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
== '$') {
804 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
805 if (number_prefix(sym
+ strlen(p
) - 1))
811 if (strcmp(p
, sym
) == 0)
819 /* sections that we do not want to do full section mismatch check on */
820 static const char *section_white_list
[] =
824 ".zdebug*", /* Compressed debug sections. */
825 ".GCC-command-line", /* mn10300 */
826 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
827 ".mdebug*", /* alpha, score, mips etc. */
828 ".pdr", /* alpha, score, mips etc. */
833 ".xt.prop", /* xtensa */
834 ".xt.lit", /* xtensa */
835 ".arcextmap*", /* arc */
836 ".gnu.linkonce.arcext*", /* arc : modules */
841 * This is used to find sections missing the SHF_ALLOC flag.
842 * The cause of this is often a section specified in assembler
843 * without "ax" / "aw".
845 static void check_section(const char *modname
, struct elf_info
*elf
,
848 const char *sec
= sech_name(elf
, sechdr
);
850 if (sechdr
->sh_type
== SHT_PROGBITS
&&
851 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
852 !match(sec
, section_white_list
)) {
853 warn("%s (%s): unexpected non-allocatable section.\n"
854 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
855 "Note that for example <linux/init.h> contains\n"
856 "section definitions for use in .S files.\n\n",
863 #define ALL_INIT_DATA_SECTIONS \
864 ".init.setup$", ".init.rodata$", \
865 ".cpuinit.rodata$", ".meminit.rodata$", \
866 ".init.data$", ".cpuinit.data$", ".meminit.data$"
867 #define ALL_EXIT_DATA_SECTIONS \
868 ".exit.data$", ".cpuexit.data$", ".memexit.data$"
870 #define ALL_INIT_TEXT_SECTIONS \
871 ".init.text$", ".cpuinit.text$", ".meminit.text$"
872 #define ALL_EXIT_TEXT_SECTIONS \
873 ".exit.text$", ".cpuexit.text$", ".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 CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
881 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_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$"
889 #define INIT_SECTIONS ".init.*"
890 #define CPU_INIT_SECTIONS ".cpuinit.*"
891 #define MEM_INIT_SECTIONS ".meminit.*"
893 #define EXIT_SECTIONS ".exit.*"
894 #define CPU_EXIT_SECTIONS ".cpuexit.*"
895 #define MEM_EXIT_SECTIONS ".memexit.*"
897 /* init data sections */
898 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
900 /* all init sections */
901 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
903 /* All init and exit sections (code + data) */
904 static const char *init_exit_sections
[] =
905 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
908 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
911 /* symbols in .data that may refer to init/exit sections */
912 #define DEFAULT_SYMBOL_WHITE_LIST \
914 "*_template", /* scsi uses *_template a lot */ \
915 "*_timer", /* arm uses ops structures named _timer a lot */ \
916 "*_sht", /* scsi also used *_sht to some extent */ \
922 static const char *head_sections
[] = { ".head.text*", NULL
};
923 static const char *linker_symbols
[] =
924 { "__init_begin", "_sinittext", "_einittext", NULL
};
931 XXXINIT_TO_SOME_INIT
,
932 XXXEXIT_TO_SOME_EXIT
,
933 ANY_INIT_TO_ANY_EXIT
,
934 ANY_EXIT_TO_ANY_INIT
,
938 struct sectioncheck
{
939 const char *fromsec
[20];
940 const char *tosec
[20];
941 enum mismatch mismatch
;
942 const char *symbol_white_list
[20];
945 const struct sectioncheck sectioncheck
[] = {
946 /* Do not reference init/exit code/data from
947 * normal code and data
950 .fromsec
= { TEXT_SECTIONS
, NULL
},
951 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
952 .mismatch
= TEXT_TO_ANY_INIT
,
953 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
956 .fromsec
= { DATA_SECTIONS
, NULL
},
957 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
958 .mismatch
= DATA_TO_ANY_INIT
,
959 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
962 .fromsec
= { DATA_SECTIONS
, NULL
},
963 .tosec
= { INIT_SECTIONS
, NULL
},
964 .mismatch
= DATA_TO_ANY_INIT
,
965 .symbol_white_list
= {
966 "*_template", "*_timer", "*_sht", "*_ops",
967 "*_probe", "*_probe_one", "*_console", NULL
971 .fromsec
= { TEXT_SECTIONS
, NULL
},
972 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
973 .mismatch
= TEXT_TO_ANY_EXIT
,
974 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
977 .fromsec
= { DATA_SECTIONS
, NULL
},
978 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
979 .mismatch
= DATA_TO_ANY_EXIT
,
980 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
982 /* Do not reference init code/data from cpuinit/meminit code/data */
984 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
985 .tosec
= { INIT_SECTIONS
, NULL
},
986 .mismatch
= XXXINIT_TO_SOME_INIT
,
987 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
989 /* Do not reference cpuinit code/data from meminit code/data */
991 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
992 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
993 .mismatch
= XXXINIT_TO_SOME_INIT
,
994 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
996 /* Do not reference meminit code/data from cpuinit code/data */
998 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
999 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
1000 .mismatch
= XXXINIT_TO_SOME_INIT
,
1001 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1003 /* Do not reference exit code/data from cpuexit/memexit code/data */
1005 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
1006 .tosec
= { EXIT_SECTIONS
, NULL
},
1007 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1008 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1010 /* Do not reference cpuexit code/data from memexit code/data */
1012 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
1013 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
1014 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1015 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1017 /* Do not reference memexit code/data from cpuexit code/data */
1019 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
1020 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
1021 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1022 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1024 /* Do not use exit code/data from init code */
1026 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
1027 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
1028 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1029 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1031 /* Do not use init code/data from exit code */
1033 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
1034 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
1035 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
1036 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1039 .fromsec
= { ALL_PCI_INIT_SECTIONS
, NULL
},
1040 .tosec
= { INIT_SECTIONS
, NULL
},
1041 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1042 .symbol_white_list
= { NULL
},
1044 /* Do not export init/exit functions or data */
1046 .fromsec
= { "__ksymtab*", NULL
},
1047 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1048 .mismatch
= EXPORT_TO_INIT_EXIT
,
1049 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1053 static const struct sectioncheck
*section_mismatch(
1054 const char *fromsec
, const char *tosec
)
1057 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1058 const struct sectioncheck
*check
= §ioncheck
[0];
1060 for (i
= 0; i
< elems
; i
++) {
1061 if (match(fromsec
, check
->fromsec
) &&
1062 match(tosec
, check
->tosec
))
1070 * Whitelist to allow certain references to pass with no warning.
1073 * If a module parameter is declared __initdata and permissions=0
1074 * then this is legal despite the warning generated.
1075 * We cannot see value of permissions here, so just ignore
1077 * The pattern is identified by:
1078 * tosec = .init.data
1083 * module_param_call() ops can refer to __init set function if permissions=0
1084 * The pattern is identified by:
1085 * tosec = .init.text
1087 * atsym = __param_ops_*
1090 * Many drivers utilise a *driver container with references to
1091 * add, remove, probe functions etc.
1092 * These functions may often be marked __cpuinit and we do not want to
1094 * the pattern is identified by:
1095 * tosec = init or exit section
1096 * fromsec = data section
1097 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1098 * *probe_one, *_console, *_timer
1101 * Whitelist all references from .head.text to any init section
1104 * Some symbols belong to init section but still it is ok to reference
1105 * these from non-init sections as these symbols don't have any memory
1106 * allocated for them and symbol address and value are same. So even
1107 * if init section is freed, its ok to reference those symbols.
1108 * For ex. symbols marking the init section boundaries.
1109 * This pattern is identified by
1110 * refsymname = __init_begin, _sinittext, _einittext
1113 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1114 const char *fromsec
, const char *fromsym
,
1115 const char *tosec
, const char *tosym
)
1117 /* Check for pattern 1 */
1118 if (match(tosec
, init_data_sections
) &&
1119 match(fromsec
, data_sections
) &&
1120 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1123 /* Check for pattern 1a */
1124 if (strcmp(tosec
, ".init.text") == 0 &&
1125 match(fromsec
, data_sections
) &&
1126 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1129 /* Check for pattern 2 */
1130 if (match(tosec
, init_exit_sections
) &&
1131 match(fromsec
, data_sections
) &&
1132 match(fromsym
, mismatch
->symbol_white_list
))
1135 /* Check for pattern 3 */
1136 if (match(fromsec
, head_sections
) &&
1137 match(tosec
, init_sections
))
1140 /* Check for pattern 4 */
1141 if (match(tosym
, linker_symbols
))
1148 * Find symbol based on relocation record info.
1149 * In some cases the symbol supplied is a valid symbol so
1150 * return refsym. If st_name != 0 we assume this is a valid symbol.
1151 * In other cases the symbol needs to be looked up in the symbol table
1152 * based on section and address.
1154 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1158 Elf_Sym
*near
= NULL
;
1159 Elf64_Sword distance
= 20;
1161 unsigned int relsym_secindex
;
1163 if (relsym
->st_name
!= 0)
1166 relsym_secindex
= get_secindex(elf
, relsym
);
1167 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1168 if (get_secindex(elf
, sym
) != relsym_secindex
)
1170 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1172 if (sym
->st_value
== addr
)
1174 /* Find a symbol nearby - addr are maybe negative */
1175 d
= sym
->st_value
- addr
;
1177 d
= addr
- sym
->st_value
;
1183 /* We need a close match */
1190 static inline int is_arm_mapping_symbol(const char *str
)
1192 return str
[0] == '$' && strchr("atd", str
[1])
1193 && (str
[2] == '\0' || str
[2] == '.');
1197 * If there's no name there, ignore it; likewise, ignore it if it's
1198 * one of the magic symbols emitted used by current ARM tools.
1200 * Otherwise if find_symbols_between() returns those symbols, they'll
1201 * fail the whitelist tests and cause lots of false alarms ... fixable
1202 * only by merging __exit and __init sections into __text, bloating
1203 * the kernel (which is especially evil on embedded platforms).
1205 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1207 const char *name
= elf
->strtab
+ sym
->st_name
;
1209 if (!name
|| !strlen(name
))
1211 return !is_arm_mapping_symbol(name
);
1215 * Find symbols before or equal addr and after addr - in the section sec.
1216 * If we find two symbols with equal offset prefer one with a valid name.
1217 * The ELF format may have a better way to detect what type of symbol
1218 * it is, but this works for now.
1220 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1224 Elf_Sym
*near
= NULL
;
1225 Elf_Addr distance
= ~0;
1227 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1230 if (is_shndx_special(sym
->st_shndx
))
1232 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1233 if (strcmp(symsec
, sec
) != 0)
1235 if (!is_valid_name(elf
, sym
))
1237 if (sym
->st_value
<= addr
) {
1238 if ((addr
- sym
->st_value
) < distance
) {
1239 distance
= addr
- sym
->st_value
;
1241 } else if ((addr
- sym
->st_value
) == distance
) {
1250 * Convert a section name to the function/data attribute
1251 * .init.text => __init
1252 * .cpuinit.data => __cpudata
1253 * .memexitconst => __memconst
1256 * The memory of returned value has been allocated on a heap. The user of this
1257 * method should free it after usage.
1259 static char *sec2annotation(const char *s
)
1261 if (match(s
, init_exit_sections
)) {
1262 char *p
= malloc(20);
1269 while (*s
&& *s
!= '.')
1274 if (strstr(s
, "rodata") != NULL
)
1275 strcat(p
, "const ");
1276 else if (strstr(s
, "data") != NULL
)
1286 static int is_function(Elf_Sym
*sym
)
1289 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1294 static void print_section_list(const char * const list
[20])
1296 const char *const *s
= list
;
1299 fprintf(stderr
, "%s", *s
);
1302 fprintf(stderr
, ", ");
1304 fprintf(stderr
, "\n");
1308 * Print a warning about a section mismatch.
1309 * Try to find symbols near it so user can find it.
1310 * Check whitelist before warning - it may be a false positive.
1312 static void report_sec_mismatch(const char *modname
,
1313 const struct sectioncheck
*mismatch
,
1314 const char *fromsec
,
1315 unsigned long long fromaddr
,
1316 const char *fromsym
,
1318 const char *tosec
, const char *tosym
,
1321 const char *from
, *from_p
;
1322 const char *to
, *to_p
;
1326 switch (from_is_func
) {
1327 case 0: from
= "variable"; from_p
= ""; break;
1328 case 1: from
= "function"; from_p
= "()"; break;
1329 default: from
= "(unknown reference)"; from_p
= ""; break;
1331 switch (to_is_func
) {
1332 case 0: to
= "variable"; to_p
= ""; break;
1333 case 1: to
= "function"; to_p
= "()"; break;
1334 default: to
= "(unknown reference)"; to_p
= ""; break;
1337 sec_mismatch_count
++;
1338 if (!sec_mismatch_verbose
)
1341 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1342 "to the %s %s:%s%s\n",
1343 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1346 switch (mismatch
->mismatch
) {
1347 case TEXT_TO_ANY_INIT
:
1348 prl_from
= sec2annotation(fromsec
);
1349 prl_to
= sec2annotation(tosec
);
1351 "The function %s%s() references\n"
1353 "This is often because %s lacks a %s\n"
1354 "annotation or the annotation of %s is wrong.\n",
1356 to
, prl_to
, tosym
, to_p
,
1357 fromsym
, prl_to
, tosym
);
1361 case DATA_TO_ANY_INIT
: {
1362 prl_to
= sec2annotation(tosec
);
1364 "The variable %s references\n"
1366 "If the reference is valid then annotate the\n"
1367 "variable with __init* or __refdata (see linux/init.h) "
1368 "or name the variable:\n",
1369 fromsym
, to
, prl_to
, tosym
, to_p
);
1370 print_section_list(mismatch
->symbol_white_list
);
1374 case TEXT_TO_ANY_EXIT
:
1375 prl_to
= sec2annotation(tosec
);
1377 "The function %s() references a %s in an exit section.\n"
1378 "Often the %s %s%s has valid usage outside the exit section\n"
1379 "and the fix is to remove the %sannotation of %s.\n",
1380 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1383 case DATA_TO_ANY_EXIT
: {
1384 prl_to
= sec2annotation(tosec
);
1386 "The variable %s references\n"
1388 "If the reference is valid then annotate the\n"
1389 "variable with __exit* (see linux/init.h) or "
1390 "name the variable:\n",
1391 fromsym
, to
, prl_to
, tosym
, to_p
);
1392 print_section_list(mismatch
->symbol_white_list
);
1396 case XXXINIT_TO_SOME_INIT
:
1397 case XXXEXIT_TO_SOME_EXIT
:
1398 prl_from
= sec2annotation(fromsec
);
1399 prl_to
= sec2annotation(tosec
);
1401 "The %s %s%s%s references\n"
1403 "If %s is only used by %s then\n"
1404 "annotate %s with a matching annotation.\n",
1405 from
, prl_from
, fromsym
, from_p
,
1406 to
, prl_to
, tosym
, to_p
,
1407 tosym
, fromsym
, tosym
);
1411 case ANY_INIT_TO_ANY_EXIT
:
1412 prl_from
= sec2annotation(fromsec
);
1413 prl_to
= sec2annotation(tosec
);
1415 "The %s %s%s%s references\n"
1417 "This is often seen when error handling "
1418 "in the init function\n"
1419 "uses functionality in the exit path.\n"
1420 "The fix is often to remove the %sannotation of\n"
1421 "%s%s so it may be used outside an exit section.\n",
1422 from
, prl_from
, fromsym
, from_p
,
1423 to
, prl_to
, tosym
, to_p
,
1424 prl_to
, tosym
, to_p
);
1428 case ANY_EXIT_TO_ANY_INIT
:
1429 prl_from
= sec2annotation(fromsec
);
1430 prl_to
= sec2annotation(tosec
);
1432 "The %s %s%s%s references\n"
1434 "This is often seen when error handling "
1435 "in the exit function\n"
1436 "uses functionality in the init path.\n"
1437 "The fix is often to remove the %sannotation of\n"
1438 "%s%s so it may be used outside an init section.\n",
1439 from
, prl_from
, fromsym
, from_p
,
1440 to
, prl_to
, tosym
, to_p
,
1441 prl_to
, tosym
, to_p
);
1445 case EXPORT_TO_INIT_EXIT
:
1446 prl_to
= sec2annotation(tosec
);
1448 "The symbol %s is exported and annotated %s\n"
1449 "Fix this by removing the %sannotation of %s "
1450 "or drop the export.\n",
1451 tosym
, prl_to
, prl_to
, tosym
);
1455 fprintf(stderr
, "\n");
1458 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1459 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1462 const struct sectioncheck
*mismatch
;
1464 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1465 mismatch
= section_mismatch(fromsec
, tosec
);
1470 const char *fromsym
;
1472 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1473 fromsym
= sym_name(elf
, from
);
1474 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1475 tosym
= sym_name(elf
, to
);
1477 /* check whitelist - we may ignore it */
1478 if (secref_whitelist(mismatch
,
1479 fromsec
, fromsym
, tosec
, tosym
)) {
1480 report_sec_mismatch(modname
, mismatch
,
1481 fromsec
, r
->r_offset
, fromsym
,
1482 is_function(from
), tosec
, tosym
,
1488 static unsigned int *reloc_location(struct elf_info
*elf
,
1489 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1491 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1492 int section
= sechdr
->sh_info
;
1494 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1498 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1500 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1501 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1505 r
->r_addend
= TO_NATIVE(*location
);
1508 r
->r_addend
= TO_NATIVE(*location
) + 4;
1509 /* For CONFIG_RELOCATABLE=y */
1510 if (elf
->hdr
->e_type
== ET_EXEC
)
1511 r
->r_addend
+= r
->r_offset
;
1518 #define R_ARM_CALL 28
1520 #ifndef R_ARM_JUMP24
1521 #define R_ARM_JUMP24 29
1524 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1526 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1530 /* From ARM ABI: (S + A) | T */
1531 r
->r_addend
= (int)(long)
1532 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1537 /* From ARM ABI: ((S + A) | T) - P */
1538 r
->r_addend
= (int)(long)(elf
->hdr
+
1540 (r
->r_offset
- sechdr
->sh_addr
));
1548 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1550 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1551 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1554 if (r_typ
== R_MIPS_HI16
)
1555 return 1; /* skip this */
1556 inst
= TO_NATIVE(*location
);
1559 r
->r_addend
= inst
& 0xffff;
1562 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1571 static void section_rela(const char *modname
, struct elf_info
*elf
,
1578 const char *fromsec
;
1580 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1581 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1583 fromsec
= sech_name(elf
, sechdr
);
1584 fromsec
+= strlen(".rela");
1585 /* if from section (name) is know good then skip it */
1586 if (match(fromsec
, section_white_list
))
1589 for (rela
= start
; rela
< stop
; rela
++) {
1590 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1591 #if KERNEL_ELFCLASS == ELFCLASS64
1592 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1594 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1595 r_sym
= TO_NATIVE(r_sym
);
1596 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1597 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1599 r
.r_info
= TO_NATIVE(rela
->r_info
);
1600 r_sym
= ELF_R_SYM(r
.r_info
);
1603 r
.r_info
= TO_NATIVE(rela
->r_info
);
1604 r_sym
= ELF_R_SYM(r
.r_info
);
1606 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1607 sym
= elf
->symtab_start
+ r_sym
;
1608 /* Skip special sections */
1609 if (is_shndx_special(sym
->st_shndx
))
1611 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1615 static void section_rel(const char *modname
, struct elf_info
*elf
,
1622 const char *fromsec
;
1624 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1625 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1627 fromsec
= sech_name(elf
, sechdr
);
1628 fromsec
+= strlen(".rel");
1629 /* if from section (name) is know good then skip it */
1630 if (match(fromsec
, section_white_list
))
1633 for (rel
= start
; rel
< stop
; rel
++) {
1634 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1635 #if KERNEL_ELFCLASS == ELFCLASS64
1636 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1638 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1639 r_sym
= TO_NATIVE(r_sym
);
1640 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1641 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1643 r
.r_info
= TO_NATIVE(rel
->r_info
);
1644 r_sym
= ELF_R_SYM(r
.r_info
);
1647 r
.r_info
= TO_NATIVE(rel
->r_info
);
1648 r_sym
= ELF_R_SYM(r
.r_info
);
1651 switch (elf
->hdr
->e_machine
) {
1653 if (addend_386_rel(elf
, sechdr
, &r
))
1657 if (addend_arm_rel(elf
, sechdr
, &r
))
1661 if (addend_mips_rel(elf
, sechdr
, &r
))
1665 sym
= elf
->symtab_start
+ r_sym
;
1666 /* Skip special sections */
1667 if (is_shndx_special(sym
->st_shndx
))
1669 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1674 * A module includes a number of sections that are discarded
1675 * either when loaded or when used as built-in.
1676 * For loaded modules all functions marked __init and all data
1677 * marked __initdata will be discarded when the module has been initialized.
1678 * Likewise for modules used built-in the sections marked __exit
1679 * are discarded because __exit marked function are supposed to be called
1680 * only when a module is unloaded which never happens for built-in modules.
1681 * The check_sec_ref() function traverses all relocation records
1682 * to find all references to a section that reference a section that will
1683 * be discarded and warns about it.
1685 static void check_sec_ref(struct module
*mod
, const char *modname
,
1686 struct elf_info
*elf
)
1689 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1691 /* Walk through all sections */
1692 for (i
= 0; i
< elf
->num_sections
; i
++) {
1693 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1694 /* We want to process only relocation sections and not .init */
1695 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1696 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1697 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1698 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1702 static void read_symbols(char *modname
)
1704 const char *symname
;
1708 struct elf_info info
= { };
1711 if (!parse_elf(&info
, modname
))
1714 mod
= new_module(modname
);
1716 /* When there's no vmlinux, don't print warnings about
1717 * unresolved symbols (since there'll be too many ;) */
1718 if (is_vmlinux(modname
)) {
1723 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1724 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1725 warn("modpost: missing MODULE_LICENSE() in %s\n"
1726 "see include/linux/module.h for "
1727 "more information\n", modname
);
1729 if (license_is_gpl_compatible(license
))
1730 mod
->gpl_compatible
= 1;
1732 mod
->gpl_compatible
= 0;
1735 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1736 "license", license
);
1739 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1740 symname
= info
.strtab
+ sym
->st_name
;
1742 handle_modversions(mod
, &info
, sym
, symname
);
1743 handle_moddevtable(mod
, &info
, sym
, symname
);
1745 if (!is_vmlinux(modname
) ||
1746 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1747 check_sec_ref(mod
, modname
, &info
);
1749 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1751 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1752 version
- (char *)info
.hdr
);
1753 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1754 get_src_version(modname
, mod
->srcversion
,
1755 sizeof(mod
->srcversion
)-1);
1757 parse_elf_finish(&info
);
1759 /* Our trick to get versioning for module struct etc. - it's
1760 * never passed as an argument to an exported function, so
1761 * the automatic versioning doesn't pick it up, but it's really
1762 * important anyhow */
1764 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1767 static void read_symbols_from_files(const char *filename
)
1770 char fname
[PATH_MAX
];
1772 if (strcmp(filename
, "-") != 0) {
1773 in
= fopen(filename
, "r");
1775 fatal("Can't open filenames file %s: %m", filename
);
1778 while (fgets(fname
, PATH_MAX
, in
) != NULL
) {
1779 if (strends(fname
, "\n"))
1780 fname
[strlen(fname
)-1] = '\0';
1781 read_symbols(fname
);
1790 /* We first write the generated file into memory using the
1791 * following helper, then compare to the file on disk and
1792 * only update the later if anything changed */
1794 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1795 const char *fmt
, ...)
1802 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1803 buf_write(buf
, tmp
, len
);
1807 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1809 if (buf
->size
- buf
->pos
< len
) {
1810 buf
->size
+= len
+ SZ
;
1811 buf
->p
= realloc(buf
->p
, buf
->size
);
1813 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1817 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1819 const char *e
= is_vmlinux(m
) ?"":".ko";
1823 fatal("modpost: GPL-incompatible module %s%s "
1824 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1826 case export_unused_gpl
:
1827 fatal("modpost: GPL-incompatible module %s%s "
1828 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1830 case export_gpl_future
:
1831 warn("modpost: GPL-incompatible module %s%s "
1832 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1836 case export_unknown
:
1842 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1844 const char *e
= is_vmlinux(m
) ?"":".ko";
1848 case export_unused_gpl
:
1849 warn("modpost: module %s%s "
1850 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1858 static void check_exports(struct module
*mod
)
1860 struct symbol
*s
, *exp
;
1862 for (s
= mod
->unres
; s
; s
= s
->next
) {
1863 const char *basename
;
1864 exp
= find_symbol(s
->name
);
1865 if (!exp
|| exp
->module
== mod
)
1867 basename
= strrchr(mod
->name
, '/');
1871 basename
= mod
->name
;
1872 if (!mod
->gpl_compatible
)
1873 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1874 check_for_unused(exp
->export
, basename
, exp
->name
);
1879 * Header for the generated file
1881 static void add_header(struct buffer
*b
, struct module
*mod
)
1883 buf_printf(b
, "#include <linux/module.h>\n");
1884 buf_printf(b
, "#include <linux/vermagic.h>\n");
1885 buf_printf(b
, "#include <linux/compiler.h>\n");
1886 buf_printf(b
, "\n");
1887 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1888 buf_printf(b
, "\n");
1889 buf_printf(b
, "struct module __this_module\n");
1890 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1891 buf_printf(b
, "\t.name = KBUILD_MODNAME,\n");
1893 buf_printf(b
, "\t.init = init_module,\n");
1894 if (mod
->has_cleanup
)
1895 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1896 "\t.exit = cleanup_module,\n"
1898 buf_printf(b
, "\t.arch = MODULE_ARCH_INIT,\n");
1899 buf_printf(b
, "};\n");
1902 static void add_intree_flag(struct buffer
*b
, int is_intree
)
1905 buf_printf(b
, "\nMODULE_INFO(intree, \"Y\");\n");
1908 static void add_staging_flag(struct buffer
*b
, const char *name
)
1910 static const char *staging_dir
= "drivers/staging";
1912 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1913 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1917 * Record CRCs for unresolved symbols
1919 static int add_versions(struct buffer
*b
, struct module
*mod
)
1921 struct symbol
*s
, *exp
;
1924 for (s
= mod
->unres
; s
; s
= s
->next
) {
1925 exp
= find_symbol(s
->name
);
1926 if (!exp
|| exp
->module
== mod
) {
1927 if (have_vmlinux
&& !s
->weak
) {
1928 if (warn_unresolved
) {
1929 warn("\"%s\" [%s.ko] undefined!\n",
1930 s
->name
, mod
->name
);
1932 merror("\"%s\" [%s.ko] undefined!\n",
1933 s
->name
, mod
->name
);
1939 s
->module
= exp
->module
;
1940 s
->crc_valid
= exp
->crc_valid
;
1947 buf_printf(b
, "\n");
1948 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1949 buf_printf(b
, "__used\n");
1950 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1952 for (s
= mod
->unres
; s
; s
= s
->next
) {
1955 if (!s
->crc_valid
) {
1956 warn("\"%s\" [%s.ko] has no CRC!\n",
1957 s
->name
, mod
->name
);
1960 buf_printf(b
, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1964 buf_printf(b
, "};\n");
1969 static void add_depends(struct buffer
*b
, struct module
*mod
,
1970 struct module
*modules
)
1976 for (m
= modules
; m
; m
= m
->next
)
1977 m
->seen
= is_vmlinux(m
->name
);
1979 buf_printf(b
, "\n");
1980 buf_printf(b
, "static const char __module_depends[]\n");
1981 buf_printf(b
, "__used\n");
1982 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1983 buf_printf(b
, "\"depends=");
1984 for (s
= mod
->unres
; s
; s
= s
->next
) {
1989 if (s
->module
->seen
)
1992 s
->module
->seen
= 1;
1993 p
= strrchr(s
->module
->name
, '/');
1997 p
= s
->module
->name
;
1998 buf_printf(b
, "%s%s", first
? "" : ",", p
);
2001 buf_printf(b
, "\";\n");
2004 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
2006 if (mod
->srcversion
[0]) {
2007 buf_printf(b
, "\n");
2008 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
2013 static void write_if_changed(struct buffer
*b
, const char *fname
)
2019 file
= fopen(fname
, "r");
2023 if (fstat(fileno(file
), &st
) < 0)
2026 if (st
.st_size
!= b
->pos
)
2029 tmp
= NOFAIL(malloc(b
->pos
));
2030 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
2033 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
2045 file
= fopen(fname
, "w");
2050 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2057 /* parse Module.symvers file. line format:
2058 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2060 static void read_dump(const char *fname
, unsigned int kernel
)
2062 unsigned long size
, pos
= 0;
2063 void *file
= grab_file(fname
, &size
);
2067 /* No symbol versions, silently ignore */
2070 while ((line
= get_next_line(&pos
, file
, size
))) {
2071 char *symname
, *modname
, *d
, *export
, *end
;
2076 if (!(symname
= strchr(line
, '\t')))
2079 if (!(modname
= strchr(symname
, '\t')))
2082 if ((export
= strchr(modname
, '\t')) != NULL
)
2084 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2086 crc
= strtoul(line
, &d
, 16);
2087 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2089 mod
= find_module(modname
);
2091 if (is_vmlinux(modname
))
2093 mod
= new_module(modname
);
2096 s
= sym_add_exported(symname
, mod
, export_no(export
));
2099 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2103 fatal("parse error in symbol dump file\n");
2106 /* For normal builds always dump all symbols.
2107 * For external modules only dump symbols
2108 * that are not read from kernel Module.symvers.
2110 static int dump_sym(struct symbol
*sym
)
2112 if (!external_module
)
2114 if (sym
->vmlinux
|| sym
->kernel
)
2119 static void write_dump(const char *fname
)
2121 struct buffer buf
= { };
2122 struct symbol
*symbol
;
2125 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2126 symbol
= symbolhash
[n
];
2128 if (dump_sym(symbol
))
2129 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2130 symbol
->crc
, symbol
->name
,
2131 symbol
->module
->name
,
2132 export_str(symbol
->export
));
2133 symbol
= symbol
->next
;
2136 write_if_changed(&buf
, fname
);
2139 struct ext_sym_list
{
2140 struct ext_sym_list
*next
;
2144 int main(int argc
, char **argv
)
2147 struct buffer buf
= { };
2148 char *kernel_read
= NULL
, *module_read
= NULL
;
2149 char *dump_write
= NULL
, *files_source
= NULL
;
2152 struct ext_sym_list
*extsym_iter
;
2153 struct ext_sym_list
*extsym_start
= NULL
;
2155 while ((opt
= getopt(argc
, argv
, "i:I:e:msST:o:awM:K:")) != -1) {
2158 kernel_read
= optarg
;
2161 module_read
= optarg
;
2162 external_module
= 1;
2165 external_module
= 1;
2167 NOFAIL(malloc(sizeof(*extsym_iter
)));
2168 extsym_iter
->next
= extsym_start
;
2169 extsym_iter
->file
= optarg
;
2170 extsym_start
= extsym_iter
;
2176 dump_write
= optarg
;
2182 vmlinux_section_warnings
= 0;
2185 sec_mismatch_verbose
= 0;
2188 files_source
= optarg
;
2191 warn_unresolved
= 1;
2199 read_dump(kernel_read
, 1);
2201 read_dump(module_read
, 0);
2202 while (extsym_start
) {
2203 read_dump(extsym_start
->file
, 0);
2204 extsym_iter
= extsym_start
->next
;
2206 extsym_start
= extsym_iter
;
2209 while (optind
< argc
)
2210 read_symbols(argv
[optind
++]);
2213 read_symbols_from_files(files_source
);
2215 for (mod
= modules
; mod
; mod
= mod
->next
) {
2223 for (mod
= modules
; mod
; mod
= mod
->next
) {
2224 char fname
[strlen(mod
->name
) + 10];
2231 add_header(&buf
, mod
);
2232 add_intree_flag(&buf
, !external_module
);
2233 add_staging_flag(&buf
, mod
->name
);
2234 err
|= add_versions(&buf
, mod
);
2235 add_depends(&buf
, mod
, modules
);
2236 add_moddevtable(&buf
, mod
);
2237 add_srcversion(&buf
, mod
);
2239 sprintf(fname
, "%s.mod.c", mod
->name
);
2240 write_if_changed(&buf
, fname
);
2244 write_dump(dump_write
);
2245 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2246 warn("modpost: Found %d section mismatch(es).\n"
2247 "To see full details build your kernel with:\n"
2248 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2249 sec_mismatch_count
);