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