summaryrefslogtreecommitdiffstats
path: root/scripts/sorttable.c
blob: a9b3324cacf91e4b4ed71de021ce4eb430f7524b (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
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
// SPDX-License-Identifier: GPL-2.0-only
/*
 * sorttable.c: Sort the kernel's table
 *
 * Added ORC unwind tables sort support and other updates:
 * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
 * Shile Zhang <shile.zhang@linux.alibaba.com>
 *
 * Copyright 2011 - 2012 Cavium, Inc.
 *
 * Based on code taken from recortmcount.c which is:
 *
 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>.  All rights reserved.
 *
 * Restructured to fit Linux format, as well as other updates:
 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
 */

/*
 * Strategy: alter the vmlinux file in-place.
 */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <getopt.h>
#include <elf.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <tools/be_byteshift.h>
#include <tools/le_byteshift.h>

#ifndef EM_ARCOMPACT
#define EM_ARCOMPACT	93
#endif

#ifndef EM_XTENSA
#define EM_XTENSA	94
#endif

#ifndef EM_AARCH64
#define EM_AARCH64	183
#endif

#ifndef EM_MICROBLAZE
#define EM_MICROBLAZE	189
#endif

#ifndef EM_ARCV2
#define EM_ARCV2	195
#endif

static uint32_t (*r)(const uint32_t *);
static uint16_t (*r2)(const uint16_t *);
static uint64_t (*r8)(const uint64_t *);
static void (*w)(uint32_t, uint32_t *);
static void (*w2)(uint16_t, uint16_t *);
static void (*w8)(uint64_t, uint64_t *);
typedef void (*table_sort_t)(char *, int);

/*
 * Get the whole file as a programming convenience in order to avoid
 * malloc+lseek+read+free of many pieces.  If successful, then mmap
 * avoids copying unused pieces; else just read the whole file.
 * Open for both read and write.
 */
static void *mmap_file(char const *fname, size_t *size)
{
	int fd;
	struct stat sb;
	void *addr = NULL;

	fd = open(fname, O_RDWR);
	if (fd < 0) {
		perror(fname);
		return NULL;
	}
	if (fstat(fd, &sb) < 0) {
		perror(fname);
		goto out;
	}
	if (!S_ISREG(sb.st_mode)) {
		fprintf(stderr, "not a regular file: %s\n", fname);
		goto out;
	}

	addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
	if (addr == MAP_FAILED) {
		fprintf(stderr, "Could not mmap file: %s\n", fname);
		goto out;
	}

	*size = sb.st_size;

out:
	close(fd);
	return addr;
}

static uint32_t rbe(const uint32_t *x)
{
	return get_unaligned_be32(x);
}

static uint16_t r2be(const uint16_t *x)
{
	return get_unaligned_be16(x);
}

static uint64_t r8be(const uint64_t *x)
{
	return get_unaligned_be64(x);
}

static uint32_t rle(const uint32_t *x)
{
	return get_unaligned_le32(x);
}

static uint16_t r2le(const uint16_t *x)
{
	return get_unaligned_le16(x);
}

static uint64_t r8le(const uint64_t *x)
{
	return get_unaligned_le64(x);
}

static void wbe(uint32_t val, uint32_t *x)
{
	put_unaligned_be32(val, x);
}

static void w2be(uint16_t val, uint16_t *x)
{
	put_unaligned_be16(val, x);
}

static void w8be(uint64_t val, uint64_t *x)
{
	put_unaligned_be64(val, x);
}

static void wle(uint32_t val, uint32_t *x)
{
	put_unaligned_le32(val, x);
}

static void w2le(uint16_t val, uint16_t *x)
{
	put_unaligned_le16(val, x);
}

static void w8le(uint64_t val, uint64_t *x)
{
	put_unaligned_le64(val, x);
}

/*
 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
 * the way to -256..-1, to avoid conflicting with real section
 * indices.
 */
#define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))

static inline int is_shndx_special(unsigned int i)
{
	return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
}

/* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
static inline unsigned int get_secindex(unsigned int shndx,
					unsigned int sym_offs,
					const Elf32_Word *symtab_shndx_start)
{
	if (is_shndx_special(shndx))
		return SPECIAL(shndx);
	if (shndx != SHN_XINDEX)
		return shndx;
	return r(&symtab_shndx_start[sym_offs]);
}

/* 32 bit and 64 bit are very similar */
#include "sorttable.h"
#define SORTTABLE_64
#include "sorttable.h"

static int compare_relative_table(const void *a, const void *b)
{
	int32_t av = (int32_t)r(a);
	int32_t bv = (int32_t)r(b);

	if (av < bv)
		return -1;
	if (av > bv)
		return 1;
	return 0;
}

static void sort_relative_table(char *extab_image, int image_size)
{
	int i = 0;

	/*
	 * Do the same thing the runtime sort does, first normalize to
	 * being relative to the start of the section.
	 */
	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);
		w(r(loc) + i, loc);
		i += 4;
	}

	qsort(extab_image, image_size / 8, 8, compare_relative_table);

	/* Now denormalize. */
	i = 0;
	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);
		w(r(loc) - i, loc);
		i += 4;
	}
}

static void x86_sort_relative_table(char *extab_image, int image_size)
{
	int i = 0;

	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);

		w(r(loc) + i, loc);
		w(r(loc + 1) + i + 4, loc + 1);
		/* Don't touch the fixup type */

		i += sizeof(uint32_t) * 3;
	}

	qsort(extab_image, image_size / 12, 12, compare_relative_table);

	i = 0;
	while (i < image_size) {
		uint32_t *loc = (uint32_t *)(extab_image + i);

		w(r(loc) - i, loc);
		w(r(loc + 1) - (i + 4), loc + 1);
		/* Don't touch the fixup type */

		i += sizeof(uint32_t) * 3;
	}
}

static void s390_sort_relative_table(char *extab_image, int image_size)
{
	int i;

	for (i = 0; i < image_size; i += 16) {
		char *loc = extab_image + i;
		uint64_t handler;

		w(r((uint32_t *)loc) + i, (uint32_t *)loc);
		w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4));
		/*
		 * 0 is a special self-relative handler value, which means that
		 * handler should be ignored. It is safe, because it means that
		 * handler field points to itself, which should never happen.
		 * When creating extable-relative values, keep it as 0, since
		 * this should never occur either: it would mean that handler
		 * field points to the first extable entry.
		 */
		handler = r8((uint64_t *)(loc + 8));
		if (handler)
			handler += i + 8;
		w8(handler, (uint64_t *)(loc + 8));
	}

	qsort(extab_image, image_size / 16, 16, compare_relative_table);

	for (i = 0; i < image_size; i += 16) {
		char *loc = extab_image + i;
		uint64_t handler;

		w(r((uint32_t *)loc) - i, (uint32_t *)loc);
		w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4));
		handler = r8((uint64_t *)(loc + 8));
		if (handler)
			handler -= i + 8;
		w8(handler, (uint64_t *)(loc + 8));
	}
}

static int do_file(char const *const fname, void *addr)
{
	int rc = -1;
	Elf32_Ehdr *ehdr = addr;
	table_sort_t custom_sort = NULL;

	switch (ehdr->e_ident[EI_DATA]) {
	case ELFDATA2LSB:
		r	= rle;
		r2	= r2le;
		r8	= r8le;
		w	= wle;
		w2	= w2le;
		w8	= w8le;
		break;
	case ELFDATA2MSB:
		r	= rbe;
		r2	= r2be;
		r8	= r8be;
		w	= wbe;
		w2	= w2be;
		w8	= w8be;
		break;
	default:
		fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
			ehdr->e_ident[EI_DATA], fname);
		return -1;
	}

	if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
	    (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
	    ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
		fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
		return -1;
	}

	switch (r2(&ehdr->e_machine)) {
	case EM_386:
	case EM_X86_64:
		custom_sort = x86_sort_relative_table;
		break;
	case EM_S390:
		custom_sort = s390_sort_relative_table;
		break;
	case EM_AARCH64:
	case EM_PARISC:
	case EM_PPC:
	case EM_PPC64:
		custom_sort = sort_relative_table;
		break;
	case EM_ARCOMPACT:
	case EM_ARCV2:
	case EM_ARM:
	case EM_MICROBLAZE:
	case EM_MIPS:
	case EM_RISCV:
	case EM_XTENSA:
		break;
	default:
		fprintf(stderr, "unrecognized e_machine %d %s\n",
			r2(&ehdr->e_machine), fname);
		return -1;
	}

	switch (ehdr->e_ident[EI_CLASS]) {
	case ELFCLASS32:
		if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
		    r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
			break;
		}
		rc = do_sort_32(ehdr, fname, custom_sort);
		break;
	case ELFCLASS64:
		{
		Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
		if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
		    r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
			fprintf(stderr,
				"unrecognized ET_EXEC/ET_DYN file: %s\n",
				fname);
			break;
		}
		rc = do_sort_64(ghdr, fname, custom_sort);
		}
		break;
	default:
		fprintf(stderr, "unrecognized ELF class %d %s\n",
			ehdr->e_ident[EI_CLASS], fname);
		break;
	}

	return rc;
}

int main(int argc, char *argv[])
{
	int i, n_error = 0;  /* gcc-4.3.0 false positive complaint */
	size_t size = 0;
	void *addr = NULL;

	if (argc < 2) {
		fprintf(stderr, "usage: sorttable vmlinux...\n");
		return 0;
	}

	/* Process each file in turn, allowing deep failure. */
	for (i = 1; i < argc; i++) {
		addr = mmap_file(argv[i], &size);
		if (!addr) {
			++n_error;
			continue;
		}

		if (do_file(argv[i], addr))
			++n_error;

		munmap(addr, size);
	}

	return !!n_error;
}