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
check_need_swap(int file_endian)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
read_build_id(void * note_data,size_t note_len,struct build_id * bid,bool need_swap)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
filename__read_debuglink(const char * filename __maybe_unused,char * debuglink __maybe_unused,size_t size __maybe_unused)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 */
filename__read_build_id(const char * filename,struct build_id * bid)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, elf32;
94 u8 e_ident[EI_NIDENT];
95 int i;
96 union {
97 struct {
98 Elf32_Ehdr ehdr32;
99 Elf32_Phdr *phdr32;
100 };
101 struct {
102 Elf64_Ehdr ehdr64;
103 Elf64_Phdr *phdr64;
104 };
105 } hdrs;
106 void *phdr;
107 size_t phdr_size;
108 void *buf = NULL;
109 size_t buf_size = 0;
110
111 fp = fopen(filename, "r");
112 if (fp == NULL)
113 return -1;
114
115 if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
116 goto out;
117
118 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
119 e_ident[EI_VERSION] != EV_CURRENT)
120 goto out;
121
122 need_swap = check_need_swap(e_ident[EI_DATA]);
123 elf32 = e_ident[EI_CLASS] == ELFCLASS32;
124
125 if (fread(elf32 ? (void *)&hdrs.ehdr32 : (void *)&hdrs.ehdr64,
126 elf32 ? sizeof(hdrs.ehdr32) : sizeof(hdrs.ehdr64),
127 1, fp) != 1)
128 goto out;
129
130 if (need_swap) {
131 if (elf32) {
132 hdrs.ehdr32.e_phoff = bswap_32(hdrs.ehdr32.e_phoff);
133 hdrs.ehdr32.e_phentsize = bswap_16(hdrs.ehdr32.e_phentsize);
134 hdrs.ehdr32.e_phnum = bswap_16(hdrs.ehdr32.e_phnum);
135 } else {
136 hdrs.ehdr64.e_phoff = bswap_64(hdrs.ehdr64.e_phoff);
137 hdrs.ehdr64.e_phentsize = bswap_16(hdrs.ehdr64.e_phentsize);
138 hdrs.ehdr64.e_phnum = bswap_16(hdrs.ehdr64.e_phnum);
139 }
140 }
141 phdr_size = elf32 ? hdrs.ehdr32.e_phentsize * hdrs.ehdr32.e_phnum
142 : hdrs.ehdr64.e_phentsize * hdrs.ehdr64.e_phnum;
143 phdr = malloc(phdr_size);
144 if (phdr == NULL)
145 goto out;
146
147 fseek(fp, elf32 ? hdrs.ehdr32.e_phoff : hdrs.ehdr64.e_phoff, SEEK_SET);
148 if (fread(phdr, phdr_size, 1, fp) != 1)
149 goto out_free;
150
151 if (elf32)
152 hdrs.phdr32 = phdr;
153 else
154 hdrs.phdr64 = phdr;
155
156 for (i = 0; i < elf32 ? hdrs.ehdr32.e_phnum : hdrs.ehdr64.e_phnum; i++) {
157 size_t p_filesz;
158
159 if (need_swap) {
160 if (elf32) {
161 hdrs.phdr32[i].p_type = bswap_32(hdrs.phdr32[i].p_type);
162 hdrs.phdr32[i].p_offset = bswap_32(hdrs.phdr32[i].p_offset);
163 hdrs.phdr32[i].p_filesz = bswap_32(hdrs.phdr32[i].p_offset);
164 } else {
165 hdrs.phdr64[i].p_type = bswap_32(hdrs.phdr64[i].p_type);
166 hdrs.phdr64[i].p_offset = bswap_64(hdrs.phdr64[i].p_offset);
167 hdrs.phdr64[i].p_filesz = bswap_64(hdrs.phdr64[i].p_filesz);
168 }
169 }
170 if ((elf32 ? hdrs.phdr32[i].p_type : hdrs.phdr64[i].p_type) != PT_NOTE)
171 continue;
172
173 p_filesz = elf32 ? hdrs.phdr32[i].p_filesz : hdrs.phdr64[i].p_filesz;
174 if (p_filesz > buf_size) {
175 void *tmp;
176
177 buf_size = p_filesz;
178 tmp = realloc(buf, buf_size);
179 if (tmp == NULL)
180 goto out_free;
181 buf = tmp;
182 }
183 fseek(fp, elf32 ? hdrs.phdr32[i].p_offset : hdrs.phdr64[i].p_offset, SEEK_SET);
184 if (fread(buf, p_filesz, 1, fp) != 1)
185 goto out_free;
186
187 ret = read_build_id(buf, p_filesz, bid, need_swap);
188 if (ret == 0) {
189 ret = bid->size;
190 break;
191 }
192 }
193 out_free:
194 free(buf);
195 free(phdr);
196 out:
197 fclose(fp);
198 return ret;
199 }
200
sysfs__read_build_id(const char * filename,struct build_id * bid)201 int sysfs__read_build_id(const char *filename, struct build_id *bid)
202 {
203 int fd;
204 int ret = -1;
205 struct stat stbuf;
206 size_t buf_size;
207 void *buf;
208
209 fd = open(filename, O_RDONLY);
210 if (fd < 0)
211 return -1;
212
213 if (fstat(fd, &stbuf) < 0)
214 goto out;
215
216 buf_size = stbuf.st_size;
217 buf = malloc(buf_size);
218 if (buf == NULL)
219 goto out;
220
221 if (read(fd, buf, buf_size) != (ssize_t) buf_size)
222 goto out_free;
223
224 ret = read_build_id(buf, buf_size, bid, false);
225 out_free:
226 free(buf);
227 out:
228 close(fd);
229 return ret;
230 }
231
symsrc__init(struct symsrc * ss,struct dso * dso,const char * name,enum dso_binary_type type)232 int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
233 enum dso_binary_type type)
234 {
235 int fd = open(name, O_RDONLY);
236 if (fd < 0)
237 goto out_errno;
238
239 ss->name = strdup(name);
240 if (!ss->name)
241 goto out_close;
242
243 ss->fd = fd;
244 ss->type = type;
245
246 return 0;
247 out_close:
248 close(fd);
249 out_errno:
250 RC_CHK_ACCESS(dso)->load_errno = errno;
251 return -1;
252 }
253
symsrc__possibly_runtime(struct symsrc * ss __maybe_unused)254 bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
255 {
256 /* Assume all sym sources could be a runtime image. */
257 return true;
258 }
259
symsrc__has_symtab(struct symsrc * ss __maybe_unused)260 bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
261 {
262 return false;
263 }
264
symsrc__destroy(struct symsrc * ss)265 void symsrc__destroy(struct symsrc *ss)
266 {
267 zfree(&ss->name);
268 close(ss->fd);
269 }
270
dso__synthesize_plt_symbols(struct dso * dso __maybe_unused,struct symsrc * ss __maybe_unused)271 int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
272 struct symsrc *ss __maybe_unused)
273 {
274 return 0;
275 }
276
fd__is_64_bit(int fd)277 static int fd__is_64_bit(int fd)
278 {
279 u8 e_ident[EI_NIDENT];
280
281 if (lseek(fd, 0, SEEK_SET))
282 return -1;
283
284 if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
285 return -1;
286
287 if (memcmp(e_ident, ELFMAG, SELFMAG) ||
288 e_ident[EI_VERSION] != EV_CURRENT)
289 return -1;
290
291 return e_ident[EI_CLASS] == ELFCLASS64;
292 }
293
dso__type_fd(int fd)294 enum dso_type dso__type_fd(int fd)
295 {
296 Elf64_Ehdr ehdr;
297 int ret;
298
299 ret = fd__is_64_bit(fd);
300 if (ret < 0)
301 return DSO__TYPE_UNKNOWN;
302
303 if (ret)
304 return DSO__TYPE_64BIT;
305
306 if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
307 return DSO__TYPE_UNKNOWN;
308
309 if (ehdr.e_machine == EM_X86_64)
310 return DSO__TYPE_X32BIT;
311
312 return DSO__TYPE_32BIT;
313 }
314
dso__load_sym(struct dso * dso,struct map * map __maybe_unused,struct symsrc * ss,struct symsrc * runtime_ss __maybe_unused,int kmodule __maybe_unused)315 int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
316 struct symsrc *ss,
317 struct symsrc *runtime_ss __maybe_unused,
318 int kmodule __maybe_unused)
319 {
320 struct build_id bid = { .size = 0, };
321 int ret;
322
323 ret = fd__is_64_bit(ss->fd);
324 if (ret >= 0)
325 RC_CHK_ACCESS(dso)->is_64_bit = ret;
326
327 if (filename__read_build_id(ss->name, &bid) > 0)
328 dso__set_build_id(dso, &bid);
329 return 0;
330 }
331
file__read_maps(int fd __maybe_unused,bool exe __maybe_unused,mapfn_t mapfn __maybe_unused,void * data __maybe_unused,bool * is_64_bit __maybe_unused)332 int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
333 mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
334 bool *is_64_bit __maybe_unused)
335 {
336 return -1;
337 }
338
kcore_extract__create(struct kcore_extract * kce __maybe_unused)339 int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
340 {
341 return -1;
342 }
343
kcore_extract__delete(struct kcore_extract * kce __maybe_unused)344 void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
345 {
346 }
347
kcore_copy(const char * from_dir __maybe_unused,const char * to_dir __maybe_unused)348 int kcore_copy(const char *from_dir __maybe_unused,
349 const char *to_dir __maybe_unused)
350 {
351 return -1;
352 }
353
symbol__elf_init(void)354 void symbol__elf_init(void)
355 {
356 }
357
filename__has_section(const char * filename __maybe_unused,const char * sec __maybe_unused)358 bool filename__has_section(const char *filename __maybe_unused, const char *sec __maybe_unused)
359 {
360 return false;
361 }
362