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 ...
19 #include "../../include/generated/autoconf.h"
20 #include "../../include/linux/license.h"
22 /* Some toolchains use a `_' prefix for all user symbols. */
23 #ifdef CONFIG_SYMBOL_PREFIX
24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
26 #define MODULE_SYMBOL_PREFIX ""
30 /* Are we using CONFIG_MODVERSIONS? */
32 /* Warn about undefined symbols? (do so if we have vmlinux) */
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static int all_versions
= 0;
36 /* If we are modposting external module set to 1 */
37 static int external_module
= 0;
38 /* Warn about section mismatch in vmlinux if set to 1 */
39 static int vmlinux_section_warnings
= 1;
40 /* Only warn about unresolved symbols */
41 static int warn_unresolved
= 0;
42 /* How a symbol is exported */
43 static int sec_mismatch_count
= 0;
44 static int sec_mismatch_verbose
= 1;
47 export_plain
, export_unused
, export_gpl
,
48 export_unused_gpl
, export_gpl_future
, export_unknown
51 #define PRINTF __attribute__ ((format (printf, 1, 2)))
53 PRINTF
void fatal(const char *fmt
, ...)
57 fprintf(stderr
, "FATAL: ");
59 va_start(arglist
, fmt
);
60 vfprintf(stderr
, fmt
, arglist
);
66 PRINTF
void warn(const char *fmt
, ...)
70 fprintf(stderr
, "WARNING: ");
72 va_start(arglist
, fmt
);
73 vfprintf(stderr
, fmt
, arglist
);
77 PRINTF
void merror(const char *fmt
, ...)
81 fprintf(stderr
, "ERROR: ");
83 va_start(arglist
, fmt
);
84 vfprintf(stderr
, fmt
, arglist
);
88 static int is_vmlinux(const char *modname
)
92 myname
= strrchr(modname
, '/');
98 return (strcmp(myname
, "vmlinux") == 0) ||
99 (strcmp(myname
, "vmlinux.o") == 0);
102 void *do_nofail(void *ptr
, const char *expr
)
105 fatal("modpost: Memory allocation failure: %s.\n", expr
);
110 /* A list of all modules we processed */
111 static struct module
*modules
;
113 static struct module
*find_module(char *modname
)
117 for (mod
= modules
; mod
; mod
= mod
->next
)
118 if (strcmp(mod
->name
, modname
) == 0)
123 static struct module
*new_module(char *modname
)
128 mod
= NOFAIL(malloc(sizeof(*mod
)));
129 memset(mod
, 0, sizeof(*mod
));
130 p
= NOFAIL(strdup(modname
));
132 /* strip trailing .o */
135 if (strcmp(s
, ".o") == 0) {
142 mod
->gpl_compatible
= -1;
149 /* A hash of all exported symbols,
150 * struct symbol is also used for lists of unresolved symbols */
152 #define SYMBOL_HASH_SIZE 1024
156 struct module
*module
;
160 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
161 unsigned int kernel
:1; /* 1 if symbol is from kernel
162 * (only for external modules) **/
163 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
164 enum export export
; /* Type of export */
168 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
170 /* This is based on the hash agorithm from gdbm, via tdb */
171 static inline unsigned int tdb_hash(const char *name
)
173 unsigned value
; /* Used to compute the hash value. */
174 unsigned i
; /* Used to cycle through random values. */
176 /* Set the initial value from the key size. */
177 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
178 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
180 return (1103515243 * value
+ 12345);
184 * Allocate a new symbols for use in the hash of exported symbols or
185 * the list of unresolved symbols per module
187 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
190 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
192 memset(s
, 0, sizeof(*s
));
193 strcpy(s
->name
, name
);
199 /* For the hash of exported symbols */
200 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
206 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
207 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
208 new->module
= module
;
209 new->export
= export
;
213 static struct symbol
*find_symbol(const char *name
)
217 /* For our purposes, .foo matches foo. PPC64 needs this. */
221 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
222 if (strcmp(s
->name
, name
) == 0)
232 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
233 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
234 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
235 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
236 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
237 { .str
= "(unknown)", .export
= export_unknown
},
241 static const char *export_str(enum export ex
)
243 return export_list
[ex
].str
;
246 static enum export
export_no(const char *s
)
251 return export_unknown
;
252 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
253 if (strcmp(export_list
[i
].str
, s
) == 0)
254 return export_list
[i
].export
;
256 return export_unknown
;
259 static const char *sec_name(struct elf_info
*elf
, int secindex
);
261 #define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)
263 static enum export
export_from_secname(struct elf_info
*elf
, unsigned int sec
)
265 const char *secname
= sec_name(elf
, sec
);
267 if (strstarts(secname
, "___ksymtab+"))
269 else if (strstarts(secname
, "___ksymtab_unused+"))
270 return export_unused
;
271 else if (strstarts(secname
, "___ksymtab_gpl+"))
273 else if (strstarts(secname
, "___ksymtab_unused_gpl+"))
274 return export_unused_gpl
;
275 else if (strstarts(secname
, "___ksymtab_gpl_future+"))
276 return export_gpl_future
;
278 return export_unknown
;
281 static enum export
export_from_sec(struct elf_info
*elf
, unsigned int sec
)
283 if (sec
== elf
->export_sec
)
285 else if (sec
== elf
->export_unused_sec
)
286 return export_unused
;
287 else if (sec
== elf
->export_gpl_sec
)
289 else if (sec
== elf
->export_unused_gpl_sec
)
290 return export_unused_gpl
;
291 else if (sec
== elf
->export_gpl_future_sec
)
292 return export_gpl_future
;
294 return export_unknown
;
298 * Add an exported symbol - it may have already been added without a
299 * CRC, in this case just update the CRC
301 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
304 struct symbol
*s
= find_symbol(name
);
307 s
= new_symbol(name
, mod
, export
);
310 warn("%s: '%s' exported twice. Previous export "
311 "was in %s%s\n", mod
->name
, name
,
313 is_vmlinux(s
->module
->name
) ?"":".ko");
315 /* In case Modules.symvers was out of date */
320 s
->vmlinux
= is_vmlinux(mod
->name
);
326 static void sym_update_crc(const char *name
, struct module
*mod
,
327 unsigned int crc
, enum export export
)
329 struct symbol
*s
= find_symbol(name
);
332 s
= new_symbol(name
, mod
, export
);
337 void *grab_file(const char *filename
, unsigned long *size
)
340 void *map
= MAP_FAILED
;
343 fd
= open(filename
, O_RDONLY
);
350 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
354 if (map
== MAP_FAILED
)
360 * Return a copy of the next line in a mmap'ed file.
361 * spaces in the beginning of the line is trimmed away.
362 * Return a pointer to a static buffer.
364 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
366 static char line
[4096];
369 signed char *p
= (signed char *)file
+ *pos
;
372 for (; *pos
< size
; (*pos
)++) {
373 if (skip
&& isspace(*p
)) {
378 if (*p
!= '\n' && (*pos
< size
)) {
382 break; /* Too long, stop */
393 void release_file(void *file
, unsigned long size
)
398 static int parse_elf(struct elf_info
*info
, const char *filename
)
404 const char *secstrings
;
405 unsigned int symtab_idx
= ~0U, symtab_shndx_idx
= ~0U;
407 hdr
= grab_file(filename
, &info
->size
);
413 if (info
->size
< sizeof(*hdr
)) {
414 /* file too small, assume this is an empty .o file */
417 /* Is this a valid ELF file? */
418 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
419 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
420 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
421 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
422 /* Not an ELF file - silently ignore it */
425 /* Fix endianness in ELF header */
426 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
427 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
428 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
429 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
430 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
431 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
432 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
433 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
434 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
435 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
436 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
437 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
438 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
439 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
440 info
->sechdrs
= sechdrs
;
442 /* Check if file offset is correct */
443 if (hdr
->e_shoff
> info
->size
) {
444 fatal("section header offset=%lu in file '%s' is bigger than "
445 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
446 filename
, info
->size
);
450 if (hdr
->e_shnum
== SHN_UNDEF
) {
452 * There are more than 64k sections,
453 * read count from .sh_size.
455 info
->num_sections
= TO_NATIVE(sechdrs
[0].sh_size
);
458 info
->num_sections
= hdr
->e_shnum
;
460 if (hdr
->e_shstrndx
== SHN_XINDEX
) {
461 info
->secindex_strings
= TO_NATIVE(sechdrs
[0].sh_link
);
464 info
->secindex_strings
= hdr
->e_shstrndx
;
467 /* Fix endianness in section headers */
468 for (i
= 0; i
< info
->num_sections
; i
++) {
469 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
470 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
471 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
472 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
473 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
474 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
475 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
476 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
477 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
478 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
480 /* Find symbol table. */
481 secstrings
= (void *)hdr
+ sechdrs
[info
->secindex_strings
].sh_offset
;
482 for (i
= 1; i
< info
->num_sections
; i
++) {
484 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
486 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
487 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
488 "sizeof(*hrd)=%zu\n", filename
,
489 (unsigned long)sechdrs
[i
].sh_offset
,
493 secname
= secstrings
+ sechdrs
[i
].sh_name
;
494 if (strcmp(secname
, ".modinfo") == 0) {
496 fatal("%s has NOBITS .modinfo\n", filename
);
497 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
498 info
->modinfo_len
= sechdrs
[i
].sh_size
;
499 } else if (strcmp(secname
, "__ksymtab") == 0)
500 info
->export_sec
= i
;
501 else if (strcmp(secname
, "__ksymtab_unused") == 0)
502 info
->export_unused_sec
= i
;
503 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
504 info
->export_gpl_sec
= i
;
505 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
506 info
->export_unused_gpl_sec
= i
;
507 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
508 info
->export_gpl_future_sec
= i
;
510 if (sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
511 unsigned int sh_link_idx
;
513 info
->symtab_start
= (void *)hdr
+
514 sechdrs
[i
].sh_offset
;
515 info
->symtab_stop
= (void *)hdr
+
516 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
517 sh_link_idx
= sechdrs
[i
].sh_link
;
518 info
->strtab
= (void *)hdr
+
519 sechdrs
[sh_link_idx
].sh_offset
;
522 /* 32bit section no. table? ("more than 64k sections") */
523 if (sechdrs
[i
].sh_type
== SHT_SYMTAB_SHNDX
) {
524 symtab_shndx_idx
= i
;
525 info
->symtab_shndx_start
= (void *)hdr
+
526 sechdrs
[i
].sh_offset
;
527 info
->symtab_shndx_stop
= (void *)hdr
+
528 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
531 if (!info
->symtab_start
)
532 fatal("%s has no symtab?\n", filename
);
534 /* Fix endianness in symbols */
535 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
536 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
537 sym
->st_name
= TO_NATIVE(sym
->st_name
);
538 sym
->st_value
= TO_NATIVE(sym
->st_value
);
539 sym
->st_size
= TO_NATIVE(sym
->st_size
);
542 if (symtab_shndx_idx
!= ~0U) {
544 if (symtab_idx
!= sechdrs
[symtab_shndx_idx
].sh_link
)
545 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
546 filename
, sechdrs
[symtab_shndx_idx
].sh_link
,
549 for (p
= info
->symtab_shndx_start
; p
< info
->symtab_shndx_stop
;
557 static void parse_elf_finish(struct elf_info
*info
)
559 release_file(info
->hdr
, info
->size
);
562 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
564 /* ignore __this_module, it will be resolved shortly */
565 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
567 /* ignore global offset table */
568 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
570 if (info
->hdr
->e_machine
== EM_PPC
)
571 /* Special register function linked on all modules during final link of .ko */
572 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
573 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
574 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
575 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
577 if (info
->hdr
->e_machine
== EM_PPC64
)
578 /* Special register function linked on all modules during final link of .ko */
579 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
580 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
582 /* Do not ignore this symbol */
586 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
587 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
589 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
590 Elf_Sym
*sym
, const char *symname
)
595 if ((!is_vmlinux(mod
->name
) || mod
->is_dot_o
) &&
596 strncmp(symname
, "__ksymtab", 9) == 0)
597 export
= export_from_secname(info
, get_secindex(info
, sym
));
599 export
= export_from_sec(info
, get_secindex(info
, sym
));
601 switch (sym
->st_shndx
) {
603 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
607 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
608 crc
= (unsigned int) sym
->st_value
;
609 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
614 /* undefined symbol */
615 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
616 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
618 if (ignore_undef_symbol(info
, symname
))
620 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
621 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
622 /* add compatibility with older glibc */
623 #ifndef STT_SPARC_REGISTER
624 #define STT_SPARC_REGISTER STT_REGISTER
626 if (info
->hdr
->e_machine
== EM_SPARC
||
627 info
->hdr
->e_machine
== EM_SPARCV9
) {
628 /* Ignore register directives. */
629 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
631 if (symname
[0] == '.') {
632 char *munged
= strdup(symname
);
634 munged
[1] = toupper(munged
[1]);
640 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
641 strlen(MODULE_SYMBOL_PREFIX
)) == 0) {
643 alloc_symbol(symname
+
644 strlen(MODULE_SYMBOL_PREFIX
),
645 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
650 /* All exported symbols */
651 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
652 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
655 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
657 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
658 mod
->has_cleanup
= 1;
664 * Parse tag=value strings from .modinfo section
666 static char *next_string(char *string
, unsigned long *secsize
)
668 /* Skip non-zero chars */
671 if ((*secsize
)-- <= 1)
675 /* Skip any zero padding. */
678 if ((*secsize
)-- <= 1)
684 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
685 const char *tag
, char *info
)
688 unsigned int taglen
= strlen(tag
);
689 unsigned long size
= modinfo_len
;
692 size
-= info
- (char *)modinfo
;
693 modinfo
= next_string(info
, &size
);
696 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
697 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
698 return p
+ taglen
+ 1;
703 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
707 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
711 * Test if string s ends in string sub
714 static int strrcmp(const char *s
, const char *sub
)
722 sublen
= strlen(sub
);
724 if ((slen
== 0) || (sublen
== 0))
730 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
733 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
736 return elf
->strtab
+ sym
->st_name
;
741 static const char *sec_name(struct elf_info
*elf
, int secindex
)
743 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
744 return (void *)elf
->hdr
+
745 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
746 sechdrs
[secindex
].sh_name
;
749 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
751 return (void *)elf
->hdr
+
752 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
756 /* if sym is empty or point to a string
757 * like ".[0-9]+" then return 1.
758 * This is the optional prefix added by ld to some sections
760 static int number_prefix(const char *sym
)
768 if (c
< '0' || c
> '9')
774 /* The pattern is an array of simple patterns.
775 * "foo" will match an exact string equal to "foo"
776 * "*foo" will match a string that ends with "foo"
777 * "foo*" will match a string that begins with "foo"
778 * "foo$" will match a string equal to "foo" or "foo.1"
779 * where the '1' can be any number including several digits.
780 * The $ syntax is for sections where ld append a dot number
781 * to make section name unique.
783 static int match(const char *sym
, const char * const pat
[])
788 const char *endp
= p
+ strlen(p
) - 1;
792 if (strrcmp(sym
, p
+ 1) == 0)
796 else if (*endp
== '*') {
797 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
801 else if (*endp
== '$') {
802 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
803 if (number_prefix(sym
+ strlen(p
) - 1))
809 if (strcmp(p
, sym
) == 0)
817 /* sections that we do not want to do full section mismatch check on */
818 static const char *section_white_list
[] =
822 ".zdebug*", /* Compressed debug sections. */
823 ".GCC-command-line", /* mn10300 */
824 ".GCC.command.line", /* record-gcc-switches, non mn10300 */
825 ".mdebug*", /* alpha, score, mips etc. */
826 ".pdr", /* alpha, score, mips etc. */
831 ".xt.prop", /* xtensa */
832 ".xt.lit", /* xtensa */
837 * This is used to find sections missing the SHF_ALLOC flag.
838 * The cause of this is often a section specified in assembler
839 * without "ax" / "aw".
841 static void check_section(const char *modname
, struct elf_info
*elf
,
844 const char *sec
= sech_name(elf
, sechdr
);
846 if (sechdr
->sh_type
== SHT_PROGBITS
&&
847 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
848 !match(sec
, section_white_list
)) {
849 warn("%s (%s): unexpected non-allocatable section.\n"
850 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
851 "Note that for example <linux/init.h> contains\n"
852 "section definitions for use in .S files.\n\n",
859 #define ALL_INIT_DATA_SECTIONS \
860 ".init.setup$", ".init.rodata$", \
861 ".cpuinit.rodata$", ".meminit.rodata$", \
862 ".init.data$", ".cpuinit.data$", ".meminit.data$"
863 #define ALL_EXIT_DATA_SECTIONS \
864 ".exit.data$", ".cpuexit.data$", ".memexit.data$"
866 #define ALL_INIT_TEXT_SECTIONS \
867 ".init.text$", ".cpuinit.text$", ".meminit.text$"
868 #define ALL_EXIT_TEXT_SECTIONS \
869 ".exit.text$", ".cpuexit.text$", ".memexit.text$"
871 #define ALL_PCI_INIT_SECTIONS \
872 ".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \
873 ".pci_fixup_enable$", ".pci_fixup_resume$", \
874 ".pci_fixup_resume_early$", ".pci_fixup_suspend$"
876 #define ALL_XXXINIT_SECTIONS CPU_INIT_SECTIONS, MEM_INIT_SECTIONS
877 #define ALL_XXXEXIT_SECTIONS CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS
879 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
880 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
882 #define DATA_SECTIONS ".data$", ".data.rel$"
883 #define TEXT_SECTIONS ".text$"
885 #define INIT_SECTIONS ".init.*"
886 #define CPU_INIT_SECTIONS ".cpuinit.*"
887 #define MEM_INIT_SECTIONS ".meminit.*"
889 #define EXIT_SECTIONS ".exit.*"
890 #define CPU_EXIT_SECTIONS ".cpuexit.*"
891 #define MEM_EXIT_SECTIONS ".memexit.*"
893 /* init data sections */
894 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
896 /* all init sections */
897 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
899 /* All init and exit sections (code + data) */
900 static const char *init_exit_sections
[] =
901 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
904 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
907 /* symbols in .data that may refer to init/exit sections */
908 #define DEFAULT_SYMBOL_WHITE_LIST \
910 "*_template", /* scsi uses *_template a lot */ \
911 "*_timer", /* arm uses ops structures named _timer a lot */ \
912 "*_sht", /* scsi also used *_sht to some extent */ \
918 static const char *head_sections
[] = { ".head.text*", NULL
};
919 static const char *linker_symbols
[] =
920 { "__init_begin", "_sinittext", "_einittext", NULL
};
927 XXXINIT_TO_SOME_INIT
,
928 XXXEXIT_TO_SOME_EXIT
,
929 ANY_INIT_TO_ANY_EXIT
,
930 ANY_EXIT_TO_ANY_INIT
,
934 struct sectioncheck
{
935 const char *fromsec
[20];
936 const char *tosec
[20];
937 enum mismatch mismatch
;
938 const char *symbol_white_list
[20];
941 const struct sectioncheck sectioncheck
[] = {
942 /* Do not reference init/exit code/data from
943 * normal code and data
946 .fromsec
= { TEXT_SECTIONS
, NULL
},
947 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
948 .mismatch
= TEXT_TO_ANY_INIT
,
949 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
952 .fromsec
= { DATA_SECTIONS
, NULL
},
953 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
954 .mismatch
= DATA_TO_ANY_INIT
,
955 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
958 .fromsec
= { DATA_SECTIONS
, NULL
},
959 .tosec
= { INIT_SECTIONS
, NULL
},
960 .mismatch
= DATA_TO_ANY_INIT
,
961 .symbol_white_list
= {
962 "*_template", "*_timer", "*_sht", "*_ops",
963 "*_probe", "*_probe_one", "*_console", NULL
967 .fromsec
= { TEXT_SECTIONS
, NULL
},
968 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
969 .mismatch
= TEXT_TO_ANY_EXIT
,
970 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
973 .fromsec
= { DATA_SECTIONS
, NULL
},
974 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
975 .mismatch
= DATA_TO_ANY_EXIT
,
976 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
978 /* Do not reference init code/data from cpuinit/meminit code/data */
980 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
981 .tosec
= { INIT_SECTIONS
, NULL
},
982 .mismatch
= XXXINIT_TO_SOME_INIT
,
983 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
985 /* Do not reference cpuinit code/data from meminit code/data */
987 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
988 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
989 .mismatch
= XXXINIT_TO_SOME_INIT
,
990 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
992 /* Do not reference meminit code/data from cpuinit code/data */
994 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
995 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
996 .mismatch
= XXXINIT_TO_SOME_INIT
,
997 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
999 /* Do not reference exit code/data from cpuexit/memexit code/data */
1001 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
1002 .tosec
= { EXIT_SECTIONS
, NULL
},
1003 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1004 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1006 /* Do not reference cpuexit code/data from memexit code/data */
1008 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
1009 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
1010 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1011 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1013 /* Do not reference memexit code/data from cpuexit code/data */
1015 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
1016 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
1017 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
1018 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1020 /* Do not use exit code/data from init code */
1022 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
1023 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
1024 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1025 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1027 /* Do not use init code/data from exit code */
1029 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
1030 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
1031 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
1032 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1035 .fromsec
= { ALL_PCI_INIT_SECTIONS
, NULL
},
1036 .tosec
= { INIT_SECTIONS
, NULL
},
1037 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
1038 .symbol_white_list
= { NULL
},
1040 /* Do not export init/exit functions or data */
1042 .fromsec
= { "__ksymtab*", NULL
},
1043 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1044 .mismatch
= EXPORT_TO_INIT_EXIT
,
1045 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1049 static const struct sectioncheck
*section_mismatch(
1050 const char *fromsec
, const char *tosec
)
1053 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1054 const struct sectioncheck
*check
= §ioncheck
[0];
1056 for (i
= 0; i
< elems
; i
++) {
1057 if (match(fromsec
, check
->fromsec
) &&
1058 match(tosec
, check
->tosec
))
1066 * Whitelist to allow certain references to pass with no warning.
1069 * If a module parameter is declared __initdata and permissions=0
1070 * then this is legal despite the warning generated.
1071 * We cannot see value of permissions here, so just ignore
1073 * The pattern is identified by:
1074 * tosec = .init.data
1079 * module_param_call() ops can refer to __init set function if permissions=0
1080 * The pattern is identified by:
1081 * tosec = .init.text
1083 * atsym = __param_ops_*
1086 * Many drivers utilise a *driver container with references to
1087 * add, remove, probe functions etc.
1088 * These functions may often be marked __cpuinit and we do not want to
1090 * the pattern is identified by:
1091 * tosec = init or exit section
1092 * fromsec = data section
1093 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1094 * *probe_one, *_console, *_timer
1097 * Whitelist all references from .head.text to any init section
1100 * Some symbols belong to init section but still it is ok to reference
1101 * these from non-init sections as these symbols don't have any memory
1102 * allocated for them and symbol address and value are same. So even
1103 * if init section is freed, its ok to reference those symbols.
1104 * For ex. symbols marking the init section boundaries.
1105 * This pattern is identified by
1106 * refsymname = __init_begin, _sinittext, _einittext
1109 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1110 const char *fromsec
, const char *fromsym
,
1111 const char *tosec
, const char *tosym
)
1113 /* Check for pattern 1 */
1114 if (match(tosec
, init_data_sections
) &&
1115 match(fromsec
, data_sections
) &&
1116 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1119 /* Check for pattern 1a */
1120 if (strcmp(tosec
, ".init.text") == 0 &&
1121 match(fromsec
, data_sections
) &&
1122 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1125 /* Check for pattern 2 */
1126 if (match(tosec
, init_exit_sections
) &&
1127 match(fromsec
, data_sections
) &&
1128 match(fromsym
, mismatch
->symbol_white_list
))
1131 /* Check for pattern 3 */
1132 if (match(fromsec
, head_sections
) &&
1133 match(tosec
, init_sections
))
1136 /* Check for pattern 4 */
1137 if (match(tosym
, linker_symbols
))
1144 * Find symbol based on relocation record info.
1145 * In some cases the symbol supplied is a valid symbol so
1146 * return refsym. If st_name != 0 we assume this is a valid symbol.
1147 * In other cases the symbol needs to be looked up in the symbol table
1148 * based on section and address.
1150 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1154 Elf_Sym
*near
= NULL
;
1155 Elf64_Sword distance
= 20;
1157 unsigned int relsym_secindex
;
1159 if (relsym
->st_name
!= 0)
1162 relsym_secindex
= get_secindex(elf
, relsym
);
1163 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1164 if (get_secindex(elf
, sym
) != relsym_secindex
)
1166 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1168 if (sym
->st_value
== addr
)
1170 /* Find a symbol nearby - addr are maybe negative */
1171 d
= sym
->st_value
- addr
;
1173 d
= addr
- sym
->st_value
;
1179 /* We need a close match */
1186 static inline int is_arm_mapping_symbol(const char *str
)
1188 return str
[0] == '$' && strchr("atd", str
[1])
1189 && (str
[2] == '\0' || str
[2] == '.');
1193 * If there's no name there, ignore it; likewise, ignore it if it's
1194 * one of the magic symbols emitted used by current ARM tools.
1196 * Otherwise if find_symbols_between() returns those symbols, they'll
1197 * fail the whitelist tests and cause lots of false alarms ... fixable
1198 * only by merging __exit and __init sections into __text, bloating
1199 * the kernel (which is especially evil on embedded platforms).
1201 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1203 const char *name
= elf
->strtab
+ sym
->st_name
;
1205 if (!name
|| !strlen(name
))
1207 return !is_arm_mapping_symbol(name
);
1211 * Find symbols before or equal addr and after addr - in the section sec.
1212 * If we find two symbols with equal offset prefer one with a valid name.
1213 * The ELF format may have a better way to detect what type of symbol
1214 * it is, but this works for now.
1216 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1220 Elf_Sym
*near
= NULL
;
1221 Elf_Addr distance
= ~0;
1223 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1226 if (is_shndx_special(sym
->st_shndx
))
1228 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1229 if (strcmp(symsec
, sec
) != 0)
1231 if (!is_valid_name(elf
, sym
))
1233 if (sym
->st_value
<= addr
) {
1234 if ((addr
- sym
->st_value
) < distance
) {
1235 distance
= addr
- sym
->st_value
;
1237 } else if ((addr
- sym
->st_value
) == distance
) {
1246 * Convert a section name to the function/data attribute
1247 * .init.text => __init
1248 * .cpuinit.data => __cpudata
1249 * .memexitconst => __memconst
1252 * The memory of returned value has been allocated on a heap. The user of this
1253 * method should free it after usage.
1255 static char *sec2annotation(const char *s
)
1257 if (match(s
, init_exit_sections
)) {
1258 char *p
= malloc(20);
1265 while (*s
&& *s
!= '.')
1270 if (strstr(s
, "rodata") != NULL
)
1271 strcat(p
, "const ");
1272 else if (strstr(s
, "data") != NULL
)
1282 static int is_function(Elf_Sym
*sym
)
1285 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1290 static void print_section_list(const char * const list
[20])
1292 const char *const *s
= list
;
1295 fprintf(stderr
, "%s", *s
);
1298 fprintf(stderr
, ", ");
1300 fprintf(stderr
, "\n");
1304 * Print a warning about a section mismatch.
1305 * Try to find symbols near it so user can find it.
1306 * Check whitelist before warning - it may be a false positive.
1308 static void report_sec_mismatch(const char *modname
,
1309 const struct sectioncheck
*mismatch
,
1310 const char *fromsec
,
1311 unsigned long long fromaddr
,
1312 const char *fromsym
,
1314 const char *tosec
, const char *tosym
,
1317 const char *from
, *from_p
;
1318 const char *to
, *to_p
;
1322 switch (from_is_func
) {
1323 case 0: from
= "variable"; from_p
= ""; break;
1324 case 1: from
= "function"; from_p
= "()"; break;
1325 default: from
= "(unknown reference)"; from_p
= ""; break;
1327 switch (to_is_func
) {
1328 case 0: to
= "variable"; to_p
= ""; break;
1329 case 1: to
= "function"; to_p
= "()"; break;
1330 default: to
= "(unknown reference)"; to_p
= ""; break;
1333 sec_mismatch_count
++;
1334 if (!sec_mismatch_verbose
)
1337 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1338 "to the %s %s:%s%s\n",
1339 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1342 switch (mismatch
->mismatch
) {
1343 case TEXT_TO_ANY_INIT
:
1344 prl_from
= sec2annotation(fromsec
);
1345 prl_to
= sec2annotation(tosec
);
1347 "The function %s%s() references\n"
1349 "This is often because %s lacks a %s\n"
1350 "annotation or the annotation of %s is wrong.\n",
1352 to
, prl_to
, tosym
, to_p
,
1353 fromsym
, prl_to
, tosym
);
1357 case DATA_TO_ANY_INIT
: {
1358 prl_to
= sec2annotation(tosec
);
1360 "The variable %s references\n"
1362 "If the reference is valid then annotate the\n"
1363 "variable with __init* or __refdata (see linux/init.h) "
1364 "or name the variable:\n",
1365 fromsym
, to
, prl_to
, tosym
, to_p
);
1366 print_section_list(mismatch
->symbol_white_list
);
1370 case TEXT_TO_ANY_EXIT
:
1371 prl_to
= sec2annotation(tosec
);
1373 "The function %s() references a %s in an exit section.\n"
1374 "Often the %s %s%s has valid usage outside the exit section\n"
1375 "and the fix is to remove the %sannotation of %s.\n",
1376 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1379 case DATA_TO_ANY_EXIT
: {
1380 prl_to
= sec2annotation(tosec
);
1382 "The variable %s references\n"
1384 "If the reference is valid then annotate the\n"
1385 "variable with __exit* (see linux/init.h) or "
1386 "name the variable:\n",
1387 fromsym
, to
, prl_to
, tosym
, to_p
);
1388 print_section_list(mismatch
->symbol_white_list
);
1392 case XXXINIT_TO_SOME_INIT
:
1393 case XXXEXIT_TO_SOME_EXIT
:
1394 prl_from
= sec2annotation(fromsec
);
1395 prl_to
= sec2annotation(tosec
);
1397 "The %s %s%s%s references\n"
1399 "If %s is only used by %s then\n"
1400 "annotate %s with a matching annotation.\n",
1401 from
, prl_from
, fromsym
, from_p
,
1402 to
, prl_to
, tosym
, to_p
,
1403 tosym
, fromsym
, tosym
);
1407 case ANY_INIT_TO_ANY_EXIT
:
1408 prl_from
= sec2annotation(fromsec
);
1409 prl_to
= sec2annotation(tosec
);
1411 "The %s %s%s%s references\n"
1413 "This is often seen when error handling "
1414 "in the init function\n"
1415 "uses functionality in the exit path.\n"
1416 "The fix is often to remove the %sannotation of\n"
1417 "%s%s so it may be used outside an exit section.\n",
1418 from
, prl_from
, fromsym
, from_p
,
1419 to
, prl_to
, tosym
, to_p
,
1420 prl_to
, tosym
, to_p
);
1424 case ANY_EXIT_TO_ANY_INIT
:
1425 prl_from
= sec2annotation(fromsec
);
1426 prl_to
= sec2annotation(tosec
);
1428 "The %s %s%s%s references\n"
1430 "This is often seen when error handling "
1431 "in the exit function\n"
1432 "uses functionality in the init path.\n"
1433 "The fix is often to remove the %sannotation of\n"
1434 "%s%s so it may be used outside an init section.\n",
1435 from
, prl_from
, fromsym
, from_p
,
1436 to
, prl_to
, tosym
, to_p
,
1437 prl_to
, tosym
, to_p
);
1441 case EXPORT_TO_INIT_EXIT
:
1442 prl_to
= sec2annotation(tosec
);
1444 "The symbol %s is exported and annotated %s\n"
1445 "Fix this by removing the %sannotation of %s "
1446 "or drop the export.\n",
1447 tosym
, prl_to
, prl_to
, tosym
);
1451 fprintf(stderr
, "\n");
1454 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1455 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1458 const struct sectioncheck
*mismatch
;
1460 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1461 mismatch
= section_mismatch(fromsec
, tosec
);
1466 const char *fromsym
;
1468 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1469 fromsym
= sym_name(elf
, from
);
1470 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1471 tosym
= sym_name(elf
, to
);
1473 /* check whitelist - we may ignore it */
1474 if (secref_whitelist(mismatch
,
1475 fromsec
, fromsym
, tosec
, tosym
)) {
1476 report_sec_mismatch(modname
, mismatch
,
1477 fromsec
, r
->r_offset
, fromsym
,
1478 is_function(from
), tosec
, tosym
,
1484 static unsigned int *reloc_location(struct elf_info
*elf
,
1485 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1487 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1488 int section
= sechdr
->sh_info
;
1490 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1494 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1496 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1497 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1501 r
->r_addend
= TO_NATIVE(*location
);
1504 r
->r_addend
= TO_NATIVE(*location
) + 4;
1505 /* For CONFIG_RELOCATABLE=y */
1506 if (elf
->hdr
->e_type
== ET_EXEC
)
1507 r
->r_addend
+= r
->r_offset
;
1514 #define R_ARM_CALL 28
1516 #ifndef R_ARM_JUMP24
1517 #define R_ARM_JUMP24 29
1520 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1522 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1526 /* From ARM ABI: (S + A) | T */
1527 r
->r_addend
= (int)(long)
1528 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1533 /* From ARM ABI: ((S + A) | T) - P */
1534 r
->r_addend
= (int)(long)(elf
->hdr
+
1536 (r
->r_offset
- sechdr
->sh_addr
));
1544 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1546 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1547 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1550 if (r_typ
== R_MIPS_HI16
)
1551 return 1; /* skip this */
1552 inst
= TO_NATIVE(*location
);
1555 r
->r_addend
= inst
& 0xffff;
1558 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1567 static void section_rela(const char *modname
, struct elf_info
*elf
,
1574 const char *fromsec
;
1576 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1577 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1579 fromsec
= sech_name(elf
, sechdr
);
1580 fromsec
+= strlen(".rela");
1581 /* if from section (name) is know good then skip it */
1582 if (match(fromsec
, section_white_list
))
1585 for (rela
= start
; rela
< stop
; rela
++) {
1586 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1587 #if KERNEL_ELFCLASS == ELFCLASS64
1588 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1590 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1591 r_sym
= TO_NATIVE(r_sym
);
1592 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1593 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1595 r
.r_info
= TO_NATIVE(rela
->r_info
);
1596 r_sym
= ELF_R_SYM(r
.r_info
);
1599 r
.r_info
= TO_NATIVE(rela
->r_info
);
1600 r_sym
= ELF_R_SYM(r
.r_info
);
1602 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1603 sym
= elf
->symtab_start
+ r_sym
;
1604 /* Skip special sections */
1605 if (is_shndx_special(sym
->st_shndx
))
1607 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1611 static void section_rel(const char *modname
, struct elf_info
*elf
,
1618 const char *fromsec
;
1620 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1621 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1623 fromsec
= sech_name(elf
, sechdr
);
1624 fromsec
+= strlen(".rel");
1625 /* if from section (name) is know good then skip it */
1626 if (match(fromsec
, section_white_list
))
1629 for (rel
= start
; rel
< stop
; rel
++) {
1630 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1631 #if KERNEL_ELFCLASS == ELFCLASS64
1632 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1634 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1635 r_sym
= TO_NATIVE(r_sym
);
1636 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1637 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1639 r
.r_info
= TO_NATIVE(rel
->r_info
);
1640 r_sym
= ELF_R_SYM(r
.r_info
);
1643 r
.r_info
= TO_NATIVE(rel
->r_info
);
1644 r_sym
= ELF_R_SYM(r
.r_info
);
1647 switch (elf
->hdr
->e_machine
) {
1649 if (addend_386_rel(elf
, sechdr
, &r
))
1653 if (addend_arm_rel(elf
, sechdr
, &r
))
1657 if (addend_mips_rel(elf
, sechdr
, &r
))
1661 sym
= elf
->symtab_start
+ r_sym
;
1662 /* Skip special sections */
1663 if (is_shndx_special(sym
->st_shndx
))
1665 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1670 * A module includes a number of sections that are discarded
1671 * either when loaded or when used as built-in.
1672 * For loaded modules all functions marked __init and all data
1673 * marked __initdata will be discarded when the module has been initialized.
1674 * Likewise for modules used built-in the sections marked __exit
1675 * are discarded because __exit marked function are supposed to be called
1676 * only when a module is unloaded which never happens for built-in modules.
1677 * The check_sec_ref() function traverses all relocation records
1678 * to find all references to a section that reference a section that will
1679 * be discarded and warns about it.
1681 static void check_sec_ref(struct module
*mod
, const char *modname
,
1682 struct elf_info
*elf
)
1685 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1687 /* Walk through all sections */
1688 for (i
= 0; i
< elf
->num_sections
; i
++) {
1689 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1690 /* We want to process only relocation sections and not .init */
1691 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1692 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1693 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1694 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1698 static void read_symbols(char *modname
)
1700 const char *symname
;
1704 struct elf_info info
= { };
1707 if (!parse_elf(&info
, modname
))
1710 mod
= new_module(modname
);
1712 /* When there's no vmlinux, don't print warnings about
1713 * unresolved symbols (since there'll be too many ;) */
1714 if (is_vmlinux(modname
)) {
1719 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1720 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1721 warn("modpost: missing MODULE_LICENSE() in %s\n"
1722 "see include/linux/module.h for "
1723 "more information\n", modname
);
1725 if (license_is_gpl_compatible(license
))
1726 mod
->gpl_compatible
= 1;
1728 mod
->gpl_compatible
= 0;
1731 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1732 "license", license
);
1735 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1736 symname
= info
.strtab
+ sym
->st_name
;
1738 handle_modversions(mod
, &info
, sym
, symname
);
1739 handle_moddevtable(mod
, &info
, sym
, symname
);
1741 if (!is_vmlinux(modname
) ||
1742 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1743 check_sec_ref(mod
, modname
, &info
);
1745 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1747 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1748 version
- (char *)info
.hdr
);
1749 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1750 get_src_version(modname
, mod
->srcversion
,
1751 sizeof(mod
->srcversion
)-1);
1753 parse_elf_finish(&info
);
1755 /* Our trick to get versioning for module struct etc. - it's
1756 * never passed as an argument to an exported function, so
1757 * the automatic versioning doesn't pick it up, but it's really
1758 * important anyhow */
1760 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1765 /* We first write the generated file into memory using the
1766 * following helper, then compare to the file on disk and
1767 * only update the later if anything changed */
1769 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1770 const char *fmt
, ...)
1777 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1778 buf_write(buf
, tmp
, len
);
1782 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1784 if (buf
->size
- buf
->pos
< len
) {
1785 buf
->size
+= len
+ SZ
;
1786 buf
->p
= realloc(buf
->p
, buf
->size
);
1788 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1792 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1794 const char *e
= is_vmlinux(m
) ?"":".ko";
1798 fatal("modpost: GPL-incompatible module %s%s "
1799 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1801 case export_unused_gpl
:
1802 fatal("modpost: GPL-incompatible module %s%s "
1803 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1805 case export_gpl_future
:
1806 warn("modpost: GPL-incompatible module %s%s "
1807 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1811 case export_unknown
:
1817 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1819 const char *e
= is_vmlinux(m
) ?"":".ko";
1823 case export_unused_gpl
:
1824 warn("modpost: module %s%s "
1825 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1833 static void check_exports(struct module
*mod
)
1835 struct symbol
*s
, *exp
;
1837 for (s
= mod
->unres
; s
; s
= s
->next
) {
1838 const char *basename
;
1839 exp
= find_symbol(s
->name
);
1840 if (!exp
|| exp
->module
== mod
)
1842 basename
= strrchr(mod
->name
, '/');
1846 basename
= mod
->name
;
1847 if (!mod
->gpl_compatible
)
1848 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1849 check_for_unused(exp
->export
, basename
, exp
->name
);
1854 * Header for the generated file
1856 static void add_header(struct buffer
*b
, struct module
*mod
)
1858 buf_printf(b
, "#include <linux/module.h>\n");
1859 buf_printf(b
, "#include <linux/vermagic.h>\n");
1860 buf_printf(b
, "#include <linux/compiler.h>\n");
1861 buf_printf(b
, "\n");
1862 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1863 buf_printf(b
, "\n");
1864 buf_printf(b
, "struct module __this_module\n");
1865 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1866 buf_printf(b
, "\t.name = KBUILD_MODNAME,\n");
1868 buf_printf(b
, "\t.init = init_module,\n");
1869 if (mod
->has_cleanup
)
1870 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1871 "\t.exit = cleanup_module,\n"
1873 buf_printf(b
, "\t.arch = MODULE_ARCH_INIT,\n");
1874 buf_printf(b
, "};\n");
1877 static void add_intree_flag(struct buffer
*b
, int is_intree
)
1880 buf_printf(b
, "\nMODULE_INFO(intree, \"Y\");\n");
1883 static void add_staging_flag(struct buffer
*b
, const char *name
)
1885 static const char *staging_dir
= "drivers/staging";
1887 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1888 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1892 * Record CRCs for unresolved symbols
1894 static int add_versions(struct buffer
*b
, struct module
*mod
)
1896 struct symbol
*s
, *exp
;
1899 for (s
= mod
->unres
; s
; s
= s
->next
) {
1900 exp
= find_symbol(s
->name
);
1901 if (!exp
|| exp
->module
== mod
) {
1902 if (have_vmlinux
&& !s
->weak
) {
1903 if (warn_unresolved
) {
1904 warn("\"%s\" [%s.ko] undefined!\n",
1905 s
->name
, mod
->name
);
1907 merror("\"%s\" [%s.ko] undefined!\n",
1908 s
->name
, mod
->name
);
1914 s
->module
= exp
->module
;
1915 s
->crc_valid
= exp
->crc_valid
;
1922 buf_printf(b
, "\n");
1923 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1924 buf_printf(b
, "__used\n");
1925 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1927 for (s
= mod
->unres
; s
; s
= s
->next
) {
1930 if (!s
->crc_valid
) {
1931 warn("\"%s\" [%s.ko] has no CRC!\n",
1932 s
->name
, mod
->name
);
1935 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1938 buf_printf(b
, "};\n");
1943 static void add_depends(struct buffer
*b
, struct module
*mod
,
1944 struct module
*modules
)
1950 for (m
= modules
; m
; m
= m
->next
)
1951 m
->seen
= is_vmlinux(m
->name
);
1953 buf_printf(b
, "\n");
1954 buf_printf(b
, "static const char __module_depends[]\n");
1955 buf_printf(b
, "__used\n");
1956 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1957 buf_printf(b
, "\"depends=");
1958 for (s
= mod
->unres
; s
; s
= s
->next
) {
1963 if (s
->module
->seen
)
1966 s
->module
->seen
= 1;
1967 p
= strrchr(s
->module
->name
, '/');
1971 p
= s
->module
->name
;
1972 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1975 buf_printf(b
, "\";\n");
1978 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1980 if (mod
->srcversion
[0]) {
1981 buf_printf(b
, "\n");
1982 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1987 static void write_if_changed(struct buffer
*b
, const char *fname
)
1993 file
= fopen(fname
, "r");
1997 if (fstat(fileno(file
), &st
) < 0)
2000 if (st
.st_size
!= b
->pos
)
2003 tmp
= NOFAIL(malloc(b
->pos
));
2004 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
2007 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
2019 file
= fopen(fname
, "w");
2024 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
2031 /* parse Module.symvers file. line format:
2032 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
2034 static void read_dump(const char *fname
, unsigned int kernel
)
2036 unsigned long size
, pos
= 0;
2037 void *file
= grab_file(fname
, &size
);
2041 /* No symbol versions, silently ignore */
2044 while ((line
= get_next_line(&pos
, file
, size
))) {
2045 char *symname
, *modname
, *d
, *export
, *end
;
2050 if (!(symname
= strchr(line
, '\t')))
2053 if (!(modname
= strchr(symname
, '\t')))
2056 if ((export
= strchr(modname
, '\t')) != NULL
)
2058 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2060 crc
= strtoul(line
, &d
, 16);
2061 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2063 mod
= find_module(modname
);
2065 if (is_vmlinux(modname
))
2067 mod
= new_module(modname
);
2070 s
= sym_add_exported(symname
, mod
, export_no(export
));
2073 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2077 fatal("parse error in symbol dump file\n");
2080 /* For normal builds always dump all symbols.
2081 * For external modules only dump symbols
2082 * that are not read from kernel Module.symvers.
2084 static int dump_sym(struct symbol
*sym
)
2086 if (!external_module
)
2088 if (sym
->vmlinux
|| sym
->kernel
)
2093 static void write_dump(const char *fname
)
2095 struct buffer buf
= { };
2096 struct symbol
*symbol
;
2099 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2100 symbol
= symbolhash
[n
];
2102 if (dump_sym(symbol
))
2103 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2104 symbol
->crc
, symbol
->name
,
2105 symbol
->module
->name
,
2106 export_str(symbol
->export
));
2107 symbol
= symbol
->next
;
2110 write_if_changed(&buf
, fname
);
2113 struct ext_sym_list
{
2114 struct ext_sym_list
*next
;
2118 int main(int argc
, char **argv
)
2121 struct buffer buf
= { };
2122 char *kernel_read
= NULL
, *module_read
= NULL
;
2123 char *dump_write
= NULL
;
2126 struct ext_sym_list
*extsym_iter
;
2127 struct ext_sym_list
*extsym_start
= NULL
;
2129 while ((opt
= getopt(argc
, argv
, "i:I:e:cmsSo:awM:K:")) != -1) {
2132 kernel_read
= optarg
;
2135 module_read
= optarg
;
2136 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 dump_write
= optarg
;
2159 vmlinux_section_warnings
= 0;
2162 sec_mismatch_verbose
= 0;
2165 warn_unresolved
= 1;
2173 read_dump(kernel_read
, 1);
2175 read_dump(module_read
, 0);
2176 while (extsym_start
) {
2177 read_dump(extsym_start
->file
, 0);
2178 extsym_iter
= extsym_start
->next
;
2180 extsym_start
= extsym_iter
;
2183 while (optind
< argc
)
2184 read_symbols(argv
[optind
++]);
2186 for (mod
= modules
; mod
; mod
= mod
->next
) {
2194 for (mod
= modules
; mod
; mod
= mod
->next
) {
2195 char fname
[strlen(mod
->name
) + 10];
2202 add_header(&buf
, mod
);
2203 add_intree_flag(&buf
, !external_module
);
2204 add_staging_flag(&buf
, mod
->name
);
2205 err
|= add_versions(&buf
, mod
);
2206 add_depends(&buf
, mod
, modules
);
2207 add_moddevtable(&buf
, mod
);
2208 add_srcversion(&buf
, mod
);
2210 sprintf(fname
, "%s.mod.c", mod
->name
);
2211 write_if_changed(&buf
, fname
);
2215 write_dump(dump_write
);
2216 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2217 warn("modpost: Found %d section mismatch(es).\n"
2218 "To see full details build your kernel with:\n"
2219 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2220 sec_mismatch_count
);