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83d290c5 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
703ec9dd PB |
2 | /* |
3 | * MIPS Relocation Data Generator | |
4 | * | |
5 | * Copyright (c) 2017 Imagination Technologies Ltd. | |
703ec9dd PB |
6 | */ |
7 | ||
e94136bd | 8 | #include <assert.h> |
703ec9dd PB |
9 | #include <elf.h> |
10 | #include <errno.h> | |
11 | #include <fcntl.h> | |
12 | #include <limits.h> | |
d2bf1152 | 13 | #include <stdbool.h> |
703ec9dd PB |
14 | #include <stdio.h> |
15 | #include <stdlib.h> | |
16 | #include <sys/mman.h> | |
17 | #include <sys/stat.h> | |
18 | #include <unistd.h> | |
19 | ||
20 | #include <asm/relocs.h> | |
21 | ||
22 | #define hdr_field(pfx, idx, field) ({ \ | |
23 | uint64_t _val; \ | |
24 | unsigned int _size; \ | |
25 | \ | |
26 | if (is_64) { \ | |
27 | _val = pfx##hdr64[idx].field; \ | |
28 | _size = sizeof(pfx##hdr64[0].field); \ | |
29 | } else { \ | |
30 | _val = pfx##hdr32[idx].field; \ | |
31 | _size = sizeof(pfx##hdr32[0].field); \ | |
32 | } \ | |
33 | \ | |
34 | switch (_size) { \ | |
35 | case 1: \ | |
36 | break; \ | |
37 | case 2: \ | |
38 | _val = is_be ? be16toh(_val) : le16toh(_val); \ | |
39 | break; \ | |
40 | case 4: \ | |
41 | _val = is_be ? be32toh(_val) : le32toh(_val); \ | |
42 | break; \ | |
43 | case 8: \ | |
44 | _val = is_be ? be64toh(_val) : le64toh(_val); \ | |
45 | break; \ | |
46 | } \ | |
47 | \ | |
48 | _val; \ | |
49 | }) | |
50 | ||
51 | #define set_hdr_field(pfx, idx, field, val) ({ \ | |
52 | uint64_t _val; \ | |
53 | unsigned int _size; \ | |
54 | \ | |
55 | if (is_64) \ | |
56 | _size = sizeof(pfx##hdr64[0].field); \ | |
57 | else \ | |
58 | _size = sizeof(pfx##hdr32[0].field); \ | |
59 | \ | |
60 | switch (_size) { \ | |
61 | case 1: \ | |
62 | _val = val; \ | |
63 | break; \ | |
64 | case 2: \ | |
65 | _val = is_be ? htobe16(val) : htole16(val); \ | |
66 | break; \ | |
67 | case 4: \ | |
68 | _val = is_be ? htobe32(val) : htole32(val); \ | |
69 | break; \ | |
70 | case 8: \ | |
71 | _val = is_be ? htobe64(val) : htole64(val); \ | |
72 | break; \ | |
e94136bd PB |
73 | default: \ |
74 | /* We should never reach here */ \ | |
75 | _val = 0; \ | |
76 | assert(0); \ | |
77 | break; \ | |
703ec9dd PB |
78 | } \ |
79 | \ | |
80 | if (is_64) \ | |
81 | pfx##hdr64[idx].field = _val; \ | |
82 | else \ | |
83 | pfx##hdr32[idx].field = _val; \ | |
84 | }) | |
85 | ||
86 | #define ehdr_field(field) \ | |
87 | hdr_field(e, 0, field) | |
88 | #define phdr_field(idx, field) \ | |
89 | hdr_field(p, idx, field) | |
90 | #define shdr_field(idx, field) \ | |
91 | hdr_field(s, idx, field) | |
92 | ||
93 | #define set_phdr_field(idx, field, val) \ | |
94 | set_hdr_field(p, idx, field, val) | |
95 | #define set_shdr_field(idx, field, val) \ | |
96 | set_hdr_field(s, idx, field, val) | |
97 | ||
98 | #define shstr(idx) (&shstrtab[idx]) | |
99 | ||
100 | bool is_64, is_be; | |
101 | uint64_t text_base; | |
102 | ||
103 | struct mips_reloc { | |
104 | uint8_t type; | |
105 | uint64_t offset; | |
106 | } *relocs; | |
107 | size_t relocs_sz, relocs_idx; | |
108 | ||
109 | static int add_reloc(unsigned int type, uint64_t off) | |
110 | { | |
111 | struct mips_reloc *new; | |
112 | size_t new_sz; | |
113 | ||
114 | switch (type) { | |
115 | case R_MIPS_NONE: | |
116 | case R_MIPS_LO16: | |
117 | case R_MIPS_PC16: | |
118 | case R_MIPS_HIGHER: | |
119 | case R_MIPS_HIGHEST: | |
120 | case R_MIPS_PC21_S2: | |
121 | case R_MIPS_PC26_S2: | |
122 | /* Skip these relocs */ | |
123 | return 0; | |
124 | ||
125 | default: | |
126 | break; | |
127 | } | |
128 | ||
129 | if (relocs_idx == relocs_sz) { | |
130 | new_sz = relocs_sz ? relocs_sz * 2 : 128; | |
131 | new = realloc(relocs, new_sz * sizeof(*relocs)); | |
132 | if (!new) { | |
133 | fprintf(stderr, "Out of memory\n"); | |
134 | return -ENOMEM; | |
135 | } | |
136 | ||
137 | relocs = new; | |
138 | relocs_sz = new_sz; | |
139 | } | |
140 | ||
141 | relocs[relocs_idx++] = (struct mips_reloc){ | |
142 | .type = type, | |
143 | .offset = off, | |
144 | }; | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | static int parse_mips32_rel(const void *_rel) | |
150 | { | |
151 | const Elf32_Rel *rel = _rel; | |
152 | uint32_t off, type; | |
153 | ||
154 | off = is_be ? be32toh(rel->r_offset) : le32toh(rel->r_offset); | |
155 | off -= text_base; | |
156 | ||
157 | type = is_be ? be32toh(rel->r_info) : le32toh(rel->r_info); | |
158 | type = ELF32_R_TYPE(type); | |
159 | ||
160 | return add_reloc(type, off); | |
161 | } | |
162 | ||
163 | static int parse_mips64_rela(const void *_rel) | |
164 | { | |
165 | const Elf64_Rela *rel = _rel; | |
166 | uint64_t off, type; | |
167 | ||
168 | off = is_be ? be64toh(rel->r_offset) : le64toh(rel->r_offset); | |
169 | off -= text_base; | |
170 | ||
171 | type = rel->r_info >> (64 - 8); | |
172 | ||
173 | return add_reloc(type, off); | |
174 | } | |
175 | ||
176 | static void output_uint(uint8_t **buf, uint64_t val) | |
177 | { | |
178 | uint64_t tmp; | |
179 | ||
180 | do { | |
181 | tmp = val & 0x7f; | |
182 | val >>= 7; | |
183 | tmp |= !!val << 7; | |
184 | *(*buf)++ = tmp; | |
185 | } while (val); | |
186 | } | |
187 | ||
188 | static int compare_relocs(const void *a, const void *b) | |
189 | { | |
190 | const struct mips_reloc *ra = a, *rb = b; | |
191 | ||
192 | return ra->offset - rb->offset; | |
193 | } | |
194 | ||
195 | int main(int argc, char *argv[]) | |
196 | { | |
197 | unsigned int i, j, i_rel_shdr, sh_type, sh_entsize, sh_entries; | |
96301464 | 198 | size_t rel_size, rel_actual_size; |
703ec9dd PB |
199 | const char *shstrtab, *sh_name, *rel_pfx; |
200 | int (*parse_fn)(const void *rel); | |
201 | uint8_t *buf_start, *buf; | |
202 | const Elf32_Ehdr *ehdr32; | |
203 | const Elf64_Ehdr *ehdr64; | |
204 | uintptr_t sh_offset; | |
703ec9dd PB |
205 | Elf32_Shdr *shdr32; |
206 | Elf64_Shdr *shdr64; | |
207 | struct stat st; | |
208 | int err, fd; | |
209 | void *elf; | |
210 | bool skip; | |
211 | ||
212 | fd = open(argv[1], O_RDWR); | |
213 | if (fd == -1) { | |
214 | fprintf(stderr, "Unable to open input file %s\n", argv[1]); | |
215 | err = errno; | |
216 | goto out_ret; | |
217 | } | |
218 | ||
219 | err = fstat(fd, &st); | |
220 | if (err) { | |
221 | fprintf(stderr, "Unable to fstat() input file\n"); | |
222 | goto out_close_fd; | |
223 | } | |
224 | ||
225 | elf = mmap(NULL, st.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); | |
226 | if (elf == MAP_FAILED) { | |
227 | fprintf(stderr, "Unable to mmap() input file\n"); | |
228 | err = errno; | |
229 | goto out_close_fd; | |
230 | } | |
231 | ||
232 | ehdr32 = elf; | |
233 | ehdr64 = elf; | |
234 | ||
235 | if (memcmp(&ehdr32->e_ident[EI_MAG0], ELFMAG, SELFMAG)) { | |
236 | fprintf(stderr, "Input file is not an ELF\n"); | |
237 | err = -EINVAL; | |
238 | goto out_free_relocs; | |
239 | } | |
240 | ||
241 | if (ehdr32->e_ident[EI_VERSION] != EV_CURRENT) { | |
242 | fprintf(stderr, "Unrecognised ELF version\n"); | |
243 | err = -EINVAL; | |
244 | goto out_free_relocs; | |
245 | } | |
246 | ||
247 | switch (ehdr32->e_ident[EI_CLASS]) { | |
248 | case ELFCLASS32: | |
249 | is_64 = false; | |
250 | break; | |
251 | case ELFCLASS64: | |
252 | is_64 = true; | |
253 | break; | |
254 | default: | |
255 | fprintf(stderr, "Unrecognised ELF class\n"); | |
256 | err = -EINVAL; | |
257 | goto out_free_relocs; | |
258 | } | |
259 | ||
260 | switch (ehdr32->e_ident[EI_DATA]) { | |
261 | case ELFDATA2LSB: | |
262 | is_be = false; | |
263 | break; | |
264 | case ELFDATA2MSB: | |
265 | is_be = true; | |
266 | break; | |
267 | default: | |
268 | fprintf(stderr, "Unrecognised ELF data encoding\n"); | |
269 | err = -EINVAL; | |
270 | goto out_free_relocs; | |
271 | } | |
272 | ||
273 | if (ehdr_field(e_type) != ET_EXEC) { | |
274 | fprintf(stderr, "Input ELF is not an executable\n"); | |
275 | printf("type 0x%lx\n", ehdr_field(e_type)); | |
276 | err = -EINVAL; | |
277 | goto out_free_relocs; | |
278 | } | |
279 | ||
280 | if (ehdr_field(e_machine) != EM_MIPS) { | |
281 | fprintf(stderr, "Input ELF does not target MIPS\n"); | |
282 | err = -EINVAL; | |
283 | goto out_free_relocs; | |
284 | } | |
285 | ||
703ec9dd PB |
286 | shdr32 = elf + ehdr_field(e_shoff); |
287 | shdr64 = elf + ehdr_field(e_shoff); | |
288 | shstrtab = elf + shdr_field(ehdr_field(e_shstrndx), sh_offset); | |
289 | ||
290 | i_rel_shdr = UINT_MAX; | |
291 | for (i = 0; i < ehdr_field(e_shnum); i++) { | |
292 | sh_name = shstr(shdr_field(i, sh_name)); | |
293 | ||
96301464 | 294 | if (!strcmp(sh_name, ".data.reloc")) { |
703ec9dd PB |
295 | i_rel_shdr = i; |
296 | continue; | |
297 | } | |
298 | ||
299 | if (!strcmp(sh_name, ".text")) { | |
300 | text_base = shdr_field(i, sh_addr); | |
301 | continue; | |
302 | } | |
303 | } | |
304 | if (i_rel_shdr == UINT_MAX) { | |
305 | fprintf(stderr, "Unable to find .rel section\n"); | |
306 | err = -EINVAL; | |
307 | goto out_free_relocs; | |
308 | } | |
309 | if (!text_base) { | |
310 | fprintf(stderr, "Unable to find .text base address\n"); | |
311 | err = -EINVAL; | |
312 | goto out_free_relocs; | |
313 | } | |
314 | ||
315 | rel_pfx = is_64 ? ".rela." : ".rel."; | |
316 | ||
317 | for (i = 0; i < ehdr_field(e_shnum); i++) { | |
318 | sh_type = shdr_field(i, sh_type); | |
319 | if ((sh_type != SHT_REL) && (sh_type != SHT_RELA)) | |
320 | continue; | |
321 | ||
322 | sh_name = shstr(shdr_field(i, sh_name)); | |
323 | if (strncmp(sh_name, rel_pfx, strlen(rel_pfx))) { | |
324 | if (strcmp(sh_name, ".rel") && strcmp(sh_name, ".rel.dyn")) | |
325 | fprintf(stderr, "WARNING: Unexpected reloc section name '%s'\n", sh_name); | |
326 | continue; | |
327 | } | |
328 | ||
329 | /* | |
330 | * Skip reloc sections which either don't correspond to another | |
331 | * section in the ELF, or whose corresponding section isn't | |
332 | * loaded as part of the U-Boot binary (ie. doesn't have the | |
333 | * alloc flags set). | |
334 | */ | |
335 | skip = true; | |
336 | for (j = 0; j < ehdr_field(e_shnum); j++) { | |
337 | if (strcmp(&sh_name[strlen(rel_pfx) - 1], shstr(shdr_field(j, sh_name)))) | |
338 | continue; | |
339 | ||
340 | skip = !(shdr_field(j, sh_flags) & SHF_ALLOC); | |
341 | break; | |
342 | } | |
343 | if (skip) | |
344 | continue; | |
345 | ||
346 | sh_offset = shdr_field(i, sh_offset); | |
347 | sh_entsize = shdr_field(i, sh_entsize); | |
348 | sh_entries = shdr_field(i, sh_size) / sh_entsize; | |
349 | ||
350 | if (sh_type == SHT_REL) { | |
351 | if (is_64) { | |
352 | fprintf(stderr, "REL-style reloc in MIPS64 ELF?\n"); | |
353 | err = -EINVAL; | |
354 | goto out_free_relocs; | |
355 | } else { | |
356 | parse_fn = parse_mips32_rel; | |
357 | } | |
358 | } else { | |
359 | if (is_64) { | |
360 | parse_fn = parse_mips64_rela; | |
361 | } else { | |
362 | fprintf(stderr, "RELA-style reloc in MIPS32 ELF?\n"); | |
363 | err = -EINVAL; | |
364 | goto out_free_relocs; | |
365 | } | |
366 | } | |
367 | ||
368 | for (j = 0; j < sh_entries; j++) { | |
369 | err = parse_fn(elf + sh_offset + (j * sh_entsize)); | |
370 | if (err) | |
371 | goto out_free_relocs; | |
372 | } | |
373 | } | |
374 | ||
375 | /* Sort relocs in ascending order of offset */ | |
376 | qsort(relocs, relocs_idx, sizeof(*relocs), compare_relocs); | |
377 | ||
378 | /* Make reloc offsets relative to their predecessor */ | |
379 | for (i = relocs_idx - 1; i > 0; i--) | |
380 | relocs[i].offset -= relocs[i - 1].offset; | |
381 | ||
382 | /* Write the relocations to the .rel section */ | |
383 | buf = buf_start = elf + shdr_field(i_rel_shdr, sh_offset); | |
384 | for (i = 0; i < relocs_idx; i++) { | |
385 | output_uint(&buf, relocs[i].type); | |
386 | output_uint(&buf, relocs[i].offset >> 2); | |
387 | } | |
388 | ||
389 | /* Write a terminating R_MIPS_NONE (0) */ | |
390 | output_uint(&buf, R_MIPS_NONE); | |
391 | ||
392 | /* Ensure the relocs didn't overflow the .rel section */ | |
393 | rel_size = shdr_field(i_rel_shdr, sh_size); | |
394 | rel_actual_size = buf - buf_start; | |
395 | if (rel_actual_size > rel_size) { | |
96301464 DS |
396 | fprintf(stderr, "Relocations overflow available space of 0x%lx (required 0x%lx)!\n", |
397 | rel_size, rel_actual_size); | |
398 | fprintf(stderr, "Please adjust CONFIG_MIPS_RELOCATION_TABLE_SIZE to at least 0x%lx\n", | |
399 | (rel_actual_size + 0x100) & ~0xFF); | |
400 | err = -ENOMEM; | |
401 | goto out_free_relocs; | |
703ec9dd PB |
402 | } |
403 | ||
404 | /* Make sure data is written back to the file */ | |
405 | err = msync(elf, st.st_size, MS_SYNC); | |
406 | if (err) { | |
407 | fprintf(stderr, "Failed to msync: %d\n", errno); | |
408 | goto out_free_relocs; | |
409 | } | |
410 | ||
411 | out_free_relocs: | |
412 | free(relocs); | |
413 | munmap(elf, st.st_size); | |
414 | out_close_fd: | |
415 | close(fd); | |
416 | out_ret: | |
417 | return err; | |
418 | } |