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 ...
22 #include "../../include/generated/autoconf.h"
23 #include "../../include/linux/license.h"
24 #include "../../include/linux/export.h"
26 /* Are we using CONFIG_MODVERSIONS? */
28 /* Warn about undefined symbols? (do so if we have vmlinux) */
30 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
31 static int all_versions
= 0;
32 /* If we are modposting external module set to 1 */
33 static int external_module
= 0;
34 /* Warn about section mismatch in vmlinux if set to 1 */
35 static int vmlinux_section_warnings
= 1;
36 /* Only warn about unresolved symbols */
37 static int warn_unresolved
= 0;
38 /* How a symbol is exported */
39 static int sec_mismatch_count
= 0;
40 static int sec_mismatch_verbose
= 1;
41 /* ignore missing files */
42 static int ignore_missing_files
;
45 export_plain
, export_unused
, export_gpl
,
46 export_unused_gpl
, export_gpl_future
, export_unknown
49 #define PRINTF __attribute__ ((format (printf, 1, 2)))
51 PRINTF
void fatal(const char *fmt
, ...)
55 fprintf(stderr
, "FATAL: ");
57 va_start(arglist
, fmt
);
58 vfprintf(stderr
, fmt
, arglist
);
64 PRINTF
void warn(const char *fmt
, ...)
68 fprintf(stderr
, "WARNING: ");
70 va_start(arglist
, fmt
);
71 vfprintf(stderr
, fmt
, arglist
);
75 PRINTF
void merror(const char *fmt
, ...)
79 fprintf(stderr
, "ERROR: ");
81 va_start(arglist
, fmt
);
82 vfprintf(stderr
, fmt
, arglist
);
86 static inline bool strends(const char *str
, const char *postfix
)
88 if (strlen(str
) < strlen(postfix
))
91 return strcmp(str
+ strlen(str
) - strlen(postfix
), postfix
) == 0;
94 static int is_vmlinux(const char *modname
)
98 myname
= strrchr(modname
, '/');
104 return (strcmp(myname
, "vmlinux") == 0) ||
105 (strcmp(myname
, "vmlinux.o") == 0);
108 void *do_nofail(void *ptr
, const char *expr
)
111 fatal("modpost: Memory allocation failure: %s.\n", expr
);
116 /* A list of all modules we processed */
117 static struct module
*modules
;
119 static struct module
*find_module(char *modname
)
123 for (mod
= modules
; mod
; mod
= mod
->next
)
124 if (strcmp(mod
->name
, modname
) == 0)
129 static struct module
*new_module(const char *modname
)
134 mod
= NOFAIL(malloc(sizeof(*mod
)));
135 memset(mod
, 0, sizeof(*mod
));
136 p
= NOFAIL(strdup(modname
));
138 /* strip trailing .o */
139 if (strends(p
, ".o")) {
140 p
[strlen(p
) - 2] = '\0';
146 mod
->gpl_compatible
= -1;
153 /* A hash of all exported symbols,
154 * struct symbol is also used for lists of unresolved symbols */
156 #define SYMBOL_HASH_SIZE 1024
160 struct module
*module
;
164 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
165 unsigned int kernel
:1; /* 1 if symbol is from kernel
166 * (only for external modules) **/
167 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers, or crc */
168 enum export export
; /* Type of export */
172 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
174 /* This is based on the hash agorithm from gdbm, via tdb */
175 static inline unsigned int tdb_hash(const char *name
)
177 unsigned value
; /* Used to compute the hash value. */
178 unsigned i
; /* Used to cycle through random values. */
180 /* Set the initial value from the key size. */
181 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
182 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
184 return (1103515243 * value
+ 12345);
188 * Allocate a new symbols for use in the hash of exported symbols or
189 * the list of unresolved symbols per module
191 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
194 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
196 memset(s
, 0, sizeof(*s
));
197 strcpy(s
->name
, name
);
203 /* For the hash of exported symbols */
204 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
210 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
211 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
212 new->module
= module
;
213 new->export
= export
;
217 static struct symbol
*find_symbol(const char *name
)
221 /* For our purposes, .foo matches foo. PPC64 needs this. */
225 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
226 if (strcmp(s
->name
, name
) == 0)
236 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
237 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
238 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
239 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
240 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
241 { .str
= "(unknown)", .export
= export_unknown
},
245 static const char *export_str(enum export ex
)
247 return export_list
[ex
].str
;
250 static enum export
export_no(const char *s
)
255 return export_unknown
;
256 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
257 if (strcmp(export_list
[i
].str
, s
) == 0)
258 return export_list
[i
].export
;
260 return export_unknown
;
263 static const char *sec_name(struct elf_info
*elf
, int secindex
);
265 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
267 static enum export
export_from_secname(struct elf_info
*elf
, unsigned int sec
)
269 const char *secname
= sec_name(elf
, sec
);
271 if (strstarts(secname
, "___ksymtab+"))
273 else if (strstarts(secname
, "___ksymtab_unused+"))
274 return export_unused
;
275 else if (strstarts(secname
, "___ksymtab_gpl+"))
277 else if (strstarts(secname
, "___ksymtab_unused_gpl+"))
278 return export_unused_gpl
;
279 else if (strstarts(secname
, "___ksymtab_gpl_future+"))
280 return export_gpl_future
;
282 return export_unknown
;
285 static enum export
export_from_sec(struct elf_info
*elf
, unsigned int sec
)
287 if (sec
== elf
->export_sec
)
289 else if (sec
== elf
->export_unused_sec
)
290 return export_unused
;
291 else if (sec
== elf
->export_gpl_sec
)
293 else if (sec
== elf
->export_unused_gpl_sec
)
294 return export_unused_gpl
;
295 else if (sec
== elf
->export_gpl_future_sec
)
296 return export_gpl_future
;
298 return export_unknown
;
302 * Add an exported symbol - it may have already been added without a
303 * CRC, in this case just update the CRC
305 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
308 struct symbol
*s
= find_symbol(name
);
311 s
= new_symbol(name
, mod
, export
);
314 warn("%s: '%s' exported twice. Previous export "
315 "was in %s%s\n", mod
->name
, name
,
317 is_vmlinux(s
->module
->name
) ?"":".ko");
319 /* In case Modules.symvers was out of date */
324 s
->vmlinux
= is_vmlinux(mod
->name
);
330 static void sym_update_crc(const char *name
, struct module
*mod
,
331 unsigned int crc
, enum export export
)
333 struct symbol
*s
= find_symbol(name
);
336 s
= new_symbol(name
, mod
, export
);
337 /* Don't complain when we find it later. */
344 void *grab_file(const char *filename
, unsigned long *size
)
347 void *map
= MAP_FAILED
;
350 fd
= open(filename
, O_RDONLY
);
357 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
361 if (map
== MAP_FAILED
)
367 * Return a copy of the next line in a mmap'ed file.
368 * spaces in the beginning of the line is trimmed away.
369 * Return a pointer to a static buffer.
371 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
373 static char line
[4096];
376 signed char *p
= (signed char *)file
+ *pos
;
379 for (; *pos
< size
; (*pos
)++) {
380 if (skip
&& isspace(*p
)) {
385 if (*p
!= '\n' && (*pos
< size
)) {
389 break; /* Too long, stop */
400 void release_file(void *file
, unsigned long size
)
405 static int parse_elf(struct elf_info
*info
, const char *filename
)
411 const char *secstrings
;
412 unsigned int symtab_idx
= ~0U, symtab_shndx_idx
= ~0U;
414 hdr
= grab_file(filename
, &info
->size
);
416 if (ignore_missing_files
) {
417 fprintf(stderr
, "%s: %s (ignored)\n", filename
,
425 if (info
->size
< sizeof(*hdr
)) {
426 /* file too small, assume this is an empty .o file */
429 /* Is this a valid ELF file? */
430 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
431 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
432 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
433 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
434 /* Not an ELF file - silently ignore it */
437 /* Fix endianness in ELF header */
438 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
439 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
440 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
441 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
442 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
443 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
444 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
445 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
446 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
447 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
448 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
449 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
450 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
451 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
452 info
->sechdrs
= sechdrs
;
454 /* Check if file offset is correct */
455 if (hdr
->e_shoff
> info
->size
) {
456 fatal("section header offset=%lu in file '%s' is bigger than "
457 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
458 filename
, info
->size
);
462 if (hdr
->e_shnum
== SHN_UNDEF
) {
464 * There are more than 64k sections,
465 * read count from .sh_size.
467 info
->num_sections
= TO_NATIVE(sechdrs
[0].sh_size
);
470 info
->num_sections
= hdr
->e_shnum
;
472 if (hdr
->e_shstrndx
== SHN_XINDEX
) {
473 info
->secindex_strings
= TO_NATIVE(sechdrs
[0].sh_link
);
476 info
->secindex_strings
= hdr
->e_shstrndx
;
479 /* Fix endianness in section headers */
480 for (i
= 0; i
< info
->num_sections
; i
++) {
481 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
482 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
483 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
484 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
485 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
486 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
487 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
488 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
489 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
490 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
492 /* Find symbol table. */
493 secstrings
= (void *)hdr
+ sechdrs
[info
->secindex_strings
].sh_offset
;
494 for (i
= 1; i
< info
->num_sections
; i
++) {
496 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
498 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
499 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
500 "sizeof(*hrd)=%zu\n", filename
,
501 (unsigned long)sechdrs
[i
].sh_offset
,
505 secname
= secstrings
+ sechdrs
[i
].sh_name
;
506 if (strcmp(secname
, ".modinfo") == 0) {
508 fatal("%s has NOBITS .modinfo\n", filename
);
509 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
510 info
->modinfo_len
= sechdrs
[i
].sh_size
;
511 } else if (strcmp(secname
, "__ksymtab") == 0)
512 info
->export_sec
= i
;
513 else if (strcmp(secname
, "__ksymtab_unused") == 0)
514 info
->export_unused_sec
= i
;
515 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
516 info
->export_gpl_sec
= i
;
517 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
518 info
->export_unused_gpl_sec
= i
;
519 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
520 info
->export_gpl_future_sec
= i
;
522 if (sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
523 unsigned int sh_link_idx
;
525 info
->symtab_start
= (void *)hdr
+
526 sechdrs
[i
].sh_offset
;
527 info
->symtab_stop
= (void *)hdr
+
528 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
529 sh_link_idx
= sechdrs
[i
].sh_link
;
530 info
->strtab
= (void *)hdr
+
531 sechdrs
[sh_link_idx
].sh_offset
;
534 /* 32bit section no. table? ("more than 64k sections") */
535 if (sechdrs
[i
].sh_type
== SHT_SYMTAB_SHNDX
) {
536 symtab_shndx_idx
= i
;
537 info
->symtab_shndx_start
= (void *)hdr
+
538 sechdrs
[i
].sh_offset
;
539 info
->symtab_shndx_stop
= (void *)hdr
+
540 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
543 if (!info
->symtab_start
)
544 fatal("%s has no symtab?\n", filename
);
546 /* Fix endianness in symbols */
547 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
548 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
549 sym
->st_name
= TO_NATIVE(sym
->st_name
);
550 sym
->st_value
= TO_NATIVE(sym
->st_value
);
551 sym
->st_size
= TO_NATIVE(sym
->st_size
);
554 if (symtab_shndx_idx
!= ~0U) {
556 if (symtab_idx
!= sechdrs
[symtab_shndx_idx
].sh_link
)
557 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
558 filename
, sechdrs
[symtab_shndx_idx
].sh_link
,
561 for (p
= info
->symtab_shndx_start
; p
< info
->symtab_shndx_stop
;
569 static void parse_elf_finish(struct elf_info
*info
)
571 release_file(info
->hdr
, info
->size
);
574 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
576 /* ignore __this_module, it will be resolved shortly */
577 if (strcmp(symname
, VMLINUX_SYMBOL_STR(__this_module
)) == 0)
579 /* ignore global offset table */
580 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
582 if (info
->hdr
->e_machine
== EM_PPC
)
583 /* Special register function linked on all modules during final link of .ko */
584 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
585 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
586 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
587 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
589 if (info
->hdr
->e_machine
== EM_PPC64
)
590 /* Special register function linked on all modules during final link of .ko */
591 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
592 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
594 /* Do not ignore this symbol */
598 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
599 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
601 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
602 Elf_Sym
*sym
, const char *symname
)
607 if ((!is_vmlinux(mod
->name
) || mod
->is_dot_o
) &&
608 strncmp(symname
, "__ksymtab", 9) == 0)
609 export
= export_from_secname(info
, get_secindex(info
, sym
));
611 export
= export_from_sec(info
, get_secindex(info
, sym
));
614 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
615 crc
= (unsigned int) sym
->st_value
;
616 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
620 switch (sym
->st_shndx
) {
622 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
625 /* undefined symbol */
626 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
627 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
629 if (ignore_undef_symbol(info
, symname
))
631 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
632 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
633 /* add compatibility with older glibc */
634 #ifndef STT_SPARC_REGISTER
635 #define STT_SPARC_REGISTER STT_REGISTER
637 if (info
->hdr
->e_machine
== EM_SPARC
||
638 info
->hdr
->e_machine
== EM_SPARCV9
) {
639 /* Ignore register directives. */
640 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
642 if (symname
[0] == '.') {
643 char *munged
= strdup(symname
);
645 munged
[1] = toupper(munged
[1]);
651 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
652 if (symname
[0] != '_')
657 mod
->unres
= alloc_symbol(symname
,
658 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
662 /* All exported symbols */
663 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
664 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
667 if (strcmp(symname
, VMLINUX_SYMBOL_STR(init_module
)) == 0)
669 if (strcmp(symname
, VMLINUX_SYMBOL_STR(cleanup_module
)) == 0)
670 mod
->has_cleanup
= 1;
676 * Parse tag=value strings from .modinfo section
678 static char *next_string(char *string
, unsigned long *secsize
)
680 /* Skip non-zero chars */
683 if ((*secsize
)-- <= 1)
687 /* Skip any zero padding. */
690 if ((*secsize
)-- <= 1)
696 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
697 const char *tag
, char *info
)
700 unsigned int taglen
= strlen(tag
);
701 unsigned long size
= modinfo_len
;
704 size
-= info
- (char *)modinfo
;
705 modinfo
= next_string(info
, &size
);
708 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
709 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
710 return p
+ taglen
+ 1;
715 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
719 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
723 * Test if string s ends in string sub
726 static int strrcmp(const char *s
, const char *sub
)
734 sublen
= strlen(sub
);
736 if ((slen
== 0) || (sublen
== 0))
742 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
745 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
748 return elf
->strtab
+ sym
->st_name
;
753 static const char *sec_name(struct elf_info
*elf
, int secindex
)
755 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
756 return (void *)elf
->hdr
+
757 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
758 sechdrs
[secindex
].sh_name
;
761 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
763 return (void *)elf
->hdr
+
764 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
768 /* if sym is empty or point to a string
769 * like ".[0-9]+" then return 1.
770 * This is the optional prefix added by ld to some sections
772 static int number_prefix(const char *sym
)
780 if (c
< '0' || c
> '9')
786 /* The pattern is an array of simple patterns.
787 * "foo" will match an exact string equal to "foo"
788 * "*foo" will match a string that ends with "foo"
789 * "foo*" will match a string that begins with "foo"
790 * "foo$" will match a string equal to "foo" or "foo.1"
791 * where the '1' can be any number including several digits.
792 * The $ syntax is for sections where ld append a dot number
793 * to make section name unique.
795 static int match(const char *sym
, const char * const pat
[])
800 const char *endp
= p
+ strlen(p
) - 1;
804 if (strrcmp(sym
, p
+ 1) == 0)
808 else if (*endp
== '*') {
809 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
813 else if (*endp
== '$') {
814 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
815 if (number_prefix(sym
+ strlen(p
) - 1))
821 if (strcmp(p
, sym
) == 0)
829 /* sections that we do not want to do full section mismatch check on */
830 static const char *section_white_list
[] =
834 ".cranges", /* sh64 */
835 ".zdebug*", /* Compressed debug sections. */
836 ".GCC-command-line", /* mn10300 */
837 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
838 ".mdebug*", /* alpha, score, mips etc. */
839 ".pdr", /* alpha, score, mips etc. */
844 ".xt.prop", /* xtensa */
845 ".xt.lit", /* xtensa */
846 ".arcextmap*", /* arc */
847 ".gnu.linkonce.arcext*", /* arc : modules */
852 * This is used to find sections missing the SHF_ALLOC flag.
853 * The cause of this is often a section specified in assembler
854 * without "ax" / "aw".
856 static void check_section(const char *modname
, struct elf_info
*elf
,
859 const char *sec
= sech_name(elf
, sechdr
);
861 if (sechdr
->sh_type
== SHT_PROGBITS
&&
862 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
863 !match(sec
, section_white_list
)) {
864 warn("%s (%s): unexpected non-allocatable section.\n"
865 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
866 "Note that for example <linux/init.h> contains\n"
867 "section definitions for use in .S files.\n\n",
874 #define ALL_INIT_DATA_SECTIONS \
875 ".init.setup$", ".init.rodata$", ".meminit.rodata$", \
876 ".init.data$", ".meminit.data$"
877 #define ALL_EXIT_DATA_SECTIONS \
878 ".exit.data$", ".memexit.data$"
880 #define ALL_INIT_TEXT_SECTIONS \
881 ".init.text$", ".meminit.text$"
882 #define ALL_EXIT_TEXT_SECTIONS \
883 ".exit.text$", ".memexit.text$"
885 #define ALL_PCI_INIT_SECTIONS \
886 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
887 ".pci_fixup_enable$", ".pci_fixup_resume$", \
888 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
890 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
891 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
893 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
894 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
896 #define DATA_SECTIONS ".data$", ".data.rel$"
897 #define TEXT_SECTIONS ".text$", ".text.unlikely$"
899 #define INIT_SECTIONS ".init.*"
900 #define MEM_INIT_SECTIONS ".meminit.*"
902 #define EXIT_SECTIONS ".exit.*"
903 #define MEM_EXIT_SECTIONS ".memexit.*"
905 /* init data sections */
906 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
908 /* all init sections */
909 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
911 /* All init and exit sections (code + data) */
912 static const char *init_exit_sections
[] =
913 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
916 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
919 /* symbols in .data that may refer to init/exit sections */
920 #define DEFAULT_SYMBOL_WHITE_LIST \
922 "*_template", /* scsi uses *_template a lot */ \
923 "*_timer", /* arm uses ops structures named _timer a lot */ \
924 "*_sht", /* scsi also used *_sht to some extent */ \
930 static const char *head_sections
[] = { ".head.text*", NULL
};
931 static const char *linker_symbols
[] =
932 { "__init_begin", "_sinittext", "_einittext", NULL
};
939 XXXINIT_TO_SOME_INIT
,
940 XXXEXIT_TO_SOME_EXIT
,
941 ANY_INIT_TO_ANY_EXIT
,
942 ANY_EXIT_TO_ANY_INIT
,
946 struct sectioncheck
{
947 const char *fromsec
[20];
948 const char *tosec
[20];
949 enum mismatch mismatch
;
950 const char *symbol_white_list
[20];
953 const struct sectioncheck sectioncheck
[] = {
954 /* Do not reference init/exit code/data from
955 * normal code and data
958 .fromsec
= { TEXT_SECTIONS
, NULL
},
959 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
960 .mismatch
= TEXT_TO_ANY_INIT
,
961 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
964 .fromsec
= { DATA_SECTIONS
, NULL
},
965 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
966 .mismatch
= DATA_TO_ANY_INIT
,
967 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
970 .fromsec
= { DATA_SECTIONS
, NULL
},
971 .tosec
= { INIT_SECTIONS
, NULL
},
972 .mismatch
= DATA_TO_ANY_INIT
,
973 .symbol_white_list
= {
974 "*_template", "*_timer", "*_sht", "*_ops",
975 "*_probe", "*_probe_one", "*_console", NULL
979 .fromsec
= { TEXT_SECTIONS
, NULL
},
980 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
981 .mismatch
= TEXT_TO_ANY_EXIT
,
982 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
985 .fromsec
= { DATA_SECTIONS
, NULL
},
986 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
987 .mismatch
= DATA_TO_ANY_EXIT
,
988 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
990 /* Do not reference init code/data from meminit code/data */
992 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
993 .tosec
= { INIT_SECTIONS
, NULL
},
994 .mismatch
= XXXINIT_TO_SOME_INIT
,
995 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
997 /* Do not reference exit code/data from memexit code/data */
999 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
1000 .tosec
= { EXIT_SECTIONS
, NULL
},
1001 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1002 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1004 /* Do not use exit code/data from init code */
1006 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
1007 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
1008 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1009 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1011 /* Do not use init code/data from exit code */
1013 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
1014 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
1015 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
1016 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1019 .fromsec
= { ALL_PCI_INIT_SECTIONS
, NULL
},
1020 .tosec
= { INIT_SECTIONS
, NULL
},
1021 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1022 .symbol_white_list
= { NULL
},
1024 /* Do not export init/exit functions or data */
1026 .fromsec
= { "__ksymtab*", NULL
},
1027 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1028 .mismatch
= EXPORT_TO_INIT_EXIT
,
1029 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1033 static const struct sectioncheck
*section_mismatch(
1034 const char *fromsec
, const char *tosec
)
1037 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1038 const struct sectioncheck
*check
= §ioncheck
[0];
1040 for (i
= 0; i
< elems
; i
++) {
1041 if (match(fromsec
, check
->fromsec
) &&
1042 match(tosec
, check
->tosec
))
1050 * Whitelist to allow certain references to pass with no warning.
1053 * If a module parameter is declared __initdata and permissions=0
1054 * then this is legal despite the warning generated.
1055 * We cannot see value of permissions here, so just ignore
1057 * The pattern is identified by:
1058 * tosec = .init.data
1063 * module_param_call() ops can refer to __init set function if permissions=0
1064 * The pattern is identified by:
1065 * tosec = .init.text
1067 * atsym = __param_ops_*
1070 * Many drivers utilise a *driver container with references to
1071 * add, remove, probe functions etc.
1072 * the pattern is identified by:
1073 * tosec = init or exit section
1074 * fromsec = data section
1075 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1076 * *probe_one, *_console, *_timer
1079 * Whitelist all references from .head.text to any init section
1082 * Some symbols belong to init section but still it is ok to reference
1083 * these from non-init sections as these symbols don't have any memory
1084 * allocated for them and symbol address and value are same. So even
1085 * if init section is freed, its ok to reference those symbols.
1086 * For ex. symbols marking the init section boundaries.
1087 * This pattern is identified by
1088 * refsymname = __init_begin, _sinittext, _einittext
1091 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1092 const char *fromsec
, const char *fromsym
,
1093 const char *tosec
, const char *tosym
)
1095 /* Check for pattern 1 */
1096 if (match(tosec
, init_data_sections
) &&
1097 match(fromsec
, data_sections
) &&
1098 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1101 /* Check for pattern 1a */
1102 if (strcmp(tosec
, ".init.text") == 0 &&
1103 match(fromsec
, data_sections
) &&
1104 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1107 /* Check for pattern 2 */
1108 if (match(tosec
, init_exit_sections
) &&
1109 match(fromsec
, data_sections
) &&
1110 match(fromsym
, mismatch
->symbol_white_list
))
1113 /* Check for pattern 3 */
1114 if (match(fromsec
, head_sections
) &&
1115 match(tosec
, init_sections
))
1118 /* Check for pattern 4 */
1119 if (match(tosym
, linker_symbols
))
1126 * Find symbol based on relocation record info.
1127 * In some cases the symbol supplied is a valid symbol so
1128 * return refsym. If st_name != 0 we assume this is a valid symbol.
1129 * In other cases the symbol needs to be looked up in the symbol table
1130 * based on section and address.
1132 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1136 Elf_Sym
*near
= NULL
;
1137 Elf64_Sword distance
= 20;
1139 unsigned int relsym_secindex
;
1141 if (relsym
->st_name
!= 0)
1144 relsym_secindex
= get_secindex(elf
, relsym
);
1145 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1146 if (get_secindex(elf
, sym
) != relsym_secindex
)
1148 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1150 if (sym
->st_value
== addr
)
1152 /* Find a symbol nearby - addr are maybe negative */
1153 d
= sym
->st_value
- addr
;
1155 d
= addr
- sym
->st_value
;
1161 /* We need a close match */
1168 static inline int is_arm_mapping_symbol(const char *str
)
1170 return str
[0] == '$' && strchr("atd", str
[1])
1171 && (str
[2] == '\0' || str
[2] == '.');
1175 * If there's no name there, ignore it; likewise, ignore it if it's
1176 * one of the magic symbols emitted used by current ARM tools.
1178 * Otherwise if find_symbols_between() returns those symbols, they'll
1179 * fail the whitelist tests and cause lots of false alarms ... fixable
1180 * only by merging __exit and __init sections into __text, bloating
1181 * the kernel (which is especially evil on embedded platforms).
1183 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1185 const char *name
= elf
->strtab
+ sym
->st_name
;
1187 if (!name
|| !strlen(name
))
1189 return !is_arm_mapping_symbol(name
);
1193 * Find symbols before or equal addr and after addr - in the section sec.
1194 * If we find two symbols with equal offset prefer one with a valid name.
1195 * The ELF format may have a better way to detect what type of symbol
1196 * it is, but this works for now.
1198 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1202 Elf_Sym
*near
= NULL
;
1203 Elf_Addr distance
= ~0;
1205 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1208 if (is_shndx_special(sym
->st_shndx
))
1210 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1211 if (strcmp(symsec
, sec
) != 0)
1213 if (!is_valid_name(elf
, sym
))
1215 if (sym
->st_value
<= addr
) {
1216 if ((addr
- sym
->st_value
) < distance
) {
1217 distance
= addr
- sym
->st_value
;
1219 } else if ((addr
- sym
->st_value
) == distance
) {
1228 * Convert a section name to the function/data attribute
1229 * .init.text => __init
1230 * .memexitconst => __memconst
1233 * The memory of returned value has been allocated on a heap. The user of this
1234 * method should free it after usage.
1236 static char *sec2annotation(const char *s
)
1238 if (match(s
, init_exit_sections
)) {
1239 char *p
= malloc(20);
1246 while (*s
&& *s
!= '.')
1251 if (strstr(s
, "rodata") != NULL
)
1252 strcat(p
, "const ");
1253 else if (strstr(s
, "data") != NULL
)
1263 static int is_function(Elf_Sym
*sym
)
1266 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1271 static void print_section_list(const char * const list
[20])
1273 const char *const *s
= list
;
1276 fprintf(stderr
, "%s", *s
);
1279 fprintf(stderr
, ", ");
1281 fprintf(stderr
, "\n");
1285 * Print a warning about a section mismatch.
1286 * Try to find symbols near it so user can find it.
1287 * Check whitelist before warning - it may be a false positive.
1289 static void report_sec_mismatch(const char *modname
,
1290 const struct sectioncheck
*mismatch
,
1291 const char *fromsec
,
1292 unsigned long long fromaddr
,
1293 const char *fromsym
,
1295 const char *tosec
, const char *tosym
,
1298 const char *from
, *from_p
;
1299 const char *to
, *to_p
;
1303 switch (from_is_func
) {
1304 case 0: from
= "variable"; from_p
= ""; break;
1305 case 1: from
= "function"; from_p
= "()"; break;
1306 default: from
= "(unknown reference)"; from_p
= ""; break;
1308 switch (to_is_func
) {
1309 case 0: to
= "variable"; to_p
= ""; break;
1310 case 1: to
= "function"; to_p
= "()"; break;
1311 default: to
= "(unknown reference)"; to_p
= ""; break;
1314 sec_mismatch_count
++;
1315 if (!sec_mismatch_verbose
)
1318 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1319 "to the %s %s:%s%s\n",
1320 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1323 switch (mismatch
->mismatch
) {
1324 case TEXT_TO_ANY_INIT
:
1325 prl_from
= sec2annotation(fromsec
);
1326 prl_to
= sec2annotation(tosec
);
1328 "The function %s%s() references\n"
1330 "This is often because %s lacks a %s\n"
1331 "annotation or the annotation of %s is wrong.\n",
1333 to
, prl_to
, tosym
, to_p
,
1334 fromsym
, prl_to
, tosym
);
1338 case DATA_TO_ANY_INIT
: {
1339 prl_to
= sec2annotation(tosec
);
1341 "The variable %s references\n"
1343 "If the reference is valid then annotate the\n"
1344 "variable with __init* or __refdata (see linux/init.h) "
1345 "or name the variable:\n",
1346 fromsym
, to
, prl_to
, tosym
, to_p
);
1347 print_section_list(mismatch
->symbol_white_list
);
1351 case TEXT_TO_ANY_EXIT
:
1352 prl_to
= sec2annotation(tosec
);
1354 "The function %s() references a %s in an exit section.\n"
1355 "Often the %s %s%s has valid usage outside the exit section\n"
1356 "and the fix is to remove the %sannotation of %s.\n",
1357 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1360 case DATA_TO_ANY_EXIT
: {
1361 prl_to
= sec2annotation(tosec
);
1363 "The variable %s references\n"
1365 "If the reference is valid then annotate the\n"
1366 "variable with __exit* (see linux/init.h) or "
1367 "name the variable:\n",
1368 fromsym
, to
, prl_to
, tosym
, to_p
);
1369 print_section_list(mismatch
->symbol_white_list
);
1373 case XXXINIT_TO_SOME_INIT
:
1374 case XXXEXIT_TO_SOME_EXIT
:
1375 prl_from
= sec2annotation(fromsec
);
1376 prl_to
= sec2annotation(tosec
);
1378 "The %s %s%s%s references\n"
1380 "If %s is only used by %s then\n"
1381 "annotate %s with a matching annotation.\n",
1382 from
, prl_from
, fromsym
, from_p
,
1383 to
, prl_to
, tosym
, to_p
,
1384 tosym
, fromsym
, tosym
);
1388 case ANY_INIT_TO_ANY_EXIT
:
1389 prl_from
= sec2annotation(fromsec
);
1390 prl_to
= sec2annotation(tosec
);
1392 "The %s %s%s%s references\n"
1394 "This is often seen when error handling "
1395 "in the init function\n"
1396 "uses functionality in the exit path.\n"
1397 "The fix is often to remove the %sannotation of\n"
1398 "%s%s so it may be used outside an exit section.\n",
1399 from
, prl_from
, fromsym
, from_p
,
1400 to
, prl_to
, tosym
, to_p
,
1401 prl_to
, tosym
, to_p
);
1405 case ANY_EXIT_TO_ANY_INIT
:
1406 prl_from
= sec2annotation(fromsec
);
1407 prl_to
= sec2annotation(tosec
);
1409 "The %s %s%s%s references\n"
1411 "This is often seen when error handling "
1412 "in the exit function\n"
1413 "uses functionality in the init path.\n"
1414 "The fix is often to remove the %sannotation of\n"
1415 "%s%s so it may be used outside an init section.\n",
1416 from
, prl_from
, fromsym
, from_p
,
1417 to
, prl_to
, tosym
, to_p
,
1418 prl_to
, tosym
, to_p
);
1422 case EXPORT_TO_INIT_EXIT
:
1423 prl_to
= sec2annotation(tosec
);
1425 "The symbol %s is exported and annotated %s\n"
1426 "Fix this by removing the %sannotation of %s "
1427 "or drop the export.\n",
1428 tosym
, prl_to
, prl_to
, tosym
);
1432 fprintf(stderr
, "\n");
1435 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1436 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1439 const struct sectioncheck
*mismatch
;
1441 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1442 mismatch
= section_mismatch(fromsec
, tosec
);
1447 const char *fromsym
;
1449 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1450 fromsym
= sym_name(elf
, from
);
1451 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1452 tosym
= sym_name(elf
, to
);
1454 /* check whitelist - we may ignore it */
1455 if (secref_whitelist(mismatch
,
1456 fromsec
, fromsym
, tosec
, tosym
)) {
1457 report_sec_mismatch(modname
, mismatch
,
1458 fromsec
, r
->r_offset
, fromsym
,
1459 is_function(from
), tosec
, tosym
,
1465 static unsigned int *reloc_location(struct elf_info
*elf
,
1466 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1468 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1469 int section
= sechdr
->sh_info
;
1471 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1475 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1477 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1478 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1482 r
->r_addend
= TO_NATIVE(*location
);
1485 r
->r_addend
= TO_NATIVE(*location
) + 4;
1486 /* For CONFIG_RELOCATABLE=y */
1487 if (elf
->hdr
->e_type
== ET_EXEC
)
1488 r
->r_addend
+= r
->r_offset
;
1495 #define R_ARM_CALL 28
1497 #ifndef R_ARM_JUMP24
1498 #define R_ARM_JUMP24 29
1501 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1503 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1507 /* From ARM ABI: (S + A) | T */
1508 r
->r_addend
= (int)(long)
1509 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1514 /* From ARM ABI: ((S + A) | T) - P */
1515 r
->r_addend
= (int)(long)(elf
->hdr
+
1517 (r
->r_offset
- sechdr
->sh_addr
));
1525 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1527 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1528 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1531 if (r_typ
== R_MIPS_HI16
)
1532 return 1; /* skip this */
1533 inst
= TO_NATIVE(*location
);
1536 r
->r_addend
= inst
& 0xffff;
1539 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1548 static void section_rela(const char *modname
, struct elf_info
*elf
,
1555 const char *fromsec
;
1557 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1558 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1560 fromsec
= sech_name(elf
, sechdr
);
1561 fromsec
+= strlen(".rela");
1562 /* if from section (name) is know good then skip it */
1563 if (match(fromsec
, section_white_list
))
1566 for (rela
= start
; rela
< stop
; rela
++) {
1567 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1568 #if KERNEL_ELFCLASS == ELFCLASS64
1569 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1571 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1572 r_sym
= TO_NATIVE(r_sym
);
1573 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1574 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1576 r
.r_info
= TO_NATIVE(rela
->r_info
);
1577 r_sym
= ELF_R_SYM(r
.r_info
);
1580 r
.r_info
= TO_NATIVE(rela
->r_info
);
1581 r_sym
= ELF_R_SYM(r
.r_info
);
1583 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1584 sym
= elf
->symtab_start
+ r_sym
;
1585 /* Skip special sections */
1586 if (is_shndx_special(sym
->st_shndx
))
1588 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1592 static void section_rel(const char *modname
, struct elf_info
*elf
,
1599 const char *fromsec
;
1601 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1602 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1604 fromsec
= sech_name(elf
, sechdr
);
1605 fromsec
+= strlen(".rel");
1606 /* if from section (name) is know good then skip it */
1607 if (match(fromsec
, section_white_list
))
1610 for (rel
= start
; rel
< stop
; rel
++) {
1611 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1612 #if KERNEL_ELFCLASS == ELFCLASS64
1613 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1615 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1616 r_sym
= TO_NATIVE(r_sym
);
1617 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1618 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1620 r
.r_info
= TO_NATIVE(rel
->r_info
);
1621 r_sym
= ELF_R_SYM(r
.r_info
);
1624 r
.r_info
= TO_NATIVE(rel
->r_info
);
1625 r_sym
= ELF_R_SYM(r
.r_info
);
1628 switch (elf
->hdr
->e_machine
) {
1630 if (addend_386_rel(elf
, sechdr
, &r
))
1634 if (addend_arm_rel(elf
, sechdr
, &r
))
1638 if (addend_mips_rel(elf
, sechdr
, &r
))
1642 sym
= elf
->symtab_start
+ r_sym
;
1643 /* Skip special sections */
1644 if (is_shndx_special(sym
->st_shndx
))
1646 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1651 * A module includes a number of sections that are discarded
1652 * either when loaded or when used as built-in.
1653 * For loaded modules all functions marked __init and all data
1654 * marked __initdata will be discarded when the module has been initialized.
1655 * Likewise for modules used built-in the sections marked __exit
1656 * are discarded because __exit marked function are supposed to be called
1657 * only when a module is unloaded which never happens for built-in modules.
1658 * The check_sec_ref() function traverses all relocation records
1659 * to find all references to a section that reference a section that will
1660 * be discarded and warns about it.
1662 static void check_sec_ref(struct module
*mod
, const char *modname
,
1663 struct elf_info
*elf
)
1666 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1668 /* Walk through all sections */
1669 for (i
= 0; i
< elf
->num_sections
; i
++) {
1670 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1671 /* We want to process only relocation sections and not .init */
1672 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1673 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1674 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1675 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1679 static void read_symbols(char *modname
)
1681 const char *symname
;
1685 struct elf_info info
= { };
1688 if (!parse_elf(&info
, modname
))
1691 mod
= new_module(modname
);
1693 /* When there's no vmlinux, don't print warnings about
1694 * unresolved symbols (since there'll be too many ;) */
1695 if (is_vmlinux(modname
)) {
1700 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1701 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1702 warn("modpost: missing MODULE_LICENSE() in %s\n"
1703 "see include/linux/module.h for "
1704 "more information\n", modname
);
1706 if (license_is_gpl_compatible(license
))
1707 mod
->gpl_compatible
= 1;
1709 mod
->gpl_compatible
= 0;
1712 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1713 "license", license
);
1716 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1717 symname
= info
.strtab
+ sym
->st_name
;
1719 handle_modversions(mod
, &info
, sym
, symname
);
1720 handle_moddevtable(mod
, &info
, sym
, symname
);
1722 if (!is_vmlinux(modname
) ||
1723 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1724 check_sec_ref(mod
, modname
, &info
);
1726 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1728 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1729 version
- (char *)info
.hdr
);
1730 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1731 get_src_version(modname
, mod
->srcversion
,
1732 sizeof(mod
->srcversion
)-1);
1734 parse_elf_finish(&info
);
1736 /* Our trick to get versioning for module struct etc. - it's
1737 * never passed as an argument to an exported function, so
1738 * the automatic versioning doesn't pick it up, but it's really
1739 * important anyhow */
1741 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1744 static void read_symbols_from_files(const char *filename
)
1747 char fname
[PATH_MAX
];
1749 if (strcmp(filename
, "-") != 0) {
1750 in
= fopen(filename
, "r");
1752 fatal("Can't open filenames file %s: %m", filename
);
1755 while (fgets(fname
, PATH_MAX
, in
) != NULL
) {
1756 if (strends(fname
, "\n"))
1757 fname
[strlen(fname
)-1] = '\0';
1758 read_symbols(fname
);
1767 /* We first write the generated file into memory using the
1768 * following helper, then compare to the file on disk and
1769 * only update the later if anything changed */
1771 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1772 const char *fmt
, ...)
1779 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1780 buf_write(buf
, tmp
, len
);
1784 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1786 if (buf
->size
- buf
->pos
< len
) {
1787 buf
->size
+= len
+ SZ
;
1788 buf
->p
= realloc(buf
->p
, buf
->size
);
1790 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1794 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1796 const char *e
= is_vmlinux(m
) ?"":".ko";
1800 fatal("modpost: GPL-incompatible module %s%s "
1801 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1803 case export_unused_gpl
:
1804 fatal("modpost: GPL-incompatible module %s%s "
1805 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1807 case export_gpl_future
:
1808 warn("modpost: GPL-incompatible module %s%s "
1809 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1813 case export_unknown
:
1819 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1821 const char *e
= is_vmlinux(m
) ?"":".ko";
1825 case export_unused_gpl
:
1826 warn("modpost: module %s%s "
1827 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1835 static void check_exports(struct module
*mod
)
1837 struct symbol
*s
, *exp
;
1839 for (s
= mod
->unres
; s
; s
= s
->next
) {
1840 const char *basename
;
1841 exp
= find_symbol(s
->name
);
1842 if (!exp
|| exp
->module
== mod
)
1844 basename
= strrchr(mod
->name
, '/');
1848 basename
= mod
->name
;
1849 if (!mod
->gpl_compatible
)
1850 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1851 check_for_unused(exp
->export
, basename
, exp
->name
);
1856 * Header for the generated file
1858 static void add_header(struct buffer
*b
, struct module
*mod
)
1860 buf_printf(b
, "#include <linux/module.h>\n");
1861 buf_printf(b
, "#include <linux/vermagic.h>\n");
1862 buf_printf(b
, "#include <linux/compiler.h>\n");
1863 buf_printf(b
, "\n");
1864 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1865 buf_printf(b
, "\n");
1866 buf_printf(b
, "__visible struct module __this_module\n");
1867 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1868 buf_printf(b
, "\t.name = KBUILD_MODNAME,\n");
1870 buf_printf(b
, "\t.init = init_module,\n");
1871 if (mod
->has_cleanup
)
1872 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1873 "\t.exit = cleanup_module,\n"
1875 buf_printf(b
, "\t.arch = MODULE_ARCH_INIT,\n");
1876 buf_printf(b
, "};\n");
1879 static void add_intree_flag(struct buffer
*b
, int is_intree
)
1882 buf_printf(b
, "\nMODULE_INFO(intree, \"Y\");\n");
1885 static void add_staging_flag(struct buffer
*b
, const char *name
)
1887 static const char *staging_dir
= "drivers/staging";
1889 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1890 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1894 * Record CRCs for unresolved symbols
1896 static int add_versions(struct buffer
*b
, struct module
*mod
)
1898 struct symbol
*s
, *exp
;
1901 for (s
= mod
->unres
; s
; s
= s
->next
) {
1902 exp
= find_symbol(s
->name
);
1903 if (!exp
|| exp
->module
== mod
) {
1904 if (have_vmlinux
&& !s
->weak
) {
1905 if (warn_unresolved
) {
1906 warn("\"%s\" [%s.ko] undefined!\n",
1907 s
->name
, mod
->name
);
1909 merror("\"%s\" [%s.ko] undefined!\n",
1910 s
->name
, mod
->name
);
1916 s
->module
= exp
->module
;
1917 s
->crc_valid
= exp
->crc_valid
;
1924 buf_printf(b
, "\n");
1925 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1926 buf_printf(b
, "__used\n");
1927 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1929 for (s
= mod
->unres
; s
; s
= s
->next
) {
1932 if (!s
->crc_valid
) {
1933 warn("\"%s\" [%s.ko] has no CRC!\n",
1934 s
->name
, mod
->name
);
1937 buf_printf(b
, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1941 buf_printf(b
, "};\n");
1946 static void add_depends(struct buffer
*b
, struct module
*mod
,
1947 struct module
*modules
)
1953 for (m
= modules
; m
; m
= m
->next
)
1954 m
->seen
= is_vmlinux(m
->name
);
1956 buf_printf(b
, "\n");
1957 buf_printf(b
, "static const char __module_depends[]\n");
1958 buf_printf(b
, "__used\n");
1959 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1960 buf_printf(b
, "\"depends=");
1961 for (s
= mod
->unres
; s
; s
= s
->next
) {
1966 if (s
->module
->seen
)
1969 s
->module
->seen
= 1;
1970 p
= strrchr(s
->module
->name
, '/');
1974 p
= s
->module
->name
;
1975 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1978 buf_printf(b
, "\";\n");
1981 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1983 if (mod
->srcversion
[0]) {
1984 buf_printf(b
, "\n");
1985 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1990 static void write_if_changed(struct buffer
*b
, const char *fname
)
1996 file
= fopen(fname
, "r");
2000 if (fstat(fileno(file
), &st
) < 0)
2003 if (st
.st_size
!= b
->pos
)
2006 tmp
= NOFAIL(malloc(b
->pos
));
2007 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
2010 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
2022 file
= fopen(fname
, "w");
2027 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2034 /* parse Module.symvers file. line format:
2035 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2037 static void read_dump(const char *fname
, unsigned int kernel
)
2039 unsigned long size
, pos
= 0;
2040 void *file
= grab_file(fname
, &size
);
2044 /* No symbol versions, silently ignore */
2047 while ((line
= get_next_line(&pos
, file
, size
))) {
2048 char *symname
, *modname
, *d
, *export
, *end
;
2053 if (!(symname
= strchr(line
, '\t')))
2056 if (!(modname
= strchr(symname
, '\t')))
2059 if ((export
= strchr(modname
, '\t')) != NULL
)
2061 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2063 crc
= strtoul(line
, &d
, 16);
2064 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2066 mod
= find_module(modname
);
2068 if (is_vmlinux(modname
))
2070 mod
= new_module(modname
);
2073 s
= sym_add_exported(symname
, mod
, export_no(export
));
2076 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2080 fatal("parse error in symbol dump file\n");
2083 /* For normal builds always dump all symbols.
2084 * For external modules only dump symbols
2085 * that are not read from kernel Module.symvers.
2087 static int dump_sym(struct symbol
*sym
)
2089 if (!external_module
)
2091 if (sym
->vmlinux
|| sym
->kernel
)
2096 static void write_dump(const char *fname
)
2098 struct buffer buf
= { };
2099 struct symbol
*symbol
;
2102 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2103 symbol
= symbolhash
[n
];
2105 if (dump_sym(symbol
))
2106 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2107 symbol
->crc
, symbol
->name
,
2108 symbol
->module
->name
,
2109 export_str(symbol
->export
));
2110 symbol
= symbol
->next
;
2113 write_if_changed(&buf
, fname
);
2116 struct ext_sym_list
{
2117 struct ext_sym_list
*next
;
2121 int main(int argc
, char **argv
)
2124 struct buffer buf
= { };
2125 char *kernel_read
= NULL
, *module_read
= NULL
;
2126 char *dump_write
= NULL
, *files_source
= NULL
;
2129 struct ext_sym_list
*extsym_iter
;
2130 struct ext_sym_list
*extsym_start
= NULL
;
2132 while ((opt
= getopt(argc
, argv
, "i:I:e:mnsST:o:awM:K:")) != -1) {
2135 kernel_read
= optarg
;
2138 module_read
= optarg
;
2139 external_module
= 1;
2142 external_module
= 1;
2144 NOFAIL(malloc(sizeof(*extsym_iter
)));
2145 extsym_iter
->next
= extsym_start
;
2146 extsym_iter
->file
= optarg
;
2147 extsym_start
= extsym_iter
;
2153 ignore_missing_files
= 1;
2156 dump_write
= optarg
;
2162 vmlinux_section_warnings
= 0;
2165 sec_mismatch_verbose
= 0;
2168 files_source
= optarg
;
2171 warn_unresolved
= 1;
2179 read_dump(kernel_read
, 1);
2181 read_dump(module_read
, 0);
2182 while (extsym_start
) {
2183 read_dump(extsym_start
->file
, 0);
2184 extsym_iter
= extsym_start
->next
;
2186 extsym_start
= extsym_iter
;
2189 while (optind
< argc
)
2190 read_symbols(argv
[optind
++]);
2193 read_symbols_from_files(files_source
);
2195 for (mod
= modules
; mod
; mod
= mod
->next
) {
2203 for (mod
= modules
; mod
; mod
= mod
->next
) {
2204 char fname
[strlen(mod
->name
) + 10];
2211 add_header(&buf
, mod
);
2212 add_intree_flag(&buf
, !external_module
);
2213 add_staging_flag(&buf
, mod
->name
);
2214 err
|= add_versions(&buf
, mod
);
2215 add_depends(&buf
, mod
, modules
);
2216 add_moddevtable(&buf
, mod
);
2217 add_srcversion(&buf
, mod
);
2219 sprintf(fname
, "%s.mod.c", mod
->name
);
2220 write_if_changed(&buf
, fname
);
2224 write_dump(dump_write
);
2225 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2226 warn("modpost: Found %d section mismatch(es).\n"
2227 "To see full details build your kernel with:\n"
2228 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2229 sec_mismatch_count
);