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 ...
21 #include "../../include/generated/autoconf.h"
22 #include "../../include/linux/license.h"
23 #include "../../include/linux/export.h"
25 /* Are we using CONFIG_MODVERSIONS? */
27 /* Warn about undefined symbols? (do so if we have vmlinux) */
29 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
30 static int all_versions
= 0;
31 /* If we are modposting external module set to 1 */
32 static int external_module
= 0;
33 /* Warn about section mismatch in vmlinux if set to 1 */
34 static int vmlinux_section_warnings
= 1;
35 /* Only warn about unresolved symbols */
36 static int warn_unresolved
= 0;
37 /* How a symbol is exported */
38 static int sec_mismatch_count
= 0;
39 static int sec_mismatch_verbose
= 1;
42 export_plain
, export_unused
, export_gpl
,
43 export_unused_gpl
, export_gpl_future
, export_unknown
46 #define PRINTF __attribute__ ((format (printf, 1, 2)))
48 PRINTF
void fatal(const char *fmt
, ...)
52 fprintf(stderr
, "FATAL: ");
54 va_start(arglist
, fmt
);
55 vfprintf(stderr
, fmt
, arglist
);
61 PRINTF
void warn(const char *fmt
, ...)
65 fprintf(stderr
, "WARNING: ");
67 va_start(arglist
, fmt
);
68 vfprintf(stderr
, fmt
, arglist
);
72 PRINTF
void merror(const char *fmt
, ...)
76 fprintf(stderr
, "ERROR: ");
78 va_start(arglist
, fmt
);
79 vfprintf(stderr
, fmt
, arglist
);
83 static inline bool strends(const char *str
, const char *postfix
)
85 if (strlen(str
) < strlen(postfix
))
88 return strcmp(str
+ strlen(str
) - strlen(postfix
), postfix
) == 0;
91 static int is_vmlinux(const char *modname
)
95 myname
= strrchr(modname
, '/');
101 return (strcmp(myname
, "vmlinux") == 0) ||
102 (strcmp(myname
, "vmlinux.o") == 0);
105 void *do_nofail(void *ptr
, const char *expr
)
108 fatal("modpost: Memory allocation failure: %s.\n", expr
);
113 /* A list of all modules we processed */
114 static struct module
*modules
;
116 static struct module
*find_module(char *modname
)
120 for (mod
= modules
; mod
; mod
= mod
->next
)
121 if (strcmp(mod
->name
, modname
) == 0)
126 static struct module
*new_module(const char *modname
)
131 mod
= NOFAIL(malloc(sizeof(*mod
)));
132 memset(mod
, 0, sizeof(*mod
));
133 p
= NOFAIL(strdup(modname
));
135 /* strip trailing .o */
136 if (strends(p
, ".o")) {
137 p
[strlen(p
) - 2] = '\0';
143 mod
->gpl_compatible
= -1;
150 /* A hash of all exported symbols,
151 * struct symbol is also used for lists of unresolved symbols */
153 #define SYMBOL_HASH_SIZE 1024
157 struct module
*module
;
161 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
162 unsigned int kernel
:1; /* 1 if symbol is from kernel
163 * (only for external modules) **/
164 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
165 enum export export
; /* Type of export */
169 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
171 /* This is based on the hash agorithm from gdbm, via tdb */
172 static inline unsigned int tdb_hash(const char *name
)
174 unsigned value
; /* Used to compute the hash value. */
175 unsigned i
; /* Used to cycle through random values. */
177 /* Set the initial value from the key size. */
178 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
179 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
181 return (1103515243 * value
+ 12345);
185 * Allocate a new symbols for use in the hash of exported symbols or
186 * the list of unresolved symbols per module
188 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
191 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
193 memset(s
, 0, sizeof(*s
));
194 strcpy(s
->name
, name
);
200 /* For the hash of exported symbols */
201 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
207 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
208 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
209 new->module
= module
;
210 new->export
= export
;
214 static struct symbol
*find_symbol(const char *name
)
218 /* For our purposes, .foo matches foo. PPC64 needs this. */
222 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
223 if (strcmp(s
->name
, name
) == 0)
233 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
234 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
235 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
236 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
237 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
238 { .str
= "(unknown)", .export
= export_unknown
},
242 static const char *export_str(enum export ex
)
244 return export_list
[ex
].str
;
247 static enum export
export_no(const char *s
)
252 return export_unknown
;
253 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
254 if (strcmp(export_list
[i
].str
, s
) == 0)
255 return export_list
[i
].export
;
257 return export_unknown
;
260 static const char *sec_name(struct elf_info
*elf
, int secindex
);
262 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
264 static enum export
export_from_secname(struct elf_info
*elf
, unsigned int sec
)
266 const char *secname
= sec_name(elf
, sec
);
268 if (strstarts(secname
, "___ksymtab+"))
270 else if (strstarts(secname
, "___ksymtab_unused+"))
271 return export_unused
;
272 else if (strstarts(secname
, "___ksymtab_gpl+"))
274 else if (strstarts(secname
, "___ksymtab_unused_gpl+"))
275 return export_unused_gpl
;
276 else if (strstarts(secname
, "___ksymtab_gpl_future+"))
277 return export_gpl_future
;
279 return export_unknown
;
282 static enum export
export_from_sec(struct elf_info
*elf
, unsigned int sec
)
284 if (sec
== elf
->export_sec
)
286 else if (sec
== elf
->export_unused_sec
)
287 return export_unused
;
288 else if (sec
== elf
->export_gpl_sec
)
290 else if (sec
== elf
->export_unused_gpl_sec
)
291 return export_unused_gpl
;
292 else if (sec
== elf
->export_gpl_future_sec
)
293 return export_gpl_future
;
295 return export_unknown
;
299 * Add an exported symbol - it may have already been added without a
300 * CRC, in this case just update the CRC
302 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
305 struct symbol
*s
= find_symbol(name
);
308 s
= new_symbol(name
, mod
, export
);
311 warn("%s: '%s' exported twice. Previous export "
312 "was in %s%s\n", mod
->name
, name
,
314 is_vmlinux(s
->module
->name
) ?"":".ko");
316 /* In case Modules.symvers was out of date */
321 s
->vmlinux
= is_vmlinux(mod
->name
);
327 static void sym_update_crc(const char *name
, struct module
*mod
,
328 unsigned int crc
, enum export export
)
330 struct symbol
*s
= find_symbol(name
);
333 s
= new_symbol(name
, mod
, export
);
338 void *grab_file(const char *filename
, unsigned long *size
)
341 void *map
= MAP_FAILED
;
344 fd
= open(filename
, O_RDONLY
);
351 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
355 if (map
== MAP_FAILED
)
361 * Return a copy of the next line in a mmap'ed file.
362 * spaces in the beginning of the line is trimmed away.
363 * Return a pointer to a static buffer.
365 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
367 static char line
[4096];
370 signed char *p
= (signed char *)file
+ *pos
;
373 for (; *pos
< size
; (*pos
)++) {
374 if (skip
&& isspace(*p
)) {
379 if (*p
!= '\n' && (*pos
< size
)) {
383 break; /* Too long, stop */
394 void release_file(void *file
, unsigned long size
)
399 static int parse_elf(struct elf_info
*info
, const char *filename
)
405 const char *secstrings
;
406 unsigned int symtab_idx
= ~0U, symtab_shndx_idx
= ~0U;
408 hdr
= grab_file(filename
, &info
->size
);
414 if (info
->size
< sizeof(*hdr
)) {
415 /* file too small, assume this is an empty .o file */
418 /* Is this a valid ELF file? */
419 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
420 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
421 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
422 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
423 /* Not an ELF file - silently ignore it */
426 /* Fix endianness in ELF header */
427 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
428 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
429 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
430 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
431 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
432 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
433 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
434 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
435 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
436 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
437 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
438 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
439 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
440 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
441 info
->sechdrs
= sechdrs
;
443 /* Check if file offset is correct */
444 if (hdr
->e_shoff
> info
->size
) {
445 fatal("section header offset=%lu in file '%s' is bigger than "
446 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
447 filename
, info
->size
);
451 if (hdr
->e_shnum
== SHN_UNDEF
) {
453 * There are more than 64k sections,
454 * read count from .sh_size.
456 info
->num_sections
= TO_NATIVE(sechdrs
[0].sh_size
);
459 info
->num_sections
= hdr
->e_shnum
;
461 if (hdr
->e_shstrndx
== SHN_XINDEX
) {
462 info
->secindex_strings
= TO_NATIVE(sechdrs
[0].sh_link
);
465 info
->secindex_strings
= hdr
->e_shstrndx
;
468 /* Fix endianness in section headers */
469 for (i
= 0; i
< info
->num_sections
; i
++) {
470 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
471 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
472 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
473 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
474 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
475 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
476 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
477 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
478 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
479 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
481 /* Find symbol table. */
482 secstrings
= (void *)hdr
+ sechdrs
[info
->secindex_strings
].sh_offset
;
483 for (i
= 1; i
< info
->num_sections
; i
++) {
485 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
487 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
488 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
489 "sizeof(*hrd)=%zu\n", filename
,
490 (unsigned long)sechdrs
[i
].sh_offset
,
494 secname
= secstrings
+ sechdrs
[i
].sh_name
;
495 if (strcmp(secname
, ".modinfo") == 0) {
497 fatal("%s has NOBITS .modinfo\n", filename
);
498 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
499 info
->modinfo_len
= sechdrs
[i
].sh_size
;
500 } else if (strcmp(secname
, "__ksymtab") == 0)
501 info
->export_sec
= i
;
502 else if (strcmp(secname
, "__ksymtab_unused") == 0)
503 info
->export_unused_sec
= i
;
504 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
505 info
->export_gpl_sec
= i
;
506 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
507 info
->export_unused_gpl_sec
= i
;
508 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
509 info
->export_gpl_future_sec
= i
;
511 if (sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
512 unsigned int sh_link_idx
;
514 info
->symtab_start
= (void *)hdr
+
515 sechdrs
[i
].sh_offset
;
516 info
->symtab_stop
= (void *)hdr
+
517 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
518 sh_link_idx
= sechdrs
[i
].sh_link
;
519 info
->strtab
= (void *)hdr
+
520 sechdrs
[sh_link_idx
].sh_offset
;
523 /* 32bit section no. table? ("more than 64k sections") */
524 if (sechdrs
[i
].sh_type
== SHT_SYMTAB_SHNDX
) {
525 symtab_shndx_idx
= i
;
526 info
->symtab_shndx_start
= (void *)hdr
+
527 sechdrs
[i
].sh_offset
;
528 info
->symtab_shndx_stop
= (void *)hdr
+
529 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
532 if (!info
->symtab_start
)
533 fatal("%s has no symtab?\n", filename
);
535 /* Fix endianness in symbols */
536 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
537 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
538 sym
->st_name
= TO_NATIVE(sym
->st_name
);
539 sym
->st_value
= TO_NATIVE(sym
->st_value
);
540 sym
->st_size
= TO_NATIVE(sym
->st_size
);
543 if (symtab_shndx_idx
!= ~0U) {
545 if (symtab_idx
!= sechdrs
[symtab_shndx_idx
].sh_link
)
546 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
547 filename
, sechdrs
[symtab_shndx_idx
].sh_link
,
550 for (p
= info
->symtab_shndx_start
; p
< info
->symtab_shndx_stop
;
558 static void parse_elf_finish(struct elf_info
*info
)
560 release_file(info
->hdr
, info
->size
);
563 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
565 /* ignore __this_module, it will be resolved shortly */
566 if (strcmp(symname
, VMLINUX_SYMBOL_STR(__this_module
)) == 0)
568 /* ignore global offset table */
569 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
571 if (info
->hdr
->e_machine
== EM_PPC
)
572 /* Special register function linked on all modules during final link of .ko */
573 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
574 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
575 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
576 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
578 if (info
->hdr
->e_machine
== EM_PPC64
)
579 /* Special register function linked on all modules during final link of .ko */
580 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
581 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
583 /* Do not ignore this symbol */
587 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
588 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
590 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
591 Elf_Sym
*sym
, const char *symname
)
596 if ((!is_vmlinux(mod
->name
) || mod
->is_dot_o
) &&
597 strncmp(symname
, "__ksymtab", 9) == 0)
598 export
= export_from_secname(info
, get_secindex(info
, sym
));
600 export
= export_from_sec(info
, get_secindex(info
, sym
));
602 switch (sym
->st_shndx
) {
604 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
608 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
609 crc
= (unsigned int) sym
->st_value
;
610 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
615 /* undefined symbol */
616 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
617 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
619 if (ignore_undef_symbol(info
, symname
))
621 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
622 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
623 /* add compatibility with older glibc */
624 #ifndef STT_SPARC_REGISTER
625 #define STT_SPARC_REGISTER STT_REGISTER
627 if (info
->hdr
->e_machine
== EM_SPARC
||
628 info
->hdr
->e_machine
== EM_SPARCV9
) {
629 /* Ignore register directives. */
630 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
632 if (symname
[0] == '.') {
633 char *munged
= strdup(symname
);
635 munged
[1] = toupper(munged
[1]);
641 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
642 if (symname
[0] != '_')
647 mod
->unres
= alloc_symbol(symname
,
648 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
652 /* All exported symbols */
653 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
654 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
657 if (strcmp(symname
, VMLINUX_SYMBOL_STR(init_module
)) == 0)
659 if (strcmp(symname
, VMLINUX_SYMBOL_STR(cleanup_module
)) == 0)
660 mod
->has_cleanup
= 1;
666 * Parse tag=value strings from .modinfo section
668 static char *next_string(char *string
, unsigned long *secsize
)
670 /* Skip non-zero chars */
673 if ((*secsize
)-- <= 1)
677 /* Skip any zero padding. */
680 if ((*secsize
)-- <= 1)
686 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
687 const char *tag
, char *info
)
690 unsigned int taglen
= strlen(tag
);
691 unsigned long size
= modinfo_len
;
694 size
-= info
- (char *)modinfo
;
695 modinfo
= next_string(info
, &size
);
698 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
699 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
700 return p
+ taglen
+ 1;
705 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
709 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
713 * Test if string s ends in string sub
716 static int strrcmp(const char *s
, const char *sub
)
724 sublen
= strlen(sub
);
726 if ((slen
== 0) || (sublen
== 0))
732 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
735 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
738 return elf
->strtab
+ sym
->st_name
;
743 static const char *sec_name(struct elf_info
*elf
, int secindex
)
745 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
746 return (void *)elf
->hdr
+
747 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
748 sechdrs
[secindex
].sh_name
;
751 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
753 return (void *)elf
->hdr
+
754 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
758 /* if sym is empty or point to a string
759 * like ".[0-9]+" then return 1.
760 * This is the optional prefix added by ld to some sections
762 static int number_prefix(const char *sym
)
770 if (c
< '0' || c
> '9')
776 /* The pattern is an array of simple patterns.
777 * "foo" will match an exact string equal to "foo"
778 * "*foo" will match a string that ends with "foo"
779 * "foo*" will match a string that begins with "foo"
780 * "foo$" will match a string equal to "foo" or "foo.1"
781 * where the '1' can be any number including several digits.
782 * The $ syntax is for sections where ld append a dot number
783 * to make section name unique.
785 static int match(const char *sym
, const char * const pat
[])
790 const char *endp
= p
+ strlen(p
) - 1;
794 if (strrcmp(sym
, p
+ 1) == 0)
798 else if (*endp
== '*') {
799 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
803 else if (*endp
== '$') {
804 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
805 if (number_prefix(sym
+ strlen(p
) - 1))
811 if (strcmp(p
, sym
) == 0)
819 /* sections that we do not want to do full section mismatch check on */
820 static const char *section_white_list
[] =
824 ".cranges", /* sh64 */
825 ".zdebug*", /* Compressed debug sections. */
826 ".GCC-command-line", /* mn10300 */
827 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
828 ".mdebug*", /* alpha, score, mips etc. */
829 ".pdr", /* alpha, score, mips etc. */
834 ".xt.prop", /* xtensa */
835 ".xt.lit", /* xtensa */
836 ".arcextmap*", /* arc */
837 ".gnu.linkonce.arcext*", /* arc : modules */
842 * This is used to find sections missing the SHF_ALLOC flag.
843 * The cause of this is often a section specified in assembler
844 * without "ax" / "aw".
846 static void check_section(const char *modname
, struct elf_info
*elf
,
849 const char *sec
= sech_name(elf
, sechdr
);
851 if (sechdr
->sh_type
== SHT_PROGBITS
&&
852 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
853 !match(sec
, section_white_list
)) {
854 warn("%s (%s): unexpected non-allocatable section.\n"
855 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
856 "Note that for example <linux/init.h> contains\n"
857 "section definitions for use in .S files.\n\n",
864 #define ALL_INIT_DATA_SECTIONS \
865 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
866 ".init.data$", ".meminit.data$"
867 #define ALL_EXIT_DATA_SECTIONS \
868 ".exit.data$", ".memexit.data$"
870 #define ALL_INIT_TEXT_SECTIONS \
871 ".init.text$", ".meminit.text$"
872 #define ALL_EXIT_TEXT_SECTIONS \
873 ".exit.text$", ".memexit.text$"
875 #define ALL_PCI_INIT_SECTIONS \
876 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
877 ".pci_fixup_enable$", ".pci_fixup_resume$", \
878 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
880 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
881 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
883 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
884 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
886 #define DATA_SECTIONS ".data$", ".data.rel$"
887 #define TEXT_SECTIONS ".text$", ".text.unlikely$"
889 #define INIT_SECTIONS ".init.*"
890 #define MEM_INIT_SECTIONS ".meminit.*"
892 #define EXIT_SECTIONS ".exit.*"
893 #define MEM_EXIT_SECTIONS ".memexit.*"
895 /* init data sections */
896 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
898 /* all init sections */
899 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
901 /* All init and exit sections (code + data) */
902 static const char *init_exit_sections
[] =
903 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
906 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
909 /* symbols in .data that may refer to init/exit sections */
910 #define DEFAULT_SYMBOL_WHITE_LIST \
912 "*_template", /* scsi uses *_template a lot */ \
913 "*_timer", /* arm uses ops structures named _timer a lot */ \
914 "*_sht", /* scsi also used *_sht to some extent */ \
920 static const char *head_sections
[] = { ".head.text*", NULL
};
921 static const char *linker_symbols
[] =
922 { "__init_begin", "_sinittext", "_einittext", NULL
};
929 XXXINIT_TO_SOME_INIT
,
930 XXXEXIT_TO_SOME_EXIT
,
931 ANY_INIT_TO_ANY_EXIT
,
932 ANY_EXIT_TO_ANY_INIT
,
936 struct sectioncheck
{
937 const char *fromsec
[20];
938 const char *tosec
[20];
939 enum mismatch mismatch
;
940 const char *symbol_white_list
[20];
943 const struct sectioncheck sectioncheck
[] = {
944 /* Do not reference init/exit code/data from
945 * normal code and data
948 .fromsec
= { TEXT_SECTIONS
, NULL
},
949 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
950 .mismatch
= TEXT_TO_ANY_INIT
,
951 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
954 .fromsec
= { DATA_SECTIONS
, NULL
},
955 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
956 .mismatch
= DATA_TO_ANY_INIT
,
957 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
960 .fromsec
= { DATA_SECTIONS
, NULL
},
961 .tosec
= { INIT_SECTIONS
, NULL
},
962 .mismatch
= DATA_TO_ANY_INIT
,
963 .symbol_white_list
= {
964 "*_template", "*_timer", "*_sht", "*_ops",
965 "*_probe", "*_probe_one", "*_console", NULL
969 .fromsec
= { TEXT_SECTIONS
, NULL
},
970 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
971 .mismatch
= TEXT_TO_ANY_EXIT
,
972 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
975 .fromsec
= { DATA_SECTIONS
, NULL
},
976 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
977 .mismatch
= DATA_TO_ANY_EXIT
,
978 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
980 /* Do not reference init code/data from meminit code/data */
982 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
983 .tosec
= { INIT_SECTIONS
, NULL
},
984 .mismatch
= XXXINIT_TO_SOME_INIT
,
985 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
987 /* Do not reference exit code/data from memexit code/data */
989 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
990 .tosec
= { EXIT_SECTIONS
, NULL
},
991 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
992 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
994 /* Do not use exit code/data from init code */
996 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
997 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
998 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
999 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1001 /* Do not use init code/data from exit code */
1003 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
1004 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
1005 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
1006 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1009 .fromsec
= { ALL_PCI_INIT_SECTIONS
, NULL
},
1010 .tosec
= { INIT_SECTIONS
, NULL
},
1011 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1012 .symbol_white_list
= { NULL
},
1014 /* Do not export init/exit functions or data */
1016 .fromsec
= { "__ksymtab*", NULL
},
1017 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1018 .mismatch
= EXPORT_TO_INIT_EXIT
,
1019 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1023 static const struct sectioncheck
*section_mismatch(
1024 const char *fromsec
, const char *tosec
)
1027 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1028 const struct sectioncheck
*check
= §ioncheck
[0];
1030 for (i
= 0; i
< elems
; i
++) {
1031 if (match(fromsec
, check
->fromsec
) &&
1032 match(tosec
, check
->tosec
))
1040 * Whitelist to allow certain references to pass with no warning.
1043 * If a module parameter is declared __initdata and permissions=0
1044 * then this is legal despite the warning generated.
1045 * We cannot see value of permissions here, so just ignore
1047 * The pattern is identified by:
1048 * tosec = .init.data
1053 * module_param_call() ops can refer to __init set function if permissions=0
1054 * The pattern is identified by:
1055 * tosec = .init.text
1057 * atsym = __param_ops_*
1060 * Many drivers utilise a *driver container with references to
1061 * add, remove, probe functions etc.
1062 * the pattern is identified by:
1063 * tosec = init or exit section
1064 * fromsec = data section
1065 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1066 * *probe_one, *_console, *_timer
1069 * Whitelist all references from .head.text to any init section
1072 * Some symbols belong to init section but still it is ok to reference
1073 * these from non-init sections as these symbols don't have any memory
1074 * allocated for them and symbol address and value are same. So even
1075 * if init section is freed, its ok to reference those symbols.
1076 * For ex. symbols marking the init section boundaries.
1077 * This pattern is identified by
1078 * refsymname = __init_begin, _sinittext, _einittext
1081 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1082 const char *fromsec
, const char *fromsym
,
1083 const char *tosec
, const char *tosym
)
1085 /* Check for pattern 1 */
1086 if (match(tosec
, init_data_sections
) &&
1087 match(fromsec
, data_sections
) &&
1088 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1091 /* Check for pattern 1a */
1092 if (strcmp(tosec
, ".init.text") == 0 &&
1093 match(fromsec
, data_sections
) &&
1094 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1097 /* Check for pattern 2 */
1098 if (match(tosec
, init_exit_sections
) &&
1099 match(fromsec
, data_sections
) &&
1100 match(fromsym
, mismatch
->symbol_white_list
))
1103 /* Check for pattern 3 */
1104 if (match(fromsec
, head_sections
) &&
1105 match(tosec
, init_sections
))
1108 /* Check for pattern 4 */
1109 if (match(tosym
, linker_symbols
))
1116 * Find symbol based on relocation record info.
1117 * In some cases the symbol supplied is a valid symbol so
1118 * return refsym. If st_name != 0 we assume this is a valid symbol.
1119 * In other cases the symbol needs to be looked up in the symbol table
1120 * based on section and address.
1122 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1126 Elf_Sym
*near
= NULL
;
1127 Elf64_Sword distance
= 20;
1129 unsigned int relsym_secindex
;
1131 if (relsym
->st_name
!= 0)
1134 relsym_secindex
= get_secindex(elf
, relsym
);
1135 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1136 if (get_secindex(elf
, sym
) != relsym_secindex
)
1138 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1140 if (sym
->st_value
== addr
)
1142 /* Find a symbol nearby - addr are maybe negative */
1143 d
= sym
->st_value
- addr
;
1145 d
= addr
- sym
->st_value
;
1151 /* We need a close match */
1158 static inline int is_arm_mapping_symbol(const char *str
)
1160 return str
[0] == '$' && strchr("atd", str
[1])
1161 && (str
[2] == '\0' || str
[2] == '.');
1165 * If there's no name there, ignore it; likewise, ignore it if it's
1166 * one of the magic symbols emitted used by current ARM tools.
1168 * Otherwise if find_symbols_between() returns those symbols, they'll
1169 * fail the whitelist tests and cause lots of false alarms ... fixable
1170 * only by merging __exit and __init sections into __text, bloating
1171 * the kernel (which is especially evil on embedded platforms).
1173 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1175 const char *name
= elf
->strtab
+ sym
->st_name
;
1177 if (!name
|| !strlen(name
))
1179 return !is_arm_mapping_symbol(name
);
1183 * Find symbols before or equal addr and after addr - in the section sec.
1184 * If we find two symbols with equal offset prefer one with a valid name.
1185 * The ELF format may have a better way to detect what type of symbol
1186 * it is, but this works for now.
1188 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1192 Elf_Sym
*near
= NULL
;
1193 Elf_Addr distance
= ~0;
1195 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1198 if (is_shndx_special(sym
->st_shndx
))
1200 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1201 if (strcmp(symsec
, sec
) != 0)
1203 if (!is_valid_name(elf
, sym
))
1205 if (sym
->st_value
<= addr
) {
1206 if ((addr
- sym
->st_value
) < distance
) {
1207 distance
= addr
- sym
->st_value
;
1209 } else if ((addr
- sym
->st_value
) == distance
) {
1218 * Convert a section name to the function/data attribute
1219 * .init.text => __init
1220 * .memexitconst => __memconst
1223 * The memory of returned value has been allocated on a heap. The user of this
1224 * method should free it after usage.
1226 static char *sec2annotation(const char *s
)
1228 if (match(s
, init_exit_sections
)) {
1229 char *p
= malloc(20);
1236 while (*s
&& *s
!= '.')
1241 if (strstr(s
, "rodata") != NULL
)
1242 strcat(p
, "const ");
1243 else if (strstr(s
, "data") != NULL
)
1253 static int is_function(Elf_Sym
*sym
)
1256 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1261 static void print_section_list(const char * const list
[20])
1263 const char *const *s
= list
;
1266 fprintf(stderr
, "%s", *s
);
1269 fprintf(stderr
, ", ");
1271 fprintf(stderr
, "\n");
1275 * Print a warning about a section mismatch.
1276 * Try to find symbols near it so user can find it.
1277 * Check whitelist before warning - it may be a false positive.
1279 static void report_sec_mismatch(const char *modname
,
1280 const struct sectioncheck
*mismatch
,
1281 const char *fromsec
,
1282 unsigned long long fromaddr
,
1283 const char *fromsym
,
1285 const char *tosec
, const char *tosym
,
1288 const char *from
, *from_p
;
1289 const char *to
, *to_p
;
1293 switch (from_is_func
) {
1294 case 0: from
= "variable"; from_p
= ""; break;
1295 case 1: from
= "function"; from_p
= "()"; break;
1296 default: from
= "(unknown reference)"; from_p
= ""; break;
1298 switch (to_is_func
) {
1299 case 0: to
= "variable"; to_p
= ""; break;
1300 case 1: to
= "function"; to_p
= "()"; break;
1301 default: to
= "(unknown reference)"; to_p
= ""; break;
1304 sec_mismatch_count
++;
1305 if (!sec_mismatch_verbose
)
1308 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1309 "to the %s %s:%s%s\n",
1310 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1313 switch (mismatch
->mismatch
) {
1314 case TEXT_TO_ANY_INIT
:
1315 prl_from
= sec2annotation(fromsec
);
1316 prl_to
= sec2annotation(tosec
);
1318 "The function %s%s() references\n"
1320 "This is often because %s lacks a %s\n"
1321 "annotation or the annotation of %s is wrong.\n",
1323 to
, prl_to
, tosym
, to_p
,
1324 fromsym
, prl_to
, tosym
);
1328 case DATA_TO_ANY_INIT
: {
1329 prl_to
= sec2annotation(tosec
);
1331 "The variable %s references\n"
1333 "If the reference is valid then annotate the\n"
1334 "variable with __init* or __refdata (see linux/init.h) "
1335 "or name the variable:\n",
1336 fromsym
, to
, prl_to
, tosym
, to_p
);
1337 print_section_list(mismatch
->symbol_white_list
);
1341 case TEXT_TO_ANY_EXIT
:
1342 prl_to
= sec2annotation(tosec
);
1344 "The function %s() references a %s in an exit section.\n"
1345 "Often the %s %s%s has valid usage outside the exit section\n"
1346 "and the fix is to remove the %sannotation of %s.\n",
1347 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1350 case DATA_TO_ANY_EXIT
: {
1351 prl_to
= sec2annotation(tosec
);
1353 "The variable %s references\n"
1355 "If the reference is valid then annotate the\n"
1356 "variable with __exit* (see linux/init.h) or "
1357 "name the variable:\n",
1358 fromsym
, to
, prl_to
, tosym
, to_p
);
1359 print_section_list(mismatch
->symbol_white_list
);
1363 case XXXINIT_TO_SOME_INIT
:
1364 case XXXEXIT_TO_SOME_EXIT
:
1365 prl_from
= sec2annotation(fromsec
);
1366 prl_to
= sec2annotation(tosec
);
1368 "The %s %s%s%s references\n"
1370 "If %s is only used by %s then\n"
1371 "annotate %s with a matching annotation.\n",
1372 from
, prl_from
, fromsym
, from_p
,
1373 to
, prl_to
, tosym
, to_p
,
1374 tosym
, fromsym
, tosym
);
1378 case ANY_INIT_TO_ANY_EXIT
:
1379 prl_from
= sec2annotation(fromsec
);
1380 prl_to
= sec2annotation(tosec
);
1382 "The %s %s%s%s references\n"
1384 "This is often seen when error handling "
1385 "in the init function\n"
1386 "uses functionality in the exit path.\n"
1387 "The fix is often to remove the %sannotation of\n"
1388 "%s%s so it may be used outside an exit section.\n",
1389 from
, prl_from
, fromsym
, from_p
,
1390 to
, prl_to
, tosym
, to_p
,
1391 prl_to
, tosym
, to_p
);
1395 case ANY_EXIT_TO_ANY_INIT
:
1396 prl_from
= sec2annotation(fromsec
);
1397 prl_to
= sec2annotation(tosec
);
1399 "The %s %s%s%s references\n"
1401 "This is often seen when error handling "
1402 "in the exit function\n"
1403 "uses functionality in the init path.\n"
1404 "The fix is often to remove the %sannotation of\n"
1405 "%s%s so it may be used outside an init section.\n",
1406 from
, prl_from
, fromsym
, from_p
,
1407 to
, prl_to
, tosym
, to_p
,
1408 prl_to
, tosym
, to_p
);
1412 case EXPORT_TO_INIT_EXIT
:
1413 prl_to
= sec2annotation(tosec
);
1415 "The symbol %s is exported and annotated %s\n"
1416 "Fix this by removing the %sannotation of %s "
1417 "or drop the export.\n",
1418 tosym
, prl_to
, prl_to
, tosym
);
1422 fprintf(stderr
, "\n");
1425 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1426 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1429 const struct sectioncheck
*mismatch
;
1431 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1432 mismatch
= section_mismatch(fromsec
, tosec
);
1437 const char *fromsym
;
1439 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1440 fromsym
= sym_name(elf
, from
);
1441 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1442 tosym
= sym_name(elf
, to
);
1444 /* check whitelist - we may ignore it */
1445 if (secref_whitelist(mismatch
,
1446 fromsec
, fromsym
, tosec
, tosym
)) {
1447 report_sec_mismatch(modname
, mismatch
,
1448 fromsec
, r
->r_offset
, fromsym
,
1449 is_function(from
), tosec
, tosym
,
1455 static unsigned int *reloc_location(struct elf_info
*elf
,
1456 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1458 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1459 int section
= sechdr
->sh_info
;
1461 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1465 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1467 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1468 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1472 r
->r_addend
= TO_NATIVE(*location
);
1475 r
->r_addend
= TO_NATIVE(*location
) + 4;
1476 /* For CONFIG_RELOCATABLE=y */
1477 if (elf
->hdr
->e_type
== ET_EXEC
)
1478 r
->r_addend
+= r
->r_offset
;
1485 #define R_ARM_CALL 28
1487 #ifndef R_ARM_JUMP24
1488 #define R_ARM_JUMP24 29
1491 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1493 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1497 /* From ARM ABI: (S + A) | T */
1498 r
->r_addend
= (int)(long)
1499 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1504 /* From ARM ABI: ((S + A) | T) - P */
1505 r
->r_addend
= (int)(long)(elf
->hdr
+
1507 (r
->r_offset
- sechdr
->sh_addr
));
1515 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1517 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1518 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1521 if (r_typ
== R_MIPS_HI16
)
1522 return 1; /* skip this */
1523 inst
= TO_NATIVE(*location
);
1526 r
->r_addend
= inst
& 0xffff;
1529 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1538 static void section_rela(const char *modname
, struct elf_info
*elf
,
1545 const char *fromsec
;
1547 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1548 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1550 fromsec
= sech_name(elf
, sechdr
);
1551 fromsec
+= strlen(".rela");
1552 /* if from section (name) is know good then skip it */
1553 if (match(fromsec
, section_white_list
))
1556 for (rela
= start
; rela
< stop
; rela
++) {
1557 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1558 #if KERNEL_ELFCLASS == ELFCLASS64
1559 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1561 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1562 r_sym
= TO_NATIVE(r_sym
);
1563 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1564 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1566 r
.r_info
= TO_NATIVE(rela
->r_info
);
1567 r_sym
= ELF_R_SYM(r
.r_info
);
1570 r
.r_info
= TO_NATIVE(rela
->r_info
);
1571 r_sym
= ELF_R_SYM(r
.r_info
);
1573 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1574 sym
= elf
->symtab_start
+ r_sym
;
1575 /* Skip special sections */
1576 if (is_shndx_special(sym
->st_shndx
))
1578 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1582 static void section_rel(const char *modname
, struct elf_info
*elf
,
1589 const char *fromsec
;
1591 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1592 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1594 fromsec
= sech_name(elf
, sechdr
);
1595 fromsec
+= strlen(".rel");
1596 /* if from section (name) is know good then skip it */
1597 if (match(fromsec
, section_white_list
))
1600 for (rel
= start
; rel
< stop
; rel
++) {
1601 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1602 #if KERNEL_ELFCLASS == ELFCLASS64
1603 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1605 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1606 r_sym
= TO_NATIVE(r_sym
);
1607 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1608 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1610 r
.r_info
= TO_NATIVE(rel
->r_info
);
1611 r_sym
= ELF_R_SYM(r
.r_info
);
1614 r
.r_info
= TO_NATIVE(rel
->r_info
);
1615 r_sym
= ELF_R_SYM(r
.r_info
);
1618 switch (elf
->hdr
->e_machine
) {
1620 if (addend_386_rel(elf
, sechdr
, &r
))
1624 if (addend_arm_rel(elf
, sechdr
, &r
))
1628 if (addend_mips_rel(elf
, sechdr
, &r
))
1632 sym
= elf
->symtab_start
+ r_sym
;
1633 /* Skip special sections */
1634 if (is_shndx_special(sym
->st_shndx
))
1636 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1641 * A module includes a number of sections that are discarded
1642 * either when loaded or when used as built-in.
1643 * For loaded modules all functions marked __init and all data
1644 * marked __initdata will be discarded when the module has been initialized.
1645 * Likewise for modules used built-in the sections marked __exit
1646 * are discarded because __exit marked function are supposed to be called
1647 * only when a module is unloaded which never happens for built-in modules.
1648 * The check_sec_ref() function traverses all relocation records
1649 * to find all references to a section that reference a section that will
1650 * be discarded and warns about it.
1652 static void check_sec_ref(struct module
*mod
, const char *modname
,
1653 struct elf_info
*elf
)
1656 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1658 /* Walk through all sections */
1659 for (i
= 0; i
< elf
->num_sections
; i
++) {
1660 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1661 /* We want to process only relocation sections and not .init */
1662 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1663 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1664 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1665 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1669 static void read_symbols(char *modname
)
1671 const char *symname
;
1675 struct elf_info info
= { };
1678 if (!parse_elf(&info
, modname
))
1681 mod
= new_module(modname
);
1683 /* When there's no vmlinux, don't print warnings about
1684 * unresolved symbols (since there'll be too many ;) */
1685 if (is_vmlinux(modname
)) {
1690 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1691 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1692 warn("modpost: missing MODULE_LICENSE() in %s\n"
1693 "see include/linux/module.h for "
1694 "more information\n", modname
);
1696 if (license_is_gpl_compatible(license
))
1697 mod
->gpl_compatible
= 1;
1699 mod
->gpl_compatible
= 0;
1702 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1703 "license", license
);
1706 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1707 symname
= info
.strtab
+ sym
->st_name
;
1709 handle_modversions(mod
, &info
, sym
, symname
);
1710 handle_moddevtable(mod
, &info
, sym
, symname
);
1712 if (!is_vmlinux(modname
) ||
1713 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1714 check_sec_ref(mod
, modname
, &info
);
1716 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1718 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1719 version
- (char *)info
.hdr
);
1720 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1721 get_src_version(modname
, mod
->srcversion
,
1722 sizeof(mod
->srcversion
)-1);
1724 parse_elf_finish(&info
);
1726 /* Our trick to get versioning for module struct etc. - it's
1727 * never passed as an argument to an exported function, so
1728 * the automatic versioning doesn't pick it up, but it's really
1729 * important anyhow */
1731 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1734 static void read_symbols_from_files(const char *filename
)
1737 char fname
[PATH_MAX
];
1739 if (strcmp(filename
, "-") != 0) {
1740 in
= fopen(filename
, "r");
1742 fatal("Can't open filenames file %s: %m", filename
);
1745 while (fgets(fname
, PATH_MAX
, in
) != NULL
) {
1746 if (strends(fname
, "\n"))
1747 fname
[strlen(fname
)-1] = '\0';
1748 read_symbols(fname
);
1757 /* We first write the generated file into memory using the
1758 * following helper, then compare to the file on disk and
1759 * only update the later if anything changed */
1761 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1762 const char *fmt
, ...)
1769 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1770 buf_write(buf
, tmp
, len
);
1774 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1776 if (buf
->size
- buf
->pos
< len
) {
1777 buf
->size
+= len
+ SZ
;
1778 buf
->p
= realloc(buf
->p
, buf
->size
);
1780 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1784 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1786 const char *e
= is_vmlinux(m
) ?"":".ko";
1790 fatal("modpost: GPL-incompatible module %s%s "
1791 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1793 case export_unused_gpl
:
1794 fatal("modpost: GPL-incompatible module %s%s "
1795 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1797 case export_gpl_future
:
1798 warn("modpost: GPL-incompatible module %s%s "
1799 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1803 case export_unknown
:
1809 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1811 const char *e
= is_vmlinux(m
) ?"":".ko";
1815 case export_unused_gpl
:
1816 warn("modpost: module %s%s "
1817 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1825 static void check_exports(struct module
*mod
)
1827 struct symbol
*s
, *exp
;
1829 for (s
= mod
->unres
; s
; s
= s
->next
) {
1830 const char *basename
;
1831 exp
= find_symbol(s
->name
);
1832 if (!exp
|| exp
->module
== mod
)
1834 basename
= strrchr(mod
->name
, '/');
1838 basename
= mod
->name
;
1839 if (!mod
->gpl_compatible
)
1840 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1841 check_for_unused(exp
->export
, basename
, exp
->name
);
1846 * Header for the generated file
1848 static void add_header(struct buffer
*b
, struct module
*mod
)
1850 buf_printf(b
, "#include <linux/module.h>\n");
1851 buf_printf(b
, "#include <linux/vermagic.h>\n");
1852 buf_printf(b
, "#include <linux/compiler.h>\n");
1853 buf_printf(b
, "\n");
1854 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1855 buf_printf(b
, "\n");
1856 buf_printf(b
, "struct module __this_module\n");
1857 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1858 buf_printf(b
, "\t.name = KBUILD_MODNAME,\n");
1860 buf_printf(b
, "\t.init = init_module,\n");
1861 if (mod
->has_cleanup
)
1862 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1863 "\t.exit = cleanup_module,\n"
1865 buf_printf(b
, "\t.arch = MODULE_ARCH_INIT,\n");
1866 buf_printf(b
, "};\n");
1869 static void add_intree_flag(struct buffer
*b
, int is_intree
)
1872 buf_printf(b
, "\nMODULE_INFO(intree, \"Y\");\n");
1875 static void add_staging_flag(struct buffer
*b
, const char *name
)
1877 static const char *staging_dir
= "drivers/staging";
1879 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1880 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1884 * Record CRCs for unresolved symbols
1886 static int add_versions(struct buffer
*b
, struct module
*mod
)
1888 struct symbol
*s
, *exp
;
1891 for (s
= mod
->unres
; s
; s
= s
->next
) {
1892 exp
= find_symbol(s
->name
);
1893 if (!exp
|| exp
->module
== mod
) {
1894 if (have_vmlinux
&& !s
->weak
) {
1895 if (warn_unresolved
) {
1896 warn("\"%s\" [%s.ko] undefined!\n",
1897 s
->name
, mod
->name
);
1899 merror("\"%s\" [%s.ko] undefined!\n",
1900 s
->name
, mod
->name
);
1906 s
->module
= exp
->module
;
1907 s
->crc_valid
= exp
->crc_valid
;
1914 buf_printf(b
, "\n");
1915 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1916 buf_printf(b
, "__used\n");
1917 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1919 for (s
= mod
->unres
; s
; s
= s
->next
) {
1922 if (!s
->crc_valid
) {
1923 warn("\"%s\" [%s.ko] has no CRC!\n",
1924 s
->name
, mod
->name
);
1927 buf_printf(b
, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1931 buf_printf(b
, "};\n");
1936 static void add_depends(struct buffer
*b
, struct module
*mod
,
1937 struct module
*modules
)
1943 for (m
= modules
; m
; m
= m
->next
)
1944 m
->seen
= is_vmlinux(m
->name
);
1946 buf_printf(b
, "\n");
1947 buf_printf(b
, "static const char __module_depends[]\n");
1948 buf_printf(b
, "__used\n");
1949 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1950 buf_printf(b
, "\"depends=");
1951 for (s
= mod
->unres
; s
; s
= s
->next
) {
1956 if (s
->module
->seen
)
1959 s
->module
->seen
= 1;
1960 p
= strrchr(s
->module
->name
, '/');
1964 p
= s
->module
->name
;
1965 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1968 buf_printf(b
, "\";\n");
1971 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1973 if (mod
->srcversion
[0]) {
1974 buf_printf(b
, "\n");
1975 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1980 static void write_if_changed(struct buffer
*b
, const char *fname
)
1986 file
= fopen(fname
, "r");
1990 if (fstat(fileno(file
), &st
) < 0)
1993 if (st
.st_size
!= b
->pos
)
1996 tmp
= NOFAIL(malloc(b
->pos
));
1997 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
2000 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
2012 file
= fopen(fname
, "w");
2017 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2024 /* parse Module.symvers file. line format:
2025 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2027 static void read_dump(const char *fname
, unsigned int kernel
)
2029 unsigned long size
, pos
= 0;
2030 void *file
= grab_file(fname
, &size
);
2034 /* No symbol versions, silently ignore */
2037 while ((line
= get_next_line(&pos
, file
, size
))) {
2038 char *symname
, *modname
, *d
, *export
, *end
;
2043 if (!(symname
= strchr(line
, '\t')))
2046 if (!(modname
= strchr(symname
, '\t')))
2049 if ((export
= strchr(modname
, '\t')) != NULL
)
2051 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2053 crc
= strtoul(line
, &d
, 16);
2054 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2056 mod
= find_module(modname
);
2058 if (is_vmlinux(modname
))
2060 mod
= new_module(modname
);
2063 s
= sym_add_exported(symname
, mod
, export_no(export
));
2066 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2070 fatal("parse error in symbol dump file\n");
2073 /* For normal builds always dump all symbols.
2074 * For external modules only dump symbols
2075 * that are not read from kernel Module.symvers.
2077 static int dump_sym(struct symbol
*sym
)
2079 if (!external_module
)
2081 if (sym
->vmlinux
|| sym
->kernel
)
2086 static void write_dump(const char *fname
)
2088 struct buffer buf
= { };
2089 struct symbol
*symbol
;
2092 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2093 symbol
= symbolhash
[n
];
2095 if (dump_sym(symbol
))
2096 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2097 symbol
->crc
, symbol
->name
,
2098 symbol
->module
->name
,
2099 export_str(symbol
->export
));
2100 symbol
= symbol
->next
;
2103 write_if_changed(&buf
, fname
);
2106 struct ext_sym_list
{
2107 struct ext_sym_list
*next
;
2111 int main(int argc
, char **argv
)
2114 struct buffer buf
= { };
2115 char *kernel_read
= NULL
, *module_read
= NULL
;
2116 char *dump_write
= NULL
, *files_source
= NULL
;
2119 struct ext_sym_list
*extsym_iter
;
2120 struct ext_sym_list
*extsym_start
= NULL
;
2122 while ((opt
= getopt(argc
, argv
, "i:I:e:msST:o:awM:K:")) != -1) {
2125 kernel_read
= optarg
;
2128 module_read
= optarg
;
2129 external_module
= 1;
2132 external_module
= 1;
2134 NOFAIL(malloc(sizeof(*extsym_iter
)));
2135 extsym_iter
->next
= extsym_start
;
2136 extsym_iter
->file
= optarg
;
2137 extsym_start
= extsym_iter
;
2143 dump_write
= optarg
;
2149 vmlinux_section_warnings
= 0;
2152 sec_mismatch_verbose
= 0;
2155 files_source
= optarg
;
2158 warn_unresolved
= 1;
2166 read_dump(kernel_read
, 1);
2168 read_dump(module_read
, 0);
2169 while (extsym_start
) {
2170 read_dump(extsym_start
->file
, 0);
2171 extsym_iter
= extsym_start
->next
;
2173 extsym_start
= extsym_iter
;
2176 while (optind
< argc
)
2177 read_symbols(argv
[optind
++]);
2180 read_symbols_from_files(files_source
);
2182 for (mod
= modules
; mod
; mod
= mod
->next
) {
2190 for (mod
= modules
; mod
; mod
= mod
->next
) {
2191 char fname
[strlen(mod
->name
) + 10];
2198 add_header(&buf
, mod
);
2199 add_intree_flag(&buf
, !external_module
);
2200 add_staging_flag(&buf
, mod
->name
);
2201 err
|= add_versions(&buf
, mod
);
2202 add_depends(&buf
, mod
, modules
);
2203 add_moddevtable(&buf
, mod
);
2204 add_srcversion(&buf
, mod
);
2206 sprintf(fname
, "%s.mod.c", mod
->name
);
2207 write_if_changed(&buf
, fname
);
2211 write_dump(dump_write
);
2212 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2213 warn("modpost: Found %d section mismatch(es).\n"
2214 "To see full details build your kernel with:\n"
2215 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2216 sec_mismatch_count
);