xref: /linux/tools/perf/util/dsos.c (revision d195c39052d1da278a00a6744ce59c383b67b191)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "debug.h"
3 #include "dsos.h"
4 #include "dso.h"
5 #include "vdso.h"
6 #include "namespaces.h"
7 #include <libgen.h>
8 #include <stdlib.h>
9 #include <string.h>
10 #include <symbol.h> // filename__read_build_id
11 
12 static int __dso_id__cmp(struct dso_id *a, struct dso_id *b)
13 {
14 	if (a->maj > b->maj) return -1;
15 	if (a->maj < b->maj) return 1;
16 
17 	if (a->min > b->min) return -1;
18 	if (a->min < b->min) return 1;
19 
20 	if (a->ino > b->ino) return -1;
21 	if (a->ino < b->ino) return 1;
22 
23 	if (a->ino_generation > b->ino_generation) return -1;
24 	if (a->ino_generation < b->ino_generation) return 1;
25 
26 	return 0;
27 }
28 
29 static bool dso_id__empty(struct dso_id *id)
30 {
31 	if (!id)
32 		return true;
33 
34 	return !id->maj && !id->min && !id->ino && !id->ino_generation;
35 }
36 
37 static void dso__inject_id(struct dso *dso, struct dso_id *id)
38 {
39 	dso->id.maj = id->maj;
40 	dso->id.min = id->min;
41 	dso->id.ino = id->ino;
42 	dso->id.ino_generation = id->ino_generation;
43 }
44 
45 static int dso_id__cmp(struct dso_id *a, struct dso_id *b)
46 {
47 	/*
48 	 * The second is always dso->id, so zeroes if not set, assume passing
49 	 * NULL for a means a zeroed id
50 	 */
51 	if (dso_id__empty(a) || dso_id__empty(b))
52 		return 0;
53 
54 	return __dso_id__cmp(a, b);
55 }
56 
57 int dso__cmp_id(struct dso *a, struct dso *b)
58 {
59 	return __dso_id__cmp(&a->id, &b->id);
60 }
61 
62 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
63 {
64 	bool have_build_id = false;
65 	struct dso *pos;
66 	struct nscookie nsc;
67 
68 	list_for_each_entry(pos, head, node) {
69 		if (with_hits && !pos->hit && !dso__is_vdso(pos))
70 			continue;
71 		if (pos->has_build_id) {
72 			have_build_id = true;
73 			continue;
74 		}
75 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
76 		if (filename__read_build_id(pos->long_name, pos->build_id,
77 					    sizeof(pos->build_id)) > 0) {
78 			have_build_id	  = true;
79 			pos->has_build_id = true;
80 		}
81 		nsinfo__mountns_exit(&nsc);
82 	}
83 
84 	return have_build_id;
85 }
86 
87 static int __dso__cmp_long_name(const char *long_name, struct dso_id *id, struct dso *b)
88 {
89 	int rc = strcmp(long_name, b->long_name);
90 	return rc ?: dso_id__cmp(id, &b->id);
91 }
92 
93 static int __dso__cmp_short_name(const char *short_name, struct dso_id *id, struct dso *b)
94 {
95 	int rc = strcmp(short_name, b->short_name);
96 	return rc ?: dso_id__cmp(id, &b->id);
97 }
98 
99 static int dso__cmp_short_name(struct dso *a, struct dso *b)
100 {
101 	return __dso__cmp_short_name(a->short_name, &a->id, b);
102 }
103 
104 /*
105  * Find a matching entry and/or link current entry to RB tree.
106  * Either one of the dso or name parameter must be non-NULL or the
107  * function will not work.
108  */
109 struct dso *__dsos__findnew_link_by_longname_id(struct rb_root *root, struct dso *dso,
110 						const char *name, struct dso_id *id)
111 {
112 	struct rb_node **p = &root->rb_node;
113 	struct rb_node  *parent = NULL;
114 
115 	if (!name)
116 		name = dso->long_name;
117 	/*
118 	 * Find node with the matching name
119 	 */
120 	while (*p) {
121 		struct dso *this = rb_entry(*p, struct dso, rb_node);
122 		int rc = __dso__cmp_long_name(name, id, this);
123 
124 		parent = *p;
125 		if (rc == 0) {
126 			/*
127 			 * In case the new DSO is a duplicate of an existing
128 			 * one, print a one-time warning & put the new entry
129 			 * at the end of the list of duplicates.
130 			 */
131 			if (!dso || (dso == this))
132 				return this;	/* Find matching dso */
133 			/*
134 			 * The core kernel DSOs may have duplicated long name.
135 			 * In this case, the short name should be different.
136 			 * Comparing the short names to differentiate the DSOs.
137 			 */
138 			rc = dso__cmp_short_name(dso, this);
139 			if (rc == 0) {
140 				pr_err("Duplicated dso name: %s\n", name);
141 				return NULL;
142 			}
143 		}
144 		if (rc < 0)
145 			p = &parent->rb_left;
146 		else
147 			p = &parent->rb_right;
148 	}
149 	if (dso) {
150 		/* Add new node and rebalance tree */
151 		rb_link_node(&dso->rb_node, parent, p);
152 		rb_insert_color(&dso->rb_node, root);
153 		dso->root = root;
154 	}
155 	return NULL;
156 }
157 
158 void __dsos__add(struct dsos *dsos, struct dso *dso)
159 {
160 	list_add_tail(&dso->node, &dsos->head);
161 	__dsos__findnew_link_by_longname_id(&dsos->root, dso, NULL, &dso->id);
162 	/*
163 	 * It is now in the linked list, grab a reference, then garbage collect
164 	 * this when needing memory, by looking at LRU dso instances in the
165 	 * list with atomic_read(&dso->refcnt) == 1, i.e. no references
166 	 * anywhere besides the one for the list, do, under a lock for the
167 	 * list: remove it from the list, then a dso__put(), that probably will
168 	 * be the last and will then call dso__delete(), end of life.
169 	 *
170 	 * That, or at the end of the 'struct machine' lifetime, when all
171 	 * 'struct dso' instances will be removed from the list, in
172 	 * dsos__exit(), if they have no other reference from some other data
173 	 * structure.
174 	 *
175 	 * E.g.: after processing a 'perf.data' file and storing references
176 	 * to objects instantiated while processing events, we will have
177 	 * references to the 'thread', 'map', 'dso' structs all from 'struct
178 	 * hist_entry' instances, but we may not need anything not referenced,
179 	 * so we might as well call machines__exit()/machines__delete() and
180 	 * garbage collect it.
181 	 */
182 	dso__get(dso);
183 }
184 
185 void dsos__add(struct dsos *dsos, struct dso *dso)
186 {
187 	down_write(&dsos->lock);
188 	__dsos__add(dsos, dso);
189 	up_write(&dsos->lock);
190 }
191 
192 static struct dso *__dsos__findnew_by_longname_id(struct rb_root *root, const char *name, struct dso_id *id)
193 {
194 	return __dsos__findnew_link_by_longname_id(root, NULL, name, id);
195 }
196 
197 static struct dso *__dsos__find_id(struct dsos *dsos, const char *name, struct dso_id *id, bool cmp_short)
198 {
199 	struct dso *pos;
200 
201 	if (cmp_short) {
202 		list_for_each_entry(pos, &dsos->head, node)
203 			if (__dso__cmp_short_name(name, id, pos) == 0)
204 				return pos;
205 		return NULL;
206 	}
207 	return __dsos__findnew_by_longname_id(&dsos->root, name, id);
208 }
209 
210 struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
211 {
212 	return __dsos__find_id(dsos, name, NULL, cmp_short);
213 }
214 
215 static void dso__set_basename(struct dso *dso)
216 {
217 	char *base, *lname;
218 	int tid;
219 
220 	if (sscanf(dso->long_name, "/tmp/perf-%d.map", &tid) == 1) {
221 		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
222 			return;
223 	} else {
224 	      /*
225 	       * basename() may modify path buffer, so we must pass
226                * a copy.
227                */
228 		lname = strdup(dso->long_name);
229 		if (!lname)
230 			return;
231 
232 		/*
233 		 * basename() may return a pointer to internal
234 		 * storage which is reused in subsequent calls
235 		 * so copy the result.
236 		 */
237 		base = strdup(basename(lname));
238 
239 		free(lname);
240 
241 		if (!base)
242 			return;
243 	}
244 	dso__set_short_name(dso, base, true);
245 }
246 
247 static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
248 {
249 	struct dso *dso = dso__new_id(name, id);
250 
251 	if (dso != NULL) {
252 		__dsos__add(dsos, dso);
253 		dso__set_basename(dso);
254 		/* Put dso here because __dsos_add already got it */
255 		dso__put(dso);
256 	}
257 	return dso;
258 }
259 
260 struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
261 {
262 	return __dsos__addnew_id(dsos, name, NULL);
263 }
264 
265 static struct dso *__dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
266 {
267 	struct dso *dso = __dsos__find_id(dsos, name, id, false);
268 
269 	if (dso && dso_id__empty(&dso->id) && !dso_id__empty(id))
270 		dso__inject_id(dso, id);
271 
272 	return dso ? dso : __dsos__addnew_id(dsos, name, id);
273 }
274 
275 struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
276 {
277 	struct dso *dso;
278 	down_write(&dsos->lock);
279 	dso = dso__get(__dsos__findnew_id(dsos, name, id));
280 	up_write(&dsos->lock);
281 	return dso;
282 }
283 
284 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
285 			       bool (skip)(struct dso *dso, int parm), int parm)
286 {
287 	struct dso *pos;
288 	size_t ret = 0;
289 
290 	list_for_each_entry(pos, head, node) {
291 		if (skip && skip(pos, parm))
292 			continue;
293 		ret += dso__fprintf_buildid(pos, fp);
294 		ret += fprintf(fp, " %s\n", pos->long_name);
295 	}
296 	return ret;
297 }
298 
299 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
300 {
301 	struct dso *pos;
302 	size_t ret = 0;
303 
304 	list_for_each_entry(pos, head, node) {
305 		ret += dso__fprintf(pos, fp);
306 	}
307 
308 	return ret;
309 }
310