1 #include "dso.h"
2 #include "symbol.h"
3 #include "symsrc.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 #include <internal/lib.h>
15
16 static bool check_need_swap(int file_endian)
17 {
18 const int data = 1;
19 u8 *check = (u8 *)&data;
20 int host_endian;
21
22 if (check[0] == 1)
23 host_endian = ELFDATA2LSB;
24 else
25 host_endian = ELFDATA2MSB;
26
27 return host_endian != file_endian;
28 }
29
30 #define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
31
32 #define NT_GNU_BUILD_ID 3
33
34 static int read_build_id(void *note_data, size_t note_len, struct build_id *bid,
35 bool need_swap)
36 {
37 size_t size = sizeof(bid->data);
38 struct {
39 u32 n_namesz;
40 u32 n_descsz;
41 u32 n_type;
42 } *nhdr;
43 void *ptr;
44
45 ptr = note_data;
46 while (ptr < (note_data + note_len)) {
47 const char *name;
48 size_t namesz, descsz;
49
50 nhdr = ptr;
51 if (need_swap) {
52 nhdr->n_namesz = bswap_32(nhdr->n_namesz);
53 nhdr->n_descsz = bswap_32(nhdr->n_descsz);
54 nhdr->n_type = bswap_32(nhdr->n_type);
55 }
56
57 namesz = NOTE_ALIGN(nhdr->n_namesz);
58 descsz = NOTE_ALIGN(nhdr->n_descsz);
59
60 ptr += sizeof(*nhdr);
61 name = ptr;
62 ptr += namesz;
63 if (nhdr->n_type == NT_GNU_BUILD_ID &&
64 nhdr->n_namesz == sizeof("GNU")) {
65 if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
66 size_t sz = min(size, descsz);
67 memcpy(bid->data, ptr, sz);
68 memset(bid->data + sz, 0, size - sz);
69 bid->size = sz;
70 return 0;
71 }
72 }
73 ptr += descsz;
74 }
75
76 return -1;
77 }
78
79 int filename__read_debuglink(const char *filename __maybe_unused,
80 char *debuglink __maybe_unused,
81 size_t size __maybe_unused)
82 {
83 return -1;
84 }
85
86 /*
87 * Just try PT_NOTE header otherwise fails
88 */
89 int filename__read_build_id(const char *filename, struct build_id *bid)
90 {
91 FILE *fp;
92 int ret = -1;
93 bool need_swap = false;
94 u8 e_ident[EI_NIDENT];
95 size_t buf_size;
96 void *buf;
97 int i;
98
99 fp = fopen(filename, "r");
100 if (fp == NULL)
101 return -1;
102
103 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
104 goto out;
105
106 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
107 e_ident[EI_VERSION] != EV_CURRENT)
108 goto out;
109
110 need_swap = check_need_swap(e_ident[EI_DATA]);
111
112 /* for simplicity */
113 fseek(fp, 0, SEEK_SET);
114
115 if (e_ident[EI_CLASS] == ELFCLASS32) {
116 Elf32_Ehdr ehdr;
117 Elf32_Phdr *phdr;
118
119 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
120 goto out;
121
122 if (need_swap) {
123 ehdr.e_phoff = bswap_32(ehdr.e_phoff);
124 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
125 ehdr.e_phnum = bswap_16(ehdr.e_phnum);
126 }
127
128 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
129 buf = malloc(buf_size);
130 if (buf == NULL)
131 goto out;
132
133 fseek(fp, ehdr.e_phoff, SEEK_SET);
134 if (fread(buf, buf_size, 1, fp) != 1)
135 goto out_free;
136
137 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
138 void *tmp;
139 long offset;
140
141 if (need_swap) {
142 phdr->p_type = bswap_32(phdr->p_type);
143 phdr->p_offset = bswap_32(phdr->p_offset);
144 phdr->p_filesz = bswap_32(phdr->p_filesz);
145 }
146
147 if (phdr->p_type != PT_NOTE)
148 continue;
149
150 buf_size = phdr->p_filesz;
151 offset = phdr->p_offset;
152 tmp = realloc(buf, buf_size);
153 if (tmp == NULL)
154 goto out_free;
155
156 buf = tmp;
157 fseek(fp, offset, SEEK_SET);
158 if (fread(buf, buf_size, 1, fp) != 1)
159 goto out_free;
160
161 ret = read_build_id(buf, buf_size, bid, need_swap);
162 if (ret == 0) {
163 ret = bid->size;
164 break;
165 }
166 }
167 } else {
168 Elf64_Ehdr ehdr;
169 Elf64_Phdr *phdr;
170
171 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
172 goto out;
173
174 if (need_swap) {
175 ehdr.e_phoff = bswap_64(ehdr.e_phoff);
176 ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
177 ehdr.e_phnum = bswap_16(ehdr.e_phnum);
178 }
179
180 buf_size = ehdr.e_phentsize * ehdr.e_phnum;
181 buf = malloc(buf_size);
182 if (buf == NULL)
183 goto out;
184
185 fseek(fp, ehdr.e_phoff, SEEK_SET);
186 if (fread(buf, buf_size, 1, fp) != 1)
187 goto out_free;
188
189 for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
190 void *tmp;
191 long offset;
192
193 if (need_swap) {
194 phdr->p_type = bswap_32(phdr->p_type);
195 phdr->p_offset = bswap_64(phdr->p_offset);
196 phdr->p_filesz = bswap_64(phdr->p_filesz);
197 }
198
199 if (phdr->p_type != PT_NOTE)
200 continue;
201
202 buf_size = phdr->p_filesz;
203 offset = phdr->p_offset;
204 tmp = realloc(buf, buf_size);
205 if (tmp == NULL)
206 goto out_free;
207
208 buf = tmp;
209 fseek(fp, offset, SEEK_SET);
210 if (fread(buf, buf_size, 1, fp) != 1)
211 goto out_free;
212
213 ret = read_build_id(buf, buf_size, bid, need_swap);
214 if (ret == 0) {
215 ret = bid->size;
216 break;
217 }
218 }
219 }
220 out_free:
221 free(buf);
222 out:
223 fclose(fp);
224 return ret;
225 }
226
227 int sysfs__read_build_id(const char *filename, struct build_id *bid)
228 {
229 int fd;
230 int ret = -1;
231 struct stat stbuf;
232 size_t buf_size;
233 void *buf;
234
235 fd = open(filename, O_RDONLY);
236 if (fd < 0)
237 return -1;
238
239 if (fstat(fd, &stbuf) < 0)
240 goto out;
241
242 buf_size = stbuf.st_size;
243 buf = malloc(buf_size);
244 if (buf == NULL)
245 goto out;
246
247 if (read(fd, buf, buf_size) != (ssize_t) buf_size)
248 goto out_free;
249
250 ret = read_build_id(buf, buf_size, bid, false);
251 out_free:
252 free(buf);
253 out:
254 close(fd);
255 return ret;
256 }
257
258 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
259 enum dso_binary_type type)
260 {
261 int fd = open(name, O_RDONLY);
262 if (fd < 0)
263 goto out_errno;
264
265 ss->name = strdup(name);
266 if (!ss->name)
267 goto out_close;
268
269 ss->fd = fd;
270 ss->type = type;
271
272 return 0;
273 out_close:
274 close(fd);
275 out_errno:
276 RC_CHK_ACCESS(dso)->load_errno = errno;
277 return -1;
278 }
279
280 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
281 {
282 /* Assume all sym sources could be a runtime image. */
283 return true;
284 }
285
286 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
287 {
288 return false;
289 }
290
291 void symsrc__destroy(struct symsrc *ss)
292 {
293 zfree(&ss->name);
294 close(ss->fd);
295 }
296
297 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
298 struct symsrc *ss __maybe_unused)
299 {
300 return 0;
301 }
302
303 static int fd__is_64_bit(int fd)
304 {
305 u8 e_ident[EI_NIDENT];
306
307 if (lseek(fd, 0, SEEK_SET))
308 return -1;
309
310 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
311 return -1;
312
313 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
314 e_ident[EI_VERSION] != EV_CURRENT)
315 return -1;
316
317 return e_ident[EI_CLASS] == ELFCLASS64;
318 }
319
320 enum dso_type dso__type_fd(int fd)
321 {
322 Elf64_Ehdr ehdr;
323 int ret;
324
325 ret = fd__is_64_bit(fd);
326 if (ret < 0)
327 return DSO__TYPE_UNKNOWN;
328
329 if (ret)
330 return DSO__TYPE_64BIT;
331
332 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
333 return DSO__TYPE_UNKNOWN;
334
335 if (ehdr.e_machine == EM_X86_64)
336 return DSO__TYPE_X32BIT;
337
338 return DSO__TYPE_32BIT;
339 }
340
341 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
342 struct symsrc *ss,
343 struct symsrc *runtime_ss __maybe_unused,
344 int kmodule __maybe_unused)
345 {
346 struct build_id bid;
347 int ret;
348
349 ret = fd__is_64_bit(ss->fd);
350 if (ret >= 0)
351 RC_CHK_ACCESS(dso)->is_64_bit = ret;
352
353 if (filename__read_build_id(ss->name, &bid) > 0)
354 dso__set_build_id(dso, &bid);
355 return 0;
356 }
357
358 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
359 mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
360 bool *is_64_bit __maybe_unused)
361 {
362 return -1;
363 }
364
365 int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
366 {
367 return -1;
368 }
369
370 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
371 {
372 }
373
374 int kcore_copy(const char *from_dir __maybe_unused,
375 const char *to_dir __maybe_unused)
376 {
377 return -1;
378 }
379
380 void symbol__elf_init(void)
381 {
382 }
383
384 char *dso__demangle_sym(struct dso *dso __maybe_unused,
385 int kmodule __maybe_unused,
386 const char *elf_name __maybe_unused)
387 {
388 return NULL;
389 }
390
391 bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused)
392 {
393 return false;
394 }
395
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