1 /* Postprocess module symbol versions
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
11 * Usage: modpost vmlinux module1.o module2.o ...
19 #include "../../include/generated/autoconf.h"
20 #include "../../include/linux/license.h"
22 /* Some toolchains use a `_' prefix for all user symbols. */
23 #ifdef CONFIG_SYMBOL_PREFIX
24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
26 #define MODULE_SYMBOL_PREFIX ""
30 /* Are we using CONFIG_MODVERSIONS? */
32 /* Warn about undefined symbols? (do so if we have vmlinux) */
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static int all_versions
= 0;
36 /* If we are modposting external module set to 1 */
37 static int external_module
= 0;
38 /* Warn about section mismatch in vmlinux if set to 1 */
39 static int vmlinux_section_warnings
= 1;
40 /* Only warn about unresolved symbols */
41 static int warn_unresolved
= 0;
42 /* How a symbol is exported */
43 static int sec_mismatch_count
= 0;
44 static int sec_mismatch_verbose
= 1;
47 export_plain
, export_unused
, export_gpl
,
48 export_unused_gpl
, export_gpl_future
, export_unknown
51 #define PRINTF __attribute__ ((format (printf, 1, 2)))
53 PRINTF
void fatal(const char *fmt
, ...)
57 fprintf(stderr
, "FATAL: ");
59 va_start(arglist
, fmt
);
60 vfprintf(stderr
, fmt
, arglist
);
66 PRINTF
void warn(const char *fmt
, ...)
70 fprintf(stderr
, "WARNING: ");
72 va_start(arglist
, fmt
);
73 vfprintf(stderr
, fmt
, arglist
);
77 PRINTF
void merror(const char *fmt
, ...)
81 fprintf(stderr
, "ERROR: ");
83 va_start(arglist
, fmt
);
84 vfprintf(stderr
, fmt
, arglist
);
88 static int is_vmlinux(const char *modname
)
92 myname
= strrchr(modname
, '/');
98 return (strcmp(myname
, "vmlinux") == 0) ||
99 (strcmp(myname
, "vmlinux.o") == 0);
102 void *do_nofail(void *ptr
, const char *expr
)
105 fatal("modpost: Memory allocation failure: %s.\n", expr
);
110 /* A list of all modules we processed */
111 static struct module
*modules
;
113 static struct module
*find_module(char *modname
)
117 for (mod
= modules
; mod
; mod
= mod
->next
)
118 if (strcmp(mod
->name
, modname
) == 0)
123 static struct module
*new_module(char *modname
)
128 mod
= NOFAIL(malloc(sizeof(*mod
)));
129 memset(mod
, 0, sizeof(*mod
));
130 p
= NOFAIL(strdup(modname
));
132 /* strip trailing .o */
135 if (strcmp(s
, ".o") == 0)
140 mod
->gpl_compatible
= -1;
147 /* A hash of all exported symbols,
148 * struct symbol is also used for lists of unresolved symbols */
150 #define SYMBOL_HASH_SIZE 1024
154 struct module
*module
;
158 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
159 unsigned int kernel
:1; /* 1 if symbol is from kernel
160 * (only for external modules) **/
161 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
162 enum export export
; /* Type of export */
166 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
168 /* This is based on the hash agorithm from gdbm, via tdb */
169 static inline unsigned int tdb_hash(const char *name
)
171 unsigned value
; /* Used to compute the hash value. */
172 unsigned i
; /* Used to cycle through random values. */
174 /* Set the initial value from the key size. */
175 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
176 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
178 return (1103515243 * value
+ 12345);
182 * Allocate a new symbols for use in the hash of exported symbols or
183 * the list of unresolved symbols per module
185 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
188 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
190 memset(s
, 0, sizeof(*s
));
191 strcpy(s
->name
, name
);
197 /* For the hash of exported symbols */
198 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
204 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
205 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
206 new->module
= module
;
207 new->export
= export
;
211 static struct symbol
*find_symbol(const char *name
)
215 /* For our purposes, .foo matches foo. PPC64 needs this. */
219 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
220 if (strcmp(s
->name
, name
) == 0)
230 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
231 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
232 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
233 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
234 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
235 { .str
= "(unknown)", .export
= export_unknown
},
239 static const char *export_str(enum export ex
)
241 return export_list
[ex
].str
;
244 static enum export
export_no(const char *s
)
249 return export_unknown
;
250 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
251 if (strcmp(export_list
[i
].str
, s
) == 0)
252 return export_list
[i
].export
;
254 return export_unknown
;
257 static const char *sec_name(struct elf_info
*elf
, int secindex
);
259 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
261 static enum export
export_from_secname(struct elf_info
*elf
, unsigned int sec
)
263 const char *secname
= sec_name(elf
, sec
);
265 if (strstarts(secname
, "___ksymtab+"))
267 else if (strstarts(secname
, "___ksymtab_unused+"))
268 return export_unused
;
269 else if (strstarts(secname
, "___ksymtab_gpl+"))
271 else if (strstarts(secname
, "___ksymtab_unused_gpl+"))
272 return export_unused_gpl
;
273 else if (strstarts(secname
, "___ksymtab_gpl_future+"))
274 return export_gpl_future
;
276 return export_unknown
;
279 static enum export
export_from_sec(struct elf_info
*elf
, unsigned int sec
)
281 if (sec
== elf
->export_sec
)
283 else if (sec
== elf
->export_unused_sec
)
284 return export_unused
;
285 else if (sec
== elf
->export_gpl_sec
)
287 else if (sec
== elf
->export_unused_gpl_sec
)
288 return export_unused_gpl
;
289 else if (sec
== elf
->export_gpl_future_sec
)
290 return export_gpl_future
;
292 return export_unknown
;
296 * Add an exported symbol - it may have already been added without a
297 * CRC, in this case just update the CRC
299 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
302 struct symbol
*s
= find_symbol(name
);
305 s
= new_symbol(name
, mod
, export
);
308 warn("%s: '%s' exported twice. Previous export "
309 "was in %s%s\n", mod
->name
, name
,
311 is_vmlinux(s
->module
->name
) ?"":".ko");
313 /* In case Modules.symvers was out of date */
318 s
->vmlinux
= is_vmlinux(mod
->name
);
324 static void sym_update_crc(const char *name
, struct module
*mod
,
325 unsigned int crc
, enum export export
)
327 struct symbol
*s
= find_symbol(name
);
330 s
= new_symbol(name
, mod
, export
);
335 void *grab_file(const char *filename
, unsigned long *size
)
341 fd
= open(filename
, O_RDONLY
);
342 if (fd
< 0 || fstat(fd
, &st
) != 0)
346 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
349 if (map
== MAP_FAILED
)
355 * Return a copy of the next line in a mmap'ed file.
356 * spaces in the beginning of the line is trimmed away.
357 * Return a pointer to a static buffer.
359 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
361 static char line
[4096];
364 signed char *p
= (signed char *)file
+ *pos
;
367 for (; *pos
< size
; (*pos
)++) {
368 if (skip
&& isspace(*p
)) {
373 if (*p
!= '\n' && (*pos
< size
)) {
377 break; /* Too long, stop */
388 void release_file(void *file
, unsigned long size
)
393 static int parse_elf(struct elf_info
*info
, const char *filename
)
399 const char *secstrings
;
400 unsigned int symtab_idx
= ~0U, symtab_shndx_idx
= ~0U;
402 hdr
= grab_file(filename
, &info
->size
);
408 if (info
->size
< sizeof(*hdr
)) {
409 /* file too small, assume this is an empty .o file */
412 /* Is this a valid ELF file? */
413 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
414 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
415 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
416 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
417 /* Not an ELF file - silently ignore it */
420 /* Fix endianness in ELF header */
421 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
422 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
423 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
424 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
425 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
426 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
427 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
428 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
429 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
430 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
431 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
432 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
433 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
434 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
435 info
->sechdrs
= sechdrs
;
437 /* Check if file offset is correct */
438 if (hdr
->e_shoff
> info
->size
) {
439 fatal("section header offset=%lu in file '%s' is bigger than "
440 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
441 filename
, info
->size
);
445 if (hdr
->e_shnum
== SHN_UNDEF
) {
447 * There are more than 64k sections,
448 * read count from .sh_size.
450 info
->num_sections
= TO_NATIVE(sechdrs
[0].sh_size
);
453 info
->num_sections
= hdr
->e_shnum
;
455 if (hdr
->e_shstrndx
== SHN_XINDEX
) {
456 info
->secindex_strings
= TO_NATIVE(sechdrs
[0].sh_link
);
459 info
->secindex_strings
= hdr
->e_shstrndx
;
462 /* Fix endianness in section headers */
463 for (i
= 0; i
< info
->num_sections
; i
++) {
464 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
465 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
466 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
467 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
468 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
469 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
470 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
471 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
472 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
473 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
475 /* Find symbol table. */
476 secstrings
= (void *)hdr
+ sechdrs
[info
->secindex_strings
].sh_offset
;
477 for (i
= 1; i
< info
->num_sections
; i
++) {
479 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
481 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
482 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
483 "sizeof(*hrd)=%zu\n", filename
,
484 (unsigned long)sechdrs
[i
].sh_offset
,
488 secname
= secstrings
+ sechdrs
[i
].sh_name
;
489 if (strcmp(secname
, ".modinfo") == 0) {
491 fatal("%s has NOBITS .modinfo\n", filename
);
492 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
493 info
->modinfo_len
= sechdrs
[i
].sh_size
;
494 } else if (strcmp(secname
, "__ksymtab") == 0)
495 info
->export_sec
= i
;
496 else if (strcmp(secname
, "__ksymtab_unused") == 0)
497 info
->export_unused_sec
= i
;
498 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
499 info
->export_gpl_sec
= i
;
500 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
501 info
->export_unused_gpl_sec
= i
;
502 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
503 info
->export_gpl_future_sec
= i
;
505 if (sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
506 unsigned int sh_link_idx
;
508 info
->symtab_start
= (void *)hdr
+
509 sechdrs
[i
].sh_offset
;
510 info
->symtab_stop
= (void *)hdr
+
511 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
512 sh_link_idx
= sechdrs
[i
].sh_link
;
513 info
->strtab
= (void *)hdr
+
514 sechdrs
[sh_link_idx
].sh_offset
;
517 /* 32bit section no. table? ("more than 64k sections") */
518 if (sechdrs
[i
].sh_type
== SHT_SYMTAB_SHNDX
) {
519 symtab_shndx_idx
= i
;
520 info
->symtab_shndx_start
= (void *)hdr
+
521 sechdrs
[i
].sh_offset
;
522 info
->symtab_shndx_stop
= (void *)hdr
+
523 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
526 if (!info
->symtab_start
)
527 fatal("%s has no symtab?\n", filename
);
529 /* Fix endianness in symbols */
530 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
531 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
532 sym
->st_name
= TO_NATIVE(sym
->st_name
);
533 sym
->st_value
= TO_NATIVE(sym
->st_value
);
534 sym
->st_size
= TO_NATIVE(sym
->st_size
);
537 if (symtab_shndx_idx
!= ~0U) {
539 if (symtab_idx
!= sechdrs
[symtab_shndx_idx
].sh_link
)
540 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
541 filename
, sechdrs
[symtab_shndx_idx
].sh_link
,
544 for (p
= info
->symtab_shndx_start
; p
< info
->symtab_shndx_stop
;
552 static void parse_elf_finish(struct elf_info
*info
)
554 release_file(info
->hdr
, info
->size
);
557 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
559 /* ignore __this_module, it will be resolved shortly */
560 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
562 /* ignore global offset table */
563 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
565 if (info
->hdr
->e_machine
== EM_PPC
)
566 /* Special register function linked on all modules during final link of .ko */
567 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
568 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
569 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
570 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
572 if (info
->hdr
->e_machine
== EM_PPC64
)
573 /* Special register function linked on all modules during final link of .ko */
574 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
575 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
577 /* Do not ignore this symbol */
581 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
582 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
584 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
585 Elf_Sym
*sym
, const char *symname
)
590 if (!is_vmlinux(mod
->name
) && strncmp(symname
, "__ksymtab", 9) == 0)
591 export
= export_from_secname(info
, get_secindex(info
, sym
));
593 export
= export_from_sec(info
, get_secindex(info
, sym
));
595 switch (sym
->st_shndx
) {
597 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
601 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
602 crc
= (unsigned int) sym
->st_value
;
603 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
608 /* undefined symbol */
609 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
610 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
612 if (ignore_undef_symbol(info
, symname
))
614 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
615 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
616 /* add compatibility with older glibc */
617 #ifndef STT_SPARC_REGISTER
618 #define STT_SPARC_REGISTER STT_REGISTER
620 if (info
->hdr
->e_machine
== EM_SPARC
||
621 info
->hdr
->e_machine
== EM_SPARCV9
) {
622 /* Ignore register directives. */
623 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
625 if (symname
[0] == '.') {
626 char *munged
= strdup(symname
);
628 munged
[1] = toupper(munged
[1]);
634 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
635 strlen(MODULE_SYMBOL_PREFIX
)) == 0) {
637 alloc_symbol(symname
+
638 strlen(MODULE_SYMBOL_PREFIX
),
639 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
644 /* All exported symbols */
645 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
646 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
649 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
651 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
652 mod
->has_cleanup
= 1;
658 * Parse tag=value strings from .modinfo section
660 static char *next_string(char *string
, unsigned long *secsize
)
662 /* Skip non-zero chars */
665 if ((*secsize
)-- <= 1)
669 /* Skip any zero padding. */
672 if ((*secsize
)-- <= 1)
678 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
679 const char *tag
, char *info
)
682 unsigned int taglen
= strlen(tag
);
683 unsigned long size
= modinfo_len
;
686 size
-= info
- (char *)modinfo
;
687 modinfo
= next_string(info
, &size
);
690 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
691 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
692 return p
+ taglen
+ 1;
697 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
701 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
705 * Test if string s ends in string sub
708 static int strrcmp(const char *s
, const char *sub
)
716 sublen
= strlen(sub
);
718 if ((slen
== 0) || (sublen
== 0))
724 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
727 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
730 return elf
->strtab
+ sym
->st_name
;
735 static const char *sec_name(struct elf_info
*elf
, int secindex
)
737 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
738 return (void *)elf
->hdr
+
739 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
740 sechdrs
[secindex
].sh_name
;
743 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
745 return (void *)elf
->hdr
+
746 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
750 /* if sym is empty or point to a string
751 * like ".[0-9]+" then return 1.
752 * This is the optional prefix added by ld to some sections
754 static int number_prefix(const char *sym
)
762 if (c
< '0' || c
> '9')
768 /* The pattern is an array of simple patterns.
769 * "foo" will match an exact string equal to "foo"
770 * "*foo" will match a string that ends with "foo"
771 * "foo*" will match a string that begins with "foo"
772 * "foo$" will match a string equal to "foo" or "foo.1"
773 * where the '1' can be any number including several digits.
774 * The $ syntax is for sections where ld append a dot number
775 * to make section name unique.
777 static int match(const char *sym
, const char * const pat
[])
782 const char *endp
= p
+ strlen(p
) - 1;
786 if (strrcmp(sym
, p
+ 1) == 0)
790 else if (*endp
== '*') {
791 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
795 else if (*endp
== '$') {
796 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
797 if (number_prefix(sym
+ strlen(p
) - 1))
803 if (strcmp(p
, sym
) == 0)
811 /* sections that we do not want to do full section mismatch check on */
812 static const char *section_white_list
[] =
816 ".zdebug*", /* Compressed debug sections. */
817 ".GCC-command-line", /* mn10300 */
818 ".mdebug*", /* alpha, score, mips etc. */
819 ".pdr", /* alpha, score, mips etc. */
828 * This is used to find sections missing the SHF_ALLOC flag.
829 * The cause of this is often a section specified in assembler
830 * without "ax" / "aw".
832 static void check_section(const char *modname
, struct elf_info
*elf
,
835 const char *sec
= sech_name(elf
, sechdr
);
837 if (sechdr
->sh_type
== SHT_PROGBITS
&&
838 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
839 !match(sec
, section_white_list
)) {
840 warn("%s (%s): unexpected non-allocatable section.\n"
841 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
842 "Note that for example <linux/init.h> contains\n"
843 "section definitions for use in .S files.\n\n",
850 #define ALL_INIT_DATA_SECTIONS \
851 ".init.setup$", ".init.rodata$", \
852 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
853 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
854 #define ALL_EXIT_DATA_SECTIONS \
855 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
857 #define ALL_INIT_TEXT_SECTIONS \
858 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
859 #define ALL_EXIT_TEXT_SECTIONS \
860 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
862 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
864 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
867 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
868 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
870 #define DATA_SECTIONS ".data$", ".data.rel$"
871 #define TEXT_SECTIONS ".text$"
873 #define INIT_SECTIONS ".init.*"
874 #define DEV_INIT_SECTIONS ".devinit.*"
875 #define CPU_INIT_SECTIONS ".cpuinit.*"
876 #define MEM_INIT_SECTIONS ".meminit.*"
878 #define EXIT_SECTIONS ".exit.*"
879 #define DEV_EXIT_SECTIONS ".devexit.*"
880 #define CPU_EXIT_SECTIONS ".cpuexit.*"
881 #define MEM_EXIT_SECTIONS ".memexit.*"
883 /* init data sections */
884 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
886 /* all init sections */
887 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
889 /* All init and exit sections (code + data) */
890 static const char *init_exit_sections
[] =
891 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
894 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
897 /* symbols in .data that may refer to init/exit sections */
898 #define DEFAULT_SYMBOL_WHITE_LIST \
900 "*_template", /* scsi uses *_template a lot */ \
901 "*_timer", /* arm uses ops structures named _timer a lot */ \
902 "*_sht", /* scsi also used *_sht to some extent */ \
908 static const char *head_sections
[] = { ".head.text*", NULL
};
909 static const char *linker_symbols
[] =
910 { "__init_begin", "_sinittext", "_einittext", NULL
};
917 XXXINIT_TO_SOME_INIT
,
918 XXXEXIT_TO_SOME_EXIT
,
919 ANY_INIT_TO_ANY_EXIT
,
920 ANY_EXIT_TO_ANY_INIT
,
924 struct sectioncheck
{
925 const char *fromsec
[20];
926 const char *tosec
[20];
927 enum mismatch mismatch
;
928 const char *symbol_white_list
[20];
931 const struct sectioncheck sectioncheck
[] = {
932 /* Do not reference init/exit code/data from
933 * normal code and data
936 .fromsec
= { TEXT_SECTIONS
, NULL
},
937 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
938 .mismatch
= TEXT_TO_ANY_INIT
,
939 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
942 .fromsec
= { DATA_SECTIONS
, NULL
},
943 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
944 .mismatch
= DATA_TO_ANY_INIT
,
945 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
948 .fromsec
= { DATA_SECTIONS
, NULL
},
949 .tosec
= { INIT_SECTIONS
, NULL
},
950 .mismatch
= DATA_TO_ANY_INIT
,
951 .symbol_white_list
= {
952 "*_template", "*_timer", "*_sht", "*_ops",
953 "*_probe", "*_probe_one", "*_console", NULL
957 .fromsec
= { TEXT_SECTIONS
, NULL
},
958 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
959 .mismatch
= TEXT_TO_ANY_EXIT
,
960 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
963 .fromsec
= { DATA_SECTIONS
, NULL
},
964 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
965 .mismatch
= DATA_TO_ANY_EXIT
,
966 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
968 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
970 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
971 .tosec
= { INIT_SECTIONS
, NULL
},
972 .mismatch
= XXXINIT_TO_SOME_INIT
,
973 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
975 /* Do not reference cpuinit code/data from meminit code/data */
977 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
978 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
979 .mismatch
= XXXINIT_TO_SOME_INIT
,
980 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
982 /* Do not reference meminit code/data from cpuinit code/data */
984 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
985 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
986 .mismatch
= XXXINIT_TO_SOME_INIT
,
987 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
989 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
991 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
992 .tosec
= { EXIT_SECTIONS
, NULL
},
993 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
994 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
996 /* Do not reference cpuexit code/data from memexit code/data */
998 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
999 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
1000 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1001 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1003 /* Do not reference memexit code/data from cpuexit code/data */
1005 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
1006 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
1007 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1008 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1010 /* Do not use exit code/data from init code */
1012 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
1013 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
1014 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1015 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1017 /* Do not use init code/data from exit code */
1019 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
1020 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
1021 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
1022 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1024 /* Do not export init/exit functions or data */
1026 .fromsec
= { "__ksymtab*", NULL
},
1027 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1028 .mismatch
= EXPORT_TO_INIT_EXIT
,
1029 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1033 static const struct sectioncheck
*section_mismatch(
1034 const char *fromsec
, const char *tosec
)
1037 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1038 const struct sectioncheck
*check
= §ioncheck
[0];
1040 for (i
= 0; i
< elems
; i
++) {
1041 if (match(fromsec
, check
->fromsec
) &&
1042 match(tosec
, check
->tosec
))
1050 * Whitelist to allow certain references to pass with no warning.
1053 * If a module parameter is declared __initdata and permissions=0
1054 * then this is legal despite the warning generated.
1055 * We cannot see value of permissions here, so just ignore
1057 * The pattern is identified by:
1058 * tosec = .init.data
1063 * module_param_call() ops can refer to __init set function if permissions=0
1064 * The pattern is identified by:
1065 * tosec = .init.text
1067 * atsym = __param_ops_*
1070 * Many drivers utilise a *driver container with references to
1071 * add, remove, probe functions etc.
1072 * These functions may often be marked __devinit and we do not want to
1074 * the pattern is identified by:
1075 * tosec = init or exit section
1076 * fromsec = data section
1077 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1078 * *probe_one, *_console, *_timer
1081 * Whitelist all references from .head.text to any init section
1084 * Some symbols belong to init section but still it is ok to reference
1085 * these from non-init sections as these symbols don't have any memory
1086 * allocated for them and symbol address and value are same. So even
1087 * if init section is freed, its ok to reference those symbols.
1088 * For ex. symbols marking the init section boundaries.
1089 * This pattern is identified by
1090 * refsymname = __init_begin, _sinittext, _einittext
1093 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1094 const char *fromsec
, const char *fromsym
,
1095 const char *tosec
, const char *tosym
)
1097 /* Check for pattern 1 */
1098 if (match(tosec
, init_data_sections
) &&
1099 match(fromsec
, data_sections
) &&
1100 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1103 /* Check for pattern 1a */
1104 if (strcmp(tosec
, ".init.text") == 0 &&
1105 match(fromsec
, data_sections
) &&
1106 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1109 /* Check for pattern 2 */
1110 if (match(tosec
, init_exit_sections
) &&
1111 match(fromsec
, data_sections
) &&
1112 match(fromsym
, mismatch
->symbol_white_list
))
1115 /* Check for pattern 3 */
1116 if (match(fromsec
, head_sections
) &&
1117 match(tosec
, init_sections
))
1120 /* Check for pattern 4 */
1121 if (match(tosym
, linker_symbols
))
1128 * Find symbol based on relocation record info.
1129 * In some cases the symbol supplied is a valid symbol so
1130 * return refsym. If st_name != 0 we assume this is a valid symbol.
1131 * In other cases the symbol needs to be looked up in the symbol table
1132 * based on section and address.
1134 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1138 Elf_Sym
*near
= NULL
;
1139 Elf64_Sword distance
= 20;
1141 unsigned int relsym_secindex
;
1143 if (relsym
->st_name
!= 0)
1146 relsym_secindex
= get_secindex(elf
, relsym
);
1147 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1148 if (get_secindex(elf
, sym
) != relsym_secindex
)
1150 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1152 if (sym
->st_value
== addr
)
1154 /* Find a symbol nearby - addr are maybe negative */
1155 d
= sym
->st_value
- addr
;
1157 d
= addr
- sym
->st_value
;
1163 /* We need a close match */
1170 static inline int is_arm_mapping_symbol(const char *str
)
1172 return str
[0] == '$' && strchr("atd", str
[1])
1173 && (str
[2] == '\0' || str
[2] == '.');
1177 * If there's no name there, ignore it; likewise, ignore it if it's
1178 * one of the magic symbols emitted used by current ARM tools.
1180 * Otherwise if find_symbols_between() returns those symbols, they'll
1181 * fail the whitelist tests and cause lots of false alarms ... fixable
1182 * only by merging __exit and __init sections into __text, bloating
1183 * the kernel (which is especially evil on embedded platforms).
1185 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1187 const char *name
= elf
->strtab
+ sym
->st_name
;
1189 if (!name
|| !strlen(name
))
1191 return !is_arm_mapping_symbol(name
);
1195 * Find symbols before or equal addr and after addr - in the section sec.
1196 * If we find two symbols with equal offset prefer one with a valid name.
1197 * The ELF format may have a better way to detect what type of symbol
1198 * it is, but this works for now.
1200 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1204 Elf_Sym
*near
= NULL
;
1205 Elf_Addr distance
= ~0;
1207 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1210 if (is_shndx_special(sym
->st_shndx
))
1212 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1213 if (strcmp(symsec
, sec
) != 0)
1215 if (!is_valid_name(elf
, sym
))
1217 if (sym
->st_value
<= addr
) {
1218 if ((addr
- sym
->st_value
) < distance
) {
1219 distance
= addr
- sym
->st_value
;
1221 } else if ((addr
- sym
->st_value
) == distance
) {
1230 * Convert a section name to the function/data attribute
1231 * .init.text => __init
1232 * .cpuinit.data => __cpudata
1233 * .memexitconst => __memconst
1236 * The memory of returned value has been allocated on a heap. The user of this
1237 * method should free it after usage.
1239 static char *sec2annotation(const char *s
)
1241 if (match(s
, init_exit_sections
)) {
1242 char *p
= malloc(20);
1249 while (*s
&& *s
!= '.')
1254 if (strstr(s
, "rodata") != NULL
)
1255 strcat(p
, "const ");
1256 else if (strstr(s
, "data") != NULL
)
1266 static int is_function(Elf_Sym
*sym
)
1269 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1274 static void print_section_list(const char * const list
[20])
1276 const char *const *s
= list
;
1279 fprintf(stderr
, "%s", *s
);
1282 fprintf(stderr
, ", ");
1284 fprintf(stderr
, "\n");
1288 * Print a warning about a section mismatch.
1289 * Try to find symbols near it so user can find it.
1290 * Check whitelist before warning - it may be a false positive.
1292 static void report_sec_mismatch(const char *modname
,
1293 const struct sectioncheck
*mismatch
,
1294 const char *fromsec
,
1295 unsigned long long fromaddr
,
1296 const char *fromsym
,
1298 const char *tosec
, const char *tosym
,
1301 const char *from
, *from_p
;
1302 const char *to
, *to_p
;
1306 switch (from_is_func
) {
1307 case 0: from
= "variable"; from_p
= ""; break;
1308 case 1: from
= "function"; from_p
= "()"; break;
1309 default: from
= "(unknown reference)"; from_p
= ""; break;
1311 switch (to_is_func
) {
1312 case 0: to
= "variable"; to_p
= ""; break;
1313 case 1: to
= "function"; to_p
= "()"; break;
1314 default: to
= "(unknown reference)"; to_p
= ""; break;
1317 sec_mismatch_count
++;
1318 if (!sec_mismatch_verbose
)
1321 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1322 "to the %s %s:%s%s\n",
1323 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1326 switch (mismatch
->mismatch
) {
1327 case TEXT_TO_ANY_INIT
:
1328 prl_from
= sec2annotation(fromsec
);
1329 prl_to
= sec2annotation(tosec
);
1331 "The function %s%s() references\n"
1333 "This is often because %s lacks a %s\n"
1334 "annotation or the annotation of %s is wrong.\n",
1336 to
, prl_to
, tosym
, to_p
,
1337 fromsym
, prl_to
, tosym
);
1341 case DATA_TO_ANY_INIT
: {
1342 prl_to
= sec2annotation(tosec
);
1344 "The variable %s references\n"
1346 "If the reference is valid then annotate the\n"
1347 "variable with __init* or __refdata (see linux/init.h) "
1348 "or name the variable:\n",
1349 fromsym
, to
, prl_to
, tosym
, to_p
);
1350 print_section_list(mismatch
->symbol_white_list
);
1354 case TEXT_TO_ANY_EXIT
:
1355 prl_to
= sec2annotation(tosec
);
1357 "The function %s() references a %s in an exit section.\n"
1358 "Often the %s %s%s has valid usage outside the exit section\n"
1359 "and the fix is to remove the %sannotation of %s.\n",
1360 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1363 case DATA_TO_ANY_EXIT
: {
1364 prl_to
= sec2annotation(tosec
);
1366 "The variable %s references\n"
1368 "If the reference is valid then annotate the\n"
1369 "variable with __exit* (see linux/init.h) or "
1370 "name the variable:\n",
1371 fromsym
, to
, prl_to
, tosym
, to_p
);
1372 print_section_list(mismatch
->symbol_white_list
);
1376 case XXXINIT_TO_SOME_INIT
:
1377 case XXXEXIT_TO_SOME_EXIT
:
1378 prl_from
= sec2annotation(fromsec
);
1379 prl_to
= sec2annotation(tosec
);
1381 "The %s %s%s%s references\n"
1383 "If %s is only used by %s then\n"
1384 "annotate %s with a matching annotation.\n",
1385 from
, prl_from
, fromsym
, from_p
,
1386 to
, prl_to
, tosym
, to_p
,
1387 tosym
, fromsym
, tosym
);
1391 case ANY_INIT_TO_ANY_EXIT
:
1392 prl_from
= sec2annotation(fromsec
);
1393 prl_to
= sec2annotation(tosec
);
1395 "The %s %s%s%s references\n"
1397 "This is often seen when error handling "
1398 "in the init function\n"
1399 "uses functionality in the exit path.\n"
1400 "The fix is often to remove the %sannotation of\n"
1401 "%s%s so it may be used outside an exit section.\n",
1402 from
, prl_from
, fromsym
, from_p
,
1403 to
, prl_to
, tosym
, to_p
,
1404 prl_to
, tosym
, to_p
);
1408 case ANY_EXIT_TO_ANY_INIT
:
1409 prl_from
= sec2annotation(fromsec
);
1410 prl_to
= sec2annotation(tosec
);
1412 "The %s %s%s%s references\n"
1414 "This is often seen when error handling "
1415 "in the exit function\n"
1416 "uses functionality in the init path.\n"
1417 "The fix is often to remove the %sannotation of\n"
1418 "%s%s so it may be used outside an init section.\n",
1419 from
, prl_from
, fromsym
, from_p
,
1420 to
, prl_to
, tosym
, to_p
,
1421 prl_to
, tosym
, to_p
);
1425 case EXPORT_TO_INIT_EXIT
:
1426 prl_to
= sec2annotation(tosec
);
1428 "The symbol %s is exported and annotated %s\n"
1429 "Fix this by removing the %sannotation of %s "
1430 "or drop the export.\n",
1431 tosym
, prl_to
, prl_to
, tosym
);
1435 fprintf(stderr
, "\n");
1438 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1439 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1442 const struct sectioncheck
*mismatch
;
1444 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1445 mismatch
= section_mismatch(fromsec
, tosec
);
1450 const char *fromsym
;
1452 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1453 fromsym
= sym_name(elf
, from
);
1454 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1455 tosym
= sym_name(elf
, to
);
1457 /* check whitelist - we may ignore it */
1458 if (secref_whitelist(mismatch
,
1459 fromsec
, fromsym
, tosec
, tosym
)) {
1460 report_sec_mismatch(modname
, mismatch
,
1461 fromsec
, r
->r_offset
, fromsym
,
1462 is_function(from
), tosec
, tosym
,
1468 static unsigned int *reloc_location(struct elf_info
*elf
,
1469 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1471 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1472 int section
= sechdr
->sh_info
;
1474 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1478 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1480 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1481 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1485 r
->r_addend
= TO_NATIVE(*location
);
1488 r
->r_addend
= TO_NATIVE(*location
) + 4;
1489 /* For CONFIG_RELOCATABLE=y */
1490 if (elf
->hdr
->e_type
== ET_EXEC
)
1491 r
->r_addend
+= r
->r_offset
;
1497 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1499 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1503 /* From ARM ABI: (S + A) | T */
1504 r
->r_addend
= (int)(long)
1505 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1508 /* From ARM ABI: ((S + A) | T) - P */
1509 r
->r_addend
= (int)(long)(elf
->hdr
+
1511 (r
->r_offset
- sechdr
->sh_addr
));
1519 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1521 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1522 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1525 if (r_typ
== R_MIPS_HI16
)
1526 return 1; /* skip this */
1527 inst
= TO_NATIVE(*location
);
1530 r
->r_addend
= inst
& 0xffff;
1533 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1542 static void section_rela(const char *modname
, struct elf_info
*elf
,
1549 const char *fromsec
;
1551 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1552 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1554 fromsec
= sech_name(elf
, sechdr
);
1555 fromsec
+= strlen(".rela");
1556 /* if from section (name) is know good then skip it */
1557 if (match(fromsec
, section_white_list
))
1560 for (rela
= start
; rela
< stop
; rela
++) {
1561 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1562 #if KERNEL_ELFCLASS == ELFCLASS64
1563 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1565 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1566 r_sym
= TO_NATIVE(r_sym
);
1567 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1568 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1570 r
.r_info
= TO_NATIVE(rela
->r_info
);
1571 r_sym
= ELF_R_SYM(r
.r_info
);
1574 r
.r_info
= TO_NATIVE(rela
->r_info
);
1575 r_sym
= ELF_R_SYM(r
.r_info
);
1577 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1578 sym
= elf
->symtab_start
+ r_sym
;
1579 /* Skip special sections */
1580 if (is_shndx_special(sym
->st_shndx
))
1582 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1586 static void section_rel(const char *modname
, struct elf_info
*elf
,
1593 const char *fromsec
;
1595 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1596 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1598 fromsec
= sech_name(elf
, sechdr
);
1599 fromsec
+= strlen(".rel");
1600 /* if from section (name) is know good then skip it */
1601 if (match(fromsec
, section_white_list
))
1604 for (rel
= start
; rel
< stop
; rel
++) {
1605 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1606 #if KERNEL_ELFCLASS == ELFCLASS64
1607 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1609 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1610 r_sym
= TO_NATIVE(r_sym
);
1611 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1612 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1614 r
.r_info
= TO_NATIVE(rel
->r_info
);
1615 r_sym
= ELF_R_SYM(r
.r_info
);
1618 r
.r_info
= TO_NATIVE(rel
->r_info
);
1619 r_sym
= ELF_R_SYM(r
.r_info
);
1622 switch (elf
->hdr
->e_machine
) {
1624 if (addend_386_rel(elf
, sechdr
, &r
))
1628 if (addend_arm_rel(elf
, sechdr
, &r
))
1632 if (addend_mips_rel(elf
, sechdr
, &r
))
1636 sym
= elf
->symtab_start
+ r_sym
;
1637 /* Skip special sections */
1638 if (is_shndx_special(sym
->st_shndx
))
1640 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1645 * A module includes a number of sections that are discarded
1646 * either when loaded or when used as built-in.
1647 * For loaded modules all functions marked __init and all data
1648 * marked __initdata will be discarded when the module has been initialized.
1649 * Likewise for modules used built-in the sections marked __exit
1650 * are discarded because __exit marked function are supposed to be called
1651 * only when a module is unloaded which never happens for built-in modules.
1652 * The check_sec_ref() function traverses all relocation records
1653 * to find all references to a section that reference a section that will
1654 * be discarded and warns about it.
1656 static void check_sec_ref(struct module
*mod
, const char *modname
,
1657 struct elf_info
*elf
)
1660 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1662 /* Walk through all sections */
1663 for (i
= 0; i
< elf
->num_sections
; i
++) {
1664 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1665 /* We want to process only relocation sections and not .init */
1666 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1667 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1668 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1669 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1673 static void read_symbols(char *modname
)
1675 const char *symname
;
1679 struct elf_info info
= { };
1682 if (!parse_elf(&info
, modname
))
1685 mod
= new_module(modname
);
1687 /* When there's no vmlinux, don't print warnings about
1688 * unresolved symbols (since there'll be too many ;) */
1689 if (is_vmlinux(modname
)) {
1694 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1695 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1696 warn("modpost: missing MODULE_LICENSE() in %s\n"
1697 "see include/linux/module.h for "
1698 "more information\n", modname
);
1700 if (license_is_gpl_compatible(license
))
1701 mod
->gpl_compatible
= 1;
1703 mod
->gpl_compatible
= 0;
1706 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1707 "license", license
);
1710 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1711 symname
= info
.strtab
+ sym
->st_name
;
1713 handle_modversions(mod
, &info
, sym
, symname
);
1714 handle_moddevtable(mod
, &info
, sym
, symname
);
1716 if (!is_vmlinux(modname
) ||
1717 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1718 check_sec_ref(mod
, modname
, &info
);
1720 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1722 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1723 version
- (char *)info
.hdr
);
1724 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1725 get_src_version(modname
, mod
->srcversion
,
1726 sizeof(mod
->srcversion
)-1);
1728 parse_elf_finish(&info
);
1730 /* Our trick to get versioning for module struct etc. - it's
1731 * never passed as an argument to an exported function, so
1732 * the automatic versioning doesn't pick it up, but it's really
1733 * important anyhow */
1735 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1740 /* We first write the generated file into memory using the
1741 * following helper, then compare to the file on disk and
1742 * only update the later if anything changed */
1744 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1745 const char *fmt
, ...)
1752 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1753 buf_write(buf
, tmp
, len
);
1757 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1759 if (buf
->size
- buf
->pos
< len
) {
1760 buf
->size
+= len
+ SZ
;
1761 buf
->p
= realloc(buf
->p
, buf
->size
);
1763 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1767 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1769 const char *e
= is_vmlinux(m
) ?"":".ko";
1773 fatal("modpost: GPL-incompatible module %s%s "
1774 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1776 case export_unused_gpl
:
1777 fatal("modpost: GPL-incompatible module %s%s "
1778 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1780 case export_gpl_future
:
1781 warn("modpost: GPL-incompatible module %s%s "
1782 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1786 case export_unknown
:
1792 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1794 const char *e
= is_vmlinux(m
) ?"":".ko";
1798 case export_unused_gpl
:
1799 warn("modpost: module %s%s "
1800 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1808 static void check_exports(struct module
*mod
)
1810 struct symbol
*s
, *exp
;
1812 for (s
= mod
->unres
; s
; s
= s
->next
) {
1813 const char *basename
;
1814 exp
= find_symbol(s
->name
);
1815 if (!exp
|| exp
->module
== mod
)
1817 basename
= strrchr(mod
->name
, '/');
1821 basename
= mod
->name
;
1822 if (!mod
->gpl_compatible
)
1823 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1824 check_for_unused(exp
->export
, basename
, exp
->name
);
1829 * Header for the generated file
1831 static void add_header(struct buffer
*b
, struct module
*mod
)
1833 buf_printf(b
, "#include <linux/module.h>\n");
1834 buf_printf(b
, "#include <linux/vermagic.h>\n");
1835 buf_printf(b
, "#include <linux/compiler.h>\n");
1836 buf_printf(b
, "\n");
1837 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1838 buf_printf(b
, "\n");
1839 buf_printf(b
, "struct module __this_module\n");
1840 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1841 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1843 buf_printf(b
, " .init = init_module,\n");
1844 if (mod
->has_cleanup
)
1845 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1846 " .exit = cleanup_module,\n"
1848 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1849 buf_printf(b
, "};\n");
1852 static void add_staging_flag(struct buffer
*b
, const char *name
)
1854 static const char *staging_dir
= "drivers/staging";
1856 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1857 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1861 * Record CRCs for unresolved symbols
1863 static int add_versions(struct buffer
*b
, struct module
*mod
)
1865 struct symbol
*s
, *exp
;
1868 for (s
= mod
->unres
; s
; s
= s
->next
) {
1869 exp
= find_symbol(s
->name
);
1870 if (!exp
|| exp
->module
== mod
) {
1871 if (have_vmlinux
&& !s
->weak
) {
1872 if (warn_unresolved
) {
1873 warn("\"%s\" [%s.ko] undefined!\n",
1874 s
->name
, mod
->name
);
1876 merror("\"%s\" [%s.ko] undefined!\n",
1877 s
->name
, mod
->name
);
1883 s
->module
= exp
->module
;
1884 s
->crc_valid
= exp
->crc_valid
;
1891 buf_printf(b
, "\n");
1892 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1893 buf_printf(b
, "__used\n");
1894 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1896 for (s
= mod
->unres
; s
; s
= s
->next
) {
1899 if (!s
->crc_valid
) {
1900 warn("\"%s\" [%s.ko] has no CRC!\n",
1901 s
->name
, mod
->name
);
1904 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1907 buf_printf(b
, "};\n");
1912 static void add_depends(struct buffer
*b
, struct module
*mod
,
1913 struct module
*modules
)
1919 for (m
= modules
; m
; m
= m
->next
)
1920 m
->seen
= is_vmlinux(m
->name
);
1922 buf_printf(b
, "\n");
1923 buf_printf(b
, "static const char __module_depends[]\n");
1924 buf_printf(b
, "__used\n");
1925 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1926 buf_printf(b
, "\"depends=");
1927 for (s
= mod
->unres
; s
; s
= s
->next
) {
1932 if (s
->module
->seen
)
1935 s
->module
->seen
= 1;
1936 p
= strrchr(s
->module
->name
, '/');
1940 p
= s
->module
->name
;
1941 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1944 buf_printf(b
, "\";\n");
1947 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1949 if (mod
->srcversion
[0]) {
1950 buf_printf(b
, "\n");
1951 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1956 static void write_if_changed(struct buffer
*b
, const char *fname
)
1962 file
= fopen(fname
, "r");
1966 if (fstat(fileno(file
), &st
) < 0)
1969 if (st
.st_size
!= b
->pos
)
1972 tmp
= NOFAIL(malloc(b
->pos
));
1973 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1976 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1988 file
= fopen(fname
, "w");
1993 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2000 /* parse Module.symvers file. line format:
2001 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2003 static void read_dump(const char *fname
, unsigned int kernel
)
2005 unsigned long size
, pos
= 0;
2006 void *file
= grab_file(fname
, &size
);
2010 /* No symbol versions, silently ignore */
2013 while ((line
= get_next_line(&pos
, file
, size
))) {
2014 char *symname
, *modname
, *d
, *export
, *end
;
2019 if (!(symname
= strchr(line
, '\t')))
2022 if (!(modname
= strchr(symname
, '\t')))
2025 if ((export
= strchr(modname
, '\t')) != NULL
)
2027 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2029 crc
= strtoul(line
, &d
, 16);
2030 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2032 mod
= find_module(modname
);
2034 if (is_vmlinux(modname
))
2036 mod
= new_module(modname
);
2039 s
= sym_add_exported(symname
, mod
, export_no(export
));
2042 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2046 fatal("parse error in symbol dump file\n");
2049 /* For normal builds always dump all symbols.
2050 * For external modules only dump symbols
2051 * that are not read from kernel Module.symvers.
2053 static int dump_sym(struct symbol
*sym
)
2055 if (!external_module
)
2057 if (sym
->vmlinux
|| sym
->kernel
)
2062 static void write_dump(const char *fname
)
2064 struct buffer buf
= { };
2065 struct symbol
*symbol
;
2068 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2069 symbol
= symbolhash
[n
];
2071 if (dump_sym(symbol
))
2072 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2073 symbol
->crc
, symbol
->name
,
2074 symbol
->module
->name
,
2075 export_str(symbol
->export
));
2076 symbol
= symbol
->next
;
2079 write_if_changed(&buf
, fname
);
2082 struct ext_sym_list
{
2083 struct ext_sym_list
*next
;
2087 int main(int argc
, char **argv
)
2090 struct buffer buf
= { };
2091 char *kernel_read
= NULL
, *module_read
= NULL
;
2092 char *dump_write
= NULL
;
2095 struct ext_sym_list
*extsym_iter
;
2096 struct ext_sym_list
*extsym_start
= NULL
;
2098 while ((opt
= getopt(argc
, argv
, "i:I:e:cmsSo:awM:K:")) != -1) {
2101 kernel_read
= optarg
;
2104 module_read
= optarg
;
2105 external_module
= 1;
2111 external_module
= 1;
2113 NOFAIL(malloc(sizeof(*extsym_iter
)));
2114 extsym_iter
->next
= extsym_start
;
2115 extsym_iter
->file
= optarg
;
2116 extsym_start
= extsym_iter
;
2122 dump_write
= optarg
;
2128 vmlinux_section_warnings
= 0;
2131 sec_mismatch_verbose
= 0;
2134 warn_unresolved
= 1;
2142 read_dump(kernel_read
, 1);
2144 read_dump(module_read
, 0);
2145 while (extsym_start
) {
2146 read_dump(extsym_start
->file
, 0);
2147 extsym_iter
= extsym_start
->next
;
2149 extsym_start
= extsym_iter
;
2152 while (optind
< argc
)
2153 read_symbols(argv
[optind
++]);
2155 for (mod
= modules
; mod
; mod
= mod
->next
) {
2163 for (mod
= modules
; mod
; mod
= mod
->next
) {
2164 char fname
[strlen(mod
->name
) + 10];
2171 add_header(&buf
, mod
);
2172 add_staging_flag(&buf
, mod
->name
);
2173 err
|= add_versions(&buf
, mod
);
2174 add_depends(&buf
, mod
, modules
);
2175 add_moddevtable(&buf
, mod
);
2176 add_srcversion(&buf
, mod
);
2178 sprintf(fname
, "%s.mod.c", mod
->name
);
2179 write_if_changed(&buf
, fname
);
2183 write_dump(dump_write
);
2184 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2185 warn("modpost: Found %d section mismatch(es).\n"
2186 "To see full details build your kernel with:\n"
2187 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2188 sec_mismatch_count
);