) {
    861 			(void) snprintf(s, n, "%s`0x%llx", dts.dts_object,
    862 			    (u_longlong_t)addr);
    863 		} else {
    864 			(void) snprintf(s, n, "0x%llx", (u_longlong_t)addr);
    865 		}
    866 	}
    867 
    868 	return (dt_string2str(s, str, nbytes));
    869 }
    870 
    871 int
    872 dtrace_uaddr2str(dtrace_hdl_t *dtp, pid_t pid,
    873     uint64_t addr, char *str, int nbytes)
    874 {
    875 	char name[PATH_MAX], objname[PATH_MAX], c[PATH_MAX * 2];
    876 	struct ps_prochandle *P = NULL;
    877 	GElf_Sym sym;
    878 	char *obj;
    879 
    880 	if (pid != 0)
    881 		P = dt_proc_grab(dtp, pid, PGRAB_RDONLY | PGRAB_FORCE, 0);
    882 
    883 	if (P == NULL) {
    884 		(void) snprintf(c, sizeof (c), "0x%llx", addr);
    885 		return (dt_string2str(c, str, nbytes));
    886 	}
    887 
    888 	dt_proc_lock(dtp, P);
    889 
    890 	if (Plookup_by_addr(P, addr, name, sizeof (name), &sym) == 0) {
    891 		(void) Pobjname(P, addr, objname, sizeof (objname));
    892 
    893 		obj = dt_basename(objname);
    894 
    895 		if (addr > sym.st_value) {
    896 			(void) snprintf(c, sizeof (c), "%s`%s+0x%llx", obj,
    897 			    name, (u_longlong_t)(addr - sym.st_value));
    898 		} else {
    899 			(void) snprintf(c, sizeof (c), "%s`%s", obj, name);
    900 		}
    901 	} else if (Pobjname(P, addr, objname, sizeof (objname)) != NULL) {
    902 		(void) snprintf(c, sizeof (c), "%s`0x%llx",
    903 		    dt_basename(objname), addr);
    904 	} else {
    905 		(void) snprintf(c, sizeof (c), "0x%llx", addr);
    906 	}
    907 
    908 	dt_proc_unlock(dtp, P);
    909 	dt_proc_release(dtp, P);
    910 
    911 	return (dt_string2str(c, str, nbytes));
    912 }
    913