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 ...
18 #include "../../include/generated/autoconf.h"
19 #include "../../include/linux/license.h"
21 /* Some toolchains use a `_' prefix for all user symbols. */
22 #ifdef CONFIG_SYMBOL_PREFIX
23 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
25 #define MODULE_SYMBOL_PREFIX ""
29 /* Are we using CONFIG_MODVERSIONS? */
31 /* Warn about undefined symbols? (do so if we have vmlinux) */
33 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
34 static int all_versions
= 0;
35 /* If we are modposting external module set to 1 */
36 static int external_module
= 0;
37 /* Warn about section mismatch in vmlinux if set to 1 */
38 static int vmlinux_section_warnings
= 1;
39 /* Only warn about unresolved symbols */
40 static int warn_unresolved
= 0;
41 /* How a symbol is exported */
42 static int sec_mismatch_count
= 0;
43 static int sec_mismatch_verbose
= 1;
46 export_plain
, export_unused
, export_gpl
,
47 export_unused_gpl
, export_gpl_future
, export_unknown
50 #define PRINTF __attribute__ ((format (printf, 1, 2)))
52 PRINTF
void fatal(const char *fmt
, ...)
56 fprintf(stderr
, "FATAL: ");
58 va_start(arglist
, fmt
);
59 vfprintf(stderr
, fmt
, arglist
);
65 PRINTF
void warn(const char *fmt
, ...)
69 fprintf(stderr
, "WARNING: ");
71 va_start(arglist
, fmt
);
72 vfprintf(stderr
, fmt
, arglist
);
76 PRINTF
void merror(const char *fmt
, ...)
80 fprintf(stderr
, "ERROR: ");
82 va_start(arglist
, fmt
);
83 vfprintf(stderr
, fmt
, arglist
);
87 static int is_vmlinux(const char *modname
)
91 myname
= strrchr(modname
, '/');
97 return (strcmp(myname
, "vmlinux") == 0) ||
98 (strcmp(myname
, "vmlinux.o") == 0);
101 void *do_nofail(void *ptr
, const char *expr
)
104 fatal("modpost: Memory allocation failure: %s.\n", expr
);
109 /* A list of all modules we processed */
110 static struct module
*modules
;
112 static struct module
*find_module(char *modname
)
116 for (mod
= modules
; mod
; mod
= mod
->next
)
117 if (strcmp(mod
->name
, modname
) == 0)
122 static struct module
*new_module(char *modname
)
127 mod
= NOFAIL(malloc(sizeof(*mod
)));
128 memset(mod
, 0, sizeof(*mod
));
129 p
= NOFAIL(strdup(modname
));
131 /* strip trailing .o */
134 if (strcmp(s
, ".o") == 0)
139 mod
->gpl_compatible
= -1;
146 /* A hash of all exported symbols,
147 * struct symbol is also used for lists of unresolved symbols */
149 #define SYMBOL_HASH_SIZE 1024
153 struct module
*module
;
157 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
158 unsigned int kernel
:1; /* 1 if symbol is from kernel
159 * (only for external modules) **/
160 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
161 enum export export
; /* Type of export */
165 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
167 /* This is based on the hash agorithm from gdbm, via tdb */
168 static inline unsigned int tdb_hash(const char *name
)
170 unsigned value
; /* Used to compute the hash value. */
171 unsigned i
; /* Used to cycle through random values. */
173 /* Set the initial value from the key size. */
174 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
175 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
177 return (1103515243 * value
+ 12345);
181 * Allocate a new symbols for use in the hash of exported symbols or
182 * the list of unresolved symbols per module
184 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
187 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
189 memset(s
, 0, sizeof(*s
));
190 strcpy(s
->name
, name
);
196 /* For the hash of exported symbols */
197 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
203 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
204 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
205 new->module
= module
;
206 new->export
= export
;
210 static struct symbol
*find_symbol(const char *name
)
214 /* For our purposes, .foo matches foo. PPC64 needs this. */
218 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
219 if (strcmp(s
->name
, name
) == 0)
229 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
230 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
231 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
232 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
233 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
234 { .str
= "(unknown)", .export
= export_unknown
},
238 static const char *export_str(enum export ex
)
240 return export_list
[ex
].str
;
243 static enum export
export_no(const char *s
)
248 return export_unknown
;
249 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
250 if (strcmp(export_list
[i
].str
, s
) == 0)
251 return export_list
[i
].export
;
253 return export_unknown
;
256 static enum export
export_from_sec(struct elf_info
*elf
, Elf_Section sec
)
258 if (sec
== elf
->export_sec
)
260 else if (sec
== elf
->export_unused_sec
)
261 return export_unused
;
262 else if (sec
== elf
->export_gpl_sec
)
264 else if (sec
== elf
->export_unused_gpl_sec
)
265 return export_unused_gpl
;
266 else if (sec
== elf
->export_gpl_future_sec
)
267 return export_gpl_future
;
269 return export_unknown
;
273 * Add an exported symbol - it may have already been added without a
274 * CRC, in this case just update the CRC
276 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
279 struct symbol
*s
= find_symbol(name
);
282 s
= new_symbol(name
, mod
, export
);
285 warn("%s: '%s' exported twice. Previous export "
286 "was in %s%s\n", mod
->name
, name
,
288 is_vmlinux(s
->module
->name
) ?"":".ko");
290 /* In case Modules.symvers was out of date */
295 s
->vmlinux
= is_vmlinux(mod
->name
);
301 static void sym_update_crc(const char *name
, struct module
*mod
,
302 unsigned int crc
, enum export export
)
304 struct symbol
*s
= find_symbol(name
);
307 s
= new_symbol(name
, mod
, export
);
312 void *grab_file(const char *filename
, unsigned long *size
)
318 fd
= open(filename
, O_RDONLY
);
319 if (fd
< 0 || fstat(fd
, &st
) != 0)
323 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
326 if (map
== MAP_FAILED
)
332 * Return a copy of the next line in a mmap'ed file.
333 * spaces in the beginning of the line is trimmed away.
334 * Return a pointer to a static buffer.
336 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
338 static char line
[4096];
341 signed char *p
= (signed char *)file
+ *pos
;
344 for (; *pos
< size
; (*pos
)++) {
345 if (skip
&& isspace(*p
)) {
350 if (*p
!= '\n' && (*pos
< size
)) {
354 break; /* Too long, stop */
365 void release_file(void *file
, unsigned long size
)
370 static int parse_elf(struct elf_info
*info
, const char *filename
)
377 hdr
= grab_file(filename
, &info
->size
);
383 if (info
->size
< sizeof(*hdr
)) {
384 /* file too small, assume this is an empty .o file */
387 /* Is this a valid ELF file? */
388 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
389 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
390 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
391 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
392 /* Not an ELF file - silently ignore it */
395 /* Fix endianness in ELF header */
396 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
397 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
398 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
399 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
400 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
401 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
402 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
403 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
404 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
405 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
406 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
407 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
408 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
409 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
410 info
->sechdrs
= sechdrs
;
412 /* Check if file offset is correct */
413 if (hdr
->e_shoff
> info
->size
) {
414 fatal("section header offset=%lu in file '%s' is bigger than "
415 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
416 filename
, info
->size
);
420 /* Fix endianness in section headers */
421 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
422 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
423 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
424 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
425 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
426 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
427 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
428 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
429 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
430 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
431 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
433 /* Find symbol table. */
434 for (i
= 1; i
< hdr
->e_shnum
; i
++) {
435 const char *secstrings
436 = (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
438 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
440 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
441 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
442 "sizeof(*hrd)=%zu\n", filename
,
443 (unsigned long)sechdrs
[i
].sh_offset
,
447 secname
= secstrings
+ sechdrs
[i
].sh_name
;
448 if (strcmp(secname
, ".modinfo") == 0) {
450 fatal("%s has NOBITS .modinfo\n", filename
);
451 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
452 info
->modinfo_len
= sechdrs
[i
].sh_size
;
453 } else if (strcmp(secname
, "__ksymtab") == 0)
454 info
->export_sec
= i
;
455 else if (strcmp(secname
, "__ksymtab_unused") == 0)
456 info
->export_unused_sec
= i
;
457 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
458 info
->export_gpl_sec
= i
;
459 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
460 info
->export_unused_gpl_sec
= i
;
461 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
462 info
->export_gpl_future_sec
= i
;
464 if (sechdrs
[i
].sh_type
!= SHT_SYMTAB
)
467 info
->symtab_start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
468 info
->symtab_stop
= (void *)hdr
+ sechdrs
[i
].sh_offset
469 + sechdrs
[i
].sh_size
;
470 info
->strtab
= (void *)hdr
+
471 sechdrs
[sechdrs
[i
].sh_link
].sh_offset
;
473 if (!info
->symtab_start
)
474 fatal("%s has no symtab?\n", filename
);
476 /* Fix endianness in symbols */
477 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
478 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
479 sym
->st_name
= TO_NATIVE(sym
->st_name
);
480 sym
->st_value
= TO_NATIVE(sym
->st_value
);
481 sym
->st_size
= TO_NATIVE(sym
->st_size
);
486 static void parse_elf_finish(struct elf_info
*info
)
488 release_file(info
->hdr
, info
->size
);
491 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
493 /* ignore __this_module, it will be resolved shortly */
494 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
496 /* ignore global offset table */
497 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
499 if (info
->hdr
->e_machine
== EM_PPC
)
500 /* Special register function linked on all modules during final link of .ko */
501 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
502 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
503 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
504 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
506 /* Do not ignore this symbol */
510 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
511 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
513 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
514 Elf_Sym
*sym
, const char *symname
)
517 enum export export
= export_from_sec(info
, sym
->st_shndx
);
519 switch (sym
->st_shndx
) {
521 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
525 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
526 crc
= (unsigned int) sym
->st_value
;
527 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
532 /* undefined symbol */
533 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
534 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
536 if (ignore_undef_symbol(info
, symname
))
538 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
539 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
540 /* add compatibility with older glibc */
541 #ifndef STT_SPARC_REGISTER
542 #define STT_SPARC_REGISTER STT_REGISTER
544 if (info
->hdr
->e_machine
== EM_SPARC
||
545 info
->hdr
->e_machine
== EM_SPARCV9
) {
546 /* Ignore register directives. */
547 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
549 if (symname
[0] == '.') {
550 char *munged
= strdup(symname
);
552 munged
[1] = toupper(munged
[1]);
558 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
559 strlen(MODULE_SYMBOL_PREFIX
)) == 0) {
561 alloc_symbol(symname
+
562 strlen(MODULE_SYMBOL_PREFIX
),
563 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
568 /* All exported symbols */
569 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
570 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
573 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
575 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
576 mod
->has_cleanup
= 1;
582 * Parse tag=value strings from .modinfo section
584 static char *next_string(char *string
, unsigned long *secsize
)
586 /* Skip non-zero chars */
589 if ((*secsize
)-- <= 1)
593 /* Skip any zero padding. */
596 if ((*secsize
)-- <= 1)
602 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
603 const char *tag
, char *info
)
606 unsigned int taglen
= strlen(tag
);
607 unsigned long size
= modinfo_len
;
610 size
-= info
- (char *)modinfo
;
611 modinfo
= next_string(info
, &size
);
614 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
615 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
616 return p
+ taglen
+ 1;
621 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
625 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
629 * Test if string s ends in string sub
632 static int strrcmp(const char *s
, const char *sub
)
640 sublen
= strlen(sub
);
642 if ((slen
== 0) || (sublen
== 0))
648 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
651 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
654 return elf
->strtab
+ sym
->st_name
;
659 static const char *sec_name(struct elf_info
*elf
, int shndx
)
661 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
662 return (void *)elf
->hdr
+
663 elf
->sechdrs
[elf
->hdr
->e_shstrndx
].sh_offset
+
664 sechdrs
[shndx
].sh_name
;
667 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
669 return (void *)elf
->hdr
+
670 elf
->sechdrs
[elf
->hdr
->e_shstrndx
].sh_offset
+
674 /* if sym is empty or point to a string
675 * like ".[0-9]+" then return 1.
676 * This is the optional prefix added by ld to some sections
678 static int number_prefix(const char *sym
)
686 if (c
< '0' || c
> '9')
692 /* The pattern is an array of simple patterns.
693 * "foo" will match an exact string equal to "foo"
694 * "*foo" will match a string that ends with "foo"
695 * "foo*" will match a string that begins with "foo"
696 * "foo$" will match a string equal to "foo" or "foo.1"
697 * where the '1' can be any number including several digits.
698 * The $ syntax is for sections where ld append a dot number
699 * to make section name unique.
701 static int match(const char *sym
, const char * const pat
[])
706 const char *endp
= p
+ strlen(p
) - 1;
710 if (strrcmp(sym
, p
+ 1) == 0)
714 else if (*endp
== '*') {
715 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
719 else if (*endp
== '$') {
720 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
721 if (number_prefix(sym
+ strlen(p
) - 1))
727 if (strcmp(p
, sym
) == 0)
735 /* sections that we do not want to do full section mismatch check on */
736 static const char *section_white_list
[] =
740 ".mdebug*", /* alpha, score, mips etc. */
741 ".pdr", /* alpha, score, mips etc. */
750 * This is used to find sections missing the SHF_ALLOC flag.
751 * The cause of this is often a section specified in assembler
752 * without "ax" / "aw".
754 static void check_section(const char *modname
, struct elf_info
*elf
,
757 const char *sec
= sech_name(elf
, sechdr
);
759 if (sechdr
->sh_type
== SHT_PROGBITS
&&
760 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
761 !match(sec
, section_white_list
)) {
762 warn("%s (%s): unexpected non-allocatable section.\n"
763 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
764 "Note that for example <linux/init.h> contains\n"
765 "section definitions for use in .S files.\n\n",
772 #define ALL_INIT_DATA_SECTIONS \
773 ".init.setup$", ".init.rodata$", \
774 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
775 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
776 #define ALL_EXIT_DATA_SECTIONS \
777 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
779 #define ALL_INIT_TEXT_SECTIONS \
780 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
781 #define ALL_EXIT_TEXT_SECTIONS \
782 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
784 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
786 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
789 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
790 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
792 #define DATA_SECTIONS ".data$", ".data.rel$"
793 #define TEXT_SECTIONS ".text$"
795 #define INIT_SECTIONS ".init.*"
796 #define DEV_INIT_SECTIONS ".devinit.*"
797 #define CPU_INIT_SECTIONS ".cpuinit.*"
798 #define MEM_INIT_SECTIONS ".meminit.*"
800 #define EXIT_SECTIONS ".exit.*"
801 #define DEV_EXIT_SECTIONS ".devexit.*"
802 #define CPU_EXIT_SECTIONS ".cpuexit.*"
803 #define MEM_EXIT_SECTIONS ".memexit.*"
805 /* init data sections */
806 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
808 /* all init sections */
809 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
811 /* All init and exit sections (code + data) */
812 static const char *init_exit_sections
[] =
813 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
816 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
819 /* symbols in .data that may refer to init/exit sections */
820 #define DEFAULT_SYMBOL_WHITE_LIST \
822 "*_template", /* scsi uses *_template a lot */ \
823 "*_timer", /* arm uses ops structures named _timer a lot */ \
824 "*_sht", /* scsi also used *_sht to some extent */ \
830 static const char *head_sections
[] = { ".head.text*", NULL
};
831 static const char *linker_symbols
[] =
832 { "__init_begin", "_sinittext", "_einittext", NULL
};
839 XXXINIT_TO_SOME_INIT
,
840 XXXEXIT_TO_SOME_EXIT
,
841 ANY_INIT_TO_ANY_EXIT
,
842 ANY_EXIT_TO_ANY_INIT
,
846 struct sectioncheck
{
847 const char *fromsec
[20];
848 const char *tosec
[20];
849 enum mismatch mismatch
;
850 const char *symbol_white_list
[20];
853 const struct sectioncheck sectioncheck
[] = {
854 /* Do not reference init/exit code/data from
855 * normal code and data
858 .fromsec
= { TEXT_SECTIONS
, NULL
},
859 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
860 .mismatch
= TEXT_TO_ANY_INIT
,
861 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
864 .fromsec
= { DATA_SECTIONS
, NULL
},
865 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
866 .mismatch
= DATA_TO_ANY_INIT
,
867 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
870 .fromsec
= { DATA_SECTIONS
, NULL
},
871 .tosec
= { INIT_SECTIONS
, NULL
},
872 .mismatch
= DATA_TO_ANY_INIT
,
873 .symbol_white_list
= {
874 "*_template", "*_timer", "*_sht", "*_ops",
875 "*_probe", "*_probe_one", "*_console", NULL
879 .fromsec
= { TEXT_SECTIONS
, NULL
},
880 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
881 .mismatch
= TEXT_TO_ANY_EXIT
,
882 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
885 .fromsec
= { DATA_SECTIONS
, NULL
},
886 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
887 .mismatch
= DATA_TO_ANY_EXIT
,
888 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
890 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
892 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
893 .tosec
= { INIT_SECTIONS
, NULL
},
894 .mismatch
= XXXINIT_TO_SOME_INIT
,
895 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
897 /* Do not reference cpuinit code/data from meminit code/data */
899 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
900 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
901 .mismatch
= XXXINIT_TO_SOME_INIT
,
902 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
904 /* Do not reference meminit code/data from cpuinit code/data */
906 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
907 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
908 .mismatch
= XXXINIT_TO_SOME_INIT
,
909 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
911 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
913 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
914 .tosec
= { EXIT_SECTIONS
, NULL
},
915 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
916 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
918 /* Do not reference cpuexit code/data from memexit code/data */
920 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
921 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
922 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
923 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
925 /* Do not reference memexit code/data from cpuexit code/data */
927 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
928 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
929 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
930 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
932 /* Do not use exit code/data from init code */
934 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
935 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
936 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
937 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
939 /* Do not use init code/data from exit code */
941 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
942 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
943 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
944 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
946 /* Do not export init/exit functions or data */
948 .fromsec
= { "__ksymtab*", NULL
},
949 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
950 .mismatch
= EXPORT_TO_INIT_EXIT
,
951 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
955 static const struct sectioncheck
*section_mismatch(
956 const char *fromsec
, const char *tosec
)
959 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
960 const struct sectioncheck
*check
= §ioncheck
[0];
962 for (i
= 0; i
< elems
; i
++) {
963 if (match(fromsec
, check
->fromsec
) &&
964 match(tosec
, check
->tosec
))
972 * Whitelist to allow certain references to pass with no warning.
975 * If a module parameter is declared __initdata and permissions=0
976 * then this is legal despite the warning generated.
977 * We cannot see value of permissions here, so just ignore
979 * The pattern is identified by:
985 * Many drivers utilise a *driver container with references to
986 * add, remove, probe functions etc.
987 * These functions may often be marked __devinit and we do not want to
989 * the pattern is identified by:
990 * tosec = init or exit section
991 * fromsec = data section
992 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
993 * *probe_one, *_console, *_timer
996 * Whitelist all references from .head.text to any init section
999 * Some symbols belong to init section but still it is ok to reference
1000 * these from non-init sections as these symbols don't have any memory
1001 * allocated for them and symbol address and value are same. So even
1002 * if init section is freed, its ok to reference those symbols.
1003 * For ex. symbols marking the init section boundaries.
1004 * This pattern is identified by
1005 * refsymname = __init_begin, _sinittext, _einittext
1008 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1009 const char *fromsec
, const char *fromsym
,
1010 const char *tosec
, const char *tosym
)
1012 /* Check for pattern 1 */
1013 if (match(tosec
, init_data_sections
) &&
1014 match(fromsec
, data_sections
) &&
1015 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1018 /* Check for pattern 2 */
1019 if (match(tosec
, init_exit_sections
) &&
1020 match(fromsec
, data_sections
) &&
1021 match(fromsym
, mismatch
->symbol_white_list
))
1024 /* Check for pattern 3 */
1025 if (match(fromsec
, head_sections
) &&
1026 match(tosec
, init_sections
))
1029 /* Check for pattern 4 */
1030 if (match(tosym
, linker_symbols
))
1037 * Find symbol based on relocation record info.
1038 * In some cases the symbol supplied is a valid symbol so
1039 * return refsym. If st_name != 0 we assume this is a valid symbol.
1040 * In other cases the symbol needs to be looked up in the symbol table
1041 * based on section and address.
1043 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1047 Elf_Sym
*near
= NULL
;
1048 Elf64_Sword distance
= 20;
1051 if (relsym
->st_name
!= 0)
1053 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1054 if (sym
->st_shndx
!= relsym
->st_shndx
)
1056 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1058 if (sym
->st_value
== addr
)
1060 /* Find a symbol nearby - addr are maybe negative */
1061 d
= sym
->st_value
- addr
;
1063 d
= addr
- sym
->st_value
;
1069 /* We need a close match */
1076 static inline int is_arm_mapping_symbol(const char *str
)
1078 return str
[0] == '$' && strchr("atd", str
[1])
1079 && (str
[2] == '\0' || str
[2] == '.');
1083 * If there's no name there, ignore it; likewise, ignore it if it's
1084 * one of the magic symbols emitted used by current ARM tools.
1086 * Otherwise if find_symbols_between() returns those symbols, they'll
1087 * fail the whitelist tests and cause lots of false alarms ... fixable
1088 * only by merging __exit and __init sections into __text, bloating
1089 * the kernel (which is especially evil on embedded platforms).
1091 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1093 const char *name
= elf
->strtab
+ sym
->st_name
;
1095 if (!name
|| !strlen(name
))
1097 return !is_arm_mapping_symbol(name
);
1101 * Find symbols before or equal addr and after addr - in the section sec.
1102 * If we find two symbols with equal offset prefer one with a valid name.
1103 * The ELF format may have a better way to detect what type of symbol
1104 * it is, but this works for now.
1106 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1110 Elf_Sym
*near
= NULL
;
1111 Elf_Addr distance
= ~0;
1113 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1116 if (sym
->st_shndx
>= SHN_LORESERVE
)
1118 symsec
= sec_name(elf
, sym
->st_shndx
);
1119 if (strcmp(symsec
, sec
) != 0)
1121 if (!is_valid_name(elf
, sym
))
1123 if (sym
->st_value
<= addr
) {
1124 if ((addr
- sym
->st_value
) < distance
) {
1125 distance
= addr
- sym
->st_value
;
1127 } else if ((addr
- sym
->st_value
) == distance
) {
1136 * Convert a section name to the function/data attribute
1137 * .init.text => __init
1138 * .cpuinit.data => __cpudata
1139 * .memexitconst => __memconst
1142 static char *sec2annotation(const char *s
)
1144 if (match(s
, init_exit_sections
)) {
1145 char *p
= malloc(20);
1152 while (*s
&& *s
!= '.')
1157 if (strstr(s
, "rodata") != NULL
)
1158 strcat(p
, "const ");
1159 else if (strstr(s
, "data") != NULL
)
1163 return r
; /* we leak her but we do not care */
1169 static int is_function(Elf_Sym
*sym
)
1172 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1178 * Print a warning about a section mismatch.
1179 * Try to find symbols near it so user can find it.
1180 * Check whitelist before warning - it may be a false positive.
1182 static void report_sec_mismatch(const char *modname
,
1183 const struct sectioncheck
*mismatch
,
1184 const char *fromsec
,
1185 unsigned long long fromaddr
,
1186 const char *fromsym
,
1188 const char *tosec
, const char *tosym
,
1191 const char *from
, *from_p
;
1192 const char *to
, *to_p
;
1194 switch (from_is_func
) {
1195 case 0: from
= "variable"; from_p
= ""; break;
1196 case 1: from
= "function"; from_p
= "()"; break;
1197 default: from
= "(unknown reference)"; from_p
= ""; break;
1199 switch (to_is_func
) {
1200 case 0: to
= "variable"; to_p
= ""; break;
1201 case 1: to
= "function"; to_p
= "()"; break;
1202 default: to
= "(unknown reference)"; to_p
= ""; break;
1205 sec_mismatch_count
++;
1206 if (!sec_mismatch_verbose
)
1209 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1210 "to the %s %s:%s%s\n",
1211 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1214 switch (mismatch
->mismatch
) {
1215 case TEXT_TO_ANY_INIT
:
1217 "The function %s%s() references\n"
1219 "This is often because %s lacks a %s\n"
1220 "annotation or the annotation of %s is wrong.\n",
1221 sec2annotation(fromsec
), fromsym
,
1222 to
, sec2annotation(tosec
), tosym
, to_p
,
1223 fromsym
, sec2annotation(tosec
), tosym
);
1225 case DATA_TO_ANY_INIT
: {
1226 const char *const *s
= mismatch
->symbol_white_list
;
1228 "The variable %s references\n"
1230 "If the reference is valid then annotate the\n"
1231 "variable with __init* or __refdata (see linux/init.h) "
1232 "or name the variable:\n",
1233 fromsym
, to
, sec2annotation(tosec
), tosym
, to_p
);
1235 fprintf(stderr
, "%s, ", *s
++);
1236 fprintf(stderr
, "\n");
1239 case TEXT_TO_ANY_EXIT
:
1241 "The function %s() references a %s in an exit section.\n"
1242 "Often the %s %s%s has valid usage outside the exit section\n"
1243 "and the fix is to remove the %sannotation of %s.\n",
1244 fromsym
, to
, to
, tosym
, to_p
, sec2annotation(tosec
), tosym
);
1246 case DATA_TO_ANY_EXIT
: {
1247 const char *const *s
= mismatch
->symbol_white_list
;
1249 "The variable %s references\n"
1251 "If the reference is valid then annotate the\n"
1252 "variable with __exit* (see linux/init.h) or "
1253 "name the variable:\n",
1254 fromsym
, to
, sec2annotation(tosec
), tosym
, to_p
);
1256 fprintf(stderr
, "%s, ", *s
++);
1257 fprintf(stderr
, "\n");
1260 case XXXINIT_TO_SOME_INIT
:
1261 case XXXEXIT_TO_SOME_EXIT
:
1263 "The %s %s%s%s references\n"
1265 "If %s is only used by %s then\n"
1266 "annotate %s with a matching annotation.\n",
1267 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1268 to
, sec2annotation(tosec
), tosym
, to_p
,
1269 tosym
, fromsym
, tosym
);
1271 case ANY_INIT_TO_ANY_EXIT
:
1273 "The %s %s%s%s references\n"
1275 "This is often seen when error handling "
1276 "in the init function\n"
1277 "uses functionality in the exit path.\n"
1278 "The fix is often to remove the %sannotation of\n"
1279 "%s%s so it may be used outside an exit section.\n",
1280 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1281 to
, sec2annotation(tosec
), tosym
, to_p
,
1282 sec2annotation(tosec
), tosym
, to_p
);
1284 case ANY_EXIT_TO_ANY_INIT
:
1286 "The %s %s%s%s references\n"
1288 "This is often seen when error handling "
1289 "in the exit function\n"
1290 "uses functionality in the init path.\n"
1291 "The fix is often to remove the %sannotation of\n"
1292 "%s%s so it may be used outside an init section.\n",
1293 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1294 to
, sec2annotation(tosec
), tosym
, to_p
,
1295 sec2annotation(tosec
), tosym
, to_p
);
1297 case EXPORT_TO_INIT_EXIT
:
1299 "The symbol %s is exported and annotated %s\n"
1300 "Fix this by removing the %sannotation of %s "
1301 "or drop the export.\n",
1302 tosym
, sec2annotation(tosec
), sec2annotation(tosec
), tosym
);
1305 fprintf(stderr
, "\n");
1308 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1309 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1312 const struct sectioncheck
*mismatch
;
1314 tosec
= sec_name(elf
, sym
->st_shndx
);
1315 mismatch
= section_mismatch(fromsec
, tosec
);
1320 const char *fromsym
;
1322 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1323 fromsym
= sym_name(elf
, from
);
1324 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1325 tosym
= sym_name(elf
, to
);
1327 /* check whitelist - we may ignore it */
1328 if (secref_whitelist(mismatch
,
1329 fromsec
, fromsym
, tosec
, tosym
)) {
1330 report_sec_mismatch(modname
, mismatch
,
1331 fromsec
, r
->r_offset
, fromsym
,
1332 is_function(from
), tosec
, tosym
,
1338 static unsigned int *reloc_location(struct elf_info
*elf
,
1339 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1341 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1342 int section
= sechdr
->sh_info
;
1344 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1345 (r
->r_offset
- sechdrs
[section
].sh_addr
);
1348 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1350 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1351 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1355 r
->r_addend
= TO_NATIVE(*location
);
1358 r
->r_addend
= TO_NATIVE(*location
) + 4;
1359 /* For CONFIG_RELOCATABLE=y */
1360 if (elf
->hdr
->e_type
== ET_EXEC
)
1361 r
->r_addend
+= r
->r_offset
;
1367 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1369 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1373 /* From ARM ABI: (S + A) | T */
1374 r
->r_addend
= (int)(long)
1375 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1378 /* From ARM ABI: ((S + A) | T) - P */
1379 r
->r_addend
= (int)(long)(elf
->hdr
+
1381 (r
->r_offset
- sechdr
->sh_addr
));
1389 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1391 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1392 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1395 if (r_typ
== R_MIPS_HI16
)
1396 return 1; /* skip this */
1397 inst
= TO_NATIVE(*location
);
1400 r
->r_addend
= inst
& 0xffff;
1403 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1412 static void section_rela(const char *modname
, struct elf_info
*elf
,
1419 const char *fromsec
;
1421 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1422 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1424 fromsec
= sech_name(elf
, sechdr
);
1425 fromsec
+= strlen(".rela");
1426 /* if from section (name) is know good then skip it */
1427 if (match(fromsec
, section_white_list
))
1430 for (rela
= start
; rela
< stop
; rela
++) {
1431 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1432 #if KERNEL_ELFCLASS == ELFCLASS64
1433 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1435 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1436 r_sym
= TO_NATIVE(r_sym
);
1437 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1438 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1440 r
.r_info
= TO_NATIVE(rela
->r_info
);
1441 r_sym
= ELF_R_SYM(r
.r_info
);
1444 r
.r_info
= TO_NATIVE(rela
->r_info
);
1445 r_sym
= ELF_R_SYM(r
.r_info
);
1447 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1448 sym
= elf
->symtab_start
+ r_sym
;
1449 /* Skip special sections */
1450 if (sym
->st_shndx
>= SHN_LORESERVE
)
1452 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1456 static void section_rel(const char *modname
, struct elf_info
*elf
,
1463 const char *fromsec
;
1465 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1466 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1468 fromsec
= sech_name(elf
, sechdr
);
1469 fromsec
+= strlen(".rel");
1470 /* if from section (name) is know good then skip it */
1471 if (match(fromsec
, section_white_list
))
1474 for (rel
= start
; rel
< stop
; rel
++) {
1475 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1476 #if KERNEL_ELFCLASS == ELFCLASS64
1477 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1479 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1480 r_sym
= TO_NATIVE(r_sym
);
1481 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1482 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1484 r
.r_info
= TO_NATIVE(rel
->r_info
);
1485 r_sym
= ELF_R_SYM(r
.r_info
);
1488 r
.r_info
= TO_NATIVE(rel
->r_info
);
1489 r_sym
= ELF_R_SYM(r
.r_info
);
1492 switch (elf
->hdr
->e_machine
) {
1494 if (addend_386_rel(elf
, sechdr
, &r
))
1498 if (addend_arm_rel(elf
, sechdr
, &r
))
1502 if (addend_mips_rel(elf
, sechdr
, &r
))
1506 sym
= elf
->symtab_start
+ r_sym
;
1507 /* Skip special sections */
1508 if (sym
->st_shndx
>= SHN_LORESERVE
)
1510 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1515 * A module includes a number of sections that are discarded
1516 * either when loaded or when used as built-in.
1517 * For loaded modules all functions marked __init and all data
1518 * marked __initdata will be discarded when the module has been intialized.
1519 * Likewise for modules used built-in the sections marked __exit
1520 * are discarded because __exit marked function are supposed to be called
1521 * only when a module is unloaded which never happens for built-in modules.
1522 * The check_sec_ref() function traverses all relocation records
1523 * to find all references to a section that reference a section that will
1524 * be discarded and warns about it.
1526 static void check_sec_ref(struct module
*mod
, const char *modname
,
1527 struct elf_info
*elf
)
1530 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1532 /* Walk through all sections */
1533 for (i
= 0; i
< elf
->hdr
->e_shnum
; i
++) {
1534 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1535 /* We want to process only relocation sections and not .init */
1536 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1537 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1538 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1539 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1543 static void read_symbols(char *modname
)
1545 const char *symname
;
1549 struct elf_info info
= { };
1552 if (!parse_elf(&info
, modname
))
1555 mod
= new_module(modname
);
1557 /* When there's no vmlinux, don't print warnings about
1558 * unresolved symbols (since there'll be too many ;) */
1559 if (is_vmlinux(modname
)) {
1564 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1565 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1566 warn("modpost: missing MODULE_LICENSE() in %s\n"
1567 "see include/linux/module.h for "
1568 "more information\n", modname
);
1570 if (license_is_gpl_compatible(license
))
1571 mod
->gpl_compatible
= 1;
1573 mod
->gpl_compatible
= 0;
1576 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1577 "license", license
);
1580 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1581 symname
= info
.strtab
+ sym
->st_name
;
1583 handle_modversions(mod
, &info
, sym
, symname
);
1584 handle_moddevtable(mod
, &info
, sym
, symname
);
1586 if (!is_vmlinux(modname
) ||
1587 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1588 check_sec_ref(mod
, modname
, &info
);
1590 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1592 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1593 version
- (char *)info
.hdr
);
1594 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1595 get_src_version(modname
, mod
->srcversion
,
1596 sizeof(mod
->srcversion
)-1);
1598 parse_elf_finish(&info
);
1600 /* Our trick to get versioning for module struct etc. - it's
1601 * never passed as an argument to an exported function, so
1602 * the automatic versioning doesn't pick it up, but it's really
1603 * important anyhow */
1605 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1610 /* We first write the generated file into memory using the
1611 * following helper, then compare to the file on disk and
1612 * only update the later if anything changed */
1614 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1615 const char *fmt
, ...)
1622 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1623 buf_write(buf
, tmp
, len
);
1627 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1629 if (buf
->size
- buf
->pos
< len
) {
1630 buf
->size
+= len
+ SZ
;
1631 buf
->p
= realloc(buf
->p
, buf
->size
);
1633 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1637 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1639 const char *e
= is_vmlinux(m
) ?"":".ko";
1643 fatal("modpost: GPL-incompatible module %s%s "
1644 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1646 case export_unused_gpl
:
1647 fatal("modpost: GPL-incompatible module %s%s "
1648 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1650 case export_gpl_future
:
1651 warn("modpost: GPL-incompatible module %s%s "
1652 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1656 case export_unknown
:
1662 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1664 const char *e
= is_vmlinux(m
) ?"":".ko";
1668 case export_unused_gpl
:
1669 warn("modpost: module %s%s "
1670 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1678 static void check_exports(struct module
*mod
)
1680 struct symbol
*s
, *exp
;
1682 for (s
= mod
->unres
; s
; s
= s
->next
) {
1683 const char *basename
;
1684 exp
= find_symbol(s
->name
);
1685 if (!exp
|| exp
->module
== mod
)
1687 basename
= strrchr(mod
->name
, '/');
1691 basename
= mod
->name
;
1692 if (!mod
->gpl_compatible
)
1693 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1694 check_for_unused(exp
->export
, basename
, exp
->name
);
1699 * Header for the generated file
1701 static void add_header(struct buffer
*b
, struct module
*mod
)
1703 buf_printf(b
, "#include <linux/module.h>\n");
1704 buf_printf(b
, "#include <linux/vermagic.h>\n");
1705 buf_printf(b
, "#include <linux/compiler.h>\n");
1706 buf_printf(b
, "\n");
1707 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1708 buf_printf(b
, "\n");
1709 buf_printf(b
, "struct module __this_module\n");
1710 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1711 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1713 buf_printf(b
, " .init = init_module,\n");
1714 if (mod
->has_cleanup
)
1715 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1716 " .exit = cleanup_module,\n"
1718 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1719 buf_printf(b
, "};\n");
1722 static void add_staging_flag(struct buffer
*b
, const char *name
)
1724 static const char *staging_dir
= "drivers/staging";
1726 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1727 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1731 * Record CRCs for unresolved symbols
1733 static int add_versions(struct buffer
*b
, struct module
*mod
)
1735 struct symbol
*s
, *exp
;
1738 for (s
= mod
->unres
; s
; s
= s
->next
) {
1739 exp
= find_symbol(s
->name
);
1740 if (!exp
|| exp
->module
== mod
) {
1741 if (have_vmlinux
&& !s
->weak
) {
1742 if (warn_unresolved
) {
1743 warn("\"%s\" [%s.ko] undefined!\n",
1744 s
->name
, mod
->name
);
1746 merror("\"%s\" [%s.ko] undefined!\n",
1747 s
->name
, mod
->name
);
1753 s
->module
= exp
->module
;
1754 s
->crc_valid
= exp
->crc_valid
;
1761 buf_printf(b
, "\n");
1762 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1763 buf_printf(b
, "__used\n");
1764 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1766 for (s
= mod
->unres
; s
; s
= s
->next
) {
1769 if (!s
->crc_valid
) {
1770 warn("\"%s\" [%s.ko] has no CRC!\n",
1771 s
->name
, mod
->name
);
1774 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1777 buf_printf(b
, "};\n");
1782 static void add_depends(struct buffer
*b
, struct module
*mod
,
1783 struct module
*modules
)
1789 for (m
= modules
; m
; m
= m
->next
)
1790 m
->seen
= is_vmlinux(m
->name
);
1792 buf_printf(b
, "\n");
1793 buf_printf(b
, "static const char __module_depends[]\n");
1794 buf_printf(b
, "__used\n");
1795 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1796 buf_printf(b
, "\"depends=");
1797 for (s
= mod
->unres
; s
; s
= s
->next
) {
1802 if (s
->module
->seen
)
1805 s
->module
->seen
= 1;
1806 p
= strrchr(s
->module
->name
, '/');
1810 p
= s
->module
->name
;
1811 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1814 buf_printf(b
, "\";\n");
1817 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1819 if (mod
->srcversion
[0]) {
1820 buf_printf(b
, "\n");
1821 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1826 static void write_if_changed(struct buffer
*b
, const char *fname
)
1832 file
= fopen(fname
, "r");
1836 if (fstat(fileno(file
), &st
) < 0)
1839 if (st
.st_size
!= b
->pos
)
1842 tmp
= NOFAIL(malloc(b
->pos
));
1843 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1846 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1858 file
= fopen(fname
, "w");
1863 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1870 /* parse Module.symvers file. line format:
1871 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1873 static void read_dump(const char *fname
, unsigned int kernel
)
1875 unsigned long size
, pos
= 0;
1876 void *file
= grab_file(fname
, &size
);
1880 /* No symbol versions, silently ignore */
1883 while ((line
= get_next_line(&pos
, file
, size
))) {
1884 char *symname
, *modname
, *d
, *export
, *end
;
1889 if (!(symname
= strchr(line
, '\t')))
1892 if (!(modname
= strchr(symname
, '\t')))
1895 if ((export
= strchr(modname
, '\t')) != NULL
)
1897 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
1899 crc
= strtoul(line
, &d
, 16);
1900 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
1902 mod
= find_module(modname
);
1904 if (is_vmlinux(modname
))
1906 mod
= new_module(modname
);
1909 s
= sym_add_exported(symname
, mod
, export_no(export
));
1912 sym_update_crc(symname
, mod
, crc
, export_no(export
));
1916 fatal("parse error in symbol dump file\n");
1919 /* For normal builds always dump all symbols.
1920 * For external modules only dump symbols
1921 * that are not read from kernel Module.symvers.
1923 static int dump_sym(struct symbol
*sym
)
1925 if (!external_module
)
1927 if (sym
->vmlinux
|| sym
->kernel
)
1932 static void write_dump(const char *fname
)
1934 struct buffer buf
= { };
1935 struct symbol
*symbol
;
1938 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
1939 symbol
= symbolhash
[n
];
1941 if (dump_sym(symbol
))
1942 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
1943 symbol
->crc
, symbol
->name
,
1944 symbol
->module
->name
,
1945 export_str(symbol
->export
));
1946 symbol
= symbol
->next
;
1949 write_if_changed(&buf
, fname
);
1952 struct ext_sym_list
{
1953 struct ext_sym_list
*next
;
1957 int main(int argc
, char **argv
)
1960 struct buffer buf
= { };
1961 char *kernel_read
= NULL
, *module_read
= NULL
;
1962 char *dump_write
= NULL
;
1965 struct ext_sym_list
*extsym_iter
;
1966 struct ext_sym_list
*extsym_start
= NULL
;
1968 while ((opt
= getopt(argc
, argv
, "i:I:e:cmsSo:awM:K:")) != -1) {
1971 kernel_read
= optarg
;
1974 module_read
= optarg
;
1975 external_module
= 1;
1981 external_module
= 1;
1983 NOFAIL(malloc(sizeof(*extsym_iter
)));
1984 extsym_iter
->next
= extsym_start
;
1985 extsym_iter
->file
= optarg
;
1986 extsym_start
= extsym_iter
;
1992 dump_write
= optarg
;
1998 vmlinux_section_warnings
= 0;
2001 sec_mismatch_verbose
= 0;
2004 warn_unresolved
= 1;
2012 read_dump(kernel_read
, 1);
2014 read_dump(module_read
, 0);
2015 while (extsym_start
) {
2016 read_dump(extsym_start
->file
, 0);
2017 extsym_iter
= extsym_start
->next
;
2019 extsym_start
= extsym_iter
;
2022 while (optind
< argc
)
2023 read_symbols(argv
[optind
++]);
2025 for (mod
= modules
; mod
; mod
= mod
->next
) {
2033 for (mod
= modules
; mod
; mod
= mod
->next
) {
2034 char fname
[strlen(mod
->name
) + 10];
2041 add_header(&buf
, mod
);
2042 add_staging_flag(&buf
, mod
->name
);
2043 err
|= add_versions(&buf
, mod
);
2044 add_depends(&buf
, mod
, modules
);
2045 add_moddevtable(&buf
, mod
);
2046 add_srcversion(&buf
, mod
);
2048 sprintf(fname
, "%s.mod.c", mod
->name
);
2049 write_if_changed(&buf
, fname
);
2053 write_dump(dump_write
);
2054 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2055 warn("modpost: Found %d section mismatch(es).\n"
2056 "To see full details build your kernel with:\n"
2057 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2058 sec_mismatch_count
);