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Commit | Line | Data |
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393be2e3 NK |
1 | #include "symbol.h" |
2 | ||
b691f643 NK |
3 | #include <elf.h> |
4 | #include <stdio.h> | |
5 | #include <fcntl.h> | |
6 | #include <string.h> | |
7 | #include <byteswap.h> | |
8 | #include <sys/stat.h> | |
393be2e3 | 9 | |
b691f643 NK |
10 | |
11 | static bool check_need_swap(int file_endian) | |
393be2e3 | 12 | { |
b691f643 NK |
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; | |
393be2e3 NK |
23 | } |
24 | ||
b691f643 NK |
25 | #define NOTE_ALIGN(sz) (((sz) + 3) & ~3) |
26 | ||
27 | #define NT_GNU_BUILD_ID 3 | |
28 | ||
29 | static int read_build_id(void *note_data, size_t note_len, void *bf, | |
30 | size_t size, bool need_swap) | |
393be2e3 | 31 | { |
b691f643 NK |
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 | ||
393be2e3 NK |
69 | return -1; |
70 | } | |
71 | ||
72 | int filename__read_debuglink(const char *filename __used, | |
73 | char *debuglink __used, size_t size __used) | |
74 | { | |
75 | return -1; | |
76 | } | |
77 | ||
b691f643 NK |
78 | /* |
79 | * Just try PT_NOTE header otherwise fails | |
80 | */ | |
81 | int filename__read_build_id(const char *filename, void *bf, size_t size) | |
82 | { | |
83 | FILE *fp; | |
84 | int ret = -1; | |
85 | bool need_swap = false; | |
86 | u8 e_ident[EI_NIDENT]; | |
87 | size_t buf_size; | |
88 | void *buf; | |
89 | int i; | |
90 | ||
91 | fp = fopen(filename, "r"); | |
92 | if (fp == NULL) | |
93 | return -1; | |
94 | ||
95 | if (fread(e_ident, sizeof(e_ident), 1, fp) != 1) | |
96 | goto out; | |
97 | ||
98 | if (memcmp(e_ident, ELFMAG, SELFMAG) || | |
99 | e_ident[EI_VERSION] != EV_CURRENT) | |
100 | goto out; | |
101 | ||
102 | need_swap = check_need_swap(e_ident[EI_DATA]); | |
103 | ||
104 | /* for simplicity */ | |
105 | fseek(fp, 0, SEEK_SET); | |
106 | ||
107 | if (e_ident[EI_CLASS] == ELFCLASS32) { | |
108 | Elf32_Ehdr ehdr; | |
109 | Elf32_Phdr *phdr; | |
110 | ||
111 | if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) | |
112 | goto out; | |
113 | ||
114 | if (need_swap) { | |
115 | ehdr.e_phoff = bswap_32(ehdr.e_phoff); | |
116 | ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); | |
117 | ehdr.e_phnum = bswap_16(ehdr.e_phnum); | |
118 | } | |
119 | ||
120 | buf_size = ehdr.e_phentsize * ehdr.e_phnum; | |
121 | buf = malloc(buf_size); | |
122 | if (buf == NULL) | |
123 | goto out; | |
124 | ||
125 | fseek(fp, ehdr.e_phoff, SEEK_SET); | |
126 | if (fread(buf, buf_size, 1, fp) != 1) | |
127 | goto out_free; | |
128 | ||
129 | for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { | |
130 | void *tmp; | |
131 | ||
132 | if (need_swap) { | |
133 | phdr->p_type = bswap_32(phdr->p_type); | |
134 | phdr->p_offset = bswap_32(phdr->p_offset); | |
135 | phdr->p_filesz = bswap_32(phdr->p_filesz); | |
136 | } | |
137 | ||
138 | if (phdr->p_type != PT_NOTE) | |
139 | continue; | |
140 | ||
141 | buf_size = phdr->p_filesz; | |
142 | tmp = realloc(buf, buf_size); | |
143 | if (tmp == NULL) | |
144 | goto out_free; | |
145 | ||
146 | buf = tmp; | |
147 | fseek(fp, phdr->p_offset, SEEK_SET); | |
148 | if (fread(buf, buf_size, 1, fp) != 1) | |
149 | goto out_free; | |
150 | ||
151 | ret = read_build_id(buf, buf_size, bf, size, need_swap); | |
152 | if (ret == 0) | |
153 | ret = size; | |
154 | break; | |
155 | } | |
156 | } else { | |
157 | Elf64_Ehdr ehdr; | |
158 | Elf64_Phdr *phdr; | |
159 | ||
160 | if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) | |
161 | goto out; | |
162 | ||
163 | if (need_swap) { | |
164 | ehdr.e_phoff = bswap_64(ehdr.e_phoff); | |
165 | ehdr.e_phentsize = bswap_16(ehdr.e_phentsize); | |
166 | ehdr.e_phnum = bswap_16(ehdr.e_phnum); | |
167 | } | |
168 | ||
169 | buf_size = ehdr.e_phentsize * ehdr.e_phnum; | |
170 | buf = malloc(buf_size); | |
171 | if (buf == NULL) | |
172 | goto out; | |
173 | ||
174 | fseek(fp, ehdr.e_phoff, SEEK_SET); | |
175 | if (fread(buf, buf_size, 1, fp) != 1) | |
176 | goto out_free; | |
177 | ||
178 | for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) { | |
179 | void *tmp; | |
180 | ||
181 | if (need_swap) { | |
182 | phdr->p_type = bswap_32(phdr->p_type); | |
183 | phdr->p_offset = bswap_64(phdr->p_offset); | |
184 | phdr->p_filesz = bswap_64(phdr->p_filesz); | |
185 | } | |
186 | ||
187 | if (phdr->p_type != PT_NOTE) | |
188 | continue; | |
189 | ||
190 | buf_size = phdr->p_filesz; | |
191 | tmp = realloc(buf, buf_size); | |
192 | if (tmp == NULL) | |
193 | goto out_free; | |
194 | ||
195 | buf = tmp; | |
196 | fseek(fp, phdr->p_offset, SEEK_SET); | |
197 | if (fread(buf, buf_size, 1, fp) != 1) | |
198 | goto out_free; | |
199 | ||
200 | ret = read_build_id(buf, buf_size, bf, size, need_swap); | |
201 | if (ret == 0) | |
202 | ret = size; | |
203 | break; | |
204 | } | |
205 | } | |
206 | out_free: | |
207 | free(buf); | |
208 | out: | |
209 | fclose(fp); | |
210 | return ret; | |
211 | } | |
212 | ||
213 | int sysfs__read_build_id(const char *filename, void *build_id, size_t size) | |
214 | { | |
215 | int fd; | |
216 | int ret = -1; | |
217 | struct stat stbuf; | |
218 | size_t buf_size; | |
219 | void *buf; | |
220 | ||
221 | fd = open(filename, O_RDONLY); | |
222 | if (fd < 0) | |
223 | return -1; | |
224 | ||
225 | if (fstat(fd, &stbuf) < 0) | |
226 | goto out; | |
227 | ||
228 | buf_size = stbuf.st_size; | |
229 | buf = malloc(buf_size); | |
230 | if (buf == NULL) | |
231 | goto out; | |
232 | ||
233 | if (read(fd, buf, buf_size) != (ssize_t) buf_size) | |
234 | goto out_free; | |
235 | ||
236 | ret = read_build_id(buf, buf_size, build_id, size, false); | |
237 | out_free: | |
238 | free(buf); | |
239 | out: | |
240 | close(fd); | |
241 | return ret; | |
242 | } | |
243 | ||
393be2e3 NK |
244 | int dso__synthesize_plt_symbols(struct dso *dso __used, char *name __used, |
245 | struct map *map __used, | |
246 | symbol_filter_t filter __used) | |
247 | { | |
248 | return 0; | |
249 | } | |
250 | ||
b691f643 NK |
251 | int dso__load_sym(struct dso *dso, struct map *map __used, |
252 | const char *name, int fd __used, | |
393be2e3 NK |
253 | symbol_filter_t filter __used, int kmodule __used, |
254 | int want_symtab __used) | |
255 | { | |
b691f643 NK |
256 | unsigned char *build_id[BUILD_ID_SIZE]; |
257 | ||
258 | if (filename__read_build_id(name, build_id, BUILD_ID_SIZE) > 0) { | |
259 | dso__set_build_id(dso, build_id); | |
260 | return 1; | |
261 | } | |
393be2e3 NK |
262 | return 0; |
263 | } | |
264 | ||
265 | void symbol__elf_init(void) | |
266 | { | |
267 | } |