xref: /openbmc/linux/tools/perf/util/dsos.c (revision fb8d6c8d)
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 
12 bool __dsos__read_build_ids(struct list_head *head, bool with_hits)
13 {
14 	bool have_build_id = false;
15 	struct dso *pos;
16 	struct nscookie nsc;
17 
18 	list_for_each_entry(pos, head, node) {
19 		if (with_hits && !pos->hit && !dso__is_vdso(pos))
20 			continue;
21 		if (pos->has_build_id) {
22 			have_build_id = true;
23 			continue;
24 		}
25 		nsinfo__mountns_enter(pos->nsinfo, &nsc);
26 		if (filename__read_build_id(pos->long_name, pos->build_id,
27 					    sizeof(pos->build_id)) > 0) {
28 			have_build_id	  = true;
29 			pos->has_build_id = true;
30 		}
31 		nsinfo__mountns_exit(&nsc);
32 	}
33 
34 	return have_build_id;
35 }
36 
37 /*
38  * Find a matching entry and/or link current entry to RB tree.
39  * Either one of the dso or name parameter must be non-NULL or the
40  * function will not work.
41  */
42 struct dso *__dsos__findnew_link_by_longname(struct rb_root *root, struct dso *dso, const char *name)
43 {
44 	struct rb_node **p = &root->rb_node;
45 	struct rb_node  *parent = NULL;
46 
47 	if (!name)
48 		name = dso->long_name;
49 	/*
50 	 * Find node with the matching name
51 	 */
52 	while (*p) {
53 		struct dso *this = rb_entry(*p, struct dso, rb_node);
54 		int rc = strcmp(name, this->long_name);
55 
56 		parent = *p;
57 		if (rc == 0) {
58 			/*
59 			 * In case the new DSO is a duplicate of an existing
60 			 * one, print a one-time warning & put the new entry
61 			 * at the end of the list of duplicates.
62 			 */
63 			if (!dso || (dso == this))
64 				return this;	/* Find matching dso */
65 			/*
66 			 * The core kernel DSOs may have duplicated long name.
67 			 * In this case, the short name should be different.
68 			 * Comparing the short names to differentiate the DSOs.
69 			 */
70 			rc = strcmp(dso->short_name, this->short_name);
71 			if (rc == 0) {
72 				pr_err("Duplicated dso name: %s\n", name);
73 				return NULL;
74 			}
75 		}
76 		if (rc < 0)
77 			p = &parent->rb_left;
78 		else
79 			p = &parent->rb_right;
80 	}
81 	if (dso) {
82 		/* Add new node and rebalance tree */
83 		rb_link_node(&dso->rb_node, parent, p);
84 		rb_insert_color(&dso->rb_node, root);
85 		dso->root = root;
86 	}
87 	return NULL;
88 }
89 
90 void __dsos__add(struct dsos *dsos, struct dso *dso)
91 {
92 	list_add_tail(&dso->node, &dsos->head);
93 	__dsos__findnew_link_by_longname(&dsos->root, dso, NULL);
94 	/*
95 	 * It is now in the linked list, grab a reference, then garbage collect
96 	 * this when needing memory, by looking at LRU dso instances in the
97 	 * list with atomic_read(&dso->refcnt) == 1, i.e. no references
98 	 * anywhere besides the one for the list, do, under a lock for the
99 	 * list: remove it from the list, then a dso__put(), that probably will
100 	 * be the last and will then call dso__delete(), end of life.
101 	 *
102 	 * That, or at the end of the 'struct machine' lifetime, when all
103 	 * 'struct dso' instances will be removed from the list, in
104 	 * dsos__exit(), if they have no other reference from some other data
105 	 * structure.
106 	 *
107 	 * E.g.: after processing a 'perf.data' file and storing references
108 	 * to objects instantiated while processing events, we will have
109 	 * references to the 'thread', 'map', 'dso' structs all from 'struct
110 	 * hist_entry' instances, but we may not need anything not referenced,
111 	 * so we might as well call machines__exit()/machines__delete() and
112 	 * garbage collect it.
113 	 */
114 	dso__get(dso);
115 }
116 
117 void dsos__add(struct dsos *dsos, struct dso *dso)
118 {
119 	down_write(&dsos->lock);
120 	__dsos__add(dsos, dso);
121 	up_write(&dsos->lock);
122 }
123 
124 struct dso *__dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
125 {
126 	struct dso *pos;
127 
128 	if (cmp_short) {
129 		list_for_each_entry(pos, &dsos->head, node)
130 			if (strcmp(pos->short_name, name) == 0)
131 				return pos;
132 		return NULL;
133 	}
134 	return __dsos__findnew_by_longname(&dsos->root, name);
135 }
136 
137 struct dso *dsos__find(struct dsos *dsos, const char *name, bool cmp_short)
138 {
139 	struct dso *dso;
140 	down_read(&dsos->lock);
141 	dso = __dsos__find(dsos, name, cmp_short);
142 	up_read(&dsos->lock);
143 	return dso;
144 }
145 
146 static void dso__set_basename(struct dso *dso)
147 {
148 	char *base, *lname;
149 	int tid;
150 
151 	if (sscanf(dso->long_name, "/tmp/perf-%d.map", &tid) == 1) {
152 		if (asprintf(&base, "[JIT] tid %d", tid) < 0)
153 			return;
154 	} else {
155 	      /*
156 	       * basename() may modify path buffer, so we must pass
157                * a copy.
158                */
159 		lname = strdup(dso->long_name);
160 		if (!lname)
161 			return;
162 
163 		/*
164 		 * basename() may return a pointer to internal
165 		 * storage which is reused in subsequent calls
166 		 * so copy the result.
167 		 */
168 		base = strdup(basename(lname));
169 
170 		free(lname);
171 
172 		if (!base)
173 			return;
174 	}
175 	dso__set_short_name(dso, base, true);
176 }
177 
178 struct dso *__dsos__addnew(struct dsos *dsos, const char *name)
179 {
180 	struct dso *dso = dso__new(name);
181 
182 	if (dso != NULL) {
183 		__dsos__add(dsos, dso);
184 		dso__set_basename(dso);
185 		/* Put dso here because __dsos_add already got it */
186 		dso__put(dso);
187 	}
188 	return dso;
189 }
190 
191 struct dso *__dsos__findnew(struct dsos *dsos, const char *name)
192 {
193 	struct dso *dso = __dsos__find(dsos, name, false);
194 
195 	return dso ? dso : __dsos__addnew(dsos, name);
196 }
197 
198 struct dso *dsos__findnew(struct dsos *dsos, const char *name)
199 {
200 	struct dso *dso;
201 	down_write(&dsos->lock);
202 	dso = dso__get(__dsos__findnew(dsos, name));
203 	up_write(&dsos->lock);
204 	return dso;
205 }
206 
207 size_t __dsos__fprintf_buildid(struct list_head *head, FILE *fp,
208 			       bool (skip)(struct dso *dso, int parm), int parm)
209 {
210 	struct dso *pos;
211 	size_t ret = 0;
212 
213 	list_for_each_entry(pos, head, node) {
214 		if (skip && skip(pos, parm))
215 			continue;
216 		ret += dso__fprintf_buildid(pos, fp);
217 		ret += fprintf(fp, " %s\n", pos->long_name);
218 	}
219 	return ret;
220 }
221 
222 size_t __dsos__fprintf(struct list_head *head, FILE *fp)
223 {
224 	struct dso *pos;
225 	size_t ret = 0;
226 
227 	list_for_each_entry(pos, head, node) {
228 		ret += dso__fprintf(pos, fp);
229 	}
230 
231 	return ret;
232 }
233