1#include <stdio.h>
  2#include <stdlib.h>
  3#include <string.h>
  4
  5#include <linux/kernel.h>
  6
  7#include "util/dso.h"
  8#include "util/util.h"
  9#include "util/debug.h"
 10
 11#ifdef HAVE_LIBBFD_SUPPORT
 12
 13/*
 14 * Implement addr2line using libbfd.
 15 */
 16#define PACKAGE "perf"
 17#include <bfd.h>
 18
 19struct a2l_data {
 20	const char 	*input;
 21	unsigned long 	addr;
 22
 23	bool 		found;
 24	const char 	*filename;
 25	const char 	*funcname;
 26	unsigned 	line;
 27
 28	bfd 		*abfd;
 29	asymbol 	**syms;
 30};
 31
 32static int bfd_error(const char *string)
 33{
 34	const char *errmsg;
 35
 36	errmsg = bfd_errmsg(bfd_get_error());
 37	fflush(stdout);
 38
 39	if (string)
 40		pr_debug("%s: %s\n", string, errmsg);
 41	else
 42		pr_debug("%s\n", errmsg);
 43
 44	return -1;
 45}
 46
 47static int slurp_symtab(bfd *abfd, struct a2l_data *a2l)
 48{
 49	long storage;
 50	long symcount;
 51	asymbol **syms;
 52	bfd_boolean dynamic = FALSE;
 53
 54	if ((bfd_get_file_flags(abfd) & HAS_SYMS) == 0)
 55		return bfd_error(bfd_get_filename(abfd));
 56
 57	storage = bfd_get_symtab_upper_bound(abfd);
 58	if (storage == 0L) {
 59		storage = bfd_get_dynamic_symtab_upper_bound(abfd);
 60		dynamic = TRUE;
 61	}
 62	if (storage < 0L)
 63		return bfd_error(bfd_get_filename(abfd));
 64
 65	syms = malloc(storage);
 66	if (dynamic)
 67		symcount = bfd_canonicalize_dynamic_symtab(abfd, syms);
 68	else
 69		symcount = bfd_canonicalize_symtab(abfd, syms);
 70
 71	if (symcount < 0) {
 72		free(syms);
 73		return bfd_error(bfd_get_filename(abfd));
 74	}
 75
 76	a2l->syms = syms;
 77	return 0;
 78}
 79
 80static void find_address_in_section(bfd *abfd, asection *section, void *data)
 81{
 82	bfd_vma pc, vma;
 83	bfd_size_type size;
 84	struct a2l_data *a2l = data;
 85
 86	if (a2l->found)
 87		return;
 88
 89	if ((bfd_get_section_flags(abfd, section) & SEC_ALLOC) == 0)
 90		return;
 91
 92	pc = a2l->addr;
 93	vma = bfd_get_section_vma(abfd, section);
 94	size = bfd_get_section_size(section);
 95
 96	if (pc < vma || pc >= vma + size)
 97		return;
 98
 99	a2l->found = bfd_find_nearest_line(abfd, section, a2l->syms, pc - vma,
100					   &a2l->filename, &a2l->funcname,
101					   &a2l->line);
102}
103
104static struct a2l_data *addr2line_init(const char *path)
105{
106	bfd *abfd;
107	struct a2l_data *a2l = NULL;
108
109	abfd = bfd_openr(path, NULL);
110	if (abfd == NULL)
111		return NULL;
112
113	if (!bfd_check_format(abfd, bfd_object))
114		goto out;
115
116	a2l = zalloc(sizeof(*a2l));
117	if (a2l == NULL)
118		goto out;
119
120	a2l->abfd = abfd;
121	a2l->input = strdup(path);
122	if (a2l->input == NULL)
123		goto out;
124
125	if (slurp_symtab(abfd, a2l))
126		goto out;
127
128	return a2l;
129
130out:
131	if (a2l) {
132		zfree((char **)&a2l->input);
133		free(a2l);
134	}
135	bfd_close(abfd);
136	return NULL;
137}
138
139static void addr2line_cleanup(struct a2l_data *a2l)
140{
141	if (a2l->abfd)
142		bfd_close(a2l->abfd);
143	zfree((char **)&a2l->input);
144	zfree(&a2l->syms);
145	free(a2l);
146}
147
148static int addr2line(const char *dso_name, unsigned long addr,
149		     char **file, unsigned int *line, struct dso *dso)
150{
151	int ret = 0;
152	struct a2l_data *a2l = dso->a2l;
153
154	if (!a2l) {
155		dso->a2l = addr2line_init(dso_name);
156		a2l = dso->a2l;
157	}
158
159	if (a2l == NULL) {
160		pr_warning("addr2line_init failed for %s\n", dso_name);
161		return 0;
162	}
163
164	a2l->addr = addr;
165	a2l->found = false;
166
167	bfd_map_over_sections(a2l->abfd, find_address_in_section, a2l);
168
169	if (a2l->found && a2l->filename) {
170		*file = strdup(a2l->filename);
171		*line = a2l->line;
172
173		if (*file)
174			ret = 1;
175	}
176
177	return ret;
178}
179
180void dso__free_a2l(struct dso *dso)
181{
182	struct a2l_data *a2l = dso->a2l;
183
184	if (!a2l)
185		return;
186
187	addr2line_cleanup(a2l);
188
189	dso->a2l = NULL;
190}
191
192#else /* HAVE_LIBBFD_SUPPORT */
193
194static int addr2line(const char *dso_name, unsigned long addr,
195		     char **file, unsigned int *line_nr,
196		     struct dso *dso __maybe_unused)
197{
198	FILE *fp;
199	char cmd[PATH_MAX];
200	char *filename = NULL;
201	size_t len;
202	char *sep;
203	int ret = 0;
204
205	scnprintf(cmd, sizeof(cmd), "addr2line -e %s %016"PRIx64,
206		  dso_name, addr);
207
208	fp = popen(cmd, "r");
209	if (fp == NULL) {
210		pr_warning("popen failed for %s\n", dso_name);
211		return 0;
212	}
213
214	if (getline(&filename, &len, fp) < 0 || !len) {
215		pr_warning("addr2line has no output for %s\n", dso_name);
216		goto out;
217	}
218
219	sep = strchr(filename, '\n');
220	if (sep)
221		*sep = '\0';
222
223	if (!strcmp(filename, "??:0")) {
224		pr_debug("no debugging info in %s\n", dso_name);
225		free(filename);
226		goto out;
227	}
228
229	sep = strchr(filename, ':');
230	if (sep) {
231		*sep++ = '\0';
232		*file = filename;
233		*line_nr = strtoul(sep, NULL, 0);
234		ret = 1;
235	}
236out:
237	pclose(fp);
238	return ret;
239}
240
241void dso__free_a2l(struct dso *dso __maybe_unused)
242{
243}
244
245#endif /* HAVE_LIBBFD_SUPPORT */
246
247/*
248 * Number of addr2line failures (without success) before disabling it for that
249 * dso.
250 */
251#define A2L_FAIL_LIMIT 123
252
253char *get_srcline(struct dso *dso, unsigned long addr)
254{
255	char *file = NULL;
256	unsigned line = 0;
257	char *srcline;
258	const char *dso_name;
259
260	if (!dso->has_srcline)
261		return SRCLINE_UNKNOWN;
262
263	if (dso->symsrc_filename)
264		dso_name = dso->symsrc_filename;
265	else
266		dso_name = dso->long_name;
267
268	if (dso_name[0] == '[')
269		goto out;
270
271	if (!strncmp(dso_name, "/tmp/perf-", 10))
272		goto out;
273
274	if (!addr2line(dso_name, addr, &file, &line, dso))
275		goto out;
276
277	if (asprintf(&srcline, "%s:%u", file, line) < 0) {
278		free(file);
279		goto out;
280	}
281
282	dso->a2l_fails = 0;
283
284	free(file);
285	return srcline;
286
287out:
288	if (dso->a2l_fails && ++dso->a2l_fails > A2L_FAIL_LIMIT) {
289		dso->has_srcline = 0;
290		dso__free_a2l(dso);
291	}
292	return SRCLINE_UNKNOWN;
293}
294
295void free_srcline(char *srcline)
296{
297	if (srcline && strcmp(srcline, SRCLINE_UNKNOWN) != 0)
298		free(srcline);
299}