1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* This is included from relocs_32/64.c */ |
3 | |
4 | #define ElfW(type) _ElfW(ELF_BITS, type) |
5 | #define _ElfW(bits, type) __ElfW(bits, type) |
6 | #define __ElfW(bits, type) Elf##bits##_##type |
7 | |
8 | #define Elf_Addr ElfW(Addr) |
9 | #define Elf_Ehdr ElfW(Ehdr) |
10 | #define Elf_Phdr ElfW(Phdr) |
11 | #define Elf_Shdr ElfW(Shdr) |
12 | #define Elf_Sym ElfW(Sym) |
13 | |
14 | static Elf_Ehdr ehdr; |
15 | static unsigned long shnum; |
16 | static unsigned int shstrndx; |
17 | static unsigned int shsymtabndx; |
18 | static unsigned int shxsymtabndx; |
19 | |
20 | static int sym_index(Elf_Sym *sym); |
21 | |
22 | struct relocs { |
23 | uint32_t *offset; |
24 | unsigned long count; |
25 | unsigned long size; |
26 | }; |
27 | |
28 | static struct relocs relocs16; |
29 | static struct relocs relocs32; |
30 | #if ELF_BITS == 64 |
31 | static struct relocs relocs32neg; |
32 | static struct relocs relocs64; |
33 | #define FMT PRIu64 |
34 | #else |
35 | #define FMT PRIu32 |
36 | #endif |
37 | |
38 | struct section { |
39 | Elf_Shdr shdr; |
40 | struct section *link; |
41 | Elf_Sym *symtab; |
42 | Elf32_Word *xsymtab; |
43 | Elf_Rel *reltab; |
44 | char *strtab; |
45 | }; |
46 | static struct section *secs; |
47 | |
48 | static const char * const sym_regex_kernel[S_NSYMTYPES] = { |
49 | /* |
50 | * Following symbols have been audited. There values are constant and do |
51 | * not change if bzImage is loaded at a different physical address than |
52 | * the address for which it has been compiled. Don't warn user about |
53 | * absolute relocations present w.r.t these symbols. |
54 | */ |
55 | [S_ABS] = |
56 | "^(xen_irq_disable_direct_reloc$|" |
57 | "xen_save_fl_direct_reloc$|" |
58 | "VDSO|" |
59 | "__kcfi_typeid_|" |
60 | "__crc_)" , |
61 | |
62 | /* |
63 | * These symbols are known to be relative, even if the linker marks them |
64 | * as absolute (typically defined outside any section in the linker script.) |
65 | */ |
66 | [S_REL] = |
67 | "^(__init_(begin|end)|" |
68 | "__x86_cpu_dev_(start|end)|" |
69 | "(__parainstructions|__alt_instructions)(_end)?|" |
70 | "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|" |
71 | "__(start|end)_pci_.*|" |
72 | #if CONFIG_FW_LOADER |
73 | "__(start|end)_builtin_fw|" |
74 | #endif |
75 | "__(start|stop)___ksymtab(_gpl)?|" |
76 | "__(start|stop)___kcrctab(_gpl)?|" |
77 | "__(start|stop)___param|" |
78 | "__(start|stop)___modver|" |
79 | "__(start|stop)___bug_table|" |
80 | "__tracedata_(start|end)|" |
81 | "__(start|stop)_notes|" |
82 | "__end_rodata|" |
83 | "__end_rodata_aligned|" |
84 | "__initramfs_start|" |
85 | "(jiffies|jiffies_64)|" |
86 | #if ELF_BITS == 64 |
87 | "__per_cpu_load|" |
88 | "init_per_cpu__.*|" |
89 | "__end_rodata_hpage_align|" |
90 | #endif |
91 | "__vvar_page|" |
92 | "_end)$" |
93 | }; |
94 | |
95 | |
96 | static const char * const sym_regex_realmode[S_NSYMTYPES] = { |
97 | /* |
98 | * These symbols are known to be relative, even if the linker marks them |
99 | * as absolute (typically defined outside any section in the linker script.) |
100 | */ |
101 | [S_REL] = |
102 | "^pa_" , |
103 | |
104 | /* |
105 | * These are 16-bit segment symbols when compiling 16-bit code. |
106 | */ |
107 | [S_SEG] = |
108 | "^real_mode_seg$" , |
109 | |
110 | /* |
111 | * These are offsets belonging to segments, as opposed to linear addresses, |
112 | * when compiling 16-bit code. |
113 | */ |
114 | [S_LIN] = |
115 | "^pa_" , |
116 | }; |
117 | |
118 | static const char * const *sym_regex; |
119 | |
120 | static regex_t sym_regex_c[S_NSYMTYPES]; |
121 | static int is_reloc(enum symtype type, const char *sym_name) |
122 | { |
123 | return sym_regex[type] && |
124 | !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0); |
125 | } |
126 | |
127 | static void regex_init(int use_real_mode) |
128 | { |
129 | char errbuf[128]; |
130 | int err; |
131 | int i; |
132 | |
133 | if (use_real_mode) |
134 | sym_regex = sym_regex_realmode; |
135 | else |
136 | sym_regex = sym_regex_kernel; |
137 | |
138 | for (i = 0; i < S_NSYMTYPES; i++) { |
139 | if (!sym_regex[i]) |
140 | continue; |
141 | |
142 | err = regcomp(&sym_regex_c[i], sym_regex[i], |
143 | REG_EXTENDED|REG_NOSUB); |
144 | |
145 | if (err) { |
146 | regerror(err, &sym_regex_c[i], errbuf, sizeof(errbuf)); |
147 | die("%s" , errbuf); |
148 | } |
149 | } |
150 | } |
151 | |
152 | static const char *sym_type(unsigned type) |
153 | { |
154 | static const char *type_name[] = { |
155 | #define SYM_TYPE(X) [X] = #X |
156 | SYM_TYPE(STT_NOTYPE), |
157 | SYM_TYPE(STT_OBJECT), |
158 | SYM_TYPE(STT_FUNC), |
159 | SYM_TYPE(STT_SECTION), |
160 | SYM_TYPE(STT_FILE), |
161 | SYM_TYPE(STT_COMMON), |
162 | SYM_TYPE(STT_TLS), |
163 | #undef SYM_TYPE |
164 | }; |
165 | const char *name = "unknown sym type name" ; |
166 | if (type < ARRAY_SIZE(type_name)) { |
167 | name = type_name[type]; |
168 | } |
169 | return name; |
170 | } |
171 | |
172 | static const char *sym_bind(unsigned bind) |
173 | { |
174 | static const char *bind_name[] = { |
175 | #define SYM_BIND(X) [X] = #X |
176 | SYM_BIND(STB_LOCAL), |
177 | SYM_BIND(STB_GLOBAL), |
178 | SYM_BIND(STB_WEAK), |
179 | #undef SYM_BIND |
180 | }; |
181 | const char *name = "unknown sym bind name" ; |
182 | if (bind < ARRAY_SIZE(bind_name)) { |
183 | name = bind_name[bind]; |
184 | } |
185 | return name; |
186 | } |
187 | |
188 | static const char *sym_visibility(unsigned visibility) |
189 | { |
190 | static const char *visibility_name[] = { |
191 | #define SYM_VISIBILITY(X) [X] = #X |
192 | SYM_VISIBILITY(STV_DEFAULT), |
193 | SYM_VISIBILITY(STV_INTERNAL), |
194 | SYM_VISIBILITY(STV_HIDDEN), |
195 | SYM_VISIBILITY(STV_PROTECTED), |
196 | #undef SYM_VISIBILITY |
197 | }; |
198 | const char *name = "unknown sym visibility name" ; |
199 | if (visibility < ARRAY_SIZE(visibility_name)) { |
200 | name = visibility_name[visibility]; |
201 | } |
202 | return name; |
203 | } |
204 | |
205 | static const char *rel_type(unsigned type) |
206 | { |
207 | static const char *type_name[] = { |
208 | #define REL_TYPE(X) [X] = #X |
209 | #if ELF_BITS == 64 |
210 | REL_TYPE(R_X86_64_NONE), |
211 | REL_TYPE(R_X86_64_64), |
212 | REL_TYPE(R_X86_64_PC64), |
213 | REL_TYPE(R_X86_64_PC32), |
214 | REL_TYPE(R_X86_64_GOT32), |
215 | REL_TYPE(R_X86_64_PLT32), |
216 | REL_TYPE(R_X86_64_COPY), |
217 | REL_TYPE(R_X86_64_GLOB_DAT), |
218 | REL_TYPE(R_X86_64_JUMP_SLOT), |
219 | REL_TYPE(R_X86_64_RELATIVE), |
220 | REL_TYPE(R_X86_64_GOTPCREL), |
221 | REL_TYPE(R_X86_64_32), |
222 | REL_TYPE(R_X86_64_32S), |
223 | REL_TYPE(R_X86_64_16), |
224 | REL_TYPE(R_X86_64_PC16), |
225 | REL_TYPE(R_X86_64_8), |
226 | REL_TYPE(R_X86_64_PC8), |
227 | #else |
228 | REL_TYPE(R_386_NONE), |
229 | REL_TYPE(R_386_32), |
230 | REL_TYPE(R_386_PC32), |
231 | REL_TYPE(R_386_GOT32), |
232 | REL_TYPE(R_386_PLT32), |
233 | REL_TYPE(R_386_COPY), |
234 | REL_TYPE(R_386_GLOB_DAT), |
235 | REL_TYPE(R_386_JMP_SLOT), |
236 | REL_TYPE(R_386_RELATIVE), |
237 | REL_TYPE(R_386_GOTOFF), |
238 | REL_TYPE(R_386_GOTPC), |
239 | REL_TYPE(R_386_8), |
240 | REL_TYPE(R_386_PC8), |
241 | REL_TYPE(R_386_16), |
242 | REL_TYPE(R_386_PC16), |
243 | #endif |
244 | #undef REL_TYPE |
245 | }; |
246 | const char *name = "unknown type rel type name" ; |
247 | if (type < ARRAY_SIZE(type_name) && type_name[type]) { |
248 | name = type_name[type]; |
249 | } |
250 | return name; |
251 | } |
252 | |
253 | static const char *sec_name(unsigned shndx) |
254 | { |
255 | const char *sec_strtab; |
256 | const char *name; |
257 | sec_strtab = secs[shstrndx].strtab; |
258 | name = "<noname>" ; |
259 | if (shndx < shnum) { |
260 | name = sec_strtab + secs[shndx].shdr.sh_name; |
261 | } |
262 | else if (shndx == SHN_ABS) { |
263 | name = "ABSOLUTE" ; |
264 | } |
265 | else if (shndx == SHN_COMMON) { |
266 | name = "COMMON" ; |
267 | } |
268 | return name; |
269 | } |
270 | |
271 | static const char *sym_name(const char *sym_strtab, Elf_Sym *sym) |
272 | { |
273 | const char *name; |
274 | name = "<noname>" ; |
275 | if (sym->st_name) { |
276 | name = sym_strtab + sym->st_name; |
277 | } |
278 | else { |
279 | name = sec_name(shndx: sym_index(sym)); |
280 | } |
281 | return name; |
282 | } |
283 | |
284 | static Elf_Sym *sym_lookup(const char *symname) |
285 | { |
286 | int i; |
287 | for (i = 0; i < shnum; i++) { |
288 | struct section *sec = &secs[i]; |
289 | long nsyms; |
290 | char *strtab; |
291 | Elf_Sym *symtab; |
292 | Elf_Sym *sym; |
293 | |
294 | if (sec->shdr.sh_type != SHT_SYMTAB) |
295 | continue; |
296 | |
297 | nsyms = sec->shdr.sh_size/sizeof(Elf_Sym); |
298 | symtab = sec->symtab; |
299 | strtab = sec->link->strtab; |
300 | |
301 | for (sym = symtab; --nsyms >= 0; sym++) { |
302 | if (!sym->st_name) |
303 | continue; |
304 | if (strcmp(symname, strtab + sym->st_name) == 0) |
305 | return sym; |
306 | } |
307 | } |
308 | return 0; |
309 | } |
310 | |
311 | #if BYTE_ORDER == LITTLE_ENDIAN |
312 | #define le16_to_cpu(val) (val) |
313 | #define le32_to_cpu(val) (val) |
314 | #define le64_to_cpu(val) (val) |
315 | #endif |
316 | #if BYTE_ORDER == BIG_ENDIAN |
317 | #define le16_to_cpu(val) bswap_16(val) |
318 | #define le32_to_cpu(val) bswap_32(val) |
319 | #define le64_to_cpu(val) bswap_64(val) |
320 | #endif |
321 | |
322 | static uint16_t elf16_to_cpu(uint16_t val) |
323 | { |
324 | return le16_to_cpu(val); |
325 | } |
326 | |
327 | static uint32_t elf32_to_cpu(uint32_t val) |
328 | { |
329 | return le32_to_cpu(val); |
330 | } |
331 | |
332 | #define elf_half_to_cpu(x) elf16_to_cpu(x) |
333 | #define elf_word_to_cpu(x) elf32_to_cpu(x) |
334 | |
335 | #if ELF_BITS == 64 |
336 | static uint64_t elf64_to_cpu(uint64_t val) |
337 | { |
338 | return le64_to_cpu(val); |
339 | } |
340 | #define elf_addr_to_cpu(x) elf64_to_cpu(x) |
341 | #define elf_off_to_cpu(x) elf64_to_cpu(x) |
342 | #define elf_xword_to_cpu(x) elf64_to_cpu(x) |
343 | #else |
344 | #define elf_addr_to_cpu(x) elf32_to_cpu(x) |
345 | #define elf_off_to_cpu(x) elf32_to_cpu(x) |
346 | #define elf_xword_to_cpu(x) elf32_to_cpu(x) |
347 | #endif |
348 | |
349 | static int sym_index(Elf_Sym *sym) |
350 | { |
351 | Elf_Sym *symtab = secs[shsymtabndx].symtab; |
352 | Elf32_Word *xsymtab = secs[shxsymtabndx].xsymtab; |
353 | unsigned long offset; |
354 | int index; |
355 | |
356 | if (sym->st_shndx != SHN_XINDEX) |
357 | return sym->st_shndx; |
358 | |
359 | /* calculate offset of sym from head of table. */ |
360 | offset = (unsigned long)sym - (unsigned long)symtab; |
361 | index = offset / sizeof(*sym); |
362 | |
363 | return elf32_to_cpu(xsymtab[index]); |
364 | } |
365 | |
366 | static void read_ehdr(FILE *fp) |
367 | { |
368 | if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) { |
369 | die("Cannot read ELF header: %s\n" , |
370 | strerror(errno)); |
371 | } |
372 | if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) { |
373 | die("No ELF magic\n" ); |
374 | } |
375 | if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) { |
376 | die("Not a %d bit executable\n" , ELF_BITS); |
377 | } |
378 | if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) { |
379 | die("Not a LSB ELF executable\n" ); |
380 | } |
381 | if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) { |
382 | die("Unknown ELF version\n" ); |
383 | } |
384 | /* Convert the fields to native endian */ |
385 | ehdr.e_type = elf_half_to_cpu(ehdr.e_type); |
386 | ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine); |
387 | ehdr.e_version = elf_word_to_cpu(ehdr.e_version); |
388 | ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry); |
389 | ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff); |
390 | ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff); |
391 | ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags); |
392 | ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize); |
393 | ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize); |
394 | ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum); |
395 | ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize); |
396 | ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum); |
397 | ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx); |
398 | |
399 | shnum = ehdr.e_shnum; |
400 | shstrndx = ehdr.e_shstrndx; |
401 | |
402 | if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) |
403 | die("Unsupported ELF header type\n" ); |
404 | if (ehdr.e_machine != ELF_MACHINE) |
405 | die("Not for %s\n" , ELF_MACHINE_NAME); |
406 | if (ehdr.e_version != EV_CURRENT) |
407 | die("Unknown ELF version\n" ); |
408 | if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) |
409 | die("Bad ELF header size\n" ); |
410 | if (ehdr.e_phentsize != sizeof(Elf_Phdr)) |
411 | die("Bad program header entry\n" ); |
412 | if (ehdr.e_shentsize != sizeof(Elf_Shdr)) |
413 | die("Bad section header entry\n" ); |
414 | |
415 | |
416 | if (shnum == SHN_UNDEF || shstrndx == SHN_XINDEX) { |
417 | Elf_Shdr shdr; |
418 | |
419 | if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) |
420 | die("Seek to %" FMT " failed: %s\n" , ehdr.e_shoff, strerror(errno)); |
421 | |
422 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
423 | die("Cannot read initial ELF section header: %s\n" , strerror(errno)); |
424 | |
425 | if (shnum == SHN_UNDEF) |
426 | shnum = elf_xword_to_cpu(shdr.sh_size); |
427 | |
428 | if (shstrndx == SHN_XINDEX) |
429 | shstrndx = elf_word_to_cpu(shdr.sh_link); |
430 | } |
431 | |
432 | if (shstrndx >= shnum) |
433 | die("String table index out of bounds\n" ); |
434 | } |
435 | |
436 | static void read_shdrs(FILE *fp) |
437 | { |
438 | int i; |
439 | Elf_Shdr shdr; |
440 | |
441 | secs = calloc(shnum, sizeof(struct section)); |
442 | if (!secs) { |
443 | die("Unable to allocate %ld section headers\n" , |
444 | shnum); |
445 | } |
446 | if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) { |
447 | die("Seek to %" FMT " failed: %s\n" , |
448 | ehdr.e_shoff, strerror(errno)); |
449 | } |
450 | for (i = 0; i < shnum; i++) { |
451 | struct section *sec = &secs[i]; |
452 | if (fread(&shdr, sizeof(shdr), 1, fp) != 1) |
453 | die("Cannot read ELF section headers %d/%ld: %s\n" , |
454 | i, shnum, strerror(errno)); |
455 | sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name); |
456 | sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type); |
457 | sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags); |
458 | sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr); |
459 | sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset); |
460 | sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size); |
461 | sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link); |
462 | sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info); |
463 | sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign); |
464 | sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize); |
465 | if (sec->shdr.sh_link < shnum) |
466 | sec->link = &secs[sec->shdr.sh_link]; |
467 | } |
468 | |
469 | } |
470 | |
471 | static void read_strtabs(FILE *fp) |
472 | { |
473 | int i; |
474 | for (i = 0; i < shnum; i++) { |
475 | struct section *sec = &secs[i]; |
476 | if (sec->shdr.sh_type != SHT_STRTAB) { |
477 | continue; |
478 | } |
479 | sec->strtab = malloc(sec->shdr.sh_size); |
480 | if (!sec->strtab) { |
481 | die("malloc of %" FMT " bytes for strtab failed\n" , |
482 | sec->shdr.sh_size); |
483 | } |
484 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
485 | die("Seek to %" FMT " failed: %s\n" , |
486 | sec->shdr.sh_offset, strerror(errno)); |
487 | } |
488 | if (fread(sec->strtab, 1, sec->shdr.sh_size, fp) |
489 | != sec->shdr.sh_size) { |
490 | die("Cannot read symbol table: %s\n" , |
491 | strerror(errno)); |
492 | } |
493 | } |
494 | } |
495 | |
496 | static void read_symtabs(FILE *fp) |
497 | { |
498 | int i,j; |
499 | |
500 | for (i = 0; i < shnum; i++) { |
501 | struct section *sec = &secs[i]; |
502 | int num_syms; |
503 | |
504 | switch (sec->shdr.sh_type) { |
505 | case SHT_SYMTAB_SHNDX: |
506 | sec->xsymtab = malloc(sec->shdr.sh_size); |
507 | if (!sec->xsymtab) { |
508 | die("malloc of %" FMT " bytes for xsymtab failed\n" , |
509 | sec->shdr.sh_size); |
510 | } |
511 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
512 | die("Seek to %" FMT " failed: %s\n" , |
513 | sec->shdr.sh_offset, strerror(errno)); |
514 | } |
515 | if (fread(sec->xsymtab, 1, sec->shdr.sh_size, fp) |
516 | != sec->shdr.sh_size) { |
517 | die("Cannot read extended symbol table: %s\n" , |
518 | strerror(errno)); |
519 | } |
520 | shxsymtabndx = i; |
521 | continue; |
522 | |
523 | case SHT_SYMTAB: |
524 | num_syms = sec->shdr.sh_size / sizeof(Elf_Sym); |
525 | |
526 | sec->symtab = malloc(sec->shdr.sh_size); |
527 | if (!sec->symtab) { |
528 | die("malloc of %" FMT " bytes for symtab failed\n" , |
529 | sec->shdr.sh_size); |
530 | } |
531 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
532 | die("Seek to %" FMT " failed: %s\n" , |
533 | sec->shdr.sh_offset, strerror(errno)); |
534 | } |
535 | if (fread(sec->symtab, 1, sec->shdr.sh_size, fp) |
536 | != sec->shdr.sh_size) { |
537 | die("Cannot read symbol table: %s\n" , |
538 | strerror(errno)); |
539 | } |
540 | for (j = 0; j < num_syms; j++) { |
541 | Elf_Sym *sym = &sec->symtab[j]; |
542 | |
543 | sym->st_name = elf_word_to_cpu(sym->st_name); |
544 | sym->st_value = elf_addr_to_cpu(sym->st_value); |
545 | sym->st_size = elf_xword_to_cpu(sym->st_size); |
546 | sym->st_shndx = elf_half_to_cpu(sym->st_shndx); |
547 | } |
548 | shsymtabndx = i; |
549 | continue; |
550 | |
551 | default: |
552 | continue; |
553 | } |
554 | } |
555 | } |
556 | |
557 | |
558 | static void read_relocs(FILE *fp) |
559 | { |
560 | int i,j; |
561 | for (i = 0; i < shnum; i++) { |
562 | struct section *sec = &secs[i]; |
563 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
564 | continue; |
565 | } |
566 | sec->reltab = malloc(sec->shdr.sh_size); |
567 | if (!sec->reltab) { |
568 | die("malloc of %" FMT " bytes for relocs failed\n" , |
569 | sec->shdr.sh_size); |
570 | } |
571 | if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) { |
572 | die("Seek to %" FMT " failed: %s\n" , |
573 | sec->shdr.sh_offset, strerror(errno)); |
574 | } |
575 | if (fread(sec->reltab, 1, sec->shdr.sh_size, fp) |
576 | != sec->shdr.sh_size) { |
577 | die("Cannot read symbol table: %s\n" , |
578 | strerror(errno)); |
579 | } |
580 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
581 | Elf_Rel *rel = &sec->reltab[j]; |
582 | rel->r_offset = elf_addr_to_cpu(rel->r_offset); |
583 | rel->r_info = elf_xword_to_cpu(rel->r_info); |
584 | #if (SHT_REL_TYPE == SHT_RELA) |
585 | rel->r_addend = elf_xword_to_cpu(rel->r_addend); |
586 | #endif |
587 | } |
588 | } |
589 | } |
590 | |
591 | |
592 | static void print_absolute_symbols(void) |
593 | { |
594 | int i; |
595 | const char *format; |
596 | |
597 | if (ELF_BITS == 64) |
598 | format = "%5d %016" PRIx64" %5" PRId64" %10s %10s %12s %s\n" ; |
599 | else |
600 | format = "%5d %08" PRIx32" %5" PRId32" %10s %10s %12s %s\n" ; |
601 | |
602 | printf("Absolute symbols\n" ); |
603 | printf(" Num: Value Size Type Bind Visibility Name\n" ); |
604 | for (i = 0; i < shnum; i++) { |
605 | struct section *sec = &secs[i]; |
606 | char *sym_strtab; |
607 | int j; |
608 | |
609 | if (sec->shdr.sh_type != SHT_SYMTAB) { |
610 | continue; |
611 | } |
612 | sym_strtab = sec->link->strtab; |
613 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) { |
614 | Elf_Sym *sym; |
615 | const char *name; |
616 | sym = &sec->symtab[j]; |
617 | name = sym_name(sym_strtab, sym); |
618 | if (sym->st_shndx != SHN_ABS) { |
619 | continue; |
620 | } |
621 | printf(format, |
622 | j, sym->st_value, sym->st_size, |
623 | sym_type(ELF_ST_TYPE(sym->st_info)), |
624 | sym_bind(ELF_ST_BIND(sym->st_info)), |
625 | sym_visibility(ELF_ST_VISIBILITY(sym->st_other)), |
626 | name); |
627 | } |
628 | } |
629 | printf("\n" ); |
630 | } |
631 | |
632 | static void print_absolute_relocs(void) |
633 | { |
634 | int i, printed = 0; |
635 | const char *format; |
636 | |
637 | if (ELF_BITS == 64) |
638 | format = "%016" PRIx64" %016" PRIx64" %10s %016" PRIx64" %s\n" ; |
639 | else |
640 | format = "%08" PRIx32" %08" PRIx32" %10s %08" PRIx32" %s\n" ; |
641 | |
642 | for (i = 0; i < shnum; i++) { |
643 | struct section *sec = &secs[i]; |
644 | struct section *sec_applies, *sec_symtab; |
645 | char *sym_strtab; |
646 | Elf_Sym *sh_symtab; |
647 | int j; |
648 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
649 | continue; |
650 | } |
651 | sec_symtab = sec->link; |
652 | sec_applies = &secs[sec->shdr.sh_info]; |
653 | if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { |
654 | continue; |
655 | } |
656 | sh_symtab = sec_symtab->symtab; |
657 | sym_strtab = sec_symtab->link->strtab; |
658 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
659 | Elf_Rel *rel; |
660 | Elf_Sym *sym; |
661 | const char *name; |
662 | rel = &sec->reltab[j]; |
663 | sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; |
664 | name = sym_name(sym_strtab, sym); |
665 | if (sym->st_shndx != SHN_ABS) { |
666 | continue; |
667 | } |
668 | |
669 | /* Absolute symbols are not relocated if bzImage is |
670 | * loaded at a non-compiled address. Display a warning |
671 | * to user at compile time about the absolute |
672 | * relocations present. |
673 | * |
674 | * User need to audit the code to make sure |
675 | * some symbols which should have been section |
676 | * relative have not become absolute because of some |
677 | * linker optimization or wrong programming usage. |
678 | * |
679 | * Before warning check if this absolute symbol |
680 | * relocation is harmless. |
681 | */ |
682 | if (is_reloc(S_ABS, name) || is_reloc(S_REL, name)) |
683 | continue; |
684 | |
685 | if (!printed) { |
686 | printf("WARNING: Absolute relocations" |
687 | " present\n" ); |
688 | printf("Offset Info Type Sym.Value " |
689 | "Sym.Name\n" ); |
690 | printed = 1; |
691 | } |
692 | |
693 | printf(format, |
694 | rel->r_offset, |
695 | rel->r_info, |
696 | rel_type(ELF_R_TYPE(rel->r_info)), |
697 | sym->st_value, |
698 | name); |
699 | } |
700 | } |
701 | |
702 | if (printed) |
703 | printf("\n" ); |
704 | } |
705 | |
706 | static void add_reloc(struct relocs *r, uint32_t offset) |
707 | { |
708 | if (r->count == r->size) { |
709 | unsigned long newsize = r->size + 50000; |
710 | void *mem = realloc(r->offset, newsize * sizeof(r->offset[0])); |
711 | |
712 | if (!mem) |
713 | die("realloc of %ld entries for relocs failed\n" , |
714 | newsize); |
715 | r->offset = mem; |
716 | r->size = newsize; |
717 | } |
718 | r->offset[r->count++] = offset; |
719 | } |
720 | |
721 | static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel, |
722 | Elf_Sym *sym, const char *symname)) |
723 | { |
724 | int i; |
725 | /* Walk through the relocations */ |
726 | for (i = 0; i < shnum; i++) { |
727 | char *sym_strtab; |
728 | Elf_Sym *sh_symtab; |
729 | struct section *sec_applies, *sec_symtab; |
730 | int j; |
731 | struct section *sec = &secs[i]; |
732 | |
733 | if (sec->shdr.sh_type != SHT_REL_TYPE) { |
734 | continue; |
735 | } |
736 | sec_symtab = sec->link; |
737 | sec_applies = &secs[sec->shdr.sh_info]; |
738 | if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) { |
739 | continue; |
740 | } |
741 | sh_symtab = sec_symtab->symtab; |
742 | sym_strtab = sec_symtab->link->strtab; |
743 | for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) { |
744 | Elf_Rel *rel = &sec->reltab[j]; |
745 | Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)]; |
746 | const char *symname = sym_name(sym_strtab, sym); |
747 | |
748 | process(sec, rel, sym, symname); |
749 | } |
750 | } |
751 | } |
752 | |
753 | /* |
754 | * The .data..percpu section is a special case for x86_64 SMP kernels. |
755 | * It is used to initialize the actual per_cpu areas and to provide |
756 | * definitions for the per_cpu variables that correspond to their offsets |
757 | * within the percpu area. Since the values of all of the symbols need |
758 | * to be offsets from the start of the per_cpu area the virtual address |
759 | * (sh_addr) of .data..percpu is 0 in SMP kernels. |
760 | * |
761 | * This means that: |
762 | * |
763 | * Relocations that reference symbols in the per_cpu area do not |
764 | * need further relocation (since the value is an offset relative |
765 | * to the start of the per_cpu area that does not change). |
766 | * |
767 | * Relocations that apply to the per_cpu area need to have their |
768 | * offset adjusted by by the value of __per_cpu_load to make them |
769 | * point to the correct place in the loaded image (because the |
770 | * virtual address of .data..percpu is 0). |
771 | * |
772 | * For non SMP kernels .data..percpu is linked as part of the normal |
773 | * kernel data and does not require special treatment. |
774 | * |
775 | */ |
776 | static int per_cpu_shndx = -1; |
777 | static Elf_Addr per_cpu_load_addr; |
778 | |
779 | static void percpu_init(void) |
780 | { |
781 | int i; |
782 | for (i = 0; i < shnum; i++) { |
783 | ElfW(Sym) *sym; |
784 | if (strcmp(sec_name(shndx: i), ".data..percpu" )) |
785 | continue; |
786 | |
787 | if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */ |
788 | return; |
789 | |
790 | sym = sym_lookup("__per_cpu_load" ); |
791 | if (!sym) |
792 | die("can't find __per_cpu_load\n" ); |
793 | |
794 | per_cpu_shndx = i; |
795 | per_cpu_load_addr = sym->st_value; |
796 | return; |
797 | } |
798 | } |
799 | |
800 | #if ELF_BITS == 64 |
801 | |
802 | /* |
803 | * Check to see if a symbol lies in the .data..percpu section. |
804 | * |
805 | * The linker incorrectly associates some symbols with the |
806 | * .data..percpu section so we also need to check the symbol |
807 | * name to make sure that we classify the symbol correctly. |
808 | * |
809 | * The GNU linker incorrectly associates: |
810 | * __init_begin |
811 | * __per_cpu_load |
812 | * |
813 | * The "gold" linker incorrectly associates: |
814 | * init_per_cpu__fixed_percpu_data |
815 | * init_per_cpu__gdt_page |
816 | */ |
817 | static int is_percpu_sym(ElfW(Sym) *sym, const char *symname) |
818 | { |
819 | int shndx = sym_index(sym); |
820 | |
821 | return (shndx == per_cpu_shndx) && |
822 | strcmp(symname, "__init_begin" ) && |
823 | strcmp(symname, "__per_cpu_load" ) && |
824 | strncmp(symname, "init_per_cpu_" , 13); |
825 | } |
826 | |
827 | |
828 | static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, |
829 | const char *symname) |
830 | { |
831 | unsigned r_type = ELF64_R_TYPE(rel->r_info); |
832 | ElfW(Addr) offset = rel->r_offset; |
833 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
834 | |
835 | if (sym->st_shndx == SHN_UNDEF) |
836 | return 0; |
837 | |
838 | /* |
839 | * Adjust the offset if this reloc applies to the percpu section. |
840 | */ |
841 | if (sec->shdr.sh_info == per_cpu_shndx) |
842 | offset += per_cpu_load_addr; |
843 | |
844 | switch (r_type) { |
845 | case R_X86_64_NONE: |
846 | /* NONE can be ignored. */ |
847 | break; |
848 | |
849 | case R_X86_64_PC32: |
850 | case R_X86_64_PLT32: |
851 | /* |
852 | * PC relative relocations don't need to be adjusted unless |
853 | * referencing a percpu symbol. |
854 | * |
855 | * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32. |
856 | */ |
857 | if (is_percpu_sym(sym, symname)) |
858 | add_reloc(&relocs32neg, offset); |
859 | break; |
860 | |
861 | case R_X86_64_PC64: |
862 | /* |
863 | * Only used by jump labels |
864 | */ |
865 | if (is_percpu_sym(sym, symname)) |
866 | die("Invalid R_X86_64_PC64 relocation against per-CPU symbol %s\n" , |
867 | symname); |
868 | break; |
869 | |
870 | case R_X86_64_32: |
871 | case R_X86_64_32S: |
872 | case R_X86_64_64: |
873 | /* |
874 | * References to the percpu area don't need to be adjusted. |
875 | */ |
876 | if (is_percpu_sym(sym, symname)) |
877 | break; |
878 | |
879 | if (shn_abs) { |
880 | /* |
881 | * Whitelisted absolute symbols do not require |
882 | * relocation. |
883 | */ |
884 | if (is_reloc(S_ABS, symname)) |
885 | break; |
886 | |
887 | die("Invalid absolute %s relocation: %s\n" , |
888 | rel_type(r_type), symname); |
889 | break; |
890 | } |
891 | |
892 | /* |
893 | * Relocation offsets for 64 bit kernels are output |
894 | * as 32 bits and sign extended back to 64 bits when |
895 | * the relocations are processed. |
896 | * Make sure that the offset will fit. |
897 | */ |
898 | if ((int32_t)offset != (int64_t)offset) |
899 | die("Relocation offset doesn't fit in 32 bits\n" ); |
900 | |
901 | if (r_type == R_X86_64_64) |
902 | add_reloc(&relocs64, offset); |
903 | else |
904 | add_reloc(&relocs32, offset); |
905 | break; |
906 | |
907 | default: |
908 | die("Unsupported relocation type: %s (%d)\n" , |
909 | rel_type(r_type), r_type); |
910 | break; |
911 | } |
912 | |
913 | return 0; |
914 | } |
915 | |
916 | #else |
917 | |
918 | static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
919 | const char *symname) |
920 | { |
921 | unsigned r_type = ELF32_R_TYPE(rel->r_info); |
922 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
923 | |
924 | switch (r_type) { |
925 | case R_386_NONE: |
926 | case R_386_PC32: |
927 | case R_386_PC16: |
928 | case R_386_PC8: |
929 | case R_386_PLT32: |
930 | /* |
931 | * NONE can be ignored and PC relative relocations don't need |
932 | * to be adjusted. Because sym must be defined, R_386_PLT32 can |
933 | * be treated the same way as R_386_PC32. |
934 | */ |
935 | break; |
936 | |
937 | case R_386_32: |
938 | if (shn_abs) { |
939 | /* |
940 | * Whitelisted absolute symbols do not require |
941 | * relocation. |
942 | */ |
943 | if (is_reloc(S_ABS, symname)) |
944 | break; |
945 | |
946 | die("Invalid absolute %s relocation: %s\n" , |
947 | rel_type(type: r_type), symname); |
948 | break; |
949 | } |
950 | |
951 | add_reloc(&relocs32, rel->r_offset); |
952 | break; |
953 | |
954 | default: |
955 | die("Unsupported relocation type: %s (%d)\n" , |
956 | rel_type(type: r_type), r_type); |
957 | break; |
958 | } |
959 | |
960 | return 0; |
961 | } |
962 | |
963 | static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
964 | const char *symname) |
965 | { |
966 | unsigned r_type = ELF32_R_TYPE(rel->r_info); |
967 | int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname); |
968 | |
969 | switch (r_type) { |
970 | case R_386_NONE: |
971 | case R_386_PC32: |
972 | case R_386_PC16: |
973 | case R_386_PC8: |
974 | case R_386_PLT32: |
975 | /* |
976 | * NONE can be ignored and PC relative relocations don't need |
977 | * to be adjusted. Because sym must be defined, R_386_PLT32 can |
978 | * be treated the same way as R_386_PC32. |
979 | */ |
980 | break; |
981 | |
982 | case R_386_16: |
983 | if (shn_abs) { |
984 | /* |
985 | * Whitelisted absolute symbols do not require |
986 | * relocation. |
987 | */ |
988 | if (is_reloc(S_ABS, symname)) |
989 | break; |
990 | |
991 | if (is_reloc(S_SEG, symname)) { |
992 | add_reloc(&relocs16, rel->r_offset); |
993 | break; |
994 | } |
995 | } else { |
996 | if (!is_reloc(S_LIN, symname)) |
997 | break; |
998 | } |
999 | die("Invalid %s %s relocation: %s\n" , |
1000 | shn_abs ? "absolute" : "relative" , |
1001 | rel_type(type: r_type), symname); |
1002 | break; |
1003 | |
1004 | case R_386_32: |
1005 | if (shn_abs) { |
1006 | /* |
1007 | * Whitelisted absolute symbols do not require |
1008 | * relocation. |
1009 | */ |
1010 | if (is_reloc(S_ABS, symname)) |
1011 | break; |
1012 | |
1013 | if (is_reloc(S_REL, symname)) { |
1014 | add_reloc(&relocs32, rel->r_offset); |
1015 | break; |
1016 | } |
1017 | } else { |
1018 | if (is_reloc(S_LIN, symname)) |
1019 | add_reloc(&relocs32, rel->r_offset); |
1020 | break; |
1021 | } |
1022 | die("Invalid %s %s relocation: %s\n" , |
1023 | shn_abs ? "absolute" : "relative" , |
1024 | rel_type(type: r_type), symname); |
1025 | break; |
1026 | |
1027 | default: |
1028 | die("Unsupported relocation type: %s (%d)\n" , |
1029 | rel_type(type: r_type), r_type); |
1030 | break; |
1031 | } |
1032 | |
1033 | return 0; |
1034 | } |
1035 | |
1036 | #endif |
1037 | |
1038 | static int cmp_relocs(const void *va, const void *vb) |
1039 | { |
1040 | const uint32_t *a, *b; |
1041 | a = va; b = vb; |
1042 | return (*a == *b)? 0 : (*a > *b)? 1 : -1; |
1043 | } |
1044 | |
1045 | static void sort_relocs(struct relocs *r) |
1046 | { |
1047 | qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs); |
1048 | } |
1049 | |
1050 | static int write32(uint32_t v, FILE *f) |
1051 | { |
1052 | unsigned char buf[4]; |
1053 | |
1054 | put_unaligned_le32(v, buf); |
1055 | return fwrite(buf, 1, 4, f) == 4 ? 0 : -1; |
1056 | } |
1057 | |
1058 | static int write32_as_text(uint32_t v, FILE *f) |
1059 | { |
1060 | return fprintf(f, "\t.long 0x%08" PRIx32"\n" , v) > 0 ? 0 : -1; |
1061 | } |
1062 | |
1063 | static void emit_relocs(int as_text, int use_real_mode) |
1064 | { |
1065 | int i; |
1066 | int (*write_reloc)(uint32_t, FILE *) = write32; |
1067 | int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym, |
1068 | const char *symname); |
1069 | |
1070 | #if ELF_BITS == 64 |
1071 | if (!use_real_mode) |
1072 | do_reloc = do_reloc64; |
1073 | else |
1074 | die("--realmode not valid for a 64-bit ELF file" ); |
1075 | #else |
1076 | if (!use_real_mode) |
1077 | do_reloc = do_reloc32; |
1078 | else |
1079 | do_reloc = do_reloc_real; |
1080 | #endif |
1081 | |
1082 | /* Collect up the relocations */ |
1083 | walk_relocs(process: do_reloc); |
1084 | |
1085 | if (relocs16.count && !use_real_mode) |
1086 | die("Segment relocations found but --realmode not specified\n" ); |
1087 | |
1088 | /* Order the relocations for more efficient processing */ |
1089 | sort_relocs(r: &relocs32); |
1090 | #if ELF_BITS == 64 |
1091 | sort_relocs(&relocs32neg); |
1092 | sort_relocs(&relocs64); |
1093 | #else |
1094 | sort_relocs(r: &relocs16); |
1095 | #endif |
1096 | |
1097 | /* Print the relocations */ |
1098 | if (as_text) { |
1099 | /* Print the relocations in a form suitable that |
1100 | * gas will like. |
1101 | */ |
1102 | printf(".section \".data.reloc\",\"a\"\n" ); |
1103 | printf(".balign 4\n" ); |
1104 | write_reloc = write32_as_text; |
1105 | } |
1106 | |
1107 | if (use_real_mode) { |
1108 | write_reloc(relocs16.count, stdout); |
1109 | for (i = 0; i < relocs16.count; i++) |
1110 | write_reloc(relocs16.offset[i], stdout); |
1111 | |
1112 | write_reloc(relocs32.count, stdout); |
1113 | for (i = 0; i < relocs32.count; i++) |
1114 | write_reloc(relocs32.offset[i], stdout); |
1115 | } else { |
1116 | #if ELF_BITS == 64 |
1117 | /* Print a stop */ |
1118 | write_reloc(0, stdout); |
1119 | |
1120 | /* Now print each relocation */ |
1121 | for (i = 0; i < relocs64.count; i++) |
1122 | write_reloc(relocs64.offset[i], stdout); |
1123 | |
1124 | /* Print a stop */ |
1125 | write_reloc(0, stdout); |
1126 | |
1127 | /* Now print each inverse 32-bit relocation */ |
1128 | for (i = 0; i < relocs32neg.count; i++) |
1129 | write_reloc(relocs32neg.offset[i], stdout); |
1130 | #endif |
1131 | |
1132 | /* Print a stop */ |
1133 | write_reloc(0, stdout); |
1134 | |
1135 | /* Now print each relocation */ |
1136 | for (i = 0; i < relocs32.count; i++) |
1137 | write_reloc(relocs32.offset[i], stdout); |
1138 | } |
1139 | } |
1140 | |
1141 | /* |
1142 | * As an aid to debugging problems with different linkers |
1143 | * print summary information about the relocs. |
1144 | * Since different linkers tend to emit the sections in |
1145 | * different orders we use the section names in the output. |
1146 | */ |
1147 | static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym, |
1148 | const char *symname) |
1149 | { |
1150 | printf("%s\t%s\t%s\t%s\n" , |
1151 | sec_name(shndx: sec->shdr.sh_info), |
1152 | rel_type(type: ELF_R_TYPE(rel->r_info)), |
1153 | symname, |
1154 | sec_name(shndx: sym_index(sym))); |
1155 | return 0; |
1156 | } |
1157 | |
1158 | static void print_reloc_info(void) |
1159 | { |
1160 | printf("reloc section\treloc type\tsymbol\tsymbol section\n" ); |
1161 | walk_relocs(process: do_reloc_info); |
1162 | } |
1163 | |
1164 | #if ELF_BITS == 64 |
1165 | # define process process_64 |
1166 | #else |
1167 | # define process process_32 |
1168 | #endif |
1169 | |
1170 | void process(FILE *fp, int use_real_mode, int as_text, |
1171 | int show_absolute_syms, int show_absolute_relocs, |
1172 | int show_reloc_info) |
1173 | { |
1174 | regex_init(use_real_mode); |
1175 | read_ehdr(fp); |
1176 | read_shdrs(fp); |
1177 | read_strtabs(fp); |
1178 | read_symtabs(fp); |
1179 | read_relocs(fp); |
1180 | if (ELF_BITS == 64) |
1181 | percpu_init(); |
1182 | if (show_absolute_syms) { |
1183 | print_absolute_symbols(); |
1184 | return; |
1185 | } |
1186 | if (show_absolute_relocs) { |
1187 | print_absolute_relocs(); |
1188 | return; |
1189 | } |
1190 | if (show_reloc_info) { |
1191 | print_reloc_info(); |
1192 | return; |
1193 | } |
1194 | emit_relocs(as_text, use_real_mode); |
1195 | } |
1196 | |