summaryrefslogtreecommitdiffstats
path: root/tools/perf/util/symbol-minimal.c
blob: 1a5aa35b0100d0a47bc5f904b5809dec3c033cbb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
#include "symbol.h"
#include "util.h"

#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
#include <byteswap.h>
#include <sys/stat.h>


static bool check_need_swap(int file_endian)
{
	const int data = 1;
	u8 *check = (u8 *)&data;
	int host_endian;

	if (check[0] == 1)
		host_endian = ELFDATA2LSB;
	else
		host_endian = ELFDATA2MSB;

	return host_endian != file_endian;
}

#define NOTE_ALIGN(sz) (((sz) + 3) & ~3)

#define NT_GNU_BUILD_ID	3

static int read_build_id(void *note_data, size_t note_len, void *bf,
			 size_t size, bool need_swap)
{
	struct {
		u32 n_namesz;
		u32 n_descsz;
		u32 n_type;
	} *nhdr;
	void *ptr;

	ptr = note_data;
	while (ptr < (note_data + note_len)) {
		const char *name;
		size_t namesz, descsz;

		nhdr = ptr;
		if (need_swap) {
			nhdr->n_namesz = bswap_32(nhdr->n_namesz);
			nhdr->n_descsz = bswap_32(nhdr->n_descsz);
			nhdr->n_type = bswap_32(nhdr->n_type);
		}

		namesz = NOTE_ALIGN(nhdr->n_namesz);
		descsz = NOTE_ALIGN(nhdr->n_descsz);

		ptr += sizeof(*nhdr);
		name = ptr;
		ptr += namesz;
		if (nhdr->n_type == NT_GNU_BUILD_ID &&
		    nhdr->n_namesz == sizeof("GNU")) {
			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
				size_t sz = min(size, descsz);
				memcpy(bf, ptr, sz);
				memset(bf + sz, 0, size - sz);
				return 0;
			}
		}
		ptr += descsz;
	}

	return -1;
}

int filename__read_debuglink(const char *filename __maybe_unused,
			     char *debuglink __maybe_unused,
			     size_t size __maybe_unused)
{
	return -1;
}

/*
 * Just try PT_NOTE header otherwise fails
 */
int filename__read_build_id(const char *filename, void *bf, size_t size)
{
	FILE *fp;
	int ret = -1;
	bool need_swap = false;
	u8 e_ident[EI_NIDENT];
	size_t buf_size;
	void *buf;
	int i;

	fp = fopen(filename, "r");
	if (fp == NULL)
		return -1;

	if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
		goto out;

	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
	    e_ident[EI_VERSION] != EV_CURRENT)
		goto out;

	need_swap = check_need_swap(e_ident[EI_DATA]);

	/* for simplicity */
	fseek(fp, 0, SEEK_SET);

	if (e_ident[EI_CLASS] == ELFCLASS32) {
		Elf32_Ehdr ehdr;
		Elf32_Phdr *phdr;

		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
			goto out;

		if (need_swap) {
			ehdr.e_phoff = bswap_32(ehdr.e_phoff);
			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
		}

		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
		buf = malloc(buf_size);
		if (buf == NULL)
			goto out;

		fseek(fp, ehdr.e_phoff, SEEK_SET);
		if (fread(buf, buf_size, 1, fp) != 1)
			goto out_free;

		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
			void *tmp;
			long offset;

			if (need_swap) {
				phdr->p_type = bswap_32(phdr->p_type);
				phdr->p_offset = bswap_32(phdr->p_offset);
				phdr->p_filesz = bswap_32(phdr->p_filesz);
			}

			if (phdr->p_type != PT_NOTE)
				continue;

			buf_size = phdr->p_filesz;
			offset = phdr->p_offset;
			tmp = realloc(buf, buf_size);
			if (tmp == NULL)
				goto out_free;

			buf = tmp;
			fseek(fp, offset, SEEK_SET);
			if (fread(buf, buf_size, 1, fp) != 1)
				goto out_free;

			ret = read_build_id(buf, buf_size, bf, size, need_swap);
			if (ret == 0)
				ret = size;
			break;
		}
	} else {
		Elf64_Ehdr ehdr;
		Elf64_Phdr *phdr;

		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
			goto out;

		if (need_swap) {
			ehdr.e_phoff = bswap_64(ehdr.e_phoff);
			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
		}

		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
		buf = malloc(buf_size);
		if (buf == NULL)
			goto out;

		fseek(fp, ehdr.e_phoff, SEEK_SET);
		if (fread(buf, buf_size, 1, fp) != 1)
			goto out_free;

		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
			void *tmp;
			long offset;

			if (need_swap) {
				phdr->p_type = bswap_32(phdr->p_type);
				phdr->p_offset = bswap_64(phdr->p_offset);
				phdr->p_filesz = bswap_64(phdr->p_filesz);
			}

			if (phdr->p_type != PT_NOTE)
				continue;

			buf_size = phdr->p_filesz;
			offset = phdr->p_offset;
			tmp = realloc(buf, buf_size);
			if (tmp == NULL)
				goto out_free;

			buf = tmp;
			fseek(fp, offset, SEEK_SET);
			if (fread(buf, buf_size, 1, fp) != 1)
				goto out_free;

			ret = read_build_id(buf, buf_size, bf, size, need_swap);
			if (ret == 0)
				ret = size;
			break;
		}
	}
out_free:
	free(buf);
out:
	fclose(fp);
	return ret;
}

int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
{
	int fd;
	int ret = -1;
	struct stat stbuf;
	size_t buf_size;
	void *buf;

	fd = open(filename, O_RDONLY);
	if (fd < 0)
		return -1;

	if (fstat(fd, &stbuf) < 0)
		goto out;

	buf_size = stbuf.st_size;
	buf = malloc(buf_size);
	if (buf == NULL)
		goto out;

	if (read(fd, buf, buf_size) != (ssize_t) buf_size)
		goto out_free;

	ret = read_build_id(buf, buf_size, build_id, size, false);
out_free:
	free(buf);
out:
	close(fd);
	return ret;
}

int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,
	         enum dso_binary_type type)
{
	int fd = open(name, O_RDONLY);
	if (fd < 0)
		goto out_errno;

	ss->name = strdup(name);
	if (!ss->name)
		goto out_close;

	ss->fd = fd;
	ss->type = type;

	return 0;
out_close:
	close(fd);
out_errno:
	dso->load_errno = errno;
	return -1;
}

bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)
{
	/* Assume all sym sources could be a runtime image. */
	return true;
}

bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)
{
	return false;
}

void symsrc__destroy(struct symsrc *ss)
{
	zfree(&ss->name);
	close(ss->fd);
}

int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
				struct symsrc *ss __maybe_unused,
				struct map *map __maybe_unused)
{
	return 0;
}

static int fd__is_64_bit(int fd)
{
	u8 e_ident[EI_NIDENT];

	if (lseek(fd, 0, SEEK_SET))
		return -1;

	if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
		return -1;

	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
	    e_ident[EI_VERSION] != EV_CURRENT)
		return -1;

	return e_ident[EI_CLASS] == ELFCLASS64;
}

enum dso_type dso__type_fd(int fd)
{
	Elf64_Ehdr ehdr;
	int ret;

	ret = fd__is_64_bit(fd);
	if (ret < 0)
		return DSO__TYPE_UNKNOWN;

	if (ret)
		return DSO__TYPE_64BIT;

	if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
		return DSO__TYPE_UNKNOWN;

	if (ehdr.e_machine == EM_X86_64)
		return DSO__TYPE_X32BIT;

	return DSO__TYPE_32BIT;
}

int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
		  struct symsrc *ss,
		  struct symsrc *runtime_ss __maybe_unused,
		  int kmodule __maybe_unused)
{
	unsigned char build_id[BUILD_ID_SIZE];
	int ret;

	ret = fd__is_64_bit(ss->fd);
	if (ret >= 0)
		dso->is_64_bit = ret;

	if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {
		dso__set_build_id(dso, build_id);
	}
	return 0;
}

int 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)
{
	return -1;
}

int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
{
	return -1;
}

void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
{
}

int kcore_copy(const char *from_dir __maybe_unused,
	       const char *to_dir __maybe_unused)
{
	return -1;
}

void symbol__elf_init(void)
{
}

char *dso__demangle_sym(struct dso *dso __maybe_unused,
			int kmodule __maybe_unused,
			const char *elf_name __maybe_unused)
{
	return NULL;
}
OpenPOWER on IntegriCloud