1 // SPDX-License-Identifier: GPL-2.0
2 /* This is included from relocs_32/64.c */
4 #define ElfW(type) _ElfW(ELF_BITS, type)
5 #define _ElfW(bits, type) __ElfW(bits, type)
6 #define __ElfW(bits, type) Elf##bits##_##type
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)
22 static struct relocs relocs16;
23 static struct relocs relocs32;
25 static struct relocs relocs32neg;
26 static struct relocs relocs64;
36 static struct section *secs;
38 static const char * const sym_regex_kernel[S_NSYMTYPES] = {
40 * Following symbols have been audited. There values are constant and do
41 * not change if bzImage is loaded at a different physical address than
42 * the address for which it has been compiled. Don't warn user about
43 * absolute relocations present w.r.t these symbols.
46 "^(xen_irq_disable_direct_reloc$|"
47 "xen_save_fl_direct_reloc$|"
52 * These symbols are known to be relative, even if the linker marks them
53 * as absolute (typically defined outside any section in the linker script.)
56 "^(__init_(begin|end)|"
57 "__x86_cpu_dev_(start|end)|"
58 "(__parainstructions|__alt_instructions)(|_end)|"
59 "(__iommu_table|__apicdrivers|__smp_locks)(|_end)|"
60 "__(start|end)_pci_.*|"
61 "__(start|end)_builtin_fw|"
62 "__(start|stop)___ksymtab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
63 "__(start|stop)___kcrctab(|_gpl|_unused|_unused_gpl|_gpl_future)|"
64 "__(start|stop)___param|"
65 "__(start|stop)___modver|"
66 "__(start|stop)___bug_table|"
67 "__tracedata_(start|end)|"
68 "__(start|stop)_notes|"
70 "__end_rodata_aligned|"
72 "(jiffies|jiffies_64)|"
76 "__end_rodata_hpage_align|"
83 static const char * const sym_regex_realmode[S_NSYMTYPES] = {
85 * These symbols are known to be relative, even if the linker marks them
86 * as absolute (typically defined outside any section in the linker script.)
92 * These are 16-bit segment symbols when compiling 16-bit code.
98 * These are offsets belonging to segments, as opposed to linear addresses,
99 * when compiling 16-bit code.
105 static const char * const *sym_regex;
107 static regex_t sym_regex_c[S_NSYMTYPES];
108 static int is_reloc(enum symtype type, const char *sym_name)
110 return sym_regex[type] &&
111 !regexec(&sym_regex_c[type], sym_name, 0, NULL, 0);
114 static void regex_init(int use_real_mode)
121 sym_regex = sym_regex_realmode;
123 sym_regex = sym_regex_kernel;
125 for (i = 0; i < S_NSYMTYPES; i++) {
129 err = regcomp(&sym_regex_c[i], sym_regex[i],
130 REG_EXTENDED|REG_NOSUB);
133 regerror(err, &sym_regex_c[i], errbuf, sizeof errbuf);
139 static const char *sym_type(unsigned type)
141 static const char *type_name[] = {
142 #define SYM_TYPE(X) [X] = #X
143 SYM_TYPE(STT_NOTYPE),
144 SYM_TYPE(STT_OBJECT),
146 SYM_TYPE(STT_SECTION),
148 SYM_TYPE(STT_COMMON),
152 const char *name = "unknown sym type name";
153 if (type < ARRAY_SIZE(type_name)) {
154 name = type_name[type];
159 static const char *sym_bind(unsigned bind)
161 static const char *bind_name[] = {
162 #define SYM_BIND(X) [X] = #X
164 SYM_BIND(STB_GLOBAL),
168 const char *name = "unknown sym bind name";
169 if (bind < ARRAY_SIZE(bind_name)) {
170 name = bind_name[bind];
175 static const char *sym_visibility(unsigned visibility)
177 static const char *visibility_name[] = {
178 #define SYM_VISIBILITY(X) [X] = #X
179 SYM_VISIBILITY(STV_DEFAULT),
180 SYM_VISIBILITY(STV_INTERNAL),
181 SYM_VISIBILITY(STV_HIDDEN),
182 SYM_VISIBILITY(STV_PROTECTED),
183 #undef SYM_VISIBILITY
185 const char *name = "unknown sym visibility name";
186 if (visibility < ARRAY_SIZE(visibility_name)) {
187 name = visibility_name[visibility];
192 static const char *rel_type(unsigned type)
194 static const char *type_name[] = {
195 #define REL_TYPE(X) [X] = #X
197 REL_TYPE(R_X86_64_NONE),
198 REL_TYPE(R_X86_64_64),
199 REL_TYPE(R_X86_64_PC32),
200 REL_TYPE(R_X86_64_GOT32),
201 REL_TYPE(R_X86_64_PLT32),
202 REL_TYPE(R_X86_64_COPY),
203 REL_TYPE(R_X86_64_GLOB_DAT),
204 REL_TYPE(R_X86_64_JUMP_SLOT),
205 REL_TYPE(R_X86_64_RELATIVE),
206 REL_TYPE(R_X86_64_GOTPCREL),
207 REL_TYPE(R_X86_64_32),
208 REL_TYPE(R_X86_64_32S),
209 REL_TYPE(R_X86_64_16),
210 REL_TYPE(R_X86_64_PC16),
211 REL_TYPE(R_X86_64_8),
212 REL_TYPE(R_X86_64_PC8),
214 REL_TYPE(R_386_NONE),
216 REL_TYPE(R_386_PC32),
217 REL_TYPE(R_386_GOT32),
218 REL_TYPE(R_386_PLT32),
219 REL_TYPE(R_386_COPY),
220 REL_TYPE(R_386_GLOB_DAT),
221 REL_TYPE(R_386_JMP_SLOT),
222 REL_TYPE(R_386_RELATIVE),
223 REL_TYPE(R_386_GOTOFF),
224 REL_TYPE(R_386_GOTPC),
228 REL_TYPE(R_386_PC16),
232 const char *name = "unknown type rel type name";
233 if (type < ARRAY_SIZE(type_name) && type_name[type]) {
234 name = type_name[type];
239 static const char *sec_name(unsigned shndx)
241 const char *sec_strtab;
243 sec_strtab = secs[ehdr.e_shstrndx].strtab;
245 if (shndx < ehdr.e_shnum) {
246 name = sec_strtab + secs[shndx].shdr.sh_name;
248 else if (shndx == SHN_ABS) {
251 else if (shndx == SHN_COMMON) {
257 static const char *sym_name(const char *sym_strtab, Elf_Sym *sym)
262 name = sym_strtab + sym->st_name;
265 name = sec_name(sym->st_shndx);
270 static Elf_Sym *sym_lookup(const char *symname)
273 for (i = 0; i < ehdr.e_shnum; i++) {
274 struct section *sec = &secs[i];
280 if (sec->shdr.sh_type != SHT_SYMTAB)
283 nsyms = sec->shdr.sh_size/sizeof(Elf_Sym);
284 symtab = sec->symtab;
285 strtab = sec->link->strtab;
287 for (sym = symtab; --nsyms >= 0; sym++) {
290 if (strcmp(symname, strtab + sym->st_name) == 0)
297 #if BYTE_ORDER == LITTLE_ENDIAN
298 #define le16_to_cpu(val) (val)
299 #define le32_to_cpu(val) (val)
300 #define le64_to_cpu(val) (val)
302 #if BYTE_ORDER == BIG_ENDIAN
303 #define le16_to_cpu(val) bswap_16(val)
304 #define le32_to_cpu(val) bswap_32(val)
305 #define le64_to_cpu(val) bswap_64(val)
308 static uint16_t elf16_to_cpu(uint16_t val)
310 return le16_to_cpu(val);
313 static uint32_t elf32_to_cpu(uint32_t val)
315 return le32_to_cpu(val);
318 #define elf_half_to_cpu(x) elf16_to_cpu(x)
319 #define elf_word_to_cpu(x) elf32_to_cpu(x)
322 static uint64_t elf64_to_cpu(uint64_t val)
324 return le64_to_cpu(val);
326 #define elf_addr_to_cpu(x) elf64_to_cpu(x)
327 #define elf_off_to_cpu(x) elf64_to_cpu(x)
328 #define elf_xword_to_cpu(x) elf64_to_cpu(x)
330 #define elf_addr_to_cpu(x) elf32_to_cpu(x)
331 #define elf_off_to_cpu(x) elf32_to_cpu(x)
332 #define elf_xword_to_cpu(x) elf32_to_cpu(x)
335 static void read_ehdr(FILE *fp)
337 if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1) {
338 die("Cannot read ELF header: %s\n",
341 if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0) {
342 die("No ELF magic\n");
344 if (ehdr.e_ident[EI_CLASS] != ELF_CLASS) {
345 die("Not a %d bit executable\n", ELF_BITS);
347 if (ehdr.e_ident[EI_DATA] != ELFDATA2LSB) {
348 die("Not a LSB ELF executable\n");
350 if (ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
351 die("Unknown ELF version\n");
353 /* Convert the fields to native endian */
354 ehdr.e_type = elf_half_to_cpu(ehdr.e_type);
355 ehdr.e_machine = elf_half_to_cpu(ehdr.e_machine);
356 ehdr.e_version = elf_word_to_cpu(ehdr.e_version);
357 ehdr.e_entry = elf_addr_to_cpu(ehdr.e_entry);
358 ehdr.e_phoff = elf_off_to_cpu(ehdr.e_phoff);
359 ehdr.e_shoff = elf_off_to_cpu(ehdr.e_shoff);
360 ehdr.e_flags = elf_word_to_cpu(ehdr.e_flags);
361 ehdr.e_ehsize = elf_half_to_cpu(ehdr.e_ehsize);
362 ehdr.e_phentsize = elf_half_to_cpu(ehdr.e_phentsize);
363 ehdr.e_phnum = elf_half_to_cpu(ehdr.e_phnum);
364 ehdr.e_shentsize = elf_half_to_cpu(ehdr.e_shentsize);
365 ehdr.e_shnum = elf_half_to_cpu(ehdr.e_shnum);
366 ehdr.e_shstrndx = elf_half_to_cpu(ehdr.e_shstrndx);
368 if ((ehdr.e_type != ET_EXEC) && (ehdr.e_type != ET_DYN)) {
369 die("Unsupported ELF header type\n");
371 if (ehdr.e_machine != ELF_MACHINE) {
372 die("Not for %s\n", ELF_MACHINE_NAME);
374 if (ehdr.e_version != EV_CURRENT) {
375 die("Unknown ELF version\n");
377 if (ehdr.e_ehsize != sizeof(Elf_Ehdr)) {
378 die("Bad Elf header size\n");
380 if (ehdr.e_phentsize != sizeof(Elf_Phdr)) {
381 die("Bad program header entry\n");
383 if (ehdr.e_shentsize != sizeof(Elf_Shdr)) {
384 die("Bad section header entry\n");
386 if (ehdr.e_shstrndx >= ehdr.e_shnum) {
387 die("String table index out of bounds\n");
391 static void read_shdrs(FILE *fp)
396 secs = calloc(ehdr.e_shnum, sizeof(struct section));
398 die("Unable to allocate %d section headers\n",
401 if (fseek(fp, ehdr.e_shoff, SEEK_SET) < 0) {
402 die("Seek to %d failed: %s\n",
403 ehdr.e_shoff, strerror(errno));
405 for (i = 0; i < ehdr.e_shnum; i++) {
406 struct section *sec = &secs[i];
407 if (fread(&shdr, sizeof shdr, 1, fp) != 1)
408 die("Cannot read ELF section headers %d/%d: %s\n",
409 i, ehdr.e_shnum, strerror(errno));
410 sec->shdr.sh_name = elf_word_to_cpu(shdr.sh_name);
411 sec->shdr.sh_type = elf_word_to_cpu(shdr.sh_type);
412 sec->shdr.sh_flags = elf_xword_to_cpu(shdr.sh_flags);
413 sec->shdr.sh_addr = elf_addr_to_cpu(shdr.sh_addr);
414 sec->shdr.sh_offset = elf_off_to_cpu(shdr.sh_offset);
415 sec->shdr.sh_size = elf_xword_to_cpu(shdr.sh_size);
416 sec->shdr.sh_link = elf_word_to_cpu(shdr.sh_link);
417 sec->shdr.sh_info = elf_word_to_cpu(shdr.sh_info);
418 sec->shdr.sh_addralign = elf_xword_to_cpu(shdr.sh_addralign);
419 sec->shdr.sh_entsize = elf_xword_to_cpu(shdr.sh_entsize);
420 if (sec->shdr.sh_link < ehdr.e_shnum)
421 sec->link = &secs[sec->shdr.sh_link];
426 static void read_strtabs(FILE *fp)
429 for (i = 0; i < ehdr.e_shnum; i++) {
430 struct section *sec = &secs[i];
431 if (sec->shdr.sh_type != SHT_STRTAB) {
434 sec->strtab = malloc(sec->shdr.sh_size);
436 die("malloc of %d bytes for strtab failed\n",
439 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
440 die("Seek to %d failed: %s\n",
441 sec->shdr.sh_offset, strerror(errno));
443 if (fread(sec->strtab, 1, sec->shdr.sh_size, fp)
444 != sec->shdr.sh_size) {
445 die("Cannot read symbol table: %s\n",
451 static void read_symtabs(FILE *fp)
454 for (i = 0; i < ehdr.e_shnum; i++) {
455 struct section *sec = &secs[i];
456 if (sec->shdr.sh_type != SHT_SYMTAB) {
459 sec->symtab = malloc(sec->shdr.sh_size);
461 die("malloc of %d bytes for symtab failed\n",
464 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
465 die("Seek to %d failed: %s\n",
466 sec->shdr.sh_offset, strerror(errno));
468 if (fread(sec->symtab, 1, sec->shdr.sh_size, fp)
469 != sec->shdr.sh_size) {
470 die("Cannot read symbol table: %s\n",
473 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) {
474 Elf_Sym *sym = &sec->symtab[j];
475 sym->st_name = elf_word_to_cpu(sym->st_name);
476 sym->st_value = elf_addr_to_cpu(sym->st_value);
477 sym->st_size = elf_xword_to_cpu(sym->st_size);
478 sym->st_shndx = elf_half_to_cpu(sym->st_shndx);
484 static void read_relocs(FILE *fp)
487 for (i = 0; i < ehdr.e_shnum; i++) {
488 struct section *sec = &secs[i];
489 if (sec->shdr.sh_type != SHT_REL_TYPE) {
492 sec->reltab = malloc(sec->shdr.sh_size);
494 die("malloc of %d bytes for relocs failed\n",
497 if (fseek(fp, sec->shdr.sh_offset, SEEK_SET) < 0) {
498 die("Seek to %d failed: %s\n",
499 sec->shdr.sh_offset, strerror(errno));
501 if (fread(sec->reltab, 1, sec->shdr.sh_size, fp)
502 != sec->shdr.sh_size) {
503 die("Cannot read symbol table: %s\n",
506 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
507 Elf_Rel *rel = &sec->reltab[j];
508 rel->r_offset = elf_addr_to_cpu(rel->r_offset);
509 rel->r_info = elf_xword_to_cpu(rel->r_info);
510 #if (SHT_REL_TYPE == SHT_RELA)
511 rel->r_addend = elf_xword_to_cpu(rel->r_addend);
518 static void print_absolute_symbols(void)
524 format = "%5d %016"PRIx64" %5"PRId64" %10s %10s %12s %s\n";
526 format = "%5d %08"PRIx32" %5"PRId32" %10s %10s %12s %s\n";
528 printf("Absolute symbols\n");
529 printf(" Num: Value Size Type Bind Visibility Name\n");
530 for (i = 0; i < ehdr.e_shnum; i++) {
531 struct section *sec = &secs[i];
535 if (sec->shdr.sh_type != SHT_SYMTAB) {
538 sym_strtab = sec->link->strtab;
539 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Sym); j++) {
542 sym = &sec->symtab[j];
543 name = sym_name(sym_strtab, sym);
544 if (sym->st_shndx != SHN_ABS) {
548 j, sym->st_value, sym->st_size,
549 sym_type(ELF_ST_TYPE(sym->st_info)),
550 sym_bind(ELF_ST_BIND(sym->st_info)),
551 sym_visibility(ELF_ST_VISIBILITY(sym->st_other)),
558 static void print_absolute_relocs(void)
564 format = "%016"PRIx64" %016"PRIx64" %10s %016"PRIx64" %s\n";
566 format = "%08"PRIx32" %08"PRIx32" %10s %08"PRIx32" %s\n";
568 for (i = 0; i < ehdr.e_shnum; i++) {
569 struct section *sec = &secs[i];
570 struct section *sec_applies, *sec_symtab;
574 if (sec->shdr.sh_type != SHT_REL_TYPE) {
577 sec_symtab = sec->link;
578 sec_applies = &secs[sec->shdr.sh_info];
579 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
582 sh_symtab = sec_symtab->symtab;
583 sym_strtab = sec_symtab->link->strtab;
584 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
588 rel = &sec->reltab[j];
589 sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
590 name = sym_name(sym_strtab, sym);
591 if (sym->st_shndx != SHN_ABS) {
595 /* Absolute symbols are not relocated if bzImage is
596 * loaded at a non-compiled address. Display a warning
597 * to user at compile time about the absolute
598 * relocations present.
600 * User need to audit the code to make sure
601 * some symbols which should have been section
602 * relative have not become absolute because of some
603 * linker optimization or wrong programming usage.
605 * Before warning check if this absolute symbol
606 * relocation is harmless.
608 if (is_reloc(S_ABS, name) || is_reloc(S_REL, name))
612 printf("WARNING: Absolute relocations"
614 printf("Offset Info Type Sym.Value "
622 rel_type(ELF_R_TYPE(rel->r_info)),
632 static void add_reloc(struct relocs *r, uint32_t offset)
634 if (r->count == r->size) {
635 unsigned long newsize = r->size + 50000;
636 void *mem = realloc(r->offset, newsize * sizeof(r->offset[0]));
639 die("realloc of %ld entries for relocs failed\n",
644 r->offset[r->count++] = offset;
647 static void walk_relocs(int (*process)(struct section *sec, Elf_Rel *rel,
648 Elf_Sym *sym, const char *symname))
651 /* Walk through the relocations */
652 for (i = 0; i < ehdr.e_shnum; i++) {
655 struct section *sec_applies, *sec_symtab;
657 struct section *sec = &secs[i];
659 if (sec->shdr.sh_type != SHT_REL_TYPE) {
662 sec_symtab = sec->link;
663 sec_applies = &secs[sec->shdr.sh_info];
664 if (!(sec_applies->shdr.sh_flags & SHF_ALLOC)) {
667 sh_symtab = sec_symtab->symtab;
668 sym_strtab = sec_symtab->link->strtab;
669 for (j = 0; j < sec->shdr.sh_size/sizeof(Elf_Rel); j++) {
670 Elf_Rel *rel = &sec->reltab[j];
671 Elf_Sym *sym = &sh_symtab[ELF_R_SYM(rel->r_info)];
672 const char *symname = sym_name(sym_strtab, sym);
674 process(sec, rel, sym, symname);
680 * The .data..percpu section is a special case for x86_64 SMP kernels.
681 * It is used to initialize the actual per_cpu areas and to provide
682 * definitions for the per_cpu variables that correspond to their offsets
683 * within the percpu area. Since the values of all of the symbols need
684 * to be offsets from the start of the per_cpu area the virtual address
685 * (sh_addr) of .data..percpu is 0 in SMP kernels.
689 * Relocations that reference symbols in the per_cpu area do not
690 * need further relocation (since the value is an offset relative
691 * to the start of the per_cpu area that does not change).
693 * Relocations that apply to the per_cpu area need to have their
694 * offset adjusted by by the value of __per_cpu_load to make them
695 * point to the correct place in the loaded image (because the
696 * virtual address of .data..percpu is 0).
698 * For non SMP kernels .data..percpu is linked as part of the normal
699 * kernel data and does not require special treatment.
702 static int per_cpu_shndx = -1;
703 static Elf_Addr per_cpu_load_addr;
705 static void percpu_init(void)
708 for (i = 0; i < ehdr.e_shnum; i++) {
710 if (strcmp(sec_name(i), ".data..percpu"))
713 if (secs[i].shdr.sh_addr != 0) /* non SMP kernel */
716 sym = sym_lookup("__per_cpu_load");
718 die("can't find __per_cpu_load\n");
721 per_cpu_load_addr = sym->st_value;
729 * Check to see if a symbol lies in the .data..percpu section.
731 * The linker incorrectly associates some symbols with the
732 * .data..percpu section so we also need to check the symbol
733 * name to make sure that we classify the symbol correctly.
735 * The GNU linker incorrectly associates:
739 * The "gold" linker incorrectly associates:
740 * init_per_cpu__irq_stack_union
741 * init_per_cpu__gdt_page
743 static int is_percpu_sym(ElfW(Sym) *sym, const char *symname)
745 return (sym->st_shndx == per_cpu_shndx) &&
746 strcmp(symname, "__init_begin") &&
747 strcmp(symname, "__per_cpu_load") &&
748 strncmp(symname, "init_per_cpu_", 13);
752 static int do_reloc64(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
755 unsigned r_type = ELF64_R_TYPE(rel->r_info);
756 ElfW(Addr) offset = rel->r_offset;
757 int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
759 if (sym->st_shndx == SHN_UNDEF)
763 * Adjust the offset if this reloc applies to the percpu section.
765 if (sec->shdr.sh_info == per_cpu_shndx)
766 offset += per_cpu_load_addr;
770 /* NONE can be ignored. */
776 * PC relative relocations don't need to be adjusted unless
777 * referencing a percpu symbol.
779 * NB: R_X86_64_PLT32 can be treated as R_X86_64_PC32.
781 if (is_percpu_sym(sym, symname))
782 add_reloc(&relocs32neg, offset);
789 * References to the percpu area don't need to be adjusted.
791 if (is_percpu_sym(sym, symname))
796 * Whitelisted absolute symbols do not require
799 if (is_reloc(S_ABS, symname))
802 die("Invalid absolute %s relocation: %s\n",
803 rel_type(r_type), symname);
808 * Relocation offsets for 64 bit kernels are output
809 * as 32 bits and sign extended back to 64 bits when
810 * the relocations are processed.
811 * Make sure that the offset will fit.
813 if ((int32_t)offset != (int64_t)offset)
814 die("Relocation offset doesn't fit in 32 bits\n");
816 if (r_type == R_X86_64_64)
817 add_reloc(&relocs64, offset);
819 add_reloc(&relocs32, offset);
823 die("Unsupported relocation type: %s (%d)\n",
824 rel_type(r_type), r_type);
833 static int do_reloc32(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
836 unsigned r_type = ELF32_R_TYPE(rel->r_info);
837 int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
846 * NONE can be ignored and PC relative relocations don't need
847 * to be adjusted. Because sym must be defined, R_386_PLT32 can
848 * be treated the same way as R_386_PC32.
855 * Whitelisted absolute symbols do not require
858 if (is_reloc(S_ABS, symname))
861 die("Invalid absolute %s relocation: %s\n",
862 rel_type(r_type), symname);
866 add_reloc(&relocs32, rel->r_offset);
870 die("Unsupported relocation type: %s (%d)\n",
871 rel_type(r_type), r_type);
878 static int do_reloc_real(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
881 unsigned r_type = ELF32_R_TYPE(rel->r_info);
882 int shn_abs = (sym->st_shndx == SHN_ABS) && !is_reloc(S_REL, symname);
891 * NONE can be ignored and PC relative relocations don't need
892 * to be adjusted. Because sym must be defined, R_386_PLT32 can
893 * be treated the same way as R_386_PC32.
900 * Whitelisted absolute symbols do not require
903 if (is_reloc(S_ABS, symname))
906 if (is_reloc(S_SEG, symname)) {
907 add_reloc(&relocs16, rel->r_offset);
911 if (!is_reloc(S_LIN, symname))
914 die("Invalid %s %s relocation: %s\n",
915 shn_abs ? "absolute" : "relative",
916 rel_type(r_type), symname);
922 * Whitelisted absolute symbols do not require
925 if (is_reloc(S_ABS, symname))
928 if (is_reloc(S_REL, symname)) {
929 add_reloc(&relocs32, rel->r_offset);
933 if (is_reloc(S_LIN, symname))
934 add_reloc(&relocs32, rel->r_offset);
937 die("Invalid %s %s relocation: %s\n",
938 shn_abs ? "absolute" : "relative",
939 rel_type(r_type), symname);
943 die("Unsupported relocation type: %s (%d)\n",
944 rel_type(r_type), r_type);
953 static int cmp_relocs(const void *va, const void *vb)
955 const uint32_t *a, *b;
957 return (*a == *b)? 0 : (*a > *b)? 1 : -1;
960 static void sort_relocs(struct relocs *r)
962 qsort(r->offset, r->count, sizeof(r->offset[0]), cmp_relocs);
965 static int write32(uint32_t v, FILE *f)
967 unsigned char buf[4];
969 put_unaligned_le32(v, buf);
970 return fwrite(buf, 1, 4, f) == 4 ? 0 : -1;
973 static int write32_as_text(uint32_t v, FILE *f)
975 return fprintf(f, "\t.long 0x%08"PRIx32"\n", v) > 0 ? 0 : -1;
978 static void emit_relocs(int as_text, int use_real_mode)
981 int (*write_reloc)(uint32_t, FILE *) = write32;
982 int (*do_reloc)(struct section *sec, Elf_Rel *rel, Elf_Sym *sym,
983 const char *symname);
987 do_reloc = do_reloc64;
989 die("--realmode not valid for a 64-bit ELF file");
992 do_reloc = do_reloc32;
994 do_reloc = do_reloc_real;
997 /* Collect up the relocations */
998 walk_relocs(do_reloc);
1000 if (relocs16.count && !use_real_mode)
1001 die("Segment relocations found but --realmode not specified\n");
1003 /* Order the relocations for more efficient processing */
1004 sort_relocs(&relocs32);
1006 sort_relocs(&relocs32neg);
1007 sort_relocs(&relocs64);
1009 sort_relocs(&relocs16);
1012 /* Print the relocations */
1014 /* Print the relocations in a form suitable that
1017 printf(".section \".data.reloc\",\"a\"\n");
1018 printf(".balign 4\n");
1019 write_reloc = write32_as_text;
1022 if (use_real_mode) {
1023 write_reloc(relocs16.count, stdout);
1024 for (i = 0; i < relocs16.count; i++)
1025 write_reloc(relocs16.offset[i], stdout);
1027 write_reloc(relocs32.count, stdout);
1028 for (i = 0; i < relocs32.count; i++)
1029 write_reloc(relocs32.offset[i], stdout);
1033 write_reloc(0, stdout);
1035 /* Now print each relocation */
1036 for (i = 0; i < relocs64.count; i++)
1037 write_reloc(relocs64.offset[i], stdout);
1040 write_reloc(0, stdout);
1042 /* Now print each inverse 32-bit relocation */
1043 for (i = 0; i < relocs32neg.count; i++)
1044 write_reloc(relocs32neg.offset[i], stdout);
1048 write_reloc(0, stdout);
1050 /* Now print each relocation */
1051 for (i = 0; i < relocs32.count; i++)
1052 write_reloc(relocs32.offset[i], stdout);
1057 * As an aid to debugging problems with different linkers
1058 * print summary information about the relocs.
1059 * Since different linkers tend to emit the sections in
1060 * different orders we use the section names in the output.
1062 static int do_reloc_info(struct section *sec, Elf_Rel *rel, ElfW(Sym) *sym,
1063 const char *symname)
1065 printf("%s\t%s\t%s\t%s\n",
1066 sec_name(sec->shdr.sh_info),
1067 rel_type(ELF_R_TYPE(rel->r_info)),
1069 sec_name(sym->st_shndx));
1073 static void print_reloc_info(void)
1075 printf("reloc section\treloc type\tsymbol\tsymbol section\n");
1076 walk_relocs(do_reloc_info);
1080 # define process process_64
1082 # define process process_32
1085 void process(FILE *fp, int use_real_mode, int as_text,
1086 int show_absolute_syms, int show_absolute_relocs,
1087 int show_reloc_info)
1089 regex_init(use_real_mode);
1097 if (show_absolute_syms) {
1098 print_absolute_symbols();
1101 if (show_absolute_relocs) {
1102 print_absolute_relocs();
1105 if (show_reloc_info) {
1109 emit_relocs(as_text, use_real_mode);