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