xref: /openbmc/linux/tools/perf/util/dsos.c (revision f71a261a)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "debug.h"
3 #include "dsos.h"
4 #include "dso.h"
5 #include "util.h"
6 #include "vdso.h"
7 #include "namespaces.h"
8 #include <errno.h>
9 #include <libgen.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <symbol.h> // filename__read_build_id
13 #include <unistd.h>
14 
15 static int __dso_id__cmp(struct dso_id *a, struct dso_id *b)
16 {
17 	if (a->maj > b->maj) return -1;
18 	if (a->maj < b->maj) return 1;
19 
20 	if (a->min > b->min) return -1;
21 	if (a->min < b->min) return 1;
22 
23 	if (a->ino > b->ino) return -1;
24 	if (a->ino < b->ino) return 1;
25 
26 	if (a->ino_generation > b->ino_generation) return -1;
27 	if (a->ino_generation < b->ino_generation) return 1;
28 
29 	return 0;
30 }
31 
32 static bool dso_id__empty(struct dso_id *id)
33 {
34 	if (!id)
35 		return true;
36 
37 	return !id->maj && !id->min && !id->ino && !id->ino_generation;
38 }
39 
40 static void dso__inject_id(struct dso *dso, struct dso_id *id)
41 {
42 	dso->id.maj = id->maj;
43 	dso->id.min = id->min;
44 	dso->id.ino = id->ino;
45 	dso->id.ino_generation = id->ino_generation;
46 }
47 
48 static int dso_id__cmp(struct dso_id *a, struct dso_id *b)
49 {
50 	/*
51 	 * The second is always dso->id, so zeroes if not set, assume passing
52 	 * NULL for a means a zeroed id
53 	 */
54 	if (dso_id__empty(a) || dso_id__empty(b))
55 		return 0;
56 
57 	return __dso_id__cmp(a, b);
58 }
59 
60 int dso__cmp_id(struct dso *a, struct dso *b)
61 {
62 	return __dso_id__cmp(&a->id, &b->id);
63 }
64 
65 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
66 {
67 	bool have_build_id = false;
68 	struct dso *pos;
69 	struct nscookie nsc;
70 
71 	list_for_each_entry(pos, head, node) {
72 		if (with_hits && !pos->hit && !dso__is_vdso(pos))
73 			continue;
74 		if (pos->has_build_id) {
75 			have_build_id = true;
76 			continue;
77 		}
78 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
79 		if (filename__read_build_id(pos->long_name, &pos->bid) > 0) {
80 			have_build_id	  = true;
81 			pos->has_build_id = true;
82 		} else if (errno == ENOENT && pos->nsinfo) {
83 			char *new_name = filename_with_chroot(pos->nsinfo->pid,
84 							      pos->long_name);
85 
86 			if (new_name && filename__read_build_id(new_name,
87 								&pos->bid) > 0) {
88 				have_build_id = true;
89 				pos->has_build_id = true;
90 			}
91 			free(new_name);
92 		}
93 		nsinfo__mountns_exit(&nsc);
94 	}
95 
96 	return have_build_id;
97 }
98 
99 static int __dso__cmp_long_name(const char *long_name, struct dso_id *id, struct dso *b)
100 {
101 	int rc = strcmp(long_name, b->long_name);
102 	return rc ?: dso_id__cmp(id, &b->id);
103 }
104 
105 static int __dso__cmp_short_name(const char *short_name, struct dso_id *id, struct dso *b)
106 {
107 	int rc = strcmp(short_name, b->short_name);
108 	return rc ?: dso_id__cmp(id, &b->id);
109 }
110 
111 static int dso__cmp_short_name(struct dso *a, struct dso *b)
112 {
113 	return __dso__cmp_short_name(a->short_name, &a->id, b);
114 }
115 
116 /*
117  * Find a matching entry and/or link current entry to RB tree.
118  * Either one of the dso or name parameter must be non-NULL or the
119  * function will not work.
120  */
121 struct dso *__dsos__findnew_link_by_longname_id(struct rb_root *root, struct dso *dso,
122 						const char *name, struct dso_id *id)
123 {
124 	struct rb_node **p = &root->rb_node;
125 	struct rb_node  *parent = NULL;
126 
127 	if (!name)
128 		name = dso->long_name;
129 	/*
130 	 * Find node with the matching name
131 	 */
132 	while (*p) {
133 		struct dso *this = rb_entry(*p, struct dso, rb_node);
134 		int rc = __dso__cmp_long_name(name, id, this);
135 
136 		parent = *p;
137 		if (rc == 0) {
138 			/*
139 			 * In case the new DSO is a duplicate of an existing
140 			 * one, print a one-time warning & put the new entry
141 			 * at the end of the list of duplicates.
142 			 */
143 			if (!dso || (dso == this))
144 				return this;	/* Find matching dso */
145 			/*
146 			 * The core kernel DSOs may have duplicated long name.
147 			 * In this case, the short name should be different.
148 			 * Comparing the short names to differentiate the DSOs.
149 			 */
150 			rc = dso__cmp_short_name(dso, this);
151 			if (rc == 0) {
152 				pr_err("Duplicated dso name: %s\n", name);
153 				return NULL;
154 			}
155 		}
156 		if (rc < 0)
157 			p = &parent->rb_left;
158 		else
159 			p = &parent->rb_right;
160 	}
161 	if (dso) {
162 		/* Add new node and rebalance tree */
163 		rb_link_node(&dso->rb_node, parent, p);
164 		rb_insert_color(&dso->rb_node, root);
165 		dso->root = root;
166 	}
167 	return NULL;
168 }
169 
170 void __dsos__add(struct dsos *dsos, struct dso *dso)
171 {
172 	list_add_tail(&dso->node, &dsos->head);
173 	__dsos__findnew_link_by_longname_id(&dsos->root, dso, NULL, &dso->id);
174 	/*
175 	 * It is now in the linked list, grab a reference, then garbage collect
176 	 * this when needing memory, by looking at LRU dso instances in the
177 	 * list with atomic_read(&dso->refcnt) == 1, i.e. no references
178 	 * anywhere besides the one for the list, do, under a lock for the
179 	 * list: remove it from the list, then a dso__put(), that probably will
180 	 * be the last and will then call dso__delete(), end of life.
181 	 *
182 	 * That, or at the end of the 'struct machine' lifetime, when all
183 	 * 'struct dso' instances will be removed from the list, in
184 	 * dsos__exit(), if they have no other reference from some other data
185 	 * structure.
186 	 *
187 	 * E.g.: after processing a 'perf.data' file and storing references
188 	 * to objects instantiated while processing events, we will have
189 	 * references to the 'thread', 'map', 'dso' structs all from 'struct
190 	 * hist_entry' instances, but we may not need anything not referenced,
191 	 * so we might as well call machines__exit()/machines__delete() and
192 	 * garbage collect it.
193 	 */
194 	dso__get(dso);
195 }
196 
197 void dsos__add(struct dsos *dsos, struct dso *dso)
198 {
199 	down_write(&dsos->lock);
200 	__dsos__add(dsos, dso);
201 	up_write(&dsos->lock);
202 }
203 
204 static struct dso *__dsos__findnew_by_longname_id(struct rb_root *root, const char *name, struct dso_id *id)
205 {
206 	return __dsos__findnew_link_by_longname_id(root, NULL, name, id);
207 }
208 
209 static struct dso *__dsos__find_id(struct dsos *dsos, const char *name, struct dso_id *id, bool cmp_short)
210 {
211 	struct dso *pos;
212 
213 	if (cmp_short) {
214 		list_for_each_entry(pos, &dsos->head, node)
215 			if (__dso__cmp_short_name(name, id, pos) == 0)
216 				return pos;
217 		return NULL;
218 	}
219 	return __dsos__findnew_by_longname_id(&dsos->root, name, id);
220 }
221 
222 struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
223 {
224 	return __dsos__find_id(dsos, name, NULL, cmp_short);
225 }
226 
227 static void dso__set_basename(struct dso *dso)
228 {
229 	char *base, *lname;
230 	int tid;
231 
232 	if (sscanf(dso->long_name, "/tmp/perf-%d.map", &tid) == 1) {
233 		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
234 			return;
235 	} else {
236 	      /*
237 	       * basename() may modify path buffer, so we must pass
238                * a copy.
239                */
240 		lname = strdup(dso->long_name);
241 		if (!lname)
242 			return;
243 
244 		/*
245 		 * basename() may return a pointer to internal
246 		 * storage which is reused in subsequent calls
247 		 * so copy the result.
248 		 */
249 		base = strdup(basename(lname));
250 
251 		free(lname);
252 
253 		if (!base)
254 			return;
255 	}
256 	dso__set_short_name(dso, base, true);
257 }
258 
259 static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
260 {
261 	struct dso *dso = dso__new_id(name, id);
262 
263 	if (dso != NULL) {
264 		__dsos__add(dsos, dso);
265 		dso__set_basename(dso);
266 		/* Put dso here because __dsos_add already got it */
267 		dso__put(dso);
268 	}
269 	return dso;
270 }
271 
272 struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
273 {
274 	return __dsos__addnew_id(dsos, name, NULL);
275 }
276 
277 static struct dso *__dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
278 {
279 	struct dso *dso = __dsos__find_id(dsos, name, id, false);
280 
281 	if (dso && dso_id__empty(&dso->id) && !dso_id__empty(id))
282 		dso__inject_id(dso, id);
283 
284 	return dso ? dso : __dsos__addnew_id(dsos, name, id);
285 }
286 
287 struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
288 {
289 	struct dso *dso;
290 	down_write(&dsos->lock);
291 	dso = dso__get(__dsos__findnew_id(dsos, name, id));
292 	up_write(&dsos->lock);
293 	return dso;
294 }
295 
296 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
297 			       bool (skip)(struct dso *dso, int parm), int parm)
298 {
299 	struct dso *pos;
300 	size_t ret = 0;
301 
302 	list_for_each_entry(pos, head, node) {
303 		char sbuild_id[SBUILD_ID_SIZE];
304 
305 		if (skip && skip(pos, parm))
306 			continue;
307 		build_id__sprintf(&pos->bid, sbuild_id);
308 		ret += fprintf(fp, "%-40s %s\n", sbuild_id, pos->long_name);
309 	}
310 	return ret;
311 }
312 
313 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
314 {
315 	struct dso *pos;
316 	size_t ret = 0;
317 
318 	list_for_each_entry(pos, head, node) {
319 		ret += dso__fprintf(pos, fp);
320 	}
321 
322 	return ret;
323 }
324