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 
__dso_id__cmp(struct dso_id * a,struct dso_id * b)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 	/*
27 	 * Synthesized MMAP events have zero ino_generation, avoid comparing
28 	 * them with MMAP events with actual ino_generation.
29 	 *
30 	 * I found it harmful because the mismatch resulted in a new
31 	 * dso that did not have a build ID whereas the original dso did have a
32 	 * build ID. The build ID was essential because the object was not found
33 	 * otherwise. - Adrian
34 	 */
35 	if (a->ino_generation && b->ino_generation) {
36 		if (a->ino_generation > b->ino_generation) return -1;
37 		if (a->ino_generation < b->ino_generation) return 1;
38 	}
39 
40 	return 0;
41 }
42 
dso_id__empty(struct dso_id * id)43 static bool dso_id__empty(struct dso_id *id)
44 {
45 	if (!id)
46 		return true;
47 
48 	return !id->maj && !id->min && !id->ino && !id->ino_generation;
49 }
50 
dso__inject_id(struct dso * dso,struct dso_id * id)51 static void dso__inject_id(struct dso *dso, struct dso_id *id)
52 {
53 	dso->id.maj = id->maj;
54 	dso->id.min = id->min;
55 	dso->id.ino = id->ino;
56 	dso->id.ino_generation = id->ino_generation;
57 }
58 
dso_id__cmp(struct dso_id * a,struct dso_id * b)59 static int dso_id__cmp(struct dso_id *a, struct dso_id *b)
60 {
61 	/*
62 	 * The second is always dso->id, so zeroes if not set, assume passing
63 	 * NULL for a means a zeroed id
64 	 */
65 	if (dso_id__empty(a) || dso_id__empty(b))
66 		return 0;
67 
68 	return __dso_id__cmp(a, b);
69 }
70 
dso__cmp_id(struct dso * a,struct dso * b)71 int dso__cmp_id(struct dso *a, struct dso *b)
72 {
73 	return __dso_id__cmp(&a->id, &b->id);
74 }
75 
__dsos__read_build_ids(struct list_head * head,bool with_hits)76 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
77 {
78 	bool have_build_id = false;
79 	struct dso *pos;
80 	struct nscookie nsc;
81 
82 	list_for_each_entry(pos, head, node) {
83 		if (with_hits && !pos->hit && !dso__is_vdso(pos))
84 			continue;
85 		if (pos->has_build_id) {
86 			have_build_id = true;
87 			continue;
88 		}
89 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
90 		if (filename__read_build_id(pos->long_name, &pos->bid) > 0) {
91 			have_build_id	  = true;
92 			pos->has_build_id = true;
93 		} else if (errno == ENOENT && pos->nsinfo) {
94 			char *new_name = dso__filename_with_chroot(pos, pos->long_name);
95 
96 			if (new_name && filename__read_build_id(new_name,
97 								&pos->bid) > 0) {
98 				have_build_id = true;
99 				pos->has_build_id = true;
100 			}
101 			free(new_name);
102 		}
103 		nsinfo__mountns_exit(&nsc);
104 	}
105 
106 	return have_build_id;
107 }
108 
__dso__cmp_long_name(const char * long_name,struct dso_id * id,struct dso * b)109 static int __dso__cmp_long_name(const char *long_name, struct dso_id *id, struct dso *b)
110 {
111 	int rc = strcmp(long_name, b->long_name);
112 	return rc ?: dso_id__cmp(id, &b->id);
113 }
114 
__dso__cmp_short_name(const char * short_name,struct dso_id * id,struct dso * b)115 static int __dso__cmp_short_name(const char *short_name, struct dso_id *id, struct dso *b)
116 {
117 	int rc = strcmp(short_name, b->short_name);
118 	return rc ?: dso_id__cmp(id, &b->id);
119 }
120 
dso__cmp_short_name(struct dso * a,struct dso * b)121 static int dso__cmp_short_name(struct dso *a, struct dso *b)
122 {
123 	return __dso__cmp_short_name(a->short_name, &a->id, b);
124 }
125 
126 /*
127  * Find a matching entry and/or link current entry to RB tree.
128  * Either one of the dso or name parameter must be non-NULL or the
129  * function will not work.
130  */
__dsos__findnew_link_by_longname_id(struct rb_root * root,struct dso * dso,const char * name,struct dso_id * id)131 struct dso *__dsos__findnew_link_by_longname_id(struct rb_root *root, struct dso *dso,
132 						const char *name, struct dso_id *id)
133 {
134 	struct rb_node **p = &root->rb_node;
135 	struct rb_node  *parent = NULL;
136 
137 	if (!name)
138 		name = dso->long_name;
139 	/*
140 	 * Find node with the matching name
141 	 */
142 	while (*p) {
143 		struct dso *this = rb_entry(*p, struct dso, rb_node);
144 		int rc = __dso__cmp_long_name(name, id, this);
145 
146 		parent = *p;
147 		if (rc == 0) {
148 			/*
149 			 * In case the new DSO is a duplicate of an existing
150 			 * one, print a one-time warning & put the new entry
151 			 * at the end of the list of duplicates.
152 			 */
153 			if (!dso || (dso == this))
154 				return this;	/* Find matching dso */
155 			/*
156 			 * The core kernel DSOs may have duplicated long name.
157 			 * In this case, the short name should be different.
158 			 * Comparing the short names to differentiate the DSOs.
159 			 */
160 			rc = dso__cmp_short_name(dso, this);
161 			if (rc == 0) {
162 				pr_err("Duplicated dso name: %s\n", name);
163 				return NULL;
164 			}
165 		}
166 		if (rc < 0)
167 			p = &parent->rb_left;
168 		else
169 			p = &parent->rb_right;
170 	}
171 	if (dso) {
172 		/* Add new node and rebalance tree */
173 		rb_link_node(&dso->rb_node, parent, p);
174 		rb_insert_color(&dso->rb_node, root);
175 		dso->root = root;
176 	}
177 	return NULL;
178 }
179 
__dsos__add(struct dsos * dsos,struct dso * dso)180 void __dsos__add(struct dsos *dsos, struct dso *dso)
181 {
182 	list_add_tail(&dso->node, &dsos->head);
183 	__dsos__findnew_link_by_longname_id(&dsos->root, dso, NULL, &dso->id);
184 	/*
185 	 * It is now in the linked list, grab a reference, then garbage collect
186 	 * this when needing memory, by looking at LRU dso instances in the
187 	 * list with atomic_read(&dso->refcnt) == 1, i.e. no references
188 	 * anywhere besides the one for the list, do, under a lock for the
189 	 * list: remove it from the list, then a dso__put(), that probably will
190 	 * be the last and will then call dso__delete(), end of life.
191 	 *
192 	 * That, or at the end of the 'struct machine' lifetime, when all
193 	 * 'struct dso' instances will be removed from the list, in
194 	 * dsos__exit(), if they have no other reference from some other data
195 	 * structure.
196 	 *
197 	 * E.g.: after processing a 'perf.data' file and storing references
198 	 * to objects instantiated while processing events, we will have
199 	 * references to the 'thread', 'map', 'dso' structs all from 'struct
200 	 * hist_entry' instances, but we may not need anything not referenced,
201 	 * so we might as well call machines__exit()/machines__delete() and
202 	 * garbage collect it.
203 	 */
204 	dso__get(dso);
205 }
206 
dsos__add(struct dsos * dsos,struct dso * dso)207 void dsos__add(struct dsos *dsos, struct dso *dso)
208 {
209 	down_write(&dsos->lock);
210 	__dsos__add(dsos, dso);
211 	up_write(&dsos->lock);
212 }
213 
__dsos__findnew_by_longname_id(struct rb_root * root,const char * name,struct dso_id * id)214 static struct dso *__dsos__findnew_by_longname_id(struct rb_root *root, const char *name, struct dso_id *id)
215 {
216 	return __dsos__findnew_link_by_longname_id(root, NULL, name, id);
217 }
218 
__dsos__find_id(struct dsos * dsos,const char * name,struct dso_id * id,bool cmp_short)219 static struct dso *__dsos__find_id(struct dsos *dsos, const char *name, struct dso_id *id, bool cmp_short)
220 {
221 	struct dso *pos;
222 
223 	if (cmp_short) {
224 		list_for_each_entry(pos, &dsos->head, node)
225 			if (__dso__cmp_short_name(name, id, pos) == 0)
226 				return pos;
227 		return NULL;
228 	}
229 	return __dsos__findnew_by_longname_id(&dsos->root, name, id);
230 }
231 
__dsos__find(struct dsos * dsos,const char * name,bool cmp_short)232 struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
233 {
234 	return __dsos__find_id(dsos, name, NULL, cmp_short);
235 }
236 
dso__set_basename(struct dso * dso)237 static void dso__set_basename(struct dso *dso)
238 {
239 	char *base, *lname;
240 	int tid;
241 
242 	if (sscanf(dso->long_name, "/tmp/perf-%d.map", &tid) == 1) {
243 		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
244 			return;
245 	} else {
246 	      /*
247 	       * basename() may modify path buffer, so we must pass
248                * a copy.
249                */
250 		lname = strdup(dso->long_name);
251 		if (!lname)
252 			return;
253 
254 		/*
255 		 * basename() may return a pointer to internal
256 		 * storage which is reused in subsequent calls
257 		 * so copy the result.
258 		 */
259 		base = strdup(basename(lname));
260 
261 		free(lname);
262 
263 		if (!base)
264 			return;
265 	}
266 	dso__set_short_name(dso, base, true);
267 }
268 
__dsos__addnew_id(struct dsos * dsos,const char * name,struct dso_id * id)269 static struct dso *__dsos__addnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
270 {
271 	struct dso *dso = dso__new_id(name, id);
272 
273 	if (dso != NULL) {
274 		__dsos__add(dsos, dso);
275 		dso__set_basename(dso);
276 		/* Put dso here because __dsos_add already got it */
277 		dso__put(dso);
278 	}
279 	return dso;
280 }
281 
__dsos__addnew(struct dsos * dsos,const char * name)282 struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
283 {
284 	return __dsos__addnew_id(dsos, name, NULL);
285 }
286 
__dsos__findnew_id(struct dsos * dsos,const char * name,struct dso_id * id)287 static struct dso *__dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
288 {
289 	struct dso *dso = __dsos__find_id(dsos, name, id, false);
290 
291 	if (dso && dso_id__empty(&dso->id) && !dso_id__empty(id))
292 		dso__inject_id(dso, id);
293 
294 	return dso ? dso : __dsos__addnew_id(dsos, name, id);
295 }
296 
dsos__findnew_id(struct dsos * dsos,const char * name,struct dso_id * id)297 struct dso *dsos__findnew_id(struct dsos *dsos, const char *name, struct dso_id *id)
298 {
299 	struct dso *dso;
300 	down_write(&dsos->lock);
301 	dso = dso__get(__dsos__findnew_id(dsos, name, id));
302 	up_write(&dsos->lock);
303 	return dso;
304 }
305 
__dsos__fprintf_buildid(struct list_head * head,FILE * fp,bool (skip)(struct dso * dso,int parm),int parm)306 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
307 			       bool (skip)(struct dso *dso, int parm), int parm)
308 {
309 	struct dso *pos;
310 	size_t ret = 0;
311 
312 	list_for_each_entry(pos, head, node) {
313 		char sbuild_id[SBUILD_ID_SIZE];
314 
315 		if (skip && skip(pos, parm))
316 			continue;
317 		build_id__sprintf(&pos->bid, sbuild_id);
318 		ret += fprintf(fp, "%-40s %s\n", sbuild_id, pos->long_name);
319 	}
320 	return ret;
321 }
322 
__dsos__fprintf(struct list_head * head,FILE * fp)323 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
324 {
325 	struct dso *pos;
326 	size_t ret = 0;
327 
328 	list_for_each_entry(pos, head, node) {
329 		ret += dso__fprintf(pos, fp);
330 	}
331 
332 	return ret;
333 }
334