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