1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * sorttable.c: Sort the kernel's table
4 *
5 * Added ORC unwind tables sort support and other updates:
6 * Copyright (C) 1999-2019 Alibaba Group Holding Limited. by:
7 * Shile Zhang <shile.zhang@linux.alibaba.com>
8 *
9 * Copyright 2011 - 2012 Cavium, Inc.
10 *
11 * Based on code taken from recortmcount.c which is:
12 *
13 * Copyright 2009 John F. Reiser <jreiser@BitWagon.com>. All rights reserved.
14 *
15 * Restructured to fit Linux format, as well as other updates:
16 * Copyright 2010 Steven Rostedt <srostedt@redhat.com>, Red Hat Inc.
17 */
18
19 /*
20 * Strategy: alter the vmlinux file in-place.
21 */
22
23 #include <sys/types.h>
24 #include <sys/mman.h>
25 #include <sys/stat.h>
26 #include <getopt.h>
27 #include <elf.h>
28 #include <fcntl.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33
34 #include <tools/be_byteshift.h>
35 #include <tools/le_byteshift.h>
36
37 #ifndef EM_ARCOMPACT
38 #define EM_ARCOMPACT 93
39 #endif
40
41 #ifndef EM_XTENSA
42 #define EM_XTENSA 94
43 #endif
44
45 #ifndef EM_AARCH64
46 #define EM_AARCH64 183
47 #endif
48
49 #ifndef EM_MICROBLAZE
50 #define EM_MICROBLAZE 189
51 #endif
52
53 #ifndef EM_ARCV2
54 #define EM_ARCV2 195
55 #endif
56
57 static uint32_t (*r)(const uint32_t *);
58 static uint16_t (*r2)(const uint16_t *);
59 static uint64_t (*r8)(const uint64_t *);
60 static void (*w)(uint32_t, uint32_t *);
61 static void (*w2)(uint16_t, uint16_t *);
62 static void (*w8)(uint64_t, uint64_t *);
63 typedef void (*table_sort_t)(char *, int);
64
65 /*
66 * Get the whole file as a programming convenience in order to avoid
67 * malloc+lseek+read+free of many pieces. If successful, then mmap
68 * avoids copying unused pieces; else just read the whole file.
69 * Open for both read and write.
70 */
mmap_file(char const * fname,size_t * size)71 static void *mmap_file(char const *fname, size_t *size)
72 {
73 int fd;
74 struct stat sb;
75 void *addr = NULL;
76
77 fd = open(fname, O_RDWR);
78 if (fd < 0) {
79 perror(fname);
80 return NULL;
81 }
82 if (fstat(fd, &sb) < 0) {
83 perror(fname);
84 goto out;
85 }
86 if (!S_ISREG(sb.st_mode)) {
87 fprintf(stderr, "not a regular file: %s\n", fname);
88 goto out;
89 }
90
91 addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
92 if (addr == MAP_FAILED) {
93 fprintf(stderr, "Could not mmap file: %s\n", fname);
94 goto out;
95 }
96
97 *size = sb.st_size;
98
99 out:
100 close(fd);
101 return addr;
102 }
103
rbe(const uint32_t * x)104 static uint32_t rbe(const uint32_t *x)
105 {
106 return get_unaligned_be32(x);
107 }
108
r2be(const uint16_t * x)109 static uint16_t r2be(const uint16_t *x)
110 {
111 return get_unaligned_be16(x);
112 }
113
r8be(const uint64_t * x)114 static uint64_t r8be(const uint64_t *x)
115 {
116 return get_unaligned_be64(x);
117 }
118
rle(const uint32_t * x)119 static uint32_t rle(const uint32_t *x)
120 {
121 return get_unaligned_le32(x);
122 }
123
r2le(const uint16_t * x)124 static uint16_t r2le(const uint16_t *x)
125 {
126 return get_unaligned_le16(x);
127 }
128
r8le(const uint64_t * x)129 static uint64_t r8le(const uint64_t *x)
130 {
131 return get_unaligned_le64(x);
132 }
133
wbe(uint32_t val,uint32_t * x)134 static void wbe(uint32_t val, uint32_t *x)
135 {
136 put_unaligned_be32(val, x);
137 }
138
w2be(uint16_t val,uint16_t * x)139 static void w2be(uint16_t val, uint16_t *x)
140 {
141 put_unaligned_be16(val, x);
142 }
143
w8be(uint64_t val,uint64_t * x)144 static void w8be(uint64_t val, uint64_t *x)
145 {
146 put_unaligned_be64(val, x);
147 }
148
wle(uint32_t val,uint32_t * x)149 static void wle(uint32_t val, uint32_t *x)
150 {
151 put_unaligned_le32(val, x);
152 }
153
w2le(uint16_t val,uint16_t * x)154 static void w2le(uint16_t val, uint16_t *x)
155 {
156 put_unaligned_le16(val, x);
157 }
158
w8le(uint64_t val,uint64_t * x)159 static void w8le(uint64_t val, uint64_t *x)
160 {
161 put_unaligned_le64(val, x);
162 }
163
164 /*
165 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
166 * the way to -256..-1, to avoid conflicting with real section
167 * indices.
168 */
169 #define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
170
is_shndx_special(unsigned int i)171 static inline int is_shndx_special(unsigned int i)
172 {
173 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
174 }
175
176 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
get_secindex(unsigned int shndx,unsigned int sym_offs,const Elf32_Word * symtab_shndx_start)177 static inline unsigned int get_secindex(unsigned int shndx,
178 unsigned int sym_offs,
179 const Elf32_Word *symtab_shndx_start)
180 {
181 if (is_shndx_special(shndx))
182 return SPECIAL(shndx);
183 if (shndx != SHN_XINDEX)
184 return shndx;
185 return r(&symtab_shndx_start[sym_offs]);
186 }
187
188 /* 32 bit and 64 bit are very similar */
189 #include "sorttable.h"
190 #define SORTTABLE_64
191 #include "sorttable.h"
192
compare_relative_table(const void * a,const void * b)193 static int compare_relative_table(const void *a, const void *b)
194 {
195 int32_t av = (int32_t)r(a);
196 int32_t bv = (int32_t)r(b);
197
198 if (av < bv)
199 return -1;
200 if (av > bv)
201 return 1;
202 return 0;
203 }
204
sort_relative_table(char * extab_image,int image_size)205 static void sort_relative_table(char *extab_image, int image_size)
206 {
207 int i = 0;
208
209 /*
210 * Do the same thing the runtime sort does, first normalize to
211 * being relative to the start of the section.
212 */
213 while (i < image_size) {
214 uint32_t *loc = (uint32_t *)(extab_image + i);
215 w(r(loc) + i, loc);
216 i += 4;
217 }
218
219 qsort(extab_image, image_size / 8, 8, compare_relative_table);
220
221 /* Now denormalize. */
222 i = 0;
223 while (i < image_size) {
224 uint32_t *loc = (uint32_t *)(extab_image + i);
225 w(r(loc) - i, loc);
226 i += 4;
227 }
228 }
229
x86_sort_relative_table(char * extab_image,int image_size)230 static void x86_sort_relative_table(char *extab_image, int image_size)
231 {
232 int i = 0;
233
234 while (i < image_size) {
235 uint32_t *loc = (uint32_t *)(extab_image + i);
236
237 w(r(loc) + i, loc);
238 w(r(loc + 1) + i + 4, loc + 1);
239 w(r(loc + 2) + i + 8, loc + 2);
240
241 i += sizeof(uint32_t) * 3;
242 }
243
244 qsort(extab_image, image_size / 12, 12, compare_relative_table);
245
246 i = 0;
247 while (i < image_size) {
248 uint32_t *loc = (uint32_t *)(extab_image + i);
249
250 w(r(loc) - i, loc);
251 w(r(loc + 1) - (i + 4), loc + 1);
252 w(r(loc + 2) - (i + 8), loc + 2);
253
254 i += sizeof(uint32_t) * 3;
255 }
256 }
257
s390_sort_relative_table(char * extab_image,int image_size)258 static void s390_sort_relative_table(char *extab_image, int image_size)
259 {
260 int i;
261
262 for (i = 0; i < image_size; i += 16) {
263 char *loc = extab_image + i;
264 uint64_t handler;
265
266 w(r((uint32_t *)loc) + i, (uint32_t *)loc);
267 w(r((uint32_t *)(loc + 4)) + (i + 4), (uint32_t *)(loc + 4));
268 /*
269 * 0 is a special self-relative handler value, which means that
270 * handler should be ignored. It is safe, because it means that
271 * handler field points to itself, which should never happen.
272 * When creating extable-relative values, keep it as 0, since
273 * this should never occur either: it would mean that handler
274 * field points to the first extable entry.
275 */
276 handler = r8((uint64_t *)(loc + 8));
277 if (handler)
278 handler += i + 8;
279 w8(handler, (uint64_t *)(loc + 8));
280 }
281
282 qsort(extab_image, image_size / 16, 16, compare_relative_table);
283
284 for (i = 0; i < image_size; i += 16) {
285 char *loc = extab_image + i;
286 uint64_t handler;
287
288 w(r((uint32_t *)loc) - i, (uint32_t *)loc);
289 w(r((uint32_t *)(loc + 4)) - (i + 4), (uint32_t *)(loc + 4));
290 handler = r8((uint64_t *)(loc + 8));
291 if (handler)
292 handler -= i + 8;
293 w8(handler, (uint64_t *)(loc + 8));
294 }
295 }
296
do_file(char const * const fname,void * addr)297 static int do_file(char const *const fname, void *addr)
298 {
299 int rc = -1;
300 Elf32_Ehdr *ehdr = addr;
301 table_sort_t custom_sort = NULL;
302
303 switch (ehdr->e_ident[EI_DATA]) {
304 case ELFDATA2LSB:
305 r = rle;
306 r2 = r2le;
307 r8 = r8le;
308 w = wle;
309 w2 = w2le;
310 w8 = w8le;
311 break;
312 case ELFDATA2MSB:
313 r = rbe;
314 r2 = r2be;
315 r8 = r8be;
316 w = wbe;
317 w2 = w2be;
318 w8 = w8be;
319 break;
320 default:
321 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
322 ehdr->e_ident[EI_DATA], fname);
323 return -1;
324 }
325
326 if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
327 (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
328 ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
329 fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
330 return -1;
331 }
332
333 switch (r2(&ehdr->e_machine)) {
334 case EM_386:
335 case EM_X86_64:
336 custom_sort = x86_sort_relative_table;
337 break;
338 case EM_S390:
339 custom_sort = s390_sort_relative_table;
340 break;
341 case EM_AARCH64:
342 case EM_PARISC:
343 case EM_PPC:
344 case EM_PPC64:
345 custom_sort = sort_relative_table;
346 break;
347 case EM_ARCOMPACT:
348 case EM_ARCV2:
349 case EM_ARM:
350 case EM_MICROBLAZE:
351 case EM_MIPS:
352 case EM_XTENSA:
353 break;
354 default:
355 fprintf(stderr, "unrecognized e_machine %d %s\n",
356 r2(&ehdr->e_machine), fname);
357 return -1;
358 }
359
360 switch (ehdr->e_ident[EI_CLASS]) {
361 case ELFCLASS32:
362 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
363 r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
364 fprintf(stderr,
365 "unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
366 break;
367 }
368 rc = do_sort_32(ehdr, fname, custom_sort);
369 break;
370 case ELFCLASS64:
371 {
372 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
373 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
374 r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
375 fprintf(stderr,
376 "unrecognized ET_EXEC/ET_DYN file: %s\n",
377 fname);
378 break;
379 }
380 rc = do_sort_64(ghdr, fname, custom_sort);
381 }
382 break;
383 default:
384 fprintf(stderr, "unrecognized ELF class %d %s\n",
385 ehdr->e_ident[EI_CLASS], fname);
386 break;
387 }
388
389 return rc;
390 }
391
main(int argc,char * argv[])392 int main(int argc, char *argv[])
393 {
394 int i, n_error = 0; /* gcc-4.3.0 false positive complaint */
395 size_t size = 0;
396 void *addr = NULL;
397
398 if (argc < 2) {
399 fprintf(stderr, "usage: sorttable vmlinux...\n");
400 return 0;
401 }
402
403 /* Process each file in turn, allowing deep failure. */
404 for (i = 1; i < argc; i++) {
405 addr = mmap_file(argv[i], &size);
406 if (!addr) {
407 ++n_error;
408 continue;
409 }
410
411 if (do_file(argv[i], addr))
412 ++n_error;
413
414 munmap(addr, size);
415 }
416
417 return !!n_error;
418 }
419
