1
2#include "symbol.h"
3#include "util.h"
4
5#include <errno.h>
6#include <unistd.h>
7#include <stdio.h>
8#include <fcntl.h>
9#include <string.h>
10#include <stdlib.h>
11#include <byteswap.h>
12#include <sys/stat.h>
13#include <linux/zalloc.h>
14
15static bool check_need_swap(int file_endian)
16{
17 const int data = 1;
18 u8 *check = (u8 *)&data;
19 int host_endian;
20
21 if (check[0] == 1)
22 host_endian = ELFDATA2LSB;
23 else
24 host_endian = ELFDATA2MSB;
25
26 return host_endian != file_endian;
27}
28
29#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
30
31#define NT_GNU_BUILD_ID 3
32
33static int read_build_id(void *note_data, size_t note_len, void *bf,
34 size_t size, bool need_swap)
35{
36 struct {
37 u32 n_namesz;
38 u32 n_descsz;
39 u32 n_type;
40 } *nhdr;
41 void *ptr;
42
43 ptr = note_data;
44 while (ptr < (note_data + note_len)) {
45 const char *name;
46 size_t namesz, descsz;
47
48 nhdr = ptr;
49 if (need_swap) {
50 nhdr->n_namesz = bswap_32(nhdr->n_namesz);
51 nhdr->n_descsz = bswap_32(nhdr->n_descsz);
52 nhdr->n_type = bswap_32(nhdr->n_type);
53 }
54
55 namesz = NOTE_ALIGN(nhdr->n_namesz);
56 descsz = NOTE_ALIGN(nhdr->n_descsz);
57
58 ptr += sizeof(*nhdr);
59 name = ptr;
60 ptr += namesz;
61 if (nhdr->n_type == NT_GNU_BUILD_ID &&
62 nhdr->n_namesz == sizeof("GNU")) {
63 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
64 size_t sz = min(size, descsz);
65 memcpy(bf, ptr, sz);
66 memset(bf + sz, 0, size - sz);
67 return 0;
68 }
69 }
70 ptr += descsz;
71 }
72
73 return -1;
74}
75
76int filename__read_debuglink(const char *filename __maybe_unused,
77 char *debuglink __maybe_unused,
78 size_t size __maybe_unused)
79{
80 return -1;
81}
82
83
84
85
86int filename__read_build_id(const char *filename, void *bf, size_t size)
87{
88 FILE *fp;
89 int ret = -1;
90 bool need_swap = false;
91 u8 e_ident[EI_NIDENT];
92 size_t buf_size;
93 void *buf;
94 int i;
95
96 fp = fopen(filename, "r");
97 if (fp == NULL)
98 return -1;
99
100 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
101 goto out;
102
103 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
104 e_ident[EI_VERSION] != EV_CURRENT)
105 goto out;
106
107 need_swap = check_need_swap(e_ident[EI_DATA]);
108
109
110 fseek(fp, 0, SEEK_SET);
111
112 if (e_ident[EI_CLASS] == ELFCLASS32) {
113 Elf32_Ehdr ehdr;
114 Elf32_Phdr *phdr;
115
116 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
117 goto out;
118
119 if (need_swap) {
120 ehdr.e_phoff = bswap_32(ehdr.e_phoff);
121 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
122 ehdr.e_phnum = bswap_16(ehdr.e_phnum);
123 }
124
125 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
126 buf = malloc(buf_size);
127 if (buf == NULL)
128 goto out;
129
130 fseek(fp, ehdr.e_phoff, SEEK_SET);
131 if (fread(buf, buf_size, 1, fp) != 1)
132 goto out_free;
133
134 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
135 void *tmp;
136 long offset;
137
138 if (need_swap) {
139 phdr->p_type = bswap_32(phdr->p_type);
140 phdr->p_offset = bswap_32(phdr->p_offset);
141 phdr->p_filesz = bswap_32(phdr->p_filesz);
142 }
143
144 if (phdr->p_type != PT_NOTE)
145 continue;
146
147 buf_size = phdr->p_filesz;
148 offset = phdr->p_offset;
149 tmp = realloc(buf, buf_size);
150 if (tmp == NULL)
151 goto out_free;
152
153 buf = tmp;
154 fseek(fp, offset, SEEK_SET);
155 if (fread(buf, buf_size, 1, fp) != 1)
156 goto out_free;
157
158 ret = read_build_id(buf, buf_size, bf, size, need_swap);
159 if (ret == 0)
160 ret = size;
161 break;
162 }
163 } else {
164 Elf64_Ehdr ehdr;
165 Elf64_Phdr *phdr;
166
167 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
168 goto out;
169
170 if (need_swap) {
171 ehdr.e_phoff = bswap_64(ehdr.e_phoff);
172 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
173 ehdr.e_phnum = bswap_16(ehdr.e_phnum);
174 }
175
176 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
177 buf = malloc(buf_size);
178 if (buf == NULL)
179 goto out;
180
181 fseek(fp, ehdr.e_phoff, SEEK_SET);
182 if (fread(buf, buf_size, 1, fp) != 1)
183 goto out_free;
184
185 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
186 void *tmp;
187 long offset;
188
189 if (need_swap) {
190 phdr->p_type = bswap_32(phdr->p_type);
191 phdr->p_offset = bswap_64(phdr->p_offset);
192 phdr->p_filesz = bswap_64(phdr->p_filesz);
193 }
194
195 if (phdr->p_type != PT_NOTE)
196 continue;
197
198 buf_size = phdr->p_filesz;
199 offset = phdr->p_offset;
200 tmp = realloc(buf, buf_size);
201 if (tmp == NULL)
202 goto out_free;
203
204 buf = tmp;
205 fseek(fp, offset, SEEK_SET);
206 if (fread(buf, buf_size, 1, fp) != 1)
207 goto out_free;
208
209 ret = read_build_id(buf, buf_size, bf, size, need_swap);
210 if (ret == 0)
211 ret = size;
212 break;
213 }
214 }
215out_free:
216 free(buf);
217out:
218 fclose(fp);
219 return ret;
220}
221
222int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
223{
224 int fd;
225 int ret = -1;
226 struct stat stbuf;
227 size_t buf_size;
228 void *buf;
229
230 fd = open(filename, O_RDONLY);
231 if (fd < 0)
232 return -1;
233
234 if (fstat(fd, &stbuf) < 0)
235 goto out;
236
237 buf_size = stbuf.st_size;
238 buf = malloc(buf_size);
239 if (buf == NULL)
240 goto out;
241
242 if (read(fd, buf, buf_size) != (ssize_t) buf_size)
243 goto out_free;
244
245 ret = read_build_id(buf, buf_size, build_id, size, false);
246out_free:
247 free(buf);
248out:
249 close(fd);
250 return ret;
251}
252
253int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
254 enum dso_binary_type type)
255{
256 int fd = open(name, O_RDONLY);
257 if (fd < 0)
258 goto out_errno;
259
260 ss->name = strdup(name);
261 if (!ss->name)
262 goto out_close;
263
264 ss->fd = fd;
265 ss->type = type;
266
267 return 0;
268out_close:
269 close(fd);
270out_errno:
271 dso->load_errno = errno;
272 return -1;
273}
274
275bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
276{
277
278 return true;
279}
280
281bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
282{
283 return false;
284}
285
286void symsrc__destroy(struct symsrc *ss)
287{
288 zfree(&ss->name);
289 close(ss->fd);
290}
291
292int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
293 struct symsrc *ss __maybe_unused)
294{
295 return 0;
296}
297
298static int fd__is_64_bit(int fd)
299{
300 u8 e_ident[EI_NIDENT];
301
302 if (lseek(fd, 0, SEEK_SET))
303 return -1;
304
305 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
306 return -1;
307
308 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
309 e_ident[EI_VERSION] != EV_CURRENT)
310 return -1;
311
312 return e_ident[EI_CLASS] == ELFCLASS64;
313}
314
315enum dso_type dso__type_fd(int fd)
316{
317 Elf64_Ehdr ehdr;
318 int ret;
319
320 ret = fd__is_64_bit(fd);
321 if (ret < 0)
322 return DSO__TYPE_UNKNOWN;
323
324 if (ret)
325 return DSO__TYPE_64BIT;
326
327 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
328 return DSO__TYPE_UNKNOWN;
329
330 if (ehdr.e_machine == EM_X86_64)
331 return DSO__TYPE_X32BIT;
332
333 return DSO__TYPE_32BIT;
334}
335
336int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
337 struct symsrc *ss,
338 struct symsrc *runtime_ss __maybe_unused,
339 int kmodule __maybe_unused)
340{
341 unsigned char build_id[BUILD_ID_SIZE];
342 int ret;
343
344 ret = fd__is_64_bit(ss->fd);
345 if (ret >= 0)
346 dso->is_64_bit = ret;
347
348 if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {
349 dso__set_build_id(dso, build_id);
350 }
351 return 0;
352}
353
354int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
355 mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
356 bool *is_64_bit __maybe_unused)
357{
358 return -1;
359}
360
361int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
362{
363 return -1;
364}
365
366void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
367{
368}
369
370int kcore_copy(const char *from_dir __maybe_unused,
371 const char *to_dir __maybe_unused)
372{
373 return -1;
374}
375
376void symbol__elf_init(void)
377{
378}
379
380char *dso__demangle_sym(struct dso *dso __maybe_unused,
381 int kmodule __maybe_unused,
382 const char *elf_name __maybe_unused)
383{
384 return NULL;
385}
386
