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 if (info
->hdr
->e_machine
== EM_PPC64
)
507 /* Special register function linked on all modules during final link of .ko */
508 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
509 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
511 /* Do not ignore this symbol */
515 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
516 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
518 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
519 Elf_Sym
*sym
, const char *symname
)
522 enum export export
= export_from_sec(info
, sym
->st_shndx
);
524 switch (sym
->st_shndx
) {
526 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
530 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
531 crc
= (unsigned int) sym
->st_value
;
532 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
537 /* undefined symbol */
538 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
539 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
541 if (ignore_undef_symbol(info
, symname
))
543 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
544 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
545 /* add compatibility with older glibc */
546 #ifndef STT_SPARC_REGISTER
547 #define STT_SPARC_REGISTER STT_REGISTER
549 if (info
->hdr
->e_machine
== EM_SPARC
||
550 info
->hdr
->e_machine
== EM_SPARCV9
) {
551 /* Ignore register directives. */
552 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
554 if (symname
[0] == '.') {
555 char *munged
= strdup(symname
);
557 munged
[1] = toupper(munged
[1]);
563 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
564 strlen(MODULE_SYMBOL_PREFIX
)) == 0) {
566 alloc_symbol(symname
+
567 strlen(MODULE_SYMBOL_PREFIX
),
568 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
573 /* All exported symbols */
574 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
575 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
578 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
580 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
581 mod
->has_cleanup
= 1;
587 * Parse tag=value strings from .modinfo section
589 static char *next_string(char *string
, unsigned long *secsize
)
591 /* Skip non-zero chars */
594 if ((*secsize
)-- <= 1)
598 /* Skip any zero padding. */
601 if ((*secsize
)-- <= 1)
607 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
608 const char *tag
, char *info
)
611 unsigned int taglen
= strlen(tag
);
612 unsigned long size
= modinfo_len
;
615 size
-= info
- (char *)modinfo
;
616 modinfo
= next_string(info
, &size
);
619 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
620 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
621 return p
+ taglen
+ 1;
626 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
630 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
634 * Test if string s ends in string sub
637 static int strrcmp(const char *s
, const char *sub
)
645 sublen
= strlen(sub
);
647 if ((slen
== 0) || (sublen
== 0))
653 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
656 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
659 return elf
->strtab
+ sym
->st_name
;
664 static const char *sec_name(struct elf_info
*elf
, int shndx
)
666 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
667 return (void *)elf
->hdr
+
668 elf
->sechdrs
[elf
->hdr
->e_shstrndx
].sh_offset
+
669 sechdrs
[shndx
].sh_name
;
672 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
674 return (void *)elf
->hdr
+
675 elf
->sechdrs
[elf
->hdr
->e_shstrndx
].sh_offset
+
679 /* if sym is empty or point to a string
680 * like ".[0-9]+" then return 1.
681 * This is the optional prefix added by ld to some sections
683 static int number_prefix(const char *sym
)
691 if (c
< '0' || c
> '9')
697 /* The pattern is an array of simple patterns.
698 * "foo" will match an exact string equal to "foo"
699 * "*foo" will match a string that ends with "foo"
700 * "foo*" will match a string that begins with "foo"
701 * "foo$" will match a string equal to "foo" or "foo.1"
702 * where the '1' can be any number including several digits.
703 * The $ syntax is for sections where ld append a dot number
704 * to make section name unique.
706 static int match(const char *sym
, const char * const pat
[])
711 const char *endp
= p
+ strlen(p
) - 1;
715 if (strrcmp(sym
, p
+ 1) == 0)
719 else if (*endp
== '*') {
720 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
724 else if (*endp
== '$') {
725 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
726 if (number_prefix(sym
+ strlen(p
) - 1))
732 if (strcmp(p
, sym
) == 0)
740 /* sections that we do not want to do full section mismatch check on */
741 static const char *section_white_list
[] =
745 ".mdebug*", /* alpha, score, mips etc. */
746 ".pdr", /* alpha, score, mips etc. */
755 * This is used to find sections missing the SHF_ALLOC flag.
756 * The cause of this is often a section specified in assembler
757 * without "ax" / "aw".
759 static void check_section(const char *modname
, struct elf_info
*elf
,
762 const char *sec
= sech_name(elf
, sechdr
);
764 if (sechdr
->sh_type
== SHT_PROGBITS
&&
765 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
766 !match(sec
, section_white_list
)) {
767 warn("%s (%s): unexpected non-allocatable section.\n"
768 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
769 "Note that for example <linux/init.h> contains\n"
770 "section definitions for use in .S files.\n\n",
777 #define ALL_INIT_DATA_SECTIONS \
778 ".init.setup$", ".init.rodata$", \
779 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
780 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
781 #define ALL_EXIT_DATA_SECTIONS \
782 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
784 #define ALL_INIT_TEXT_SECTIONS \
785 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
786 #define ALL_EXIT_TEXT_SECTIONS \
787 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
789 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
791 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
794 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
795 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
797 #define DATA_SECTIONS ".data$", ".data.rel$"
798 #define TEXT_SECTIONS ".text$"
800 #define INIT_SECTIONS ".init.*"
801 #define DEV_INIT_SECTIONS ".devinit.*"
802 #define CPU_INIT_SECTIONS ".cpuinit.*"
803 #define MEM_INIT_SECTIONS ".meminit.*"
805 #define EXIT_SECTIONS ".exit.*"
806 #define DEV_EXIT_SECTIONS ".devexit.*"
807 #define CPU_EXIT_SECTIONS ".cpuexit.*"
808 #define MEM_EXIT_SECTIONS ".memexit.*"
810 /* init data sections */
811 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
813 /* all init sections */
814 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
816 /* All init and exit sections (code + data) */
817 static const char *init_exit_sections
[] =
818 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
821 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
824 /* symbols in .data that may refer to init/exit sections */
825 #define DEFAULT_SYMBOL_WHITE_LIST \
827 "*_template", /* scsi uses *_template a lot */ \
828 "*_timer", /* arm uses ops structures named _timer a lot */ \
829 "*_sht", /* scsi also used *_sht to some extent */ \
835 static const char *head_sections
[] = { ".head.text*", NULL
};
836 static const char *linker_symbols
[] =
837 { "__init_begin", "_sinittext", "_einittext", NULL
};
844 XXXINIT_TO_SOME_INIT
,
845 XXXEXIT_TO_SOME_EXIT
,
846 ANY_INIT_TO_ANY_EXIT
,
847 ANY_EXIT_TO_ANY_INIT
,
851 struct sectioncheck
{
852 const char *fromsec
[20];
853 const char *tosec
[20];
854 enum mismatch mismatch
;
855 const char *symbol_white_list
[20];
858 const struct sectioncheck sectioncheck
[] = {
859 /* Do not reference init/exit code/data from
860 * normal code and data
863 .fromsec
= { TEXT_SECTIONS
, NULL
},
864 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
865 .mismatch
= TEXT_TO_ANY_INIT
,
866 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
869 .fromsec
= { DATA_SECTIONS
, NULL
},
870 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
871 .mismatch
= DATA_TO_ANY_INIT
,
872 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
875 .fromsec
= { DATA_SECTIONS
, NULL
},
876 .tosec
= { INIT_SECTIONS
, NULL
},
877 .mismatch
= DATA_TO_ANY_INIT
,
878 .symbol_white_list
= {
879 "*_template", "*_timer", "*_sht", "*_ops",
880 "*_probe", "*_probe_one", "*_console", NULL
884 .fromsec
= { TEXT_SECTIONS
, NULL
},
885 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
886 .mismatch
= TEXT_TO_ANY_EXIT
,
887 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
890 .fromsec
= { DATA_SECTIONS
, NULL
},
891 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
892 .mismatch
= DATA_TO_ANY_EXIT
,
893 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
895 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
897 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
898 .tosec
= { INIT_SECTIONS
, NULL
},
899 .mismatch
= XXXINIT_TO_SOME_INIT
,
900 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
902 /* Do not reference cpuinit code/data from meminit code/data */
904 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
905 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
906 .mismatch
= XXXINIT_TO_SOME_INIT
,
907 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
909 /* Do not reference meminit code/data from cpuinit code/data */
911 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
912 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
913 .mismatch
= XXXINIT_TO_SOME_INIT
,
914 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
916 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
918 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
919 .tosec
= { EXIT_SECTIONS
, NULL
},
920 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
921 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
923 /* Do not reference cpuexit code/data from memexit code/data */
925 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
926 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
927 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
928 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
930 /* Do not reference memexit code/data from cpuexit code/data */
932 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
933 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
934 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
935 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
937 /* Do not use exit code/data from init code */
939 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
940 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
941 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
942 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
944 /* Do not use init code/data from exit code */
946 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
947 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
948 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
949 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
951 /* Do not export init/exit functions or data */
953 .fromsec
= { "__ksymtab*", NULL
},
954 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
955 .mismatch
= EXPORT_TO_INIT_EXIT
,
956 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
960 static const struct sectioncheck
*section_mismatch(
961 const char *fromsec
, const char *tosec
)
964 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
965 const struct sectioncheck
*check
= §ioncheck
[0];
967 for (i
= 0; i
< elems
; i
++) {
968 if (match(fromsec
, check
->fromsec
) &&
969 match(tosec
, check
->tosec
))
977 * Whitelist to allow certain references to pass with no warning.
980 * If a module parameter is declared __initdata and permissions=0
981 * then this is legal despite the warning generated.
982 * We cannot see value of permissions here, so just ignore
984 * The pattern is identified by:
990 * Many drivers utilise a *driver container with references to
991 * add, remove, probe functions etc.
992 * These functions may often be marked __devinit and we do not want to
994 * the pattern is identified by:
995 * tosec = init or exit section
996 * fromsec = data section
997 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
998 * *probe_one, *_console, *_timer
1001 * Whitelist all references from .head.text to any init section
1004 * Some symbols belong to init section but still it is ok to reference
1005 * these from non-init sections as these symbols don't have any memory
1006 * allocated for them and symbol address and value are same. So even
1007 * if init section is freed, its ok to reference those symbols.
1008 * For ex. symbols marking the init section boundaries.
1009 * This pattern is identified by
1010 * refsymname = __init_begin, _sinittext, _einittext
1013 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1014 const char *fromsec
, const char *fromsym
,
1015 const char *tosec
, const char *tosym
)
1017 /* Check for pattern 1 */
1018 if (match(tosec
, init_data_sections
) &&
1019 match(fromsec
, data_sections
) &&
1020 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1023 /* Check for pattern 2 */
1024 if (match(tosec
, init_exit_sections
) &&
1025 match(fromsec
, data_sections
) &&
1026 match(fromsym
, mismatch
->symbol_white_list
))
1029 /* Check for pattern 3 */
1030 if (match(fromsec
, head_sections
) &&
1031 match(tosec
, init_sections
))
1034 /* Check for pattern 4 */
1035 if (match(tosym
, linker_symbols
))
1042 * Find symbol based on relocation record info.
1043 * In some cases the symbol supplied is a valid symbol so
1044 * return refsym. If st_name != 0 we assume this is a valid symbol.
1045 * In other cases the symbol needs to be looked up in the symbol table
1046 * based on section and address.
1048 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1052 Elf_Sym
*near
= NULL
;
1053 Elf64_Sword distance
= 20;
1056 if (relsym
->st_name
!= 0)
1058 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1059 if (sym
->st_shndx
!= relsym
->st_shndx
)
1061 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1063 if (sym
->st_value
== addr
)
1065 /* Find a symbol nearby - addr are maybe negative */
1066 d
= sym
->st_value
- addr
;
1068 d
= addr
- sym
->st_value
;
1074 /* We need a close match */
1081 static inline int is_arm_mapping_symbol(const char *str
)
1083 return str
[0] == '$' && strchr("atd", str
[1])
1084 && (str
[2] == '\0' || str
[2] == '.');
1088 * If there's no name there, ignore it; likewise, ignore it if it's
1089 * one of the magic symbols emitted used by current ARM tools.
1091 * Otherwise if find_symbols_between() returns those symbols, they'll
1092 * fail the whitelist tests and cause lots of false alarms ... fixable
1093 * only by merging __exit and __init sections into __text, bloating
1094 * the kernel (which is especially evil on embedded platforms).
1096 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1098 const char *name
= elf
->strtab
+ sym
->st_name
;
1100 if (!name
|| !strlen(name
))
1102 return !is_arm_mapping_symbol(name
);
1106 * Find symbols before or equal addr and after addr - in the section sec.
1107 * If we find two symbols with equal offset prefer one with a valid name.
1108 * The ELF format may have a better way to detect what type of symbol
1109 * it is, but this works for now.
1111 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1115 Elf_Sym
*near
= NULL
;
1116 Elf_Addr distance
= ~0;
1118 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1121 if (sym
->st_shndx
>= SHN_LORESERVE
)
1123 symsec
= sec_name(elf
, sym
->st_shndx
);
1124 if (strcmp(symsec
, sec
) != 0)
1126 if (!is_valid_name(elf
, sym
))
1128 if (sym
->st_value
<= addr
) {
1129 if ((addr
- sym
->st_value
) < distance
) {
1130 distance
= addr
- sym
->st_value
;
1132 } else if ((addr
- sym
->st_value
) == distance
) {
1141 * Convert a section name to the function/data attribute
1142 * .init.text => __init
1143 * .cpuinit.data => __cpudata
1144 * .memexitconst => __memconst
1147 static char *sec2annotation(const char *s
)
1149 if (match(s
, init_exit_sections
)) {
1150 char *p
= malloc(20);
1157 while (*s
&& *s
!= '.')
1162 if (strstr(s
, "rodata") != NULL
)
1163 strcat(p
, "const ");
1164 else if (strstr(s
, "data") != NULL
)
1168 return r
; /* we leak her but we do not care */
1174 static int is_function(Elf_Sym
*sym
)
1177 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1183 * Print a warning about a section mismatch.
1184 * Try to find symbols near it so user can find it.
1185 * Check whitelist before warning - it may be a false positive.
1187 static void report_sec_mismatch(const char *modname
,
1188 const struct sectioncheck
*mismatch
,
1189 const char *fromsec
,
1190 unsigned long long fromaddr
,
1191 const char *fromsym
,
1193 const char *tosec
, const char *tosym
,
1196 const char *from
, *from_p
;
1197 const char *to
, *to_p
;
1199 switch (from_is_func
) {
1200 case 0: from
= "variable"; from_p
= ""; break;
1201 case 1: from
= "function"; from_p
= "()"; break;
1202 default: from
= "(unknown reference)"; from_p
= ""; break;
1204 switch (to_is_func
) {
1205 case 0: to
= "variable"; to_p
= ""; break;
1206 case 1: to
= "function"; to_p
= "()"; break;
1207 default: to
= "(unknown reference)"; to_p
= ""; break;
1210 sec_mismatch_count
++;
1211 if (!sec_mismatch_verbose
)
1214 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1215 "to the %s %s:%s%s\n",
1216 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1219 switch (mismatch
->mismatch
) {
1220 case TEXT_TO_ANY_INIT
:
1222 "The function %s%s() references\n"
1224 "This is often because %s lacks a %s\n"
1225 "annotation or the annotation of %s is wrong.\n",
1226 sec2annotation(fromsec
), fromsym
,
1227 to
, sec2annotation(tosec
), tosym
, to_p
,
1228 fromsym
, sec2annotation(tosec
), tosym
);
1230 case DATA_TO_ANY_INIT
: {
1231 const char *const *s
= mismatch
->symbol_white_list
;
1233 "The variable %s references\n"
1235 "If the reference is valid then annotate the\n"
1236 "variable with __init* or __refdata (see linux/init.h) "
1237 "or name the variable:\n",
1238 fromsym
, to
, sec2annotation(tosec
), tosym
, to_p
);
1240 fprintf(stderr
, "%s, ", *s
++);
1241 fprintf(stderr
, "\n");
1244 case TEXT_TO_ANY_EXIT
:
1246 "The function %s() references a %s in an exit section.\n"
1247 "Often the %s %s%s has valid usage outside the exit section\n"
1248 "and the fix is to remove the %sannotation of %s.\n",
1249 fromsym
, to
, to
, tosym
, to_p
, sec2annotation(tosec
), tosym
);
1251 case DATA_TO_ANY_EXIT
: {
1252 const char *const *s
= mismatch
->symbol_white_list
;
1254 "The variable %s references\n"
1256 "If the reference is valid then annotate the\n"
1257 "variable with __exit* (see linux/init.h) or "
1258 "name the variable:\n",
1259 fromsym
, to
, sec2annotation(tosec
), tosym
, to_p
);
1261 fprintf(stderr
, "%s, ", *s
++);
1262 fprintf(stderr
, "\n");
1265 case XXXINIT_TO_SOME_INIT
:
1266 case XXXEXIT_TO_SOME_EXIT
:
1268 "The %s %s%s%s references\n"
1270 "If %s is only used by %s then\n"
1271 "annotate %s with a matching annotation.\n",
1272 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1273 to
, sec2annotation(tosec
), tosym
, to_p
,
1274 tosym
, fromsym
, tosym
);
1276 case ANY_INIT_TO_ANY_EXIT
:
1278 "The %s %s%s%s references\n"
1280 "This is often seen when error handling "
1281 "in the init function\n"
1282 "uses functionality in the exit path.\n"
1283 "The fix is often to remove the %sannotation of\n"
1284 "%s%s so it may be used outside an exit section.\n",
1285 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1286 to
, sec2annotation(tosec
), tosym
, to_p
,
1287 sec2annotation(tosec
), tosym
, to_p
);
1289 case ANY_EXIT_TO_ANY_INIT
:
1291 "The %s %s%s%s references\n"
1293 "This is often seen when error handling "
1294 "in the exit function\n"
1295 "uses functionality in the init path.\n"
1296 "The fix is often to remove the %sannotation of\n"
1297 "%s%s so it may be used outside an init section.\n",
1298 from
, sec2annotation(fromsec
), fromsym
, from_p
,
1299 to
, sec2annotation(tosec
), tosym
, to_p
,
1300 sec2annotation(tosec
), tosym
, to_p
);
1302 case EXPORT_TO_INIT_EXIT
:
1304 "The symbol %s is exported and annotated %s\n"
1305 "Fix this by removing the %sannotation of %s "
1306 "or drop the export.\n",
1307 tosym
, sec2annotation(tosec
), sec2annotation(tosec
), tosym
);
1310 fprintf(stderr
, "\n");
1313 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1314 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1317 const struct sectioncheck
*mismatch
;
1319 tosec
= sec_name(elf
, sym
->st_shndx
);
1320 mismatch
= section_mismatch(fromsec
, tosec
);
1325 const char *fromsym
;
1327 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1328 fromsym
= sym_name(elf
, from
);
1329 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1330 tosym
= sym_name(elf
, to
);
1332 /* check whitelist - we may ignore it */
1333 if (secref_whitelist(mismatch
,
1334 fromsec
, fromsym
, tosec
, tosym
)) {
1335 report_sec_mismatch(modname
, mismatch
,
1336 fromsec
, r
->r_offset
, fromsym
,
1337 is_function(from
), tosec
, tosym
,
1343 static unsigned int *reloc_location(struct elf_info
*elf
,
1344 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1346 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1347 int section
= sechdr
->sh_info
;
1349 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1350 r
->r_offset
- sechdrs
[section
].sh_addr
;
1353 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1355 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1356 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1360 r
->r_addend
= TO_NATIVE(*location
);
1363 r
->r_addend
= TO_NATIVE(*location
) + 4;
1364 /* For CONFIG_RELOCATABLE=y */
1365 if (elf
->hdr
->e_type
== ET_EXEC
)
1366 r
->r_addend
+= r
->r_offset
;
1372 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1374 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1378 /* From ARM ABI: (S + A) | T */
1379 r
->r_addend
= (int)(long)
1380 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1383 /* From ARM ABI: ((S + A) | T) - P */
1384 r
->r_addend
= (int)(long)(elf
->hdr
+
1386 (r
->r_offset
- sechdr
->sh_addr
));
1394 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1396 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1397 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1400 if (r_typ
== R_MIPS_HI16
)
1401 return 1; /* skip this */
1402 inst
= TO_NATIVE(*location
);
1405 r
->r_addend
= inst
& 0xffff;
1408 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1417 static void section_rela(const char *modname
, struct elf_info
*elf
,
1424 const char *fromsec
;
1426 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1427 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1429 fromsec
= sech_name(elf
, sechdr
);
1430 fromsec
+= strlen(".rela");
1431 /* if from section (name) is know good then skip it */
1432 if (match(fromsec
, section_white_list
))
1435 for (rela
= start
; rela
< stop
; rela
++) {
1436 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1437 #if KERNEL_ELFCLASS == ELFCLASS64
1438 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1440 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1441 r_sym
= TO_NATIVE(r_sym
);
1442 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1443 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1445 r
.r_info
= TO_NATIVE(rela
->r_info
);
1446 r_sym
= ELF_R_SYM(r
.r_info
);
1449 r
.r_info
= TO_NATIVE(rela
->r_info
);
1450 r_sym
= ELF_R_SYM(r
.r_info
);
1452 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1453 sym
= elf
->symtab_start
+ r_sym
;
1454 /* Skip special sections */
1455 if (sym
->st_shndx
>= SHN_LORESERVE
)
1457 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1461 static void section_rel(const char *modname
, struct elf_info
*elf
,
1468 const char *fromsec
;
1470 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1471 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1473 fromsec
= sech_name(elf
, sechdr
);
1474 fromsec
+= strlen(".rel");
1475 /* if from section (name) is know good then skip it */
1476 if (match(fromsec
, section_white_list
))
1479 for (rel
= start
; rel
< stop
; rel
++) {
1480 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1481 #if KERNEL_ELFCLASS == ELFCLASS64
1482 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1484 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1485 r_sym
= TO_NATIVE(r_sym
);
1486 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1487 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1489 r
.r_info
= TO_NATIVE(rel
->r_info
);
1490 r_sym
= ELF_R_SYM(r
.r_info
);
1493 r
.r_info
= TO_NATIVE(rel
->r_info
);
1494 r_sym
= ELF_R_SYM(r
.r_info
);
1497 switch (elf
->hdr
->e_machine
) {
1499 if (addend_386_rel(elf
, sechdr
, &r
))
1503 if (addend_arm_rel(elf
, sechdr
, &r
))
1507 if (addend_mips_rel(elf
, sechdr
, &r
))
1511 sym
= elf
->symtab_start
+ r_sym
;
1512 /* Skip special sections */
1513 if (sym
->st_shndx
>= SHN_LORESERVE
)
1515 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1520 * A module includes a number of sections that are discarded
1521 * either when loaded or when used as built-in.
1522 * For loaded modules all functions marked __init and all data
1523 * marked __initdata will be discarded when the module has been intialized.
1524 * Likewise for modules used built-in the sections marked __exit
1525 * are discarded because __exit marked function are supposed to be called
1526 * only when a module is unloaded which never happens for built-in modules.
1527 * The check_sec_ref() function traverses all relocation records
1528 * to find all references to a section that reference a section that will
1529 * be discarded and warns about it.
1531 static void check_sec_ref(struct module
*mod
, const char *modname
,
1532 struct elf_info
*elf
)
1535 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1537 /* Walk through all sections */
1538 for (i
= 0; i
< elf
->hdr
->e_shnum
; i
++) {
1539 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1540 /* We want to process only relocation sections and not .init */
1541 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1542 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1543 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1544 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1548 static void read_symbols(char *modname
)
1550 const char *symname
;
1554 struct elf_info info
= { };
1557 if (!parse_elf(&info
, modname
))
1560 mod
= new_module(modname
);
1562 /* When there's no vmlinux, don't print warnings about
1563 * unresolved symbols (since there'll be too many ;) */
1564 if (is_vmlinux(modname
)) {
1569 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1570 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1571 warn("modpost: missing MODULE_LICENSE() in %s\n"
1572 "see include/linux/module.h for "
1573 "more information\n", modname
);
1575 if (license_is_gpl_compatible(license
))
1576 mod
->gpl_compatible
= 1;
1578 mod
->gpl_compatible
= 0;
1581 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1582 "license", license
);
1585 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1586 symname
= info
.strtab
+ sym
->st_name
;
1588 handle_modversions(mod
, &info
, sym
, symname
);
1589 handle_moddevtable(mod
, &info
, sym
, symname
);
1591 if (!is_vmlinux(modname
) ||
1592 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1593 check_sec_ref(mod
, modname
, &info
);
1595 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1597 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1598 version
- (char *)info
.hdr
);
1599 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1600 get_src_version(modname
, mod
->srcversion
,
1601 sizeof(mod
->srcversion
)-1);
1603 parse_elf_finish(&info
);
1605 /* Our trick to get versioning for module struct etc. - it's
1606 * never passed as an argument to an exported function, so
1607 * the automatic versioning doesn't pick it up, but it's really
1608 * important anyhow */
1610 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1615 /* We first write the generated file into memory using the
1616 * following helper, then compare to the file on disk and
1617 * only update the later if anything changed */
1619 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1620 const char *fmt
, ...)
1627 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1628 buf_write(buf
, tmp
, len
);
1632 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1634 if (buf
->size
- buf
->pos
< len
) {
1635 buf
->size
+= len
+ SZ
;
1636 buf
->p
= realloc(buf
->p
, buf
->size
);
1638 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1642 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1644 const char *e
= is_vmlinux(m
) ?"":".ko";
1648 fatal("modpost: GPL-incompatible module %s%s "
1649 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1651 case export_unused_gpl
:
1652 fatal("modpost: GPL-incompatible module %s%s "
1653 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1655 case export_gpl_future
:
1656 warn("modpost: GPL-incompatible module %s%s "
1657 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1661 case export_unknown
:
1667 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1669 const char *e
= is_vmlinux(m
) ?"":".ko";
1673 case export_unused_gpl
:
1674 warn("modpost: module %s%s "
1675 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1683 static void check_exports(struct module
*mod
)
1685 struct symbol
*s
, *exp
;
1687 for (s
= mod
->unres
; s
; s
= s
->next
) {
1688 const char *basename
;
1689 exp
= find_symbol(s
->name
);
1690 if (!exp
|| exp
->module
== mod
)
1692 basename
= strrchr(mod
->name
, '/');
1696 basename
= mod
->name
;
1697 if (!mod
->gpl_compatible
)
1698 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1699 check_for_unused(exp
->export
, basename
, exp
->name
);
1704 * Header for the generated file
1706 static void add_header(struct buffer
*b
, struct module
*mod
)
1708 buf_printf(b
, "#include <linux/module.h>\n");
1709 buf_printf(b
, "#include <linux/vermagic.h>\n");
1710 buf_printf(b
, "#include <linux/compiler.h>\n");
1711 buf_printf(b
, "\n");
1712 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1713 buf_printf(b
, "\n");
1714 buf_printf(b
, "struct module __this_module\n");
1715 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1716 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1718 buf_printf(b
, " .init = init_module,\n");
1719 if (mod
->has_cleanup
)
1720 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1721 " .exit = cleanup_module,\n"
1723 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1724 buf_printf(b
, "};\n");
1727 static void add_staging_flag(struct buffer
*b
, const char *name
)
1729 static const char *staging_dir
= "drivers/staging";
1731 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1732 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1736 * Record CRCs for unresolved symbols
1738 static int add_versions(struct buffer
*b
, struct module
*mod
)
1740 struct symbol
*s
, *exp
;
1743 for (s
= mod
->unres
; s
; s
= s
->next
) {
1744 exp
= find_symbol(s
->name
);
1745 if (!exp
|| exp
->module
== mod
) {
1746 if (have_vmlinux
&& !s
->weak
) {
1747 if (warn_unresolved
) {
1748 warn("\"%s\" [%s.ko] undefined!\n",
1749 s
->name
, mod
->name
);
1751 merror("\"%s\" [%s.ko] undefined!\n",
1752 s
->name
, mod
->name
);
1758 s
->module
= exp
->module
;
1759 s
->crc_valid
= exp
->crc_valid
;
1766 buf_printf(b
, "\n");
1767 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1768 buf_printf(b
, "__used\n");
1769 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1771 for (s
= mod
->unres
; s
; s
= s
->next
) {
1774 if (!s
->crc_valid
) {
1775 warn("\"%s\" [%s.ko] has no CRC!\n",
1776 s
->name
, mod
->name
);
1779 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1782 buf_printf(b
, "};\n");
1787 static void add_depends(struct buffer
*b
, struct module
*mod
,
1788 struct module
*modules
)
1794 for (m
= modules
; m
; m
= m
->next
)
1795 m
->seen
= is_vmlinux(m
->name
);
1797 buf_printf(b
, "\n");
1798 buf_printf(b
, "static const char __module_depends[]\n");
1799 buf_printf(b
, "__used\n");
1800 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1801 buf_printf(b
, "\"depends=");
1802 for (s
= mod
->unres
; s
; s
= s
->next
) {
1807 if (s
->module
->seen
)
1810 s
->module
->seen
= 1;
1811 p
= strrchr(s
->module
->name
, '/');
1815 p
= s
->module
->name
;
1816 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1819 buf_printf(b
, "\";\n");
1822 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1824 if (mod
->srcversion
[0]) {
1825 buf_printf(b
, "\n");
1826 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1831 static void write_if_changed(struct buffer
*b
, const char *fname
)
1837 file
= fopen(fname
, "r");
1841 if (fstat(fileno(file
), &st
) < 0)
1844 if (st
.st_size
!= b
->pos
)
1847 tmp
= NOFAIL(malloc(b
->pos
));
1848 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1851 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1863 file
= fopen(fname
, "w");
1868 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1875 /* parse Module.symvers file. line format:
1876 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1878 static void read_dump(const char *fname
, unsigned int kernel
)
1880 unsigned long size
, pos
= 0;
1881 void *file
= grab_file(fname
, &size
);
1885 /* No symbol versions, silently ignore */
1888 while ((line
= get_next_line(&pos
, file
, size
))) {
1889 char *symname
, *modname
, *d
, *export
, *end
;
1894 if (!(symname
= strchr(line
, '\t')))
1897 if (!(modname
= strchr(symname
, '\t')))
1900 if ((export
= strchr(modname
, '\t')) != NULL
)
1902 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
1904 crc
= strtoul(line
, &d
, 16);
1905 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
1907 mod
= find_module(modname
);
1909 if (is_vmlinux(modname
))
1911 mod
= new_module(modname
);
1914 s
= sym_add_exported(symname
, mod
, export_no(export
));
1917 sym_update_crc(symname
, mod
, crc
, export_no(export
));
1921 fatal("parse error in symbol dump file\n");
1924 /* For normal builds always dump all symbols.
1925 * For external modules only dump symbols
1926 * that are not read from kernel Module.symvers.
1928 static int dump_sym(struct symbol
*sym
)
1930 if (!external_module
)
1932 if (sym
->vmlinux
|| sym
->kernel
)
1937 static void write_dump(const char *fname
)
1939 struct buffer buf
= { };
1940 struct symbol
*symbol
;
1943 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
1944 symbol
= symbolhash
[n
];
1946 if (dump_sym(symbol
))
1947 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
1948 symbol
->crc
, symbol
->name
,
1949 symbol
->module
->name
,
1950 export_str(symbol
->export
));
1951 symbol
= symbol
->next
;
1954 write_if_changed(&buf
, fname
);
1957 struct ext_sym_list
{
1958 struct ext_sym_list
*next
;
1962 int main(int argc
, char **argv
)
1965 struct buffer buf
= { };
1966 char *kernel_read
= NULL
, *module_read
= NULL
;
1967 char *dump_write
= NULL
;
1970 struct ext_sym_list
*extsym_iter
;
1971 struct ext_sym_list
*extsym_start
= NULL
;
1973 while ((opt
= getopt(argc
, argv
, "i:I:e:cmsSo:awM:K:")) != -1) {
1976 kernel_read
= optarg
;
1979 module_read
= optarg
;
1980 external_module
= 1;
1986 external_module
= 1;
1988 NOFAIL(malloc(sizeof(*extsym_iter
)));
1989 extsym_iter
->next
= extsym_start
;
1990 extsym_iter
->file
= optarg
;
1991 extsym_start
= extsym_iter
;
1997 dump_write
= optarg
;
2003 vmlinux_section_warnings
= 0;
2006 sec_mismatch_verbose
= 0;
2009 warn_unresolved
= 1;
2017 read_dump(kernel_read
, 1);
2019 read_dump(module_read
, 0);
2020 while (extsym_start
) {
2021 read_dump(extsym_start
->file
, 0);
2022 extsym_iter
= extsym_start
->next
;
2024 extsym_start
= extsym_iter
;
2027 while (optind
< argc
)
2028 read_symbols(argv
[optind
++]);
2030 for (mod
= modules
; mod
; mod
= mod
->next
) {
2038 for (mod
= modules
; mod
; mod
= mod
->next
) {
2039 char fname
[strlen(mod
->name
) + 10];
2046 add_header(&buf
, mod
);
2047 add_staging_flag(&buf
, mod
->name
);
2048 err
|= add_versions(&buf
, mod
);
2049 add_depends(&buf
, mod
, modules
);
2050 add_moddevtable(&buf
, mod
);
2051 add_srcversion(&buf
, mod
);
2053 sprintf(fname
, "%s.mod.c", mod
->name
);
2054 write_if_changed(&buf
, fname
);
2058 write_dump(dump_write
);
2059 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2060 warn("modpost: Found %d section mismatch(es).\n"
2061 "To see full details build your kernel with:\n"
2062 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2063 sec_mismatch_count
);