xref: /illumos-gate/usr/src/cmd/mdb/common/mdb/mdb_nv.c (revision 581cede61ac9c14d8d4ea452562a567189eead78) 
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, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <mdb/mdb_debug.h>
30 #include <mdb/mdb_string.h>
31 #include <mdb/mdb_modapi.h>
32 #include <mdb/mdb_err.h>
33 #include <mdb/mdb_nv.h>
34 #include <mdb/mdb.h>
35 
36 #define	NV_NAME(v) \
37 	(((v)->v_flags & MDB_NV_EXTNAME) ? (v)->v_ename : (v)->v_lname)
38 
39 #define	NV_SIZE(v) \
40 	(((v)->v_flags & MDB_NV_EXTNAME) ? sizeof (mdb_var_t) : \
41 	sizeof (mdb_var_t) + MDB_NV_NAMELEN - 1)
42 
43 #define	NV_HASHSZ	211
44 
45 static size_t
46 nv_hashstring(const char *key)
47 {
48 	size_t g, h = 0;
49 	const char *p;
50 
51 	ASSERT(key != NULL);
52 
53 	for (p = key; *p != '\0'; p++) {
54 		h = (h << 4) + *p;
55 
56 		if ((g = (h & 0xf0000000)) != 0) {
57 			h ^= (g >> 24);
58 			h ^= g;
59 		}
60 	}
61 
62 	return (h);
63 }
64 
65 static mdb_var_t *
66 nv_var_alloc(const char *name, const mdb_nv_disc_t *disc,
67 	uintmax_t value, uint_t flags, uint_t um_flags, mdb_var_t *next)
68 {
69 	size_t nbytes = (flags & MDB_NV_EXTNAME) ? sizeof (mdb_var_t) :
70 	    (sizeof (mdb_var_t) + MDB_NV_NAMELEN - 1);
71 
72 	mdb_var_t *v = mdb_alloc(nbytes, um_flags);
73 
74 	if (v == NULL)
75 		return (NULL);
76 
77 	if (flags & MDB_NV_EXTNAME) {
78 		v->v_ename = name;
79 		v->v_lname[0] = 0;
80 	} else {
81 		(void) strncpy(v->v_lname, name, MDB_NV_NAMELEN - 1);
82 		v->v_lname[MDB_NV_NAMELEN - 1] = '\0';
83 		v->v_ename = NULL;
84 	}
85 
86 	v->v_uvalue = value;
87 	v->v_flags = flags & ~(MDB_NV_SILENT | MDB_NV_INTERPOS);
88 	v->v_disc = disc;
89 	v->v_next = next;
90 
91 	return (v);
92 }
93 
94 static void
95 nv_var_free(mdb_var_t *v, uint_t um_flags)
96 {
97 	if (um_flags & UM_GC)
98 		return;
99 
100 	if (v->v_flags & MDB_NV_OVERLOAD) {
101 		mdb_var_t *w, *nw;
102 
103 		for (w = v->v_ndef; w != NULL; w = nw) {
104 			nw = w->v_ndef;
105 			mdb_free(w, NV_SIZE(w));
106 		}
107 	}
108 
109 	mdb_free(v, NV_SIZE(v));
110 }
111 
112 /*
113  * Can return NULL only if the nv's memory allocation flags include UM_NOSLEEP
114  */
115 mdb_nv_t *
116 mdb_nv_create(mdb_nv_t *nv, uint_t um_flags)
117 {
118 	nv->nv_hash = mdb_zalloc(sizeof (mdb_var_t *) * NV_HASHSZ, um_flags);
119 
120 	if (nv->nv_hash == NULL)
121 		return (NULL);
122 
123 	nv->nv_hashsz = NV_HASHSZ;
124 	nv->nv_nelems = 0;
125 	nv->nv_iter_elt = NULL;
126 	nv->nv_iter_bucket = 0;
127 	nv->nv_um_flags = um_flags;
128 
129 	return (nv);
130 }
131 
132 void
133 mdb_nv_destroy(mdb_nv_t *nv)
134 {
135 	mdb_var_t *v, *w;
136 	size_t i;
137 
138 	if (nv->nv_um_flags & UM_GC)
139 		return;
140 
141 	for (i = 0; i < nv->nv_hashsz; i++) {
142 		for (v = nv->nv_hash[i]; v != NULL; v = w) {
143 			w = v->v_next;
144 			nv_var_free(v, nv->nv_um_flags);
145 		}
146 	}
147 
148 	mdb_free(nv->nv_hash, sizeof (mdb_var_t *) * NV_HASHSZ);
149 }
150 
151 mdb_var_t *
152 mdb_nv_lookup(mdb_nv_t *nv, const char *name)
153 {
154 	size_t i = nv_hashstring(name) % nv->nv_hashsz;
155 	mdb_var_t *v;
156 
157 	for (v = nv->nv_hash[i]; v != NULL; v = v->v_next) {
158 		if (strcmp(NV_NAME(v), name) == 0)
159 			return (v);
160 	}
161 
162 	return (NULL);
163 }
164 
165 /*
166  * Interpose W in place of V.  We replace V with W in nv_hash, and then
167  * set W's v_ndef overload chain to point at V.
168  */
169 static mdb_var_t *
170 nv_var_interpos(mdb_nv_t *nv, size_t i, mdb_var_t *v, mdb_var_t *w)
171 {
172 	mdb_var_t **pvp = &nv->nv_hash[i];
173 
174 	while (*pvp != v) {
175 		mdb_var_t *vp = *pvp;
176 		ASSERT(vp != NULL);
177 		pvp = &vp->v_next;
178 	}
179 
180 	*pvp = w;
181 	w->v_next = v->v_next;
182 	w->v_ndef = v;
183 	v->v_next = NULL;
184 
185 	return (w);
186 }
187 
188 /*
189  * Add W to the end of V's overload chain.  We simply follow v_ndef to the
190  * end, and then append W.  We don't expect these chains to grow very long.
191  */
192 static mdb_var_t *
193 nv_var_overload(mdb_var_t *v, mdb_var_t *w)
194 {
195 	while (v->v_ndef != NULL)
196 		v = v->v_ndef;
197 
198 	v->v_ndef = w;
199 	return (w);
200 }
201 
202 /*
203  * Can return NULL only if the nv's memory allocation flags include UM_NOSLEEP
204  */
205 mdb_var_t *
206 mdb_nv_insert(mdb_nv_t *nv, const char *name, const mdb_nv_disc_t *disc,
207     uintmax_t value, uint_t flags)
208 {
209 	size_t i = nv_hashstring(name) % nv->nv_hashsz;
210 	mdb_var_t *v;
211 
212 	ASSERT(!(flags & MDB_NV_EXTNAME) || !(flags & MDB_NV_OVERLOAD));
213 	ASSERT(!(flags & MDB_NV_RDONLY) || !(flags & MDB_NV_OVERLOAD));
214 
215 	/*
216 	 * If the specified name is already hashed,
217 	 * and MDB_NV_OVERLOAD is set:	insert new var into overload chain
218 	 * and MDB_NV_RDONLY is set:	leave var unchanged, issue warning
219 	 * otherwise:			update var with new value
220 	 */
221 	for (v = nv->nv_hash[i]; v != NULL; v = v->v_next) {
222 		if (strcmp(NV_NAME(v), name) == 0) {
223 			if (v->v_flags & MDB_NV_OVERLOAD) {
224 				mdb_var_t *w = nv_var_alloc(NV_NAME(v), disc,
225 				    value, flags, nv->nv_um_flags, NULL);
226 
227 				if (w == NULL) {
228 					ASSERT(nv->nv_um_flags & UM_NOSLEEP);
229 					return (NULL);
230 				}
231 
232 				if (flags & MDB_NV_INTERPOS)
233 					v = nv_var_interpos(nv, i, v, w);
234 				else
235 					v = nv_var_overload(v, w);
236 
237 			} else if (v->v_flags & MDB_NV_RDONLY) {
238 				if (!(flags & MDB_NV_SILENT)) {
239 					warn("cannot modify read-only "
240 					    "variable '%s'\n", NV_NAME(v));
241 				}
242 			} else
243 				v->v_uvalue = value;
244 
245 			ASSERT(v != NULL);
246 			return (v);
247 		}
248 	}
249 
250 	/*
251 	 * If the specified name was not found, initialize a new element
252 	 * and add it to the hash table at the beginning of this chain:
253 	 */
254 	v = nv_var_alloc(name, disc, value, flags, nv->nv_um_flags,
255 	    nv->nv_hash[i]);
256 
257 	if (v == NULL) {
258 		ASSERT(nv->nv_um_flags & UM_NOSLEEP);
259 		return (NULL);
260 	}
261 
262 	nv->nv_hash[i] = v;
263 	nv->nv_nelems++;
264 
265 	return (v);
266 }
267 
268 static void
269 nv_var_defn_remove(mdb_var_t *v, mdb_var_t *corpse, uint_t um_flags)
270 {
271 	mdb_var_t *w = v;
272 
273 	while (v->v_ndef != NULL && v->v_ndef != corpse)
274 		v = v->v_ndef;
275 
276 	if (v == NULL) {
277 		fail("var %p ('%s') not found on defn chain of %p\n",
278 		    (void *)corpse, NV_NAME(corpse), (void *)w);
279 	}
280 
281 	v->v_ndef = corpse->v_ndef;
282 	corpse->v_ndef = NULL;
283 	nv_var_free(corpse, um_flags);
284 }
285 
286 void
287 mdb_nv_remove(mdb_nv_t *nv, mdb_var_t *corpse)
288 {
289 	const char *cname = NV_NAME(corpse);
290 	size_t i = nv_hashstring(cname) % nv->nv_hashsz;
291 	mdb_var_t *v = nv->nv_hash[i];
292 	mdb_var_t **pvp;
293 
294 	if (corpse->v_flags & MDB_NV_PERSIST) {
295 		warn("cannot remove persistent variable '%s'\n", cname);
296 		return;
297 	}
298 
299 	if (v != corpse) {
300 		do {
301 			if (strcmp(NV_NAME(v), cname) == 0) {
302 				if (corpse->v_flags & MDB_NV_OVERLOAD) {
303 					nv_var_defn_remove(v, corpse,
304 					    nv->nv_um_flags);
305 					return; /* No v_next changes needed */
306 				} else
307 					goto notfound;
308 			}
309 
310 			if (v->v_next == corpse)
311 				break; /* Corpse is next on the chain */
312 
313 		} while ((v = v->v_next) != NULL);
314 
315 		if (v == NULL)
316 			goto notfound;
317 
318 		pvp = &v->v_next;
319 	} else
320 		pvp = &nv->nv_hash[i];
321 
322 	if ((corpse->v_flags & MDB_NV_OVERLOAD) && corpse->v_ndef != NULL) {
323 		corpse->v_ndef->v_next = corpse->v_next;
324 		*pvp = corpse->v_ndef;
325 		corpse->v_ndef = NULL;
326 	} else {
327 		*pvp = corpse->v_next;
328 		nv->nv_nelems--;
329 	}
330 
331 	nv_var_free(corpse, nv->nv_um_flags);
332 	return;
333 
334 notfound:
335 	fail("var %p ('%s') not found on hash chain: nv=%p [%lu]\n",
336 	    (void *)corpse, cname, (void *)nv, (ulong_t)i);
337 }
338 
339 void
340 mdb_nv_rewind(mdb_nv_t *nv)
341 {
342 	size_t i;
343 
344 	for (i = 0; i < nv->nv_hashsz; i++) {
345 		if (nv->nv_hash[i] != NULL)
346 			break;
347 	}
348 
349 	nv->nv_iter_elt = i < nv->nv_hashsz ? nv->nv_hash[i] : NULL;
350 	nv->nv_iter_bucket = i;
351 }
352 
353 mdb_var_t *
354 mdb_nv_advance(mdb_nv_t *nv)
355 {
356 	mdb_var_t *v = nv->nv_iter_elt;
357 	size_t i;
358 
359 	if (v == NULL)
360 		return (NULL);
361 
362 	if (v->v_next != NULL) {
363 		nv->nv_iter_elt = v->v_next;
364 		return (v);
365 	}
366 
367 	for (i = nv->nv_iter_bucket + 1; i < nv->nv_hashsz; i++) {
368 		if (nv->nv_hash[i] != NULL)
369 			break;
370 	}
371 
372 	nv->nv_iter_elt = i < nv->nv_hashsz ? nv->nv_hash[i] : NULL;
373 	nv->nv_iter_bucket = i;
374 
375 	return (v);
376 }
377 
378 mdb_var_t *
379 mdb_nv_peek(mdb_nv_t *nv)
380 {
381 	return (nv->nv_iter_elt);
382 }
383 
384 size_t
385 mdb_nv_size(mdb_nv_t *nv)
386 {
387 	return (nv->nv_nelems);
388 }
389 
390 static int
391 nv_compare(const mdb_var_t **lp, const mdb_var_t **rp)
392 {
393 	return (strcmp(mdb_nv_get_name(*lp), mdb_nv_get_name(*rp)));
394 }
395 
396 void
397 mdb_nv_sort_iter(mdb_nv_t *nv, int (*func)(mdb_var_t *, void *),
398     void *private, uint_t um_flags)
399 {
400 	mdb_var_t **vps =
401 	    mdb_alloc(nv->nv_nelems * sizeof (mdb_var_t *), um_flags);
402 
403 	if (nv->nv_nelems != 0 && vps != NULL) {
404 		mdb_var_t *v, **vpp = vps;
405 		size_t i;
406 
407 		for (mdb_nv_rewind(nv); (v = mdb_nv_advance(nv)) != NULL; )
408 			*vpp++ = v;
409 
410 		qsort(vps, nv->nv_nelems, sizeof (mdb_var_t *),
411 		    (int (*)(const void *, const void *))nv_compare);
412 
413 		for (vpp = vps, i = 0; i < nv->nv_nelems; i++) {
414 			if (func(*vpp++, private) == -1)
415 				break;
416 		}
417 
418 		if (!(um_flags & UM_GC))
419 			mdb_free(vps, nv->nv_nelems * sizeof (mdb_var_t *));
420 	}
421 }
422 
423 void
424 mdb_nv_defn_iter(mdb_var_t *v, int (*func)(mdb_var_t *, void *), void *private)
425 {
426 	if (func(v, private) == -1 || !(v->v_flags & MDB_NV_OVERLOAD))
427 		return;
428 
429 	for (v = v->v_ndef; v != NULL; v = v->v_ndef) {
430 		if (func(v, private) == -1)
431 			break;
432 	}
433 }
434 
435 uintmax_t
436 mdb_nv_get_value(const mdb_var_t *v)
437 {
438 	if (v->v_disc)
439 		return (v->v_disc->disc_get(v));
440 
441 	return (v->v_uvalue);
442 }
443 
444 void
445 mdb_nv_set_value(mdb_var_t *v, uintmax_t l)
446 {
447 	if (v->v_flags & MDB_NV_RDONLY) {
448 		warn("cannot modify read-only variable '%s'\n", NV_NAME(v));
449 		return;
450 	}
451 
452 	if (v->v_disc)
453 		v->v_disc->disc_set(v, l);
454 	else
455 		v->v_uvalue = l;
456 }
457 
458 void *
459 mdb_nv_get_cookie(const mdb_var_t *v)
460 {
461 	if (v->v_disc)
462 		return ((void *)(uintptr_t)v->v_disc->disc_get(v));
463 
464 	return (MDB_NV_COOKIE(v));
465 }
466 
467 void
468 mdb_nv_set_cookie(mdb_var_t *v, void *cookie)
469 {
470 	mdb_nv_set_value(v, (uintmax_t)(uintptr_t)cookie);
471 }
472 
473 const char *
474 mdb_nv_get_name(const mdb_var_t *v)
475 {
476 	return (NV_NAME(v));
477 }
478 
479 mdb_var_t *
480 mdb_nv_get_ndef(const mdb_var_t *v)
481 {
482 	if (v->v_flags & MDB_NV_OVERLOAD)
483 		return (v->v_ndef);
484 
485 	return (NULL);
486 }
487