xref: /openbmc/linux/tools/perf/util/dsos.c (revision f9834f18)
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 int dso_id__cmp(struct dso_id *a, struct dso_id *b)
30 {
31 	/*
32 	 * The second is always dso->id, so zeroes if not set, assume passing
33 	 * NULL for a means a zeroed id
34 	 */
35 	if (a == NULL)
36 		return 0;
37 
38 	return __dso_id__cmp(a, b);
39 }
40 
41 int dso__cmp_id(struct dso *a, struct dso *b)
42 {
43 	return __dso_id__cmp(&a->id, &b->id);
44 }
45 
46 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
47 {
48 	bool have_build_id = false;
49 	struct dso *pos;
50 	struct nscookie nsc;
51 
52 	list_for_each_entry(pos, head, node) {
53 		if (with_hits && !pos->hit && !dso__is_vdso(pos))
54 			continue;
55 		if (pos->has_build_id) {
56 			have_build_id = true;
57 			continue;
58 		}
59 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
60 		if (filename__read_build_id(pos->long_name, pos->build_id,
61 					    sizeof(pos->build_id)) > 0) {
62 			have_build_id	  = true;
63 			pos->has_build_id = true;
64 		}
65 		nsinfo__mountns_exit(&nsc);
66 	}
67 
68 	return have_build_id;
69 }
70 
71 static int __dso__cmp_long_name(const char *long_name, struct dso_id *id, struct dso *b)
72 {
73 	int rc = strcmp(long_name, b->long_name);
74 	return rc ?: dso_id__cmp(id, &b->id);
75 }
76 
77 static int __dso__cmp_short_name(const char *short_name, struct dso_id *id, struct dso *b)
78 {
79 	int rc = strcmp(short_name, b->short_name);
80 	return rc ?: dso_id__cmp(id, &b->id);
81 }
82 
83 static int dso__cmp_short_name(struct dso *a, struct dso *b)
84 {
85 	return __dso__cmp_short_name(a->short_name, &a->id, b);
86 }
87 
88 /*
89  * Find a matching entry and/or link current entry to RB tree.
90  * Either one of the dso or name parameter must be non-NULL or the
91  * function will not work.
92  */
93 struct dso *__dsos__findnew_link_by_longname_id(struct rb_root *root, struct dso *dso,
94 						const char *name, struct dso_id *id)
95 {
96 	struct rb_node **p = &root->rb_node;
97 	struct rb_node  *parent = NULL;
98 
99 	if (!name)
100 		name = dso->long_name;
101 	/*
102 	 * Find node with the matching name
103 	 */
104 	while (*p) {
105 		struct dso *this = rb_entry(*p, struct dso, rb_node);
106 		int rc = __dso__cmp_long_name(name, id, this);
107 
108 		parent = *p;
109 		if (rc == 0) {
110 			/*
111 			 * In case the new DSO is a duplicate of an existing
112 			 * one, print a one-time warning & put the new entry
113 			 * at the end of the list of duplicates.
114 			 */
115 			if (!dso || (dso == this))
116 				return this;	/* Find matching dso */
117 			/*
118 			 * The core kernel DSOs may have duplicated long name.
119 			 * In this case, the short name should be different.
120 			 * Comparing the short names to differentiate the DSOs.
121 			 */
122 			rc = dso__cmp_short_name(dso, this);
123 			if (rc == 0) {
124 				pr_err("Duplicated dso name: %s\n", name);
125 				return NULL;
126 			}
127 		}
128 		if (rc < 0)
129 			p = &parent->rb_left;
130 		else
131 			p = &parent->rb_right;
132 	}
133 	if (dso) {
134 		/* Add new node and rebalance tree */
135 		rb_link_node(&dso->rb_node, parent, p);
136 		rb_insert_color(&dso->rb_node, root);
137 		dso->root = root;
138 	}
139 	return NULL;
140 }
141 
142 void __dsos__add(struct dsos *dsos, struct dso *dso)
143 {
144 	list_add_tail(&dso->node, &dsos->head);
145 	__dsos__findnew_link_by_longname_id(&dsos->root, dso, NULL, &dso->id);
146 	/*
147 	 * It is now in the linked list, grab a reference, then garbage collect
148 	 * this when needing memory, by looking at LRU dso instances in the
149 	 * list with atomic_read(&dso->refcnt) == 1, i.e. no references
150 	 * anywhere besides the one for the list, do, under a lock for the
151 	 * list: remove it from the list, then a dso__put(), that probably will
152 	 * be the last and will then call dso__delete(), end of life.
153 	 *
154 	 * That, or at the end of the 'struct machine' lifetime, when all
155 	 * 'struct dso' instances will be removed from the list, in
156 	 * dsos__exit(), if they have no other reference from some other data
157 	 * structure.
158 	 *
159 	 * E.g.: after processing a 'perf.data' file and storing references
160 	 * to objects instantiated while processing events, we will have
161 	 * references to the 'thread', 'map', 'dso' structs all from 'struct
162 	 * hist_entry' instances, but we may not need anything not referenced,
163 	 * so we might as well call machines__exit()/machines__delete() and
164 	 * garbage collect it.
165 	 */
166 	dso__get(dso);
167 }
168 
169 void dsos__add(struct dsos *dsos, struct dso *dso)
170 {
171 	down_write(&dsos->lock);
172 	__dsos__add(dsos, dso);
173 	up_write(&dsos->lock);
174 }
175 
176 static struct dso *__dsos__findnew_by_longname_id(struct rb_root *root, const char *name, struct dso_id *id)
177 {
178 	return __dsos__findnew_link_by_longname_id(root, NULL, name, id);
179 }
180 
181 static struct dso *__dsos__find_id(struct dsos *dsos, const char *name, struct dso_id *id, bool cmp_short)
182 {
183 	struct dso *pos;
184 
185 	if (cmp_short) {
186 		list_for_each_entry(pos, &dsos->head, node)
187 			if (__dso__cmp_short_name(name, id, pos) == 0)
188 				return pos;
189 		return NULL;
190 	}
191 	return __dsos__findnew_by_longname_id(&dsos->root, name, id);
192 }
193 
194 struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
195 {
196 	return __dsos__find_id(dsos, name, NULL, cmp_short);
197 }
198 
199 static void dso__set_basename(struct dso *dso)
200 {
201 	char *base, *lname;
202 	int tid;
203 
204 	if (sscanf(dso->long_name, "/tmp/perf-%d.map", &tid) == 1) {
205 		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
206 			return;
207 	} else {
208 	      /*
209 	       * basename() may modify path buffer, so we must pass
210                * a copy.
211                */
212 		lname = strdup(dso->long_name);
213 		if (!lname)
214 			return;
215 
216 		/*
217 		 * basename() may return a pointer to internal
218 		 * storage which is reused in subsequent calls
219 		 * so copy the result.
220 		 */
221 		base = strdup(basename(lname));
222 
223 		free(lname);
224 
225 		if (!base)
226 			return;
227 	}
228 	dso__set_short_name(dso, base, true);
229 }
230 
231 static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
232 {
233 	struct dso *dso = dso__new_id(name, id);
234 
235 	if (dso != NULL) {
236 		__dsos__add(dsos, dso);
237 		dso__set_basename(dso);
238 		/* Put dso here because __dsos_add already got it */
239 		dso__put(dso);
240 	}
241 	return dso;
242 }
243 
244 struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
245 {
246 	return __dsos__addnew_id(dsos, name, NULL);
247 }
248 
249 static struct dso *__dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
250 {
251 	struct dso *dso = __dsos__find_id(dsos, name, id, false);
252 	return dso ? dso : __dsos__addnew_id(dsos, name, id);
253 }
254 
255 struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
256 {
257 	struct dso *dso;
258 	down_write(&dsos->lock);
259 	dso = dso__get(__dsos__findnew_id(dsos, name, id));
260 	up_write(&dsos->lock);
261 	return dso;
262 }
263 
264 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
265 			       bool (skip)(struct dso *dso, int parm), int parm)
266 {
267 	struct dso *pos;
268 	size_t ret = 0;
269 
270 	list_for_each_entry(pos, head, node) {
271 		if (skip && skip(pos, parm))
272 			continue;
273 		ret += dso__fprintf_buildid(pos, fp);
274 		ret += fprintf(fp, " %s\n", pos->long_name);
275 	}
276 	return ret;
277 }
278 
279 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
280 {
281 	struct dso *pos;
282 	size_t ret = 0;
283 
284 	list_for_each_entry(pos, head, node) {
285 		ret += dso__fprintf(pos, fp);
286 	}
287 
288 	return ret;
289 }
290