1 /* Postprocess module symbol versions
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006 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 ...
16 #include "../../include/linux/license.h"
18 /* Are we using CONFIG_MODVERSIONS? */
20 /* Warn about undefined symbols? (do so if we have vmlinux) */
22 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
23 static int all_versions
= 0;
24 /* If we are modposting external module set to 1 */
25 static int external_module
= 0;
26 /* Only warn about unresolved symbols */
27 static int warn_unresolved
= 0;
28 /* How a symbol is exported */
30 export_plain
, export_unused
, export_gpl
,
31 export_unused_gpl
, export_gpl_future
, export_unknown
34 void fatal(const char *fmt
, ...)
38 fprintf(stderr
, "FATAL: ");
40 va_start(arglist
, fmt
);
41 vfprintf(stderr
, fmt
, arglist
);
47 void warn(const char *fmt
, ...)
51 fprintf(stderr
, "WARNING: ");
53 va_start(arglist
, fmt
);
54 vfprintf(stderr
, fmt
, arglist
);
58 void merror(const char *fmt
, ...)
62 fprintf(stderr
, "ERROR: ");
64 va_start(arglist
, fmt
);
65 vfprintf(stderr
, fmt
, arglist
);
69 static int is_vmlinux(const char *modname
)
73 if ((myname
= strrchr(modname
, '/')))
78 return strcmp(myname
, "vmlinux") == 0;
81 void *do_nofail(void *ptr
, const char *expr
)
84 fatal("modpost: Memory allocation failure: %s.\n", expr
);
89 /* A list of all modules we processed */
91 static struct module
*modules
;
93 static struct module
*find_module(char *modname
)
97 for (mod
= modules
; mod
; mod
= mod
->next
)
98 if (strcmp(mod
->name
, modname
) == 0)
103 static struct module
*new_module(char *modname
)
108 mod
= NOFAIL(malloc(sizeof(*mod
)));
109 memset(mod
, 0, sizeof(*mod
));
110 p
= NOFAIL(strdup(modname
));
112 /* strip trailing .o */
113 if ((s
= strrchr(p
, '.')) != NULL
)
114 if (strcmp(s
, ".o") == 0)
119 mod
->gpl_compatible
= -1;
126 /* A hash of all exported symbols,
127 * struct symbol is also used for lists of unresolved symbols */
129 #define SYMBOL_HASH_SIZE 1024
133 struct module
*module
;
137 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
138 unsigned int kernel
:1; /* 1 if symbol is from kernel
139 * (only for external modules) **/
140 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
141 enum export export
; /* Type of export */
145 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
147 /* This is based on the hash agorithm from gdbm, via tdb */
148 static inline unsigned int tdb_hash(const char *name
)
150 unsigned value
; /* Used to compute the hash value. */
151 unsigned i
; /* Used to cycle through random values. */
153 /* Set the initial value from the key size. */
154 for (value
= 0x238F13AF * strlen(name
), i
=0; name
[i
]; i
++)
155 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
157 return (1103515243 * value
+ 12345);
161 * Allocate a new symbols for use in the hash of exported symbols or
162 * the list of unresolved symbols per module
164 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
167 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
169 memset(s
, 0, sizeof(*s
));
170 strcpy(s
->name
, name
);
176 /* For the hash of exported symbols */
177 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
183 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
184 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
185 new->module
= module
;
186 new->export
= export
;
190 static struct symbol
*find_symbol(const char *name
)
194 /* For our purposes, .foo matches foo. PPC64 needs this. */
198 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
=s
->next
) {
199 if (strcmp(s
->name
, name
) == 0)
209 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
210 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
211 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
212 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
213 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
214 { .str
= "(unknown)", .export
= export_unknown
},
218 static const char *export_str(enum export ex
)
220 return export_list
[ex
].str
;
223 static enum export
export_no(const char * s
)
227 return export_unknown
;
228 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
229 if (strcmp(export_list
[i
].str
, s
) == 0)
230 return export_list
[i
].export
;
232 return export_unknown
;
235 static enum export
export_from_sec(struct elf_info
*elf
, Elf_Section sec
)
237 if (sec
== elf
->export_sec
)
239 else if (sec
== elf
->export_unused_sec
)
240 return export_unused
;
241 else if (sec
== elf
->export_gpl_sec
)
243 else if (sec
== elf
->export_unused_gpl_sec
)
244 return export_unused_gpl
;
245 else if (sec
== elf
->export_gpl_future_sec
)
246 return export_gpl_future
;
248 return export_unknown
;
252 * Add an exported symbol - it may have already been added without a
253 * CRC, in this case just update the CRC
255 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
258 struct symbol
*s
= find_symbol(name
);
261 s
= new_symbol(name
, mod
, export
);
264 warn("%s: '%s' exported twice. Previous export "
265 "was in %s%s\n", mod
->name
, name
,
267 is_vmlinux(s
->module
->name
) ?"":".ko");
271 s
->vmlinux
= is_vmlinux(mod
->name
);
277 static void sym_update_crc(const char *name
, struct module
*mod
,
278 unsigned int crc
, enum export export
)
280 struct symbol
*s
= find_symbol(name
);
283 s
= new_symbol(name
, mod
, export
);
288 void *grab_file(const char *filename
, unsigned long *size
)
294 fd
= open(filename
, O_RDONLY
);
295 if (fd
< 0 || fstat(fd
, &st
) != 0)
299 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
302 if (map
== MAP_FAILED
)
308 * Return a copy of the next line in a mmap'ed file.
309 * spaces in the beginning of the line is trimmed away.
310 * Return a pointer to a static buffer.
312 char* get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
314 static char line
[4096];
317 signed char *p
= (signed char *)file
+ *pos
;
320 for (; *pos
< size
; (*pos
)++)
322 if (skip
&& isspace(*p
)) {
327 if (*p
!= '\n' && (*pos
< size
)) {
331 break; /* Too long, stop */
342 void release_file(void *file
, unsigned long size
)
347 static int parse_elf(struct elf_info
*info
, const char *filename
)
354 hdr
= grab_file(filename
, &info
->size
);
360 if (info
->size
< sizeof(*hdr
)) {
361 /* file too small, assume this is an empty .o file */
364 /* Is this a valid ELF file? */
365 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
366 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
367 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
368 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
369 /* Not an ELF file - silently ignore it */
372 /* Fix endianness in ELF header */
373 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
374 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
375 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
376 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
377 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
378 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
379 info
->sechdrs
= sechdrs
;
381 /* Fix endianness in section headers */
382 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
383 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
384 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
385 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
386 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
387 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
388 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
389 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
391 /* Find symbol table. */
392 for (i
= 1; i
< hdr
->e_shnum
; i
++) {
393 const char *secstrings
394 = (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
397 if (sechdrs
[i
].sh_offset
> info
->size
) {
398 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename
, (unsigned int)sechdrs
[i
].sh_offset
, sizeof(*hdr
));
401 secname
= secstrings
+ sechdrs
[i
].sh_name
;
402 if (strcmp(secname
, ".modinfo") == 0) {
403 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
404 info
->modinfo_len
= sechdrs
[i
].sh_size
;
405 } else if (strcmp(secname
, "__ksymtab") == 0)
406 info
->export_sec
= i
;
407 else if (strcmp(secname
, "__ksymtab_unused") == 0)
408 info
->export_unused_sec
= i
;
409 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
410 info
->export_gpl_sec
= i
;
411 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
412 info
->export_unused_gpl_sec
= i
;
413 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
414 info
->export_gpl_future_sec
= i
;
416 if (sechdrs
[i
].sh_type
!= SHT_SYMTAB
)
419 info
->symtab_start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
420 info
->symtab_stop
= (void *)hdr
+ sechdrs
[i
].sh_offset
421 + sechdrs
[i
].sh_size
;
422 info
->strtab
= (void *)hdr
+
423 sechdrs
[sechdrs
[i
].sh_link
].sh_offset
;
425 if (!info
->symtab_start
) {
426 fatal("%s has no symtab?\n", filename
);
428 /* Fix endianness in symbols */
429 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
430 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
431 sym
->st_name
= TO_NATIVE(sym
->st_name
);
432 sym
->st_value
= TO_NATIVE(sym
->st_value
);
433 sym
->st_size
= TO_NATIVE(sym
->st_size
);
438 static void parse_elf_finish(struct elf_info
*info
)
440 release_file(info
->hdr
, info
->size
);
443 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
444 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
446 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
447 Elf_Sym
*sym
, const char *symname
)
450 enum export export
= export_from_sec(info
, sym
->st_shndx
);
452 switch (sym
->st_shndx
) {
454 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
458 if (memcmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
459 crc
= (unsigned int) sym
->st_value
;
460 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
465 /* undefined symbol */
466 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
467 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
469 /* ignore global offset table */
470 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
472 /* ignore __this_module, it will be resolved shortly */
473 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
475 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
476 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
477 /* add compatibility with older glibc */
478 #ifndef STT_SPARC_REGISTER
479 #define STT_SPARC_REGISTER STT_REGISTER
481 if (info
->hdr
->e_machine
== EM_SPARC
||
482 info
->hdr
->e_machine
== EM_SPARCV9
) {
483 /* Ignore register directives. */
484 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
486 if (symname
[0] == '.') {
487 char *munged
= strdup(symname
);
489 munged
[1] = toupper(munged
[1]);
495 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
496 strlen(MODULE_SYMBOL_PREFIX
)) == 0)
497 mod
->unres
= alloc_symbol(symname
+
498 strlen(MODULE_SYMBOL_PREFIX
),
499 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
503 /* All exported symbols */
504 if (memcmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
505 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
508 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
510 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
511 mod
->has_cleanup
= 1;
517 * Parse tag=value strings from .modinfo section
519 static char *next_string(char *string
, unsigned long *secsize
)
521 /* Skip non-zero chars */
524 if ((*secsize
)-- <= 1)
528 /* Skip any zero padding. */
531 if ((*secsize
)-- <= 1)
537 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
538 const char *tag
, char *info
)
541 unsigned int taglen
= strlen(tag
);
542 unsigned long size
= modinfo_len
;
545 size
-= info
- (char *)modinfo
;
546 modinfo
= next_string(info
, &size
);
549 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
550 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
551 return p
+ taglen
+ 1;
556 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
560 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
564 * Test if string s ends in string sub
567 static int strrcmp(const char *s
, const char *sub
)
575 sublen
= strlen(sub
);
577 if ((slen
== 0) || (sublen
== 0))
583 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
587 * Whitelist to allow certain references to pass with no warning.
590 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
591 * The pattern is identified by:
592 * fromsec = .text.init.refok | .data.init.refok
595 * If a module parameter is declared __initdata and permissions=0
596 * then this is legal despite the warning generated.
597 * We cannot see value of permissions here, so just ignore
599 * The pattern is identified by:
605 * Many drivers utilise a *driver container with references to
606 * add, remove, probe functions etc.
607 * These functions may often be marked __init and we do not want to
609 * the pattern is identified by:
610 * tosec = .init.text | .exit.text | .init.data
612 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console
615 * Whitelist all references from .pci_fixup* section to .init.text
616 * This is part of the PCI init when built-in
619 * Whitelist all refereces from .text.head to .init.data
620 * Whitelist all refereces from .text.head to .init.text
623 * Some symbols belong to init section but still it is ok to reference
624 * these from non-init sections as these symbols don't have any memory
625 * allocated for them and symbol address and value are same. So even
626 * if init section is freed, its ok to reference those symbols.
627 * For ex. symbols marking the init section boundaries.
628 * This pattern is identified by
629 * refsymname = __init_begin, _sinittext, _einittext
632 * Logos used in drivers/video/logo reside in __initdata but the
633 * funtion that references them are EXPORT_SYMBOL() so cannot be
634 * marker __init. So we whitelist them here.
641 * ia64 has machvec table for each platform and
642 * powerpc has a machine desc table for each platform.
643 * It is mixture of function pointers of .init.text and .text.
644 * fromsec = .machvec | .machine.desc
646 static int secref_whitelist(const char *modname
, const char *tosec
,
647 const char *fromsec
, const char *atsym
,
648 const char *refsymname
)
652 const char *pat2sym
[] = {
654 "_template", /* scsi uses *_template a lot */
655 "_sht", /* scsi also used *_sht to some extent */
664 const char *pat3refsym
[] = {
671 /* Check for pattern 0 */
672 if ((strcmp(fromsec
, ".text.init.refok") == 0) ||
673 (strcmp(fromsec
, ".data.init.refok") == 0))
676 /* Check for pattern 1 */
677 if (strcmp(tosec
, ".init.data") != 0)
679 if (strncmp(fromsec
, ".data", strlen(".data")) != 0)
681 if (strncmp(atsym
, "__param", strlen("__param")) != 0)
687 /* Check for pattern 2 */
688 if ((strcmp(tosec
, ".init.text") != 0) &&
689 (strcmp(tosec
, ".exit.text") != 0) &&
690 (strcmp(tosec
, ".init.data") != 0))
692 if (strcmp(fromsec
, ".data") != 0)
695 for (s
= pat2sym
; *s
; s
++)
696 if (strrcmp(atsym
, *s
) == 0)
701 /* Check for pattern 3 */
702 if ((strncmp(fromsec
, ".pci_fixup", strlen(".pci_fixup")) == 0) &&
703 (strcmp(tosec
, ".init.text") == 0))
706 /* Check for pattern 4 */
707 if ((strcmp(fromsec
, ".text.head") == 0) &&
708 ((strcmp(tosec
, ".init.data") == 0) ||
709 (strcmp(tosec
, ".init.text") == 0)))
712 /* Check for pattern 5 */
713 for (s
= pat3refsym
; *s
; s
++)
714 if (strcmp(refsymname
, *s
) == 0)
717 /* Check for pattern 7 */
718 if ((strcmp(tosec
, ".init.data") == 0) &&
719 (strncmp(fromsec
, ".text", strlen(".text")) == 0) &&
720 (strncmp(refsymname
, "logo_", strlen("logo_")) == 0))
723 /* Check for pattern 10 */
724 if ((strcmp(fromsec
, ".machvec") == 0) ||
725 (strcmp(fromsec
, ".machine.desc") == 0))
732 * Find symbol based on relocation record info.
733 * In some cases the symbol supplied is a valid symbol so
734 * return refsym. If st_name != 0 we assume this is a valid symbol.
735 * In other cases the symbol needs to be looked up in the symbol table
736 * based on section and address.
738 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf_Addr addr
,
743 if (relsym
->st_name
!= 0)
745 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
746 if (sym
->st_shndx
!= relsym
->st_shndx
)
748 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
750 if (sym
->st_value
== addr
)
756 static inline int is_arm_mapping_symbol(const char *str
)
758 return str
[0] == '$' && strchr("atd", str
[1])
759 && (str
[2] == '\0' || str
[2] == '.');
763 * If there's no name there, ignore it; likewise, ignore it if it's
764 * one of the magic symbols emitted used by current ARM tools.
766 * Otherwise if find_symbols_between() returns those symbols, they'll
767 * fail the whitelist tests and cause lots of false alarms ... fixable
768 * only by merging __exit and __init sections into __text, bloating
769 * the kernel (which is especially evil on embedded platforms).
771 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
773 const char *name
= elf
->strtab
+ sym
->st_name
;
775 if (!name
|| !strlen(name
))
777 return !is_arm_mapping_symbol(name
);
781 * Find symbols before or equal addr and after addr - in the section sec.
782 * If we find two symbols with equal offset prefer one with a valid name.
783 * The ELF format may have a better way to detect what type of symbol
784 * it is, but this works for now.
786 static void find_symbols_between(struct elf_info
*elf
, Elf_Addr addr
,
788 Elf_Sym
**before
, Elf_Sym
**after
)
791 Elf_Ehdr
*hdr
= elf
->hdr
;
792 Elf_Addr beforediff
= ~0;
793 Elf_Addr afterdiff
= ~0;
794 const char *secstrings
= (void *)hdr
+
795 elf
->sechdrs
[hdr
->e_shstrndx
].sh_offset
;
800 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
803 if (sym
->st_shndx
>= SHN_LORESERVE
)
805 symsec
= secstrings
+ elf
->sechdrs
[sym
->st_shndx
].sh_name
;
806 if (strcmp(symsec
, sec
) != 0)
808 if (!is_valid_name(elf
, sym
))
810 if (sym
->st_value
<= addr
) {
811 if ((addr
- sym
->st_value
) < beforediff
) {
812 beforediff
= addr
- sym
->st_value
;
815 else if ((addr
- sym
->st_value
) == beforediff
) {
821 if ((sym
->st_value
- addr
) < afterdiff
) {
822 afterdiff
= sym
->st_value
- addr
;
825 else if ((sym
->st_value
- addr
) == afterdiff
) {
833 * Print a warning about a section mismatch.
834 * Try to find symbols near it so user can find it.
835 * Check whitelist before warning - it may be a false positive.
837 static void warn_sec_mismatch(const char *modname
, const char *fromsec
,
838 struct elf_info
*elf
, Elf_Sym
*sym
, Elf_Rela r
)
840 const char *refsymname
= "";
841 Elf_Sym
*before
, *after
;
843 Elf_Ehdr
*hdr
= elf
->hdr
;
844 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
845 const char *secstrings
= (void *)hdr
+
846 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
847 const char *secname
= secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
;
849 find_symbols_between(elf
, r
.r_offset
, fromsec
, &before
, &after
);
851 refsym
= find_elf_symbol(elf
, r
.r_addend
, sym
);
852 if (refsym
&& strlen(elf
->strtab
+ refsym
->st_name
))
853 refsymname
= elf
->strtab
+ refsym
->st_name
;
855 /* check whitelist - we may ignore it */
857 secref_whitelist(modname
, secname
, fromsec
,
858 elf
->strtab
+ before
->st_name
, refsymname
))
861 if (before
&& after
) {
862 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
863 "(between '%s' and '%s')\n",
864 modname
, fromsec
, (unsigned long long)r
.r_offset
,
866 elf
->strtab
+ before
->st_name
,
867 elf
->strtab
+ after
->st_name
);
869 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
871 modname
, fromsec
, (unsigned long long)r
.r_offset
,
873 elf
->strtab
+ before
->st_name
);
875 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
876 "before '%s' (at offset -0x%llx)\n",
877 modname
, fromsec
, (unsigned long long)r
.r_offset
,
879 elf
->strtab
+ after
->st_name
);
881 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
882 modname
, fromsec
, (unsigned long long)r
.r_offset
,
883 secname
, refsymname
);
887 static unsigned int *reloc_location(struct elf_info
*elf
,
888 int rsection
, Elf_Rela
*r
)
890 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
891 int section
= sechdrs
[rsection
].sh_info
;
893 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
894 (r
->r_offset
- sechdrs
[section
].sh_addr
);
897 static int addend_386_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
899 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
900 unsigned int *location
= reloc_location(elf
, rsection
, r
);
904 r
->r_addend
= TO_NATIVE(*location
);
907 r
->r_addend
= TO_NATIVE(*location
) + 4;
908 /* For CONFIG_RELOCATABLE=y */
909 if (elf
->hdr
->e_type
== ET_EXEC
)
910 r
->r_addend
+= r
->r_offset
;
916 static int addend_arm_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
918 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
922 /* From ARM ABI: (S + A) | T */
923 r
->r_addend
= (int)(long)(elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
926 /* From ARM ABI: ((S + A) | T) - P */
927 r
->r_addend
= (int)(long)(elf
->hdr
+ elf
->sechdrs
[rsection
].sh_offset
+
928 (r
->r_offset
- elf
->sechdrs
[rsection
].sh_addr
));
936 static int addend_mips_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
938 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
939 unsigned int *location
= reloc_location(elf
, rsection
, r
);
942 if (r_typ
== R_MIPS_HI16
)
943 return 1; /* skip this */
944 inst
= TO_NATIVE(*location
);
947 r
->r_addend
= inst
& 0xffff;
950 r
->r_addend
= (inst
& 0x03ffffff) << 2;
960 * A module includes a number of sections that are discarded
961 * either when loaded or when used as built-in.
962 * For loaded modules all functions marked __init and all data
963 * marked __initdata will be discarded when the module has been intialized.
964 * Likewise for modules used built-in the sections marked __exit
965 * are discarded because __exit marked function are supposed to be called
966 * only when a moduel is unloaded which never happes for built-in modules.
967 * The check_sec_ref() function traverses all relocation records
968 * to find all references to a section that reference a section that will
969 * be discarded and warns about it.
971 static void check_sec_ref(struct module
*mod
, const char *modname
,
972 struct elf_info
*elf
,
973 int section(const char*),
974 int section_ref_ok(const char *))
978 Elf_Ehdr
*hdr
= elf
->hdr
;
979 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
980 const char *secstrings
= (void *)hdr
+
981 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
983 /* Walk through all sections */
984 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
985 const char *name
= secstrings
+ sechdrs
[i
].sh_name
;
989 /* We want to process only relocation sections and not .init */
990 if (sechdrs
[i
].sh_type
== SHT_RELA
) {
992 Elf_Rela
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
993 Elf_Rela
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
994 name
+= strlen(".rela");
995 if (section_ref_ok(name
))
998 for (rela
= start
; rela
< stop
; rela
++) {
999 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1000 #if KERNEL_ELFCLASS == ELFCLASS64
1001 if (hdr
->e_machine
== EM_MIPS
) {
1003 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1004 r_sym
= TO_NATIVE(r_sym
);
1005 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1006 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1008 r
.r_info
= TO_NATIVE(rela
->r_info
);
1009 r_sym
= ELF_R_SYM(r
.r_info
);
1012 r
.r_info
= TO_NATIVE(rela
->r_info
);
1013 r_sym
= ELF_R_SYM(r
.r_info
);
1015 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1016 sym
= elf
->symtab_start
+ r_sym
;
1017 /* Skip special sections */
1018 if (sym
->st_shndx
>= SHN_LORESERVE
)
1021 secname
= secstrings
+
1022 sechdrs
[sym
->st_shndx
].sh_name
;
1023 if (section(secname
))
1024 warn_sec_mismatch(modname
, name
,
1027 } else if (sechdrs
[i
].sh_type
== SHT_REL
) {
1029 Elf_Rel
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
1030 Elf_Rel
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
1031 name
+= strlen(".rel");
1032 if (section_ref_ok(name
))
1035 for (rel
= start
; rel
< stop
; rel
++) {
1036 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1037 #if KERNEL_ELFCLASS == ELFCLASS64
1038 if (hdr
->e_machine
== EM_MIPS
) {
1040 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1041 r_sym
= TO_NATIVE(r_sym
);
1042 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1043 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1045 r
.r_info
= TO_NATIVE(rel
->r_info
);
1046 r_sym
= ELF_R_SYM(r
.r_info
);
1049 r
.r_info
= TO_NATIVE(rel
->r_info
);
1050 r_sym
= ELF_R_SYM(r
.r_info
);
1053 switch (hdr
->e_machine
) {
1055 if (addend_386_rel(elf
, i
, &r
))
1059 if(addend_arm_rel(elf
, i
, &r
))
1063 if (addend_mips_rel(elf
, i
, &r
))
1067 sym
= elf
->symtab_start
+ r_sym
;
1068 /* Skip special sections */
1069 if (sym
->st_shndx
>= SHN_LORESERVE
)
1072 secname
= secstrings
+
1073 sechdrs
[sym
->st_shndx
].sh_name
;
1074 if (section(secname
))
1075 warn_sec_mismatch(modname
, name
,
1083 * Identify sections from which references to either a
1084 * .init or a .exit section is OK.
1086 * [OPD] Keith Ownes <kaos@sgi.com> commented:
1087 * For our future {in}sanity, add a comment that this is the ppc .opd
1088 * section, not the ia64 .opd section.
1089 * ia64 .opd should not point to discarded sections.
1090 * [.rodata] like for .init.text we ignore .rodata references -same reason
1092 static int initexit_section_ref_ok(const char *name
)
1095 /* Absolute section names */
1096 const char *namelist1
[] = {
1097 "__bug_table", /* used by powerpc for BUG() */
1100 ".cranges", /* used by sh64 */
1102 ".opd", /* See comment [OPD] */
1103 ".parainstructions",
1105 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
1110 /* Start of section names */
1111 const char *namelist2
[] = {
1114 ".note", /* ignore ELF notes - may contain anything */
1115 ".got", /* powerpc - global offset table */
1116 ".toc", /* powerpc - table of contents */
1119 /* part of section name */
1120 const char *namelist3
[] = {
1121 ".unwind", /* Sample: IA_64.unwind.exit.text */
1125 for (s
= namelist1
; *s
; s
++)
1126 if (strcmp(*s
, name
) == 0)
1128 for (s
= namelist2
; *s
; s
++)
1129 if (strncmp(*s
, name
, strlen(*s
)) == 0)
1131 for (s
= namelist3
; *s
; s
++)
1132 if (strstr(name
, *s
) != NULL
)
1138 * Functions used only during module init is marked __init and is stored in
1139 * a .init.text section. Likewise data is marked __initdata and stored in
1140 * a .init.data section.
1141 * If this section is one of these sections return 1
1142 * See include/linux/init.h for the details
1144 static int init_section(const char *name
)
1146 if (strcmp(name
, ".init") == 0)
1148 if (strncmp(name
, ".init.", strlen(".init.")) == 0)
1154 * Identify sections from which references to a .init section is OK.
1156 * Unfortunately references to read only data that referenced .init
1157 * sections had to be excluded. Almost all of these are false
1158 * positives, they are created by gcc. The downside of excluding rodata
1159 * is that there really are some user references from rodata to
1160 * init code, e.g. drivers/video/vgacon.c:
1162 * const struct consw vga_con = {
1163 * con_startup: vgacon_startup,
1165 * where vgacon_startup is __init. If you want to wade through the false
1166 * positives, take out the check for rodata.
1168 static int init_section_ref_ok(const char *name
)
1171 /* Absolute section names */
1172 const char *namelist1
[] = {
1173 "__ftr_fixup", /* powerpc cpu feature fixup */
1174 "__fw_ftr_fixup", /* powerpc firmware feature fixup */
1176 ".data.rel.ro", /* used by parisc64 */
1181 /* Start of section names */
1182 const char *namelist2
[] = {
1189 if (initexit_section_ref_ok(name
))
1192 for (s
= namelist1
; *s
; s
++)
1193 if (strcmp(*s
, name
) == 0)
1195 for (s
= namelist2
; *s
; s
++)
1196 if (strncmp(*s
, name
, strlen(*s
)) == 0)
1199 /* If section name ends with ".init" we allow references
1200 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc
1202 if (strrcmp(name
, ".init") == 0)
1208 * Functions used only during module exit is marked __exit and is stored in
1209 * a .exit.text section. Likewise data is marked __exitdata and stored in
1210 * a .exit.data section.
1211 * If this section is one of these sections return 1
1212 * See include/linux/init.h for the details
1214 static int exit_section(const char *name
)
1216 if (strcmp(name
, ".exit.text") == 0)
1218 if (strcmp(name
, ".exit.data") == 0)
1225 * Identify sections from which references to a .exit section is OK.
1227 static int exit_section_ref_ok(const char *name
)
1230 /* Absolute section names */
1231 const char *namelist1
[] = {
1240 if (initexit_section_ref_ok(name
))
1243 for (s
= namelist1
; *s
; s
++)
1244 if (strcmp(*s
, name
) == 0)
1249 static void read_symbols(char *modname
)
1251 const char *symname
;
1255 struct elf_info info
= { };
1258 if (!parse_elf(&info
, modname
))
1261 mod
= new_module(modname
);
1263 /* When there's no vmlinux, don't print warnings about
1264 * unresolved symbols (since there'll be too many ;) */
1265 if (is_vmlinux(modname
)) {
1270 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1272 if (license_is_gpl_compatible(license
))
1273 mod
->gpl_compatible
= 1;
1275 mod
->gpl_compatible
= 0;
1278 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1279 "license", license
);
1282 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1283 symname
= info
.strtab
+ sym
->st_name
;
1285 handle_modversions(mod
, &info
, sym
, symname
);
1286 handle_moddevtable(mod
, &info
, sym
, symname
);
1288 check_sec_ref(mod
, modname
, &info
, init_section
, init_section_ref_ok
);
1289 check_sec_ref(mod
, modname
, &info
, exit_section
, exit_section_ref_ok
);
1291 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1293 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1294 version
- (char *)info
.hdr
);
1295 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1296 get_src_version(modname
, mod
->srcversion
,
1297 sizeof(mod
->srcversion
)-1);
1299 parse_elf_finish(&info
);
1301 /* Our trick to get versioning for struct_module - it's
1302 * never passed as an argument to an exported function, so
1303 * the automatic versioning doesn't pick it up, but it's really
1304 * important anyhow */
1306 mod
->unres
= alloc_symbol("struct_module", 0, mod
->unres
);
1311 /* We first write the generated file into memory using the
1312 * following helper, then compare to the file on disk and
1313 * only update the later if anything changed */
1315 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1316 const char *fmt
, ...)
1323 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1324 buf_write(buf
, tmp
, len
);
1328 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1330 if (buf
->size
- buf
->pos
< len
) {
1331 buf
->size
+= len
+ SZ
;
1332 buf
->p
= realloc(buf
->p
, buf
->size
);
1334 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1338 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1340 const char *e
= is_vmlinux(m
) ?"":".ko";
1344 fatal("modpost: GPL-incompatible module %s%s "
1345 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1347 case export_unused_gpl
:
1348 fatal("modpost: GPL-incompatible module %s%s "
1349 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1351 case export_gpl_future
:
1352 warn("modpost: GPL-incompatible module %s%s "
1353 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1357 case export_unknown
:
1363 static void check_for_unused(enum export exp
, const char* m
, const char* s
)
1365 const char *e
= is_vmlinux(m
) ?"":".ko";
1369 case export_unused_gpl
:
1370 warn("modpost: module %s%s "
1371 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1379 static void check_exports(struct module
*mod
)
1381 struct symbol
*s
, *exp
;
1383 for (s
= mod
->unres
; s
; s
= s
->next
) {
1384 const char *basename
;
1385 exp
= find_symbol(s
->name
);
1386 if (!exp
|| exp
->module
== mod
)
1388 basename
= strrchr(mod
->name
, '/');
1392 basename
= mod
->name
;
1393 if (!mod
->gpl_compatible
)
1394 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1395 check_for_unused(exp
->export
, basename
, exp
->name
);
1400 * Header for the generated file
1402 static void add_header(struct buffer
*b
, struct module
*mod
)
1404 buf_printf(b
, "#include <linux/module.h>\n");
1405 buf_printf(b
, "#include <linux/vermagic.h>\n");
1406 buf_printf(b
, "#include <linux/compiler.h>\n");
1407 buf_printf(b
, "\n");
1408 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1409 buf_printf(b
, "\n");
1410 buf_printf(b
, "struct module __this_module\n");
1411 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1412 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1414 buf_printf(b
, " .init = init_module,\n");
1415 if (mod
->has_cleanup
)
1416 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1417 " .exit = cleanup_module,\n"
1419 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1420 buf_printf(b
, "};\n");
1424 * Record CRCs for unresolved symbols
1426 static int add_versions(struct buffer
*b
, struct module
*mod
)
1428 struct symbol
*s
, *exp
;
1431 for (s
= mod
->unres
; s
; s
= s
->next
) {
1432 exp
= find_symbol(s
->name
);
1433 if (!exp
|| exp
->module
== mod
) {
1434 if (have_vmlinux
&& !s
->weak
) {
1435 if (warn_unresolved
) {
1436 warn("\"%s\" [%s.ko] undefined!\n",
1437 s
->name
, mod
->name
);
1439 merror("\"%s\" [%s.ko] undefined!\n",
1440 s
->name
, mod
->name
);
1446 s
->module
= exp
->module
;
1447 s
->crc_valid
= exp
->crc_valid
;
1454 buf_printf(b
, "\n");
1455 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1456 buf_printf(b
, "__attribute_used__\n");
1457 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1459 for (s
= mod
->unres
; s
; s
= s
->next
) {
1463 if (!s
->crc_valid
) {
1464 warn("\"%s\" [%s.ko] has no CRC!\n",
1465 s
->name
, mod
->name
);
1468 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1471 buf_printf(b
, "};\n");
1476 static void add_depends(struct buffer
*b
, struct module
*mod
,
1477 struct module
*modules
)
1483 for (m
= modules
; m
; m
= m
->next
) {
1484 m
->seen
= is_vmlinux(m
->name
);
1487 buf_printf(b
, "\n");
1488 buf_printf(b
, "static const char __module_depends[]\n");
1489 buf_printf(b
, "__attribute_used__\n");
1490 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1491 buf_printf(b
, "\"depends=");
1492 for (s
= mod
->unres
; s
; s
= s
->next
) {
1497 if (s
->module
->seen
)
1500 s
->module
->seen
= 1;
1501 if ((p
= strrchr(s
->module
->name
, '/')) != NULL
)
1504 p
= s
->module
->name
;
1505 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1508 buf_printf(b
, "\";\n");
1511 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1513 if (mod
->srcversion
[0]) {
1514 buf_printf(b
, "\n");
1515 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1520 static void write_if_changed(struct buffer
*b
, const char *fname
)
1526 file
= fopen(fname
, "r");
1530 if (fstat(fileno(file
), &st
) < 0)
1533 if (st
.st_size
!= b
->pos
)
1536 tmp
= NOFAIL(malloc(b
->pos
));
1537 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1540 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1552 file
= fopen(fname
, "w");
1557 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1564 /* parse Module.symvers file. line format:
1565 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1567 static void read_dump(const char *fname
, unsigned int kernel
)
1569 unsigned long size
, pos
= 0;
1570 void *file
= grab_file(fname
, &size
);
1574 /* No symbol versions, silently ignore */
1577 while ((line
= get_next_line(&pos
, file
, size
))) {
1578 char *symname
, *modname
, *d
, *export
, *end
;
1583 if (!(symname
= strchr(line
, '\t')))
1586 if (!(modname
= strchr(symname
, '\t')))
1589 if ((export
= strchr(modname
, '\t')) != NULL
)
1591 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
1593 crc
= strtoul(line
, &d
, 16);
1594 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
1597 if (!(mod
= find_module(modname
))) {
1598 if (is_vmlinux(modname
)) {
1601 mod
= new_module(NOFAIL(strdup(modname
)));
1604 s
= sym_add_exported(symname
, mod
, export_no(export
));
1607 sym_update_crc(symname
, mod
, crc
, export_no(export
));
1611 fatal("parse error in symbol dump file\n");
1614 /* For normal builds always dump all symbols.
1615 * For external modules only dump symbols
1616 * that are not read from kernel Module.symvers.
1618 static int dump_sym(struct symbol
*sym
)
1620 if (!external_module
)
1622 if (sym
->vmlinux
|| sym
->kernel
)
1627 static void write_dump(const char *fname
)
1629 struct buffer buf
= { };
1630 struct symbol
*symbol
;
1633 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
1634 symbol
= symbolhash
[n
];
1636 if (dump_sym(symbol
))
1637 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
1638 symbol
->crc
, symbol
->name
,
1639 symbol
->module
->name
,
1640 export_str(symbol
->export
));
1641 symbol
= symbol
->next
;
1644 write_if_changed(&buf
, fname
);
1647 int main(int argc
, char **argv
)
1650 struct buffer buf
= { };
1652 char *kernel_read
= NULL
, *module_read
= NULL
;
1653 char *dump_write
= NULL
;
1657 while ((opt
= getopt(argc
, argv
, "i:I:mo:aw")) != -1) {
1660 kernel_read
= optarg
;
1663 module_read
= optarg
;
1664 external_module
= 1;
1670 dump_write
= optarg
;
1676 warn_unresolved
= 1;
1684 read_dump(kernel_read
, 1);
1686 read_dump(module_read
, 0);
1688 while (optind
< argc
) {
1689 read_symbols(argv
[optind
++]);
1692 for (mod
= modules
; mod
; mod
= mod
->next
) {
1700 for (mod
= modules
; mod
; mod
= mod
->next
) {
1706 add_header(&buf
, mod
);
1707 err
|= add_versions(&buf
, mod
);
1708 add_depends(&buf
, mod
, modules
);
1709 add_moddevtable(&buf
, mod
);
1710 add_srcversion(&buf
, mod
);
1712 sprintf(fname
, "%s.mod.c", mod
->name
);
1713 write_if_changed(&buf
, fname
);
1717 write_dump(dump_write
);
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