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 #include <errno.h>
34 #include <pthread.h>
35
36 #include <tools/be_byteshift.h>
37 #include <tools/le_byteshift.h>
38
39 #ifndef EM_ARCOMPACT
40 #define EM_ARCOMPACT 93
41 #endif
42
43 #ifndef EM_XTENSA
44 #define EM_XTENSA 94
45 #endif
46
47 #ifndef EM_AARCH64
48 #define EM_AARCH64 183
49 #endif
50
51 #ifndef EM_MICROBLAZE
52 #define EM_MICROBLAZE 189
53 #endif
54
55 #ifndef EM_ARCV2
56 #define EM_ARCV2 195
57 #endif
58
59 #ifndef EM_RISCV
60 #define EM_RISCV 243
61 #endif
62
63 #ifndef EM_LOONGARCH
64 #define EM_LOONGARCH 258
65 #endif
66
67 static uint32_t (*r)(const uint32_t *);
68 static uint16_t (*r2)(const uint16_t *);
69 static uint64_t (*r8)(const uint64_t *);
70 static void (*w)(uint32_t, uint32_t *);
71 static void (*w2)(uint16_t, uint16_t *);
72 static void (*w8)(uint64_t, uint64_t *);
73 typedef void (*table_sort_t)(char *, int);
74
75 /*
76 * Get the whole file as a programming convenience in order to avoid
77 * malloc+lseek+read+free of many pieces. If successful, then mmap
78 * avoids copying unused pieces; else just read the whole file.
79 * Open for both read and write.
80 */
81 static void *mmap_file(char const *fname, size_t *size)
82 {
83 int fd;
84 struct stat sb;
85 void *addr = NULL;
86
87 fd = open(fname, O_RDWR);
88 if (fd < 0) {
89 perror(fname);
90 return NULL;
91 }
92 if (fstat(fd, &sb) < 0) {
93 perror(fname);
94 goto out;
95 }
96 if (!S_ISREG(sb.st_mode)) {
97 fprintf(stderr, "not a regular file: %s\n", fname);
98 goto out;
99 }
100
101 addr = mmap(0, sb.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
102 if (addr == MAP_FAILED) {
103 fprintf(stderr, "Could not mmap file: %s\n", fname);
104 goto out;
105 }
106
107 *size = sb.st_size;
108
109 out:
110 close(fd);
111 return addr;
112 }
113
114 static uint32_t rbe(const uint32_t *x)
115 {
116 return get_unaligned_be32(x);
117 }
118
119 static uint16_t r2be(const uint16_t *x)
120 {
121 return get_unaligned_be16(x);
122 }
123
124 static uint64_t r8be(const uint64_t *x)
125 {
126 return get_unaligned_be64(x);
127 }
128
129 static uint32_t rle(const uint32_t *x)
130 {
131 return get_unaligned_le32(x);
132 }
133
134 static uint16_t r2le(const uint16_t *x)
135 {
136 return get_unaligned_le16(x);
137 }
138
139 static uint64_t r8le(const uint64_t *x)
140 {
141 return get_unaligned_le64(x);
142 }
143
144 static void wbe(uint32_t val, uint32_t *x)
145 {
146 put_unaligned_be32(val, x);
147 }
148
149 static void w2be(uint16_t val, uint16_t *x)
150 {
151 put_unaligned_be16(val, x);
152 }
153
154 static void w8be(uint64_t val, uint64_t *x)
155 {
156 put_unaligned_be64(val, x);
157 }
158
159 static void wle(uint32_t val, uint32_t *x)
160 {
161 put_unaligned_le32(val, x);
162 }
163
164 static void w2le(uint16_t val, uint16_t *x)
165 {
166 put_unaligned_le16(val, x);
167 }
168
169 static void w8le(uint64_t val, uint64_t *x)
170 {
171 put_unaligned_le64(val, x);
172 }
173
174 /*
175 * Move reserved section indices SHN_LORESERVE..SHN_HIRESERVE out of
176 * the way to -256..-1, to avoid conflicting with real section
177 * indices.
178 */
179 #define SPECIAL(i) ((i) - (SHN_HIRESERVE + 1))
180
181 static inline int is_shndx_special(unsigned int i)
182 {
183 return i != SHN_XINDEX && i >= SHN_LORESERVE && i <= SHN_HIRESERVE;
184 }
185
186 /* Accessor for sym->st_shndx, hides ugliness of "64k sections" */
187 static inline unsigned int get_secindex(unsigned int shndx,
188 unsigned int sym_offs,
189 const Elf32_Word *symtab_shndx_start)
190 {
191 if (is_shndx_special(shndx))
192 return SPECIAL(shndx);
193 if (shndx != SHN_XINDEX)
194 return shndx;
195 return r(&symtab_shndx_start[sym_offs]);
196 }
197
198 /* 32 bit and 64 bit are very similar */
199 #include "sorttable.h"
200 #define SORTTABLE_64
201 #include "sorttable.h"
202
203 static int compare_relative_table(const void *a, const void *b)
204 {
205 int32_t av = (int32_t)r(a);
206 int32_t bv = (int32_t)r(b);
207
208 if (av < bv)
209 return -1;
210 if (av > bv)
211 return 1;
212 return 0;
213 }
214
215 static void sort_relative_table(char *extab_image, int image_size)
216 {
217 int i = 0;
218
219 /*
220 * Do the same thing the runtime sort does, first normalize to
221 * being relative to the start of the section.
222 */
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 qsort(extab_image, image_size / 8, 8, compare_relative_table);
230
231 /* Now denormalize. */
232 i = 0;
233 while (i < image_size) {
234 uint32_t *loc = (uint32_t *)(extab_image + i);
235 w(r(loc) - i, loc);
236 i += 4;
237 }
238 }
239
240 static void sort_relative_table_with_data(char *extab_image, int image_size)
241 {
242 int i = 0;
243
244 while (i < image_size) {
245 uint32_t *loc = (uint32_t *)(extab_image + i);
246
247 w(r(loc) + i, loc);
248 w(r(loc + 1) + i + 4, loc + 1);
249 /* Don't touch the fixup type or data */
250
251 i += sizeof(uint32_t) * 3;
252 }
253
254 qsort(extab_image, image_size / 12, 12, compare_relative_table);
255
256 i = 0;
257 while (i < image_size) {
258 uint32_t *loc = (uint32_t *)(extab_image + i);
259
260 w(r(loc) - i, loc);
261 w(r(loc + 1) - (i + 4), loc + 1);
262 /* Don't touch the fixup type or data */
263
264 i += sizeof(uint32_t) * 3;
265 }
266 }
267
268 static int do_file(char const *const fname, void *addr)
269 {
270 int rc = -1;
271 Elf32_Ehdr *ehdr = addr;
272 table_sort_t custom_sort = NULL;
273
274 switch (ehdr->e_ident[EI_DATA]) {
275 case ELFDATA2LSB:
276 r = rle;
277 r2 = r2le;
278 r8 = r8le;
279 w = wle;
280 w2 = w2le;
281 w8 = w8le;
282 break;
283 case ELFDATA2MSB:
284 r = rbe;
285 r2 = r2be;
286 r8 = r8be;
287 w = wbe;
288 w2 = w2be;
289 w8 = w8be;
290 break;
291 default:
292 fprintf(stderr, "unrecognized ELF data encoding %d: %s\n",
293 ehdr->e_ident[EI_DATA], fname);
294 return -1;
295 }
296
297 if (memcmp(ELFMAG, ehdr->e_ident, SELFMAG) != 0 ||
298 (r2(&ehdr->e_type) != ET_EXEC && r2(&ehdr->e_type) != ET_DYN) ||
299 ehdr->e_ident[EI_VERSION] != EV_CURRENT) {
300 fprintf(stderr, "unrecognized ET_EXEC/ET_DYN file %s\n", fname);
301 return -1;
302 }
303
304 switch (r2(&ehdr->e_machine)) {
305 case EM_386:
306 case EM_AARCH64:
307 case EM_LOONGARCH:
308 case EM_RISCV:
309 case EM_S390:
310 case EM_X86_64:
311 custom_sort = sort_relative_table_with_data;
312 break;
313 case EM_PARISC:
314 case EM_PPC:
315 case EM_PPC64:
316 custom_sort = sort_relative_table;
317 break;
318 case EM_ARCOMPACT:
319 case EM_ARCV2:
320 case EM_ARM:
321 case EM_MICROBLAZE:
322 case EM_MIPS:
323 case EM_XTENSA:
324 break;
325 default:
326 fprintf(stderr, "unrecognized e_machine %d %s\n",
327 r2(&ehdr->e_machine), fname);
328 return -1;
329 }
330
331 switch (ehdr->e_ident[EI_CLASS]) {
332 case ELFCLASS32:
333 if (r2(&ehdr->e_ehsize) != sizeof(Elf32_Ehdr) ||
334 r2(&ehdr->e_shentsize) != sizeof(Elf32_Shdr)) {
335 fprintf(stderr,
336 "unrecognized ET_EXEC/ET_DYN file: %s\n", fname);
337 break;
338 }
339 rc = do_sort_32(ehdr, fname, custom_sort);
340 break;
341 case ELFCLASS64:
342 {
343 Elf64_Ehdr *const ghdr = (Elf64_Ehdr *)ehdr;
344 if (r2(&ghdr->e_ehsize) != sizeof(Elf64_Ehdr) ||
345 r2(&ghdr->e_shentsize) != sizeof(Elf64_Shdr)) {
346 fprintf(stderr,
347 "unrecognized ET_EXEC/ET_DYN file: %s\n",
348 fname);
349 break;
350 }
351 rc = do_sort_64(ghdr, fname, custom_sort);
352 }
353 break;
354 default:
355 fprintf(stderr, "unrecognized ELF class %d %s\n",
356 ehdr->e_ident[EI_CLASS], fname);
357 break;
358 }
359
360 return rc;
361 }
362
363 int main(int argc, char *argv[])
364 {
365 int i, n_error = 0; /* gcc-4.3.0 false positive complaint */
366 size_t size = 0;
367 void *addr = NULL;
368
369 if (argc < 2) {
370 fprintf(stderr, "usage: sorttable vmlinux...\n");
371 return 0;
372 }
373
374 /* Process each file in turn, allowing deep failure. */
375 for (i = 1; i < argc; i++) {
376 addr = mmap_file(argv[i], &size);
377 if (!addr) {
378 ++n_error;
379 continue;
380 }
381
382 if (do_file(argv[i], addr))
383 ++n_error;
384
385 munmap(addr, size);
386 }
387
388 return !!n_error;
389 }
390
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