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 Module.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 ||
588 strncmp(symname
, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
589 strncmp(symname
, "_savevr_", sizeof("_savevr_") - 1) == 0)
591 if (info
->hdr
->e_machine
== EM_PPC64
)
592 /* Special register function linked on all modules during final link of .ko */
593 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
594 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0 ||
595 strncmp(symname
, "_restvr_", sizeof("_restvr_") - 1) == 0 ||
596 strncmp(symname
, "_savevr_", sizeof("_savevr_") - 1) == 0)
598 /* Do not ignore this symbol */
602 #define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)
603 #define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)
605 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
606 Elf_Sym
*sym
, const char *symname
)
611 if ((!is_vmlinux(mod
->name
) || mod
->is_dot_o
) &&
612 strncmp(symname
, "__ksymtab", 9) == 0)
613 export
= export_from_secname(info
, get_secindex(info
, sym
));
615 export
= export_from_sec(info
, get_secindex(info
, sym
));
618 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
619 crc
= (unsigned int) sym
->st_value
;
620 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
624 switch (sym
->st_shndx
) {
626 if (!strncmp(symname
, "__gnu_lto_", sizeof("__gnu_lto_")-1)) {
627 /* Should warn here, but modpost runs before the linker */
629 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
632 /* undefined symbol */
633 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
634 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
636 if (ignore_undef_symbol(info
, symname
))
638 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
639 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
640 /* add compatibility with older glibc */
641 #ifndef STT_SPARC_REGISTER
642 #define STT_SPARC_REGISTER STT_REGISTER
644 if (info
->hdr
->e_machine
== EM_SPARC
||
645 info
->hdr
->e_machine
== EM_SPARCV9
) {
646 /* Ignore register directives. */
647 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
649 if (symname
[0] == '.') {
650 char *munged
= strdup(symname
);
652 munged
[1] = toupper(munged
[1]);
658 #ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX
659 if (symname
[0] != '_')
664 mod
->unres
= alloc_symbol(symname
,
665 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
669 /* All exported symbols */
670 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
671 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
674 if (strcmp(symname
, VMLINUX_SYMBOL_STR(init_module
)) == 0)
676 if (strcmp(symname
, VMLINUX_SYMBOL_STR(cleanup_module
)) == 0)
677 mod
->has_cleanup
= 1;
683 * Parse tag=value strings from .modinfo section
685 static char *next_string(char *string
, unsigned long *secsize
)
687 /* Skip non-zero chars */
690 if ((*secsize
)-- <= 1)
694 /* Skip any zero padding. */
697 if ((*secsize
)-- <= 1)
703 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
704 const char *tag
, char *info
)
707 unsigned int taglen
= strlen(tag
);
708 unsigned long size
= modinfo_len
;
711 size
-= info
- (char *)modinfo
;
712 modinfo
= next_string(info
, &size
);
715 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
716 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
717 return p
+ taglen
+ 1;
722 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
726 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
730 * Test if string s ends in string sub
733 static int strrcmp(const char *s
, const char *sub
)
741 sublen
= strlen(sub
);
743 if ((slen
== 0) || (sublen
== 0))
749 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
752 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
755 return elf
->strtab
+ sym
->st_name
;
760 static const char *sec_name(struct elf_info
*elf
, int secindex
)
762 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
763 return (void *)elf
->hdr
+
764 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
765 sechdrs
[secindex
].sh_name
;
768 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
770 return (void *)elf
->hdr
+
771 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
775 /* The pattern is an array of simple patterns.
776 * "foo" will match an exact string equal to "foo"
777 * "*foo" will match a string that ends with "foo"
778 * "foo*" will match a string that begins with "foo"
780 static int match(const char *sym
, const char * const pat
[])
785 const char *endp
= p
+ strlen(p
) - 1;
789 if (strrcmp(sym
, p
+ 1) == 0)
793 else if (*endp
== '*') {
794 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
799 if (strcmp(p
, sym
) == 0)
807 /* sections that we do not want to do full section mismatch check on */
808 static const char *section_white_list
[] =
812 ".cranges", /* sh64 */
813 ".zdebug*", /* Compressed debug sections. */
814 ".GCC-command-line", /* mn10300 */
815 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
816 ".mdebug*", /* alpha, score, mips etc. */
817 ".pdr", /* alpha, score, mips etc. */
822 ".xt.prop", /* xtensa */
823 ".xt.lit", /* xtensa */
824 ".arcextmap*", /* arc */
825 ".gnu.linkonce.arcext*", /* arc : modules */
831 * This is used to find sections missing the SHF_ALLOC flag.
832 * The cause of this is often a section specified in assembler
833 * without "ax" / "aw".
835 static void check_section(const char *modname
, struct elf_info
*elf
,
838 const char *sec
= sech_name(elf
, sechdr
);
840 if (sechdr
->sh_type
== SHT_PROGBITS
&&
841 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
842 !match(sec
, section_white_list
)) {
843 warn("%s (%s): unexpected non-allocatable section.\n"
844 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
845 "Note that for example <linux/init.h> contains\n"
846 "section definitions for use in .S files.\n\n",
853 #define ALL_INIT_DATA_SECTIONS \
854 ".init.setup", ".init.rodata", ".meminit.rodata", \
855 ".init.data", ".meminit.data"
856 #define ALL_EXIT_DATA_SECTIONS \
857 ".exit.data", ".memexit.data"
859 #define ALL_INIT_TEXT_SECTIONS \
860 ".init.text", ".meminit.text"
861 #define ALL_EXIT_TEXT_SECTIONS \
862 ".exit.text", ".memexit.text"
864 #define ALL_PCI_INIT_SECTIONS \
865 ".pci_fixup_early", ".pci_fixup_header", ".pci_fixup_final", \
866 ".pci_fixup_enable", ".pci_fixup_resume", \
867 ".pci_fixup_resume_early", ".pci_fixup_suspend"
869 #define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS
870 #define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS
872 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
873 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
875 #define DATA_SECTIONS ".data", ".data.rel"
876 #define TEXT_SECTIONS ".text", ".text.unlikely"
878 #define INIT_SECTIONS ".init.*"
879 #define MEM_INIT_SECTIONS ".meminit.*"
881 #define EXIT_SECTIONS ".exit.*"
882 #define MEM_EXIT_SECTIONS ".memexit.*"
884 /* init data sections */
885 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
887 /* all init sections */
888 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
890 /* All init and exit sections (code + data) */
891 static const char *init_exit_sections
[] =
892 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
895 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
898 /* symbols in .data that may refer to init/exit sections */
899 #define DEFAULT_SYMBOL_WHITE_LIST \
901 "*_template", /* scsi uses *_template a lot */ \
902 "*_timer", /* arm uses ops structures named _timer a lot */ \
903 "*_sht", /* scsi also used *_sht to some extent */ \
909 static const char *head_sections
[] = { ".head.text*", NULL
};
910 static const char *linker_symbols
[] =
911 { "__init_begin", "_sinittext", "_einittext", NULL
};
918 XXXINIT_TO_SOME_INIT
,
919 XXXEXIT_TO_SOME_EXIT
,
920 ANY_INIT_TO_ANY_EXIT
,
921 ANY_EXIT_TO_ANY_INIT
,
925 struct sectioncheck
{
926 const char *fromsec
[20];
927 const char *tosec
[20];
928 enum mismatch mismatch
;
929 const char *symbol_white_list
[20];
932 const struct sectioncheck sectioncheck
[] = {
933 /* Do not reference init/exit code/data from
934 * normal code and data
937 .fromsec
= { TEXT_SECTIONS
, NULL
},
938 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
939 .mismatch
= TEXT_TO_ANY_INIT
,
940 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
943 .fromsec
= { DATA_SECTIONS
, NULL
},
944 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
945 .mismatch
= DATA_TO_ANY_INIT
,
946 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
949 .fromsec
= { DATA_SECTIONS
, NULL
},
950 .tosec
= { INIT_SECTIONS
, NULL
},
951 .mismatch
= DATA_TO_ANY_INIT
,
952 .symbol_white_list
= {
953 "*_template", "*_timer", "*_sht", "*_ops",
954 "*_probe", "*_probe_one", "*_console", NULL
958 .fromsec
= { TEXT_SECTIONS
, NULL
},
959 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
960 .mismatch
= TEXT_TO_ANY_EXIT
,
961 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
964 .fromsec
= { DATA_SECTIONS
, NULL
},
965 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
966 .mismatch
= DATA_TO_ANY_EXIT
,
967 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
969 /* Do not reference init code/data from meminit code/data */
971 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
972 .tosec
= { INIT_SECTIONS
, NULL
},
973 .mismatch
= XXXINIT_TO_SOME_INIT
,
974 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
976 /* Do not reference exit code/data from memexit code/data */
978 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
979 .tosec
= { EXIT_SECTIONS
, NULL
},
980 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
981 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
983 /* Do not use exit code/data from init code */
985 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
986 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
987 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
988 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
990 /* Do not use init code/data from exit code */
992 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
993 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
994 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
995 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
998 .fromsec
= { ALL_PCI_INIT_SECTIONS
, NULL
},
999 .tosec
= { INIT_SECTIONS
, NULL
},
1000 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1001 .symbol_white_list
= { NULL
},
1003 /* Do not export init/exit functions or data */
1005 .fromsec
= { "__ksymtab*", NULL
},
1006 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1007 .mismatch
= EXPORT_TO_INIT_EXIT
,
1008 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1012 static const struct sectioncheck
*section_mismatch(
1013 const char *fromsec
, const char *tosec
)
1016 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1017 const struct sectioncheck
*check
= §ioncheck
[0];
1019 for (i
= 0; i
< elems
; i
++) {
1020 if (match(fromsec
, check
->fromsec
) &&
1021 match(tosec
, check
->tosec
))
1029 * Whitelist to allow certain references to pass with no warning.
1032 * If a module parameter is declared __initdata and permissions=0
1033 * then this is legal despite the warning generated.
1034 * We cannot see value of permissions here, so just ignore
1036 * The pattern is identified by:
1037 * tosec = .init.data
1042 * module_param_call() ops can refer to __init set function if permissions=0
1043 * The pattern is identified by:
1044 * tosec = .init.text
1046 * atsym = __param_ops_*
1049 * Many drivers utilise a *driver container with references to
1050 * add, remove, probe functions etc.
1051 * the pattern is identified by:
1052 * tosec = init or exit section
1053 * fromsec = data section
1054 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1055 * *probe_one, *_console, *_timer
1058 * Whitelist all references from .head.text to any init section
1061 * Some symbols belong to init section but still it is ok to reference
1062 * these from non-init sections as these symbols don't have any memory
1063 * allocated for them and symbol address and value are same. So even
1064 * if init section is freed, its ok to reference those symbols.
1065 * For ex. symbols marking the init section boundaries.
1066 * This pattern is identified by
1067 * refsymname = __init_begin, _sinittext, _einittext
1070 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1071 const char *fromsec
, const char *fromsym
,
1072 const char *tosec
, const char *tosym
)
1074 /* Check for pattern 1 */
1075 if (match(tosec
, init_data_sections
) &&
1076 match(fromsec
, data_sections
) &&
1077 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1080 /* Check for pattern 1a */
1081 if (strcmp(tosec
, ".init.text") == 0 &&
1082 match(fromsec
, data_sections
) &&
1083 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1086 /* Check for pattern 2 */
1087 if (match(tosec
, init_exit_sections
) &&
1088 match(fromsec
, data_sections
) &&
1089 match(fromsym
, mismatch
->symbol_white_list
))
1092 /* Check for pattern 3 */
1093 if (match(fromsec
, head_sections
) &&
1094 match(tosec
, init_sections
))
1097 /* Check for pattern 4 */
1098 if (match(tosym
, linker_symbols
))
1105 * Find symbol based on relocation record info.
1106 * In some cases the symbol supplied is a valid symbol so
1107 * return refsym. If st_name != 0 we assume this is a valid symbol.
1108 * In other cases the symbol needs to be looked up in the symbol table
1109 * based on section and address.
1111 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1115 Elf_Sym
*near
= NULL
;
1116 Elf64_Sword distance
= 20;
1118 unsigned int relsym_secindex
;
1120 if (relsym
->st_name
!= 0)
1123 relsym_secindex
= get_secindex(elf
, relsym
);
1124 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1125 if (get_secindex(elf
, sym
) != relsym_secindex
)
1127 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1129 if (sym
->st_value
== addr
)
1131 /* Find a symbol nearby - addr are maybe negative */
1132 d
= sym
->st_value
- addr
;
1134 d
= addr
- sym
->st_value
;
1140 /* We need a close match */
1147 static inline int is_arm_mapping_symbol(const char *str
)
1149 return str
[0] == '$' && strchr("atd", str
[1])
1150 && (str
[2] == '\0' || str
[2] == '.');
1154 * If there's no name there, ignore it; likewise, ignore it if it's
1155 * one of the magic symbols emitted used by current ARM tools.
1157 * Otherwise if find_symbols_between() returns those symbols, they'll
1158 * fail the whitelist tests and cause lots of false alarms ... fixable
1159 * only by merging __exit and __init sections into __text, bloating
1160 * the kernel (which is especially evil on embedded platforms).
1162 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1164 const char *name
= elf
->strtab
+ sym
->st_name
;
1166 if (!name
|| !strlen(name
))
1168 return !is_arm_mapping_symbol(name
);
1172 * Find symbols before or equal addr and after addr - in the section sec.
1173 * If we find two symbols with equal offset prefer one with a valid name.
1174 * The ELF format may have a better way to detect what type of symbol
1175 * it is, but this works for now.
1177 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1181 Elf_Sym
*near
= NULL
;
1182 Elf_Addr distance
= ~0;
1184 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1187 if (is_shndx_special(sym
->st_shndx
))
1189 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1190 if (strcmp(symsec
, sec
) != 0)
1192 if (!is_valid_name(elf
, sym
))
1194 if (sym
->st_value
<= addr
) {
1195 if ((addr
- sym
->st_value
) < distance
) {
1196 distance
= addr
- sym
->st_value
;
1198 } else if ((addr
- sym
->st_value
) == distance
) {
1207 * Convert a section name to the function/data attribute
1208 * .init.text => __init
1209 * .memexitconst => __memconst
1212 * The memory of returned value has been allocated on a heap. The user of this
1213 * method should free it after usage.
1215 static char *sec2annotation(const char *s
)
1217 if (match(s
, init_exit_sections
)) {
1218 char *p
= malloc(20);
1225 while (*s
&& *s
!= '.')
1230 if (strstr(s
, "rodata") != NULL
)
1231 strcat(p
, "const ");
1232 else if (strstr(s
, "data") != NULL
)
1242 static int is_function(Elf_Sym
*sym
)
1245 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1250 static void print_section_list(const char * const list
[20])
1252 const char *const *s
= list
;
1255 fprintf(stderr
, "%s", *s
);
1258 fprintf(stderr
, ", ");
1260 fprintf(stderr
, "\n");
1264 * Print a warning about a section mismatch.
1265 * Try to find symbols near it so user can find it.
1266 * Check whitelist before warning - it may be a false positive.
1268 static void report_sec_mismatch(const char *modname
,
1269 const struct sectioncheck
*mismatch
,
1270 const char *fromsec
,
1271 unsigned long long fromaddr
,
1272 const char *fromsym
,
1274 const char *tosec
, const char *tosym
,
1277 const char *from
, *from_p
;
1278 const char *to
, *to_p
;
1282 switch (from_is_func
) {
1283 case 0: from
= "variable"; from_p
= ""; break;
1284 case 1: from
= "function"; from_p
= "()"; break;
1285 default: from
= "(unknown reference)"; from_p
= ""; break;
1287 switch (to_is_func
) {
1288 case 0: to
= "variable"; to_p
= ""; break;
1289 case 1: to
= "function"; to_p
= "()"; break;
1290 default: to
= "(unknown reference)"; to_p
= ""; break;
1293 sec_mismatch_count
++;
1294 if (!sec_mismatch_verbose
)
1297 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1298 "to the %s %s:%s%s\n",
1299 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1302 switch (mismatch
->mismatch
) {
1303 case TEXT_TO_ANY_INIT
:
1304 prl_from
= sec2annotation(fromsec
);
1305 prl_to
= sec2annotation(tosec
);
1307 "The function %s%s() references\n"
1309 "This is often because %s lacks a %s\n"
1310 "annotation or the annotation of %s is wrong.\n",
1312 to
, prl_to
, tosym
, to_p
,
1313 fromsym
, prl_to
, tosym
);
1317 case DATA_TO_ANY_INIT
: {
1318 prl_to
= sec2annotation(tosec
);
1320 "The variable %s references\n"
1322 "If the reference is valid then annotate the\n"
1323 "variable with __init* or __refdata (see linux/init.h) "
1324 "or name the variable:\n",
1325 fromsym
, to
, prl_to
, tosym
, to_p
);
1326 print_section_list(mismatch
->symbol_white_list
);
1330 case TEXT_TO_ANY_EXIT
:
1331 prl_to
= sec2annotation(tosec
);
1333 "The function %s() references a %s in an exit section.\n"
1334 "Often the %s %s%s has valid usage outside the exit section\n"
1335 "and the fix is to remove the %sannotation of %s.\n",
1336 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1339 case DATA_TO_ANY_EXIT
: {
1340 prl_to
= sec2annotation(tosec
);
1342 "The variable %s references\n"
1344 "If the reference is valid then annotate the\n"
1345 "variable with __exit* (see linux/init.h) or "
1346 "name the variable:\n",
1347 fromsym
, to
, prl_to
, tosym
, to_p
);
1348 print_section_list(mismatch
->symbol_white_list
);
1352 case XXXINIT_TO_SOME_INIT
:
1353 case XXXEXIT_TO_SOME_EXIT
:
1354 prl_from
= sec2annotation(fromsec
);
1355 prl_to
= sec2annotation(tosec
);
1357 "The %s %s%s%s references\n"
1359 "If %s is only used by %s then\n"
1360 "annotate %s with a matching annotation.\n",
1361 from
, prl_from
, fromsym
, from_p
,
1362 to
, prl_to
, tosym
, to_p
,
1363 tosym
, fromsym
, tosym
);
1367 case ANY_INIT_TO_ANY_EXIT
:
1368 prl_from
= sec2annotation(fromsec
);
1369 prl_to
= sec2annotation(tosec
);
1371 "The %s %s%s%s references\n"
1373 "This is often seen when error handling "
1374 "in the init function\n"
1375 "uses functionality in the exit path.\n"
1376 "The fix is often to remove the %sannotation of\n"
1377 "%s%s so it may be used outside an exit section.\n",
1378 from
, prl_from
, fromsym
, from_p
,
1379 to
, prl_to
, tosym
, to_p
,
1380 prl_to
, tosym
, to_p
);
1384 case ANY_EXIT_TO_ANY_INIT
:
1385 prl_from
= sec2annotation(fromsec
);
1386 prl_to
= sec2annotation(tosec
);
1388 "The %s %s%s%s references\n"
1390 "This is often seen when error handling "
1391 "in the exit function\n"
1392 "uses functionality in the init path.\n"
1393 "The fix is often to remove the %sannotation of\n"
1394 "%s%s so it may be used outside an init section.\n",
1395 from
, prl_from
, fromsym
, from_p
,
1396 to
, prl_to
, tosym
, to_p
,
1397 prl_to
, tosym
, to_p
);
1401 case EXPORT_TO_INIT_EXIT
:
1402 prl_to
= sec2annotation(tosec
);
1404 "The symbol %s is exported and annotated %s\n"
1405 "Fix this by removing the %sannotation of %s "
1406 "or drop the export.\n",
1407 tosym
, prl_to
, prl_to
, tosym
);
1411 fprintf(stderr
, "\n");
1414 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1415 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1418 const struct sectioncheck
*mismatch
;
1420 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1421 mismatch
= section_mismatch(fromsec
, tosec
);
1426 const char *fromsym
;
1428 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1429 fromsym
= sym_name(elf
, from
);
1430 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1431 tosym
= sym_name(elf
, to
);
1433 if (!strncmp(fromsym
, "reference___initcall",
1434 sizeof("reference___initcall")-1))
1437 /* check whitelist - we may ignore it */
1438 if (secref_whitelist(mismatch
,
1439 fromsec
, fromsym
, tosec
, tosym
)) {
1440 report_sec_mismatch(modname
, mismatch
,
1441 fromsec
, r
->r_offset
, fromsym
,
1442 is_function(from
), tosec
, tosym
,
1448 static unsigned int *reloc_location(struct elf_info
*elf
,
1449 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1451 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1452 int section
= sechdr
->sh_info
;
1454 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1458 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1460 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1461 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1465 r
->r_addend
= TO_NATIVE(*location
);
1468 r
->r_addend
= TO_NATIVE(*location
) + 4;
1469 /* For CONFIG_RELOCATABLE=y */
1470 if (elf
->hdr
->e_type
== ET_EXEC
)
1471 r
->r_addend
+= r
->r_offset
;
1478 #define R_ARM_CALL 28
1480 #ifndef R_ARM_JUMP24
1481 #define R_ARM_JUMP24 29
1484 #ifndef R_ARM_THM_CALL
1485 #define R_ARM_THM_CALL 10
1487 #ifndef R_ARM_THM_JUMP24
1488 #define R_ARM_THM_JUMP24 30
1490 #ifndef R_ARM_THM_JUMP19
1491 #define R_ARM_THM_JUMP19 51
1494 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1496 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1500 /* From ARM ABI: (S + A) | T */
1501 r
->r_addend
= (int)(long)
1502 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1507 case R_ARM_THM_CALL
:
1508 case R_ARM_THM_JUMP24
:
1509 case R_ARM_THM_JUMP19
:
1510 /* From ARM ABI: ((S + A) | T) - P */
1511 r
->r_addend
= (int)(long)(elf
->hdr
+
1513 (r
->r_offset
- sechdr
->sh_addr
));
1521 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1523 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1524 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1527 if (r_typ
== R_MIPS_HI16
)
1528 return 1; /* skip this */
1529 inst
= TO_NATIVE(*location
);
1532 r
->r_addend
= inst
& 0xffff;
1535 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1544 static void section_rela(const char *modname
, struct elf_info
*elf
,
1551 const char *fromsec
;
1553 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1554 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1556 fromsec
= sech_name(elf
, sechdr
);
1557 fromsec
+= strlen(".rela");
1558 /* if from section (name) is know good then skip it */
1559 if (match(fromsec
, section_white_list
))
1562 for (rela
= start
; rela
< stop
; rela
++) {
1563 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1564 #if KERNEL_ELFCLASS == ELFCLASS64
1565 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1567 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1568 r_sym
= TO_NATIVE(r_sym
);
1569 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1570 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1572 r
.r_info
= TO_NATIVE(rela
->r_info
);
1573 r_sym
= ELF_R_SYM(r
.r_info
);
1576 r
.r_info
= TO_NATIVE(rela
->r_info
);
1577 r_sym
= ELF_R_SYM(r
.r_info
);
1579 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1580 sym
= elf
->symtab_start
+ r_sym
;
1581 /* Skip special sections */
1582 if (is_shndx_special(sym
->st_shndx
))
1584 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1588 static void section_rel(const char *modname
, struct elf_info
*elf
,
1595 const char *fromsec
;
1597 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1598 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1600 fromsec
= sech_name(elf
, sechdr
);
1601 fromsec
+= strlen(".rel");
1602 /* if from section (name) is know good then skip it */
1603 if (match(fromsec
, section_white_list
))
1606 for (rel
= start
; rel
< stop
; rel
++) {
1607 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1608 #if KERNEL_ELFCLASS == ELFCLASS64
1609 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1611 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1612 r_sym
= TO_NATIVE(r_sym
);
1613 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1614 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1616 r
.r_info
= TO_NATIVE(rel
->r_info
);
1617 r_sym
= ELF_R_SYM(r
.r_info
);
1620 r
.r_info
= TO_NATIVE(rel
->r_info
);
1621 r_sym
= ELF_R_SYM(r
.r_info
);
1624 switch (elf
->hdr
->e_machine
) {
1626 if (addend_386_rel(elf
, sechdr
, &r
))
1630 if (addend_arm_rel(elf
, sechdr
, &r
))
1634 if (addend_mips_rel(elf
, sechdr
, &r
))
1638 sym
= elf
->symtab_start
+ r_sym
;
1639 /* Skip special sections */
1640 if (is_shndx_special(sym
->st_shndx
))
1642 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1647 * A module includes a number of sections that are discarded
1648 * either when loaded or when used as built-in.
1649 * For loaded modules all functions marked __init and all data
1650 * marked __initdata will be discarded when the module has been initialized.
1651 * Likewise for modules used built-in the sections marked __exit
1652 * are discarded because __exit marked function are supposed to be called
1653 * only when a module is unloaded which never happens for built-in modules.
1654 * The check_sec_ref() function traverses all relocation records
1655 * to find all references to a section that reference a section that will
1656 * be discarded and warns about it.
1658 static void check_sec_ref(struct module
*mod
, const char *modname
,
1659 struct elf_info
*elf
)
1662 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1664 /* Walk through all sections */
1665 for (i
= 0; i
< elf
->num_sections
; i
++) {
1666 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1667 /* We want to process only relocation sections and not .init */
1668 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1669 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1670 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1671 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1675 static char *remove_dot(char *s
)
1677 size_t n
= strcspn(s
, ".");
1680 size_t m
= strspn(s
+ n
+ 1, "0123456789");
1681 if (m
&& (s
[n
+ m
] == '.' || s
[n
+ m
] == 0))
1687 static void read_symbols(char *modname
)
1689 const char *symname
;
1693 struct elf_info info
= { };
1696 if (!parse_elf(&info
, modname
))
1699 mod
= new_module(modname
);
1701 /* When there's no vmlinux, don't print warnings about
1702 * unresolved symbols (since there'll be too many ;) */
1703 if (is_vmlinux(modname
)) {
1708 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1709 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1710 warn("modpost: missing MODULE_LICENSE() in %s\n"
1711 "see include/linux/module.h for "
1712 "more information\n", modname
);
1714 if (license_is_gpl_compatible(license
))
1715 mod
->gpl_compatible
= 1;
1717 mod
->gpl_compatible
= 0;
1720 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1721 "license", license
);
1724 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1725 symname
= remove_dot(info
.strtab
+ sym
->st_name
);
1727 handle_modversions(mod
, &info
, sym
, symname
);
1728 handle_moddevtable(mod
, &info
, sym
, symname
);
1730 if (!is_vmlinux(modname
) ||
1731 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1732 check_sec_ref(mod
, modname
, &info
);
1734 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1736 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1737 version
- (char *)info
.hdr
);
1738 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1739 get_src_version(modname
, mod
->srcversion
,
1740 sizeof(mod
->srcversion
)-1);
1742 parse_elf_finish(&info
);
1744 /* Our trick to get versioning for module struct etc. - it's
1745 * never passed as an argument to an exported function, so
1746 * the automatic versioning doesn't pick it up, but it's really
1747 * important anyhow */
1749 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1752 static void read_symbols_from_files(const char *filename
)
1755 char fname
[PATH_MAX
];
1757 if (strcmp(filename
, "-") != 0) {
1758 in
= fopen(filename
, "r");
1760 fatal("Can't open filenames file %s: %m", filename
);
1763 while (fgets(fname
, PATH_MAX
, in
) != NULL
) {
1764 if (strends(fname
, "\n"))
1765 fname
[strlen(fname
)-1] = '\0';
1766 read_symbols(fname
);
1775 /* We first write the generated file into memory using the
1776 * following helper, then compare to the file on disk and
1777 * only update the later if anything changed */
1779 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1780 const char *fmt
, ...)
1787 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1788 buf_write(buf
, tmp
, len
);
1792 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1794 if (buf
->size
- buf
->pos
< len
) {
1795 buf
->size
+= len
+ SZ
;
1796 buf
->p
= realloc(buf
->p
, buf
->size
);
1798 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1802 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1804 const char *e
= is_vmlinux(m
) ?"":".ko";
1808 fatal("modpost: GPL-incompatible module %s%s "
1809 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1811 case export_unused_gpl
:
1812 fatal("modpost: GPL-incompatible module %s%s "
1813 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1815 case export_gpl_future
:
1816 warn("modpost: GPL-incompatible module %s%s "
1817 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1821 case export_unknown
:
1827 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1829 const char *e
= is_vmlinux(m
) ?"":".ko";
1833 case export_unused_gpl
:
1834 warn("modpost: module %s%s "
1835 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1843 static void check_exports(struct module
*mod
)
1845 struct symbol
*s
, *exp
;
1847 for (s
= mod
->unres
; s
; s
= s
->next
) {
1848 const char *basename
;
1849 exp
= find_symbol(s
->name
);
1850 if (!exp
|| exp
->module
== mod
)
1852 basename
= strrchr(mod
->name
, '/');
1856 basename
= mod
->name
;
1857 if (!mod
->gpl_compatible
)
1858 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1859 check_for_unused(exp
->export
, basename
, exp
->name
);
1864 * Header for the generated file
1866 static void add_header(struct buffer
*b
, struct module
*mod
)
1868 buf_printf(b
, "#include <linux/module.h>\n");
1869 buf_printf(b
, "#include <linux/vermagic.h>\n");
1870 buf_printf(b
, "#include <linux/compiler.h>\n");
1871 buf_printf(b
, "\n");
1872 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1873 buf_printf(b
, "\n");
1874 buf_printf(b
, "__visible struct module __this_module\n");
1875 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1876 buf_printf(b
, "\t.name = KBUILD_MODNAME,\n");
1878 buf_printf(b
, "\t.init = init_module,\n");
1879 if (mod
->has_cleanup
)
1880 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1881 "\t.exit = cleanup_module,\n"
1883 buf_printf(b
, "\t.arch = MODULE_ARCH_INIT,\n");
1884 buf_printf(b
, "};\n");
1887 static void add_intree_flag(struct buffer
*b
, int is_intree
)
1890 buf_printf(b
, "\nMODULE_INFO(intree, \"Y\");\n");
1893 static void add_staging_flag(struct buffer
*b
, const char *name
)
1895 static const char *staging_dir
= "drivers/staging";
1897 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1898 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1902 * Record CRCs for unresolved symbols
1904 static int add_versions(struct buffer
*b
, struct module
*mod
)
1906 struct symbol
*s
, *exp
;
1909 for (s
= mod
->unres
; s
; s
= s
->next
) {
1910 exp
= find_symbol(s
->name
);
1911 if (!exp
|| exp
->module
== mod
) {
1912 if (have_vmlinux
&& !s
->weak
) {
1913 if (warn_unresolved
) {
1914 warn("\"%s\" [%s.ko] undefined!\n",
1915 s
->name
, mod
->name
);
1917 merror("\"%s\" [%s.ko] undefined!\n",
1918 s
->name
, mod
->name
);
1924 s
->module
= exp
->module
;
1925 s
->crc_valid
= exp
->crc_valid
;
1932 buf_printf(b
, "\n");
1933 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1934 buf_printf(b
, "__used\n");
1935 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1937 for (s
= mod
->unres
; s
; s
= s
->next
) {
1940 if (!s
->crc_valid
) {
1941 warn("\"%s\" [%s.ko] has no CRC!\n",
1942 s
->name
, mod
->name
);
1945 buf_printf(b
, "\t{ %#8x, __VMLINUX_SYMBOL_STR(%s) },\n",
1949 buf_printf(b
, "};\n");
1954 static void add_depends(struct buffer
*b
, struct module
*mod
,
1955 struct module
*modules
)
1961 for (m
= modules
; m
; m
= m
->next
)
1962 m
->seen
= is_vmlinux(m
->name
);
1964 buf_printf(b
, "\n");
1965 buf_printf(b
, "static const char __module_depends[]\n");
1966 buf_printf(b
, "__used\n");
1967 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1968 buf_printf(b
, "\"depends=");
1969 for (s
= mod
->unres
; s
; s
= s
->next
) {
1974 if (s
->module
->seen
)
1977 s
->module
->seen
= 1;
1978 p
= strrchr(s
->module
->name
, '/');
1982 p
= s
->module
->name
;
1983 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1986 buf_printf(b
, "\";\n");
1989 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1991 if (mod
->srcversion
[0]) {
1992 buf_printf(b
, "\n");
1993 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1998 static void write_if_changed(struct buffer
*b
, const char *fname
)
2004 file
= fopen(fname
, "r");
2008 if (fstat(fileno(file
), &st
) < 0)
2011 if (st
.st_size
!= b
->pos
)
2014 tmp
= NOFAIL(malloc(b
->pos
));
2015 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
2018 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
2030 file
= fopen(fname
, "w");
2035 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2042 /* parse Module.symvers file. line format:
2043 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2045 static void read_dump(const char *fname
, unsigned int kernel
)
2047 unsigned long size
, pos
= 0;
2048 void *file
= grab_file(fname
, &size
);
2052 /* No symbol versions, silently ignore */
2055 while ((line
= get_next_line(&pos
, file
, size
))) {
2056 char *symname
, *modname
, *d
, *export
, *end
;
2061 if (!(symname
= strchr(line
, '\t')))
2064 if (!(modname
= strchr(symname
, '\t')))
2067 if ((export
= strchr(modname
, '\t')) != NULL
)
2069 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2071 crc
= strtoul(line
, &d
, 16);
2072 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2074 mod
= find_module(modname
);
2076 if (is_vmlinux(modname
))
2078 mod
= new_module(modname
);
2081 s
= sym_add_exported(symname
, mod
, export_no(export
));
2084 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2086 release_file(file
, size
);
2089 release_file(file
, size
);
2090 fatal("parse error in symbol dump file\n");
2093 /* For normal builds always dump all symbols.
2094 * For external modules only dump symbols
2095 * that are not read from kernel Module.symvers.
2097 static int dump_sym(struct symbol
*sym
)
2099 if (!external_module
)
2101 if (sym
->vmlinux
|| sym
->kernel
)
2106 static void write_dump(const char *fname
)
2108 struct buffer buf
= { };
2109 struct symbol
*symbol
;
2112 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2113 symbol
= symbolhash
[n
];
2115 if (dump_sym(symbol
))
2116 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2117 symbol
->crc
, symbol
->name
,
2118 symbol
->module
->name
,
2119 export_str(symbol
->export
));
2120 symbol
= symbol
->next
;
2123 write_if_changed(&buf
, fname
);
2126 struct ext_sym_list
{
2127 struct ext_sym_list
*next
;
2131 int main(int argc
, char **argv
)
2134 struct buffer buf
= { };
2135 char *kernel_read
= NULL
, *module_read
= NULL
;
2136 char *dump_write
= NULL
, *files_source
= NULL
;
2139 struct ext_sym_list
*extsym_iter
;
2140 struct ext_sym_list
*extsym_start
= NULL
;
2142 while ((opt
= getopt(argc
, argv
, "i:I:e:mnsST:o:awM:K:")) != -1) {
2145 kernel_read
= optarg
;
2148 module_read
= optarg
;
2149 external_module
= 1;
2152 external_module
= 1;
2154 NOFAIL(malloc(sizeof(*extsym_iter
)));
2155 extsym_iter
->next
= extsym_start
;
2156 extsym_iter
->file
= optarg
;
2157 extsym_start
= extsym_iter
;
2163 ignore_missing_files
= 1;
2166 dump_write
= optarg
;
2172 vmlinux_section_warnings
= 0;
2175 sec_mismatch_verbose
= 0;
2178 files_source
= optarg
;
2181 warn_unresolved
= 1;
2189 read_dump(kernel_read
, 1);
2191 read_dump(module_read
, 0);
2192 while (extsym_start
) {
2193 read_dump(extsym_start
->file
, 0);
2194 extsym_iter
= extsym_start
->next
;
2196 extsym_start
= extsym_iter
;
2199 while (optind
< argc
)
2200 read_symbols(argv
[optind
++]);
2203 read_symbols_from_files(files_source
);
2205 for (mod
= modules
; mod
; mod
= mod
->next
) {
2213 for (mod
= modules
; mod
; mod
= mod
->next
) {
2214 char fname
[strlen(mod
->name
) + 10];
2221 add_header(&buf
, mod
);
2222 add_intree_flag(&buf
, !external_module
);
2223 add_staging_flag(&buf
, mod
->name
);
2224 err
|= add_versions(&buf
, mod
);
2225 add_depends(&buf
, mod
, modules
);
2226 add_moddevtable(&buf
, mod
);
2227 add_srcversion(&buf
, mod
);
2229 sprintf(fname
, "%s.mod.c", mod
->name
);
2230 write_if_changed(&buf
, fname
);
2234 write_dump(dump_write
);
2235 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2236 warn("modpost: Found %d section mismatch(es).\n"
2237 "To see full details build your kernel with:\n"
2238 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2239 sec_mismatch_count
);