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