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 relocs
;
32 static struct section
*secs
;
34 static const char * const regex_sym_kernel
= {
35 /* Symbols matching these regex's should never be relocated */
39 static regex_t sym_regex_c
;
41 static int regex_skip_reloc(const char *sym_name
)
43 return !regexec(&sym_regex_c
, sym_name
, 0, NULL
, 0);
46 static void regex_init(void)
51 err
= regcomp(&sym_regex_c
, regex_sym_kernel
,
52 REG_EXTENDED
|REG_NOSUB
);
55 regerror(err
, &sym_regex_c
, errbuf
, sizeof(errbuf
));
60 static const char *rel_type(unsigned type
)
62 static const char * const type_name
[] = {
63 #define REL_TYPE(X)[X] = #X
64 REL_TYPE(R_MIPS_NONE
),
67 REL_TYPE(R_MIPS_REL32
),
69 REL_TYPE(R_MIPS_HI16
),
70 REL_TYPE(R_MIPS_LO16
),
71 REL_TYPE(R_MIPS_GPREL16
),
72 REL_TYPE(R_MIPS_LITERAL
),
73 REL_TYPE(R_MIPS_GOT16
),
74 REL_TYPE(R_MIPS_PC16
),
75 REL_TYPE(R_MIPS_CALL16
),
76 REL_TYPE(R_MIPS_GPREL32
),
78 REL_TYPE(R_MIPS_HIGHER
),
79 REL_TYPE(R_MIPS_HIGHEST
),
80 REL_TYPE(R_MIPS_PC21_S2
),
81 REL_TYPE(R_MIPS_PC26_S2
),
84 const char *name
= "unknown type rel type name";
86 if (type
< ARRAY_SIZE(type_name
) && type_name
[type
])
87 name
= type_name
[type
];
91 static const char *sec_name(unsigned shndx
)
93 const char *sec_strtab
;
96 sec_strtab
= secs
[ehdr
.e_shstrndx
].strtab
;
97 if (shndx
< ehdr
.e_shnum
)
98 name
= sec_strtab
+ secs
[shndx
].shdr
.sh_name
;
99 else if (shndx
== SHN_ABS
)
101 else if (shndx
== SHN_COMMON
)
108 static struct section
*sec_lookup(const char *secname
)
112 for (i
= 0; i
< ehdr
.e_shnum
; i
++)
113 if (strcmp(secname
, sec_name(i
)) == 0)
119 static const char *sym_name(const char *sym_strtab
, Elf_Sym
*sym
)
124 name
= sym_strtab
+ sym
->st_name
;
126 name
= sec_name(sym
->st_shndx
);
130 #if BYTE_ORDER == LITTLE_ENDIAN
131 #define le16_to_cpu(val) (val)
132 #define le32_to_cpu(val) (val)
133 #define le64_to_cpu(val) (val)
134 #define be16_to_cpu(val) bswap_16(val)
135 #define be32_to_cpu(val) bswap_32(val)
136 #define be64_to_cpu(val) bswap_64(val)
138 #define cpu_to_le16(val) (val)
139 #define cpu_to_le32(val) (val)
140 #define cpu_to_le64(val) (val)
141 #define cpu_to_be16(val) bswap_16(val)
142 #define cpu_to_be32(val) bswap_32(val)
143 #define cpu_to_be64(val) bswap_64(val)
145 #if BYTE_ORDER == BIG_ENDIAN
146 #define le16_to_cpu(val) bswap_16(val)
147 #define le32_to_cpu(val) bswap_32(val)
148 #define le64_to_cpu(val) bswap_64(val)
149 #define be16_to_cpu(val) (val)
150 #define be32_to_cpu(val) (val)
151 #define be64_to_cpu(val) (val)
153 #define cpu_to_le16(val) bswap_16(val)
154 #define cpu_to_le32(val) bswap_32(val)
155 #define cpu_to_le64(val) bswap_64(val)
156 #define cpu_to_be16(val) (val)
157 #define cpu_to_be32(val) (val)
158 #define cpu_to_be64(val) (val)
161 static uint16_t elf16_to_cpu(uint16_t val
)
163 if (ehdr
.e_ident
[EI_DATA
] == ELFDATA2LSB
)
164 return le16_to_cpu(val
);
166 return be16_to_cpu(val
);
169 static uint32_t elf32_to_cpu(uint32_t val
)
171 if (ehdr
.e_ident
[EI_DATA
] == ELFDATA2LSB
)
172 return le32_to_cpu(val
);
174 return be32_to_cpu(val
);
177 static uint32_t cpu_to_elf32(uint32_t val
)
179 if (ehdr
.e_ident
[EI_DATA
] == ELFDATA2LSB
)
180 return cpu_to_le32(val
);
182 return cpu_to_be32(val
);
185 #define elf_half_to_cpu(x) elf16_to_cpu(x)
186 #define elf_word_to_cpu(x) elf32_to_cpu(x)
189 static uint64_t elf64_to_cpu(uint64_t val
)
191 if (ehdr
.e_ident
[EI_DATA
] == ELFDATA2LSB
)
192 return le64_to_cpu(val
);
194 return be64_to_cpu(val
);
196 #define elf_addr_to_cpu(x) elf64_to_cpu(x)
197 #define elf_off_to_cpu(x) elf64_to_cpu(x)
198 #define elf_xword_to_cpu(x) elf64_to_cpu(x)
200 #define elf_addr_to_cpu(x) elf32_to_cpu(x)
201 #define elf_off_to_cpu(x) elf32_to_cpu(x)
202 #define elf_xword_to_cpu(x) elf32_to_cpu(x)
205 static void read_ehdr(FILE *fp
)
207 if (fread(&ehdr
, sizeof(ehdr
), 1, fp
) != 1)
208 die("Cannot read ELF header: %s\n", strerror(errno
));
210 if (memcmp(ehdr
.e_ident
, ELFMAG
, SELFMAG
) != 0)
211 die("No ELF magic\n");
213 if (ehdr
.e_ident
[EI_CLASS
] != ELF_CLASS
)
214 die("Not a %d bit executable\n", ELF_BITS
);
216 if ((ehdr
.e_ident
[EI_DATA
] != ELFDATA2LSB
) &&
217 (ehdr
.e_ident
[EI_DATA
] != ELFDATA2MSB
))
218 die("Unknown ELF Endianness\n");
220 if (ehdr
.e_ident
[EI_VERSION
] != EV_CURRENT
)
221 die("Unknown ELF version\n");
223 /* Convert the fields to native endian */
224 ehdr
.e_type
= elf_half_to_cpu(ehdr
.e_type
);
225 ehdr
.e_machine
= elf_half_to_cpu(ehdr
.e_machine
);
226 ehdr
.e_version
= elf_word_to_cpu(ehdr
.e_version
);
227 ehdr
.e_entry
= elf_addr_to_cpu(ehdr
.e_entry
);
228 ehdr
.e_phoff
= elf_off_to_cpu(ehdr
.e_phoff
);
229 ehdr
.e_shoff
= elf_off_to_cpu(ehdr
.e_shoff
);
230 ehdr
.e_flags
= elf_word_to_cpu(ehdr
.e_flags
);
231 ehdr
.e_ehsize
= elf_half_to_cpu(ehdr
.e_ehsize
);
232 ehdr
.e_phentsize
= elf_half_to_cpu(ehdr
.e_phentsize
);
233 ehdr
.e_phnum
= elf_half_to_cpu(ehdr
.e_phnum
);
234 ehdr
.e_shentsize
= elf_half_to_cpu(ehdr
.e_shentsize
);
235 ehdr
.e_shnum
= elf_half_to_cpu(ehdr
.e_shnum
);
236 ehdr
.e_shstrndx
= elf_half_to_cpu(ehdr
.e_shstrndx
);
238 if ((ehdr
.e_type
!= ET_EXEC
) && (ehdr
.e_type
!= ET_DYN
))
239 die("Unsupported ELF header type\n");
241 if (ehdr
.e_machine
!= ELF_MACHINE
)
242 die("Not for %s\n", ELF_MACHINE_NAME
);
244 if (ehdr
.e_version
!= EV_CURRENT
)
245 die("Unknown ELF version\n");
247 if (ehdr
.e_ehsize
!= sizeof(Elf_Ehdr
))
248 die("Bad Elf header size\n");
250 if (ehdr
.e_phentsize
!= sizeof(Elf_Phdr
))
251 die("Bad program header entry\n");
253 if (ehdr
.e_shentsize
!= sizeof(Elf_Shdr
))
254 die("Bad section header entry\n");
256 if (ehdr
.e_shstrndx
>= ehdr
.e_shnum
)
257 die("String table index out of bounds\n");
260 static void read_shdrs(FILE *fp
)
265 secs
= calloc(ehdr
.e_shnum
, sizeof(struct section
));
267 die("Unable to allocate %d section headers\n", ehdr
.e_shnum
);
269 if (fseek(fp
, ehdr
.e_shoff
, SEEK_SET
) < 0)
270 die("Seek to %d failed: %s\n", ehdr
.e_shoff
, strerror(errno
));
272 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
273 struct section
*sec
= &secs
[i
];
275 sec
->shdr_offset
= ftell(fp
);
276 if (fread(&shdr
, sizeof(shdr
), 1, fp
) != 1)
277 die("Cannot read ELF section headers %d/%d: %s\n",
278 i
, ehdr
.e_shnum
, strerror(errno
));
279 sec
->shdr
.sh_name
= elf_word_to_cpu(shdr
.sh_name
);
280 sec
->shdr
.sh_type
= elf_word_to_cpu(shdr
.sh_type
);
281 sec
->shdr
.sh_flags
= elf_xword_to_cpu(shdr
.sh_flags
);
282 sec
->shdr
.sh_addr
= elf_addr_to_cpu(shdr
.sh_addr
);
283 sec
->shdr
.sh_offset
= elf_off_to_cpu(shdr
.sh_offset
);
284 sec
->shdr
.sh_size
= elf_xword_to_cpu(shdr
.sh_size
);
285 sec
->shdr
.sh_link
= elf_word_to_cpu(shdr
.sh_link
);
286 sec
->shdr
.sh_info
= elf_word_to_cpu(shdr
.sh_info
);
287 sec
->shdr
.sh_addralign
= elf_xword_to_cpu(shdr
.sh_addralign
);
288 sec
->shdr
.sh_entsize
= elf_xword_to_cpu(shdr
.sh_entsize
);
289 if (sec
->shdr
.sh_link
< ehdr
.e_shnum
)
290 sec
->link
= &secs
[sec
->shdr
.sh_link
];
294 static void read_strtabs(FILE *fp
)
298 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
299 struct section
*sec
= &secs
[i
];
301 if (sec
->shdr
.sh_type
!= SHT_STRTAB
)
304 sec
->strtab
= malloc(sec
->shdr
.sh_size
);
306 die("malloc of %d bytes for strtab failed\n",
309 if (fseek(fp
, sec
->shdr
.sh_offset
, SEEK_SET
) < 0)
310 die("Seek to %d failed: %s\n",
311 sec
->shdr
.sh_offset
, strerror(errno
));
313 if (fread(sec
->strtab
, 1, sec
->shdr
.sh_size
, fp
) !=
315 die("Cannot read symbol table: %s\n", strerror(errno
));
319 static void read_symtabs(FILE *fp
)
323 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
324 struct section
*sec
= &secs
[i
];
325 if (sec
->shdr
.sh_type
!= SHT_SYMTAB
)
328 sec
->symtab
= malloc(sec
->shdr
.sh_size
);
330 die("malloc of %d bytes for symtab failed\n",
333 if (fseek(fp
, sec
->shdr
.sh_offset
, SEEK_SET
) < 0)
334 die("Seek to %d failed: %s\n",
335 sec
->shdr
.sh_offset
, strerror(errno
));
337 if (fread(sec
->symtab
, 1, sec
->shdr
.sh_size
, fp
) !=
339 die("Cannot read symbol table: %s\n", strerror(errno
));
341 for (j
= 0; j
< sec
->shdr
.sh_size
/sizeof(Elf_Sym
); j
++) {
342 Elf_Sym
*sym
= &sec
->symtab
[j
];
344 sym
->st_name
= elf_word_to_cpu(sym
->st_name
);
345 sym
->st_value
= elf_addr_to_cpu(sym
->st_value
);
346 sym
->st_size
= elf_xword_to_cpu(sym
->st_size
);
347 sym
->st_shndx
= elf_half_to_cpu(sym
->st_shndx
);
352 static void read_relocs(FILE *fp
)
354 static unsigned long base
= 0;
358 struct section
*sec
= sec_lookup(".text");
361 die("Could not find .text section\n");
363 base
= sec
->shdr
.sh_addr
;
366 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
367 struct section
*sec
= &secs
[i
];
369 if (sec
->shdr
.sh_type
!= SHT_REL_TYPE
)
372 sec
->reltab
= malloc(sec
->shdr
.sh_size
);
374 die("malloc of %d bytes for relocs failed\n",
377 if (fseek(fp
, sec
->shdr
.sh_offset
, SEEK_SET
) < 0)
378 die("Seek to %d failed: %s\n",
379 sec
->shdr
.sh_offset
, strerror(errno
));
381 if (fread(sec
->reltab
, 1, sec
->shdr
.sh_size
, fp
) !=
383 die("Cannot read symbol table: %s\n", strerror(errno
));
385 for (j
= 0; j
< sec
->shdr
.sh_size
/sizeof(Elf_Rel
); j
++) {
386 Elf_Rel
*rel
= &sec
->reltab
[j
];
388 rel
->r_offset
= elf_addr_to_cpu(rel
->r_offset
);
389 /* Set offset into kernel image */
390 rel
->r_offset
-= base
;
392 rel
->r_info
= elf_xword_to_cpu(rel
->r_info
);
394 /* Convert MIPS64 RELA format - only the symbol
395 * index needs converting to native endianness
397 rel
->r_info
= rel
->r_info
;
398 ELF_R_SYM(rel
->r_info
) = elf32_to_cpu(ELF_R_SYM(rel
->r_info
));
400 #if (SHT_REL_TYPE == SHT_RELA)
401 rel
->r_addend
= elf_xword_to_cpu(rel
->r_addend
);
407 static void remove_relocs(FILE *fp
)
412 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
413 struct section
*sec
= &secs
[i
];
415 if (sec
->shdr
.sh_type
!= SHT_REL_TYPE
)
418 if (fseek(fp
, sec
->shdr_offset
, SEEK_SET
) < 0)
419 die("Seek to %d failed: %s\n",
420 sec
->shdr_offset
, strerror(errno
));
422 if (fread(&shdr
, sizeof(shdr
), 1, fp
) != 1)
423 die("Cannot read ELF section headers %d/%d: %s\n",
424 i
, ehdr
.e_shnum
, strerror(errno
));
426 /* Set relocation section size to 0, effectively removing it.
427 * This is necessary due to lack of support for relocations
428 * in objcopy when creating 32bit elf from 64bit elf.
432 if (fseek(fp
, sec
->shdr_offset
, SEEK_SET
) < 0)
433 die("Seek to %d failed: %s\n",
434 sec
->shdr_offset
, strerror(errno
));
436 if (fwrite(&shdr
, sizeof(shdr
), 1, fp
) != 1)
437 die("Cannot write ELF section headers %d/%d: %s\n",
438 i
, ehdr
.e_shnum
, strerror(errno
));
442 static void add_reloc(struct relocs
*r
, uint32_t offset
, unsigned type
)
444 /* Relocation representation in binary table:
445 * |76543210|76543210|76543210|76543210|
446 * | Type | offset from _text >> 2 |
449 if (offset
> 0x00FFFFFF)
450 die("Kernel image exceeds maximum size for relocation!\n");
452 offset
= (offset
& 0x00FFFFFF) | ((type
& 0xFF) << 24);
454 if (r
->count
== r
->size
) {
455 unsigned long newsize
= r
->size
+ 50000;
456 void *mem
= realloc(r
->offset
, newsize
* sizeof(r
->offset
[0]));
459 die("realloc failed\n");
464 r
->offset
[r
->count
++] = offset
;
467 static void walk_relocs(int (*process
)(struct section
*sec
, Elf_Rel
*rel
,
468 Elf_Sym
*sym
, const char *symname
))
472 /* Walk through the relocations */
473 for (i
= 0; i
< ehdr
.e_shnum
; i
++) {
476 struct section
*sec_applies
, *sec_symtab
;
478 struct section
*sec
= &secs
[i
];
480 if (sec
->shdr
.sh_type
!= SHT_REL_TYPE
)
483 sec_symtab
= sec
->link
;
484 sec_applies
= &secs
[sec
->shdr
.sh_info
];
485 if (!(sec_applies
->shdr
.sh_flags
& SHF_ALLOC
))
488 sh_symtab
= sec_symtab
->symtab
;
489 sym_strtab
= sec_symtab
->link
->strtab
;
490 for (j
= 0; j
< sec
->shdr
.sh_size
/sizeof(Elf_Rel
); j
++) {
491 Elf_Rel
*rel
= &sec
->reltab
[j
];
492 Elf_Sym
*sym
= &sh_symtab
[ELF_R_SYM(rel
->r_info
)];
493 const char *symname
= sym_name(sym_strtab
, sym
);
495 process(sec
, rel
, sym
, symname
);
500 static int do_reloc(struct section
*sec
, Elf_Rel
*rel
, Elf_Sym
*sym
,
503 unsigned r_type
= ELF_R_TYPE(rel
->r_info
);
504 unsigned bind
= ELF_ST_BIND(sym
->st_info
);
506 if ((bind
== STB_WEAK
) && (sym
->st_value
== 0)) {
507 /* Don't relocate weak symbols without a target */
511 if (regex_skip_reloc(symname
))
521 * NONE can be ignored and PC relative relocations don't
522 * need to be adjusted.
526 /* We support relocating within the same 4Gb segment only,
527 * thus leaving the top 32bits unchanged
530 /* We support relocating by 64k jumps only
531 * thus leaving the bottom 16bits unchanged
539 add_reloc(&relocs
, rel
->r_offset
, r_type
);
543 die("Unsupported relocation type: %s (%d)\n",
544 rel_type(r_type
), r_type
);
551 static int write_reloc_as_bin(uint32_t v
, FILE *f
)
553 unsigned char buf
[4];
557 memcpy(buf
, &v
, sizeof(uint32_t));
558 return fwrite(buf
, 1, 4, f
);
561 static int write_reloc_as_text(uint32_t v
, FILE *f
)
565 res
= fprintf(f
, "\t.long 0x%08"PRIx32
"\n", v
);
569 return sizeof(uint32_t);
572 static void emit_relocs(int as_text
, int as_bin
, FILE *outf
)
575 int (*write_reloc
)(uint32_t, FILE *) = write_reloc_as_bin
;
578 struct section
*sec_reloc
;
580 sec_reloc
= sec_lookup(".data.reloc");
582 die("Could not find relocation section\n");
584 size_reserved
= sec_reloc
->shdr
.sh_size
;
586 /* Collect up the relocations */
587 walk_relocs(do_reloc
);
589 /* Print the relocations */
591 /* Print the relocations in a form suitable that
594 printf(".section \".data.reloc\",\"a\"\n");
595 printf(".balign 4\n");
596 /* Output text to stdout */
597 write_reloc
= write_reloc_as_text
;
600 /* Output raw binary to stdout */
603 /* Seek to offset of the relocation section.
604 * Each relocation is then written into the
605 * vmlinux kernel image.
607 if (fseek(outf
, sec_reloc
->shdr
.sh_offset
, SEEK_SET
) < 0) {
608 die("Seek to %d failed: %s\n",
609 sec_reloc
->shdr
.sh_offset
, strerror(errno
));
613 for (i
= 0; i
< relocs
.count
; i
++)
614 size
+= write_reloc(relocs
.offset
[i
], outf
);
616 /* Print a stop, but only if we've actually written some relocs */
618 size
+= write_reloc(0, outf
);
620 if (size
> size_reserved
)
621 /* Die, but suggest a value for CONFIG_RELOCATION_TABLE_SIZE
622 * which will fix this problem and allow a bit of headroom
623 * if more kernel features are enabled
625 die("Relocations overflow available space!\n" \
626 "Please adjust CONFIG_RELOCATION_TABLE_SIZE " \
627 "to at least 0x%08x\n", (size
+ 0x1000) & ~0xFFF);
631 * As an aid to debugging problems with different linkers
632 * print summary information about the relocs.
633 * Since different linkers tend to emit the sections in
634 * different orders we use the section names in the output.
636 static int do_reloc_info(struct section
*sec
, Elf_Rel
*rel
, ElfW(Sym
) *sym
,
639 printf("%16s 0x%08x %16s %40s %16s\n",
640 sec_name(sec
->shdr
.sh_info
),
641 (unsigned int)rel
->r_offset
,
642 rel_type(ELF_R_TYPE(rel
->r_info
)),
644 sec_name(sym
->st_shndx
));
648 static void print_reloc_info(void)
650 printf("%16s %10s %16s %40s %16s\n",
656 walk_relocs(do_reloc_info
);
660 # define process process_64
662 # define process process_32
665 void process(FILE *fp
, int as_text
, int as_bin
,
666 int show_reloc_info
, int keep_relocs
)
674 if (show_reloc_info
) {
678 emit_relocs(as_text
, as_bin
, fp
);