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