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