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 /* How a symbol is exported */
28 export_plain
, export_unused
, export_gpl
,
29 export_unused_gpl
, export_gpl_future
, export_unknown
32 void fatal(const char *fmt
, ...)
36 fprintf(stderr
, "FATAL: ");
38 va_start(arglist
, fmt
);
39 vfprintf(stderr
, fmt
, arglist
);
45 void warn(const char *fmt
, ...)
49 fprintf(stderr
, "WARNING: ");
51 va_start(arglist
, fmt
);
52 vfprintf(stderr
, fmt
, arglist
);
56 static int is_vmlinux(const char *modname
)
60 if ((myname
= strrchr(modname
, '/')))
65 return strcmp(myname
, "vmlinux") == 0;
68 void *do_nofail(void *ptr
, const char *expr
)
71 fatal("modpost: Memory allocation failure: %s.\n", expr
);
76 /* A list of all modules we processed */
78 static struct module
*modules
;
80 static struct module
*find_module(char *modname
)
84 for (mod
= modules
; mod
; mod
= mod
->next
)
85 if (strcmp(mod
->name
, modname
) == 0)
90 static struct module
*new_module(char *modname
)
95 mod
= NOFAIL(malloc(sizeof(*mod
)));
96 memset(mod
, 0, sizeof(*mod
));
97 p
= NOFAIL(strdup(modname
));
99 /* strip trailing .o */
100 if ((s
= strrchr(p
, '.')) != NULL
)
101 if (strcmp(s
, ".o") == 0)
106 mod
->gpl_compatible
= -1;
113 /* A hash of all exported symbols,
114 * struct symbol is also used for lists of unresolved symbols */
116 #define SYMBOL_HASH_SIZE 1024
120 struct module
*module
;
124 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
125 unsigned int kernel
:1; /* 1 if symbol is from kernel
126 * (only for external modules) **/
127 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
128 enum export export
; /* Type of export */
132 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
134 /* This is based on the hash agorithm from gdbm, via tdb */
135 static inline unsigned int tdb_hash(const char *name
)
137 unsigned value
; /* Used to compute the hash value. */
138 unsigned i
; /* Used to cycle through random values. */
140 /* Set the initial value from the key size. */
141 for (value
= 0x238F13AF * strlen(name
), i
=0; name
[i
]; i
++)
142 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
144 return (1103515243 * value
+ 12345);
148 * Allocate a new symbols for use in the hash of exported symbols or
149 * the list of unresolved symbols per module
151 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
154 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
156 memset(s
, 0, sizeof(*s
));
157 strcpy(s
->name
, name
);
163 /* For the hash of exported symbols */
164 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
170 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
171 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
172 new->module
= module
;
173 new->export
= export
;
177 static struct symbol
*find_symbol(const char *name
)
181 /* For our purposes, .foo matches foo. PPC64 needs this. */
185 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
=s
->next
) {
186 if (strcmp(s
->name
, name
) == 0)
196 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
197 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
198 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
199 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
200 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
201 { .str
= "(unknown)", .export
= export_unknown
},
205 static const char *export_str(enum export ex
)
207 return export_list
[ex
].str
;
210 static enum export
export_no(const char * s
)
214 return export_unknown
;
215 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
216 if (strcmp(export_list
[i
].str
, s
) == 0)
217 return export_list
[i
].export
;
219 return export_unknown
;
222 static enum export
export_from_sec(struct elf_info
*elf
, Elf_Section sec
)
224 if (sec
== elf
->export_sec
)
226 else if (sec
== elf
->export_unused_sec
)
227 return export_unused
;
228 else if (sec
== elf
->export_gpl_sec
)
230 else if (sec
== elf
->export_unused_gpl_sec
)
231 return export_unused_gpl
;
232 else if (sec
== elf
->export_gpl_future_sec
)
233 return export_gpl_future
;
235 return export_unknown
;
239 * Add an exported symbol - it may have already been added without a
240 * CRC, in this case just update the CRC
242 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
245 struct symbol
*s
= find_symbol(name
);
248 s
= new_symbol(name
, mod
, export
);
251 warn("%s: '%s' exported twice. Previous export "
252 "was in %s%s\n", mod
->name
, name
,
254 is_vmlinux(s
->module
->name
) ?"":".ko");
258 s
->vmlinux
= is_vmlinux(mod
->name
);
264 static void sym_update_crc(const char *name
, struct module
*mod
,
265 unsigned int crc
, enum export export
)
267 struct symbol
*s
= find_symbol(name
);
270 s
= new_symbol(name
, mod
, export
);
275 void *grab_file(const char *filename
, unsigned long *size
)
281 fd
= open(filename
, O_RDONLY
);
282 if (fd
< 0 || fstat(fd
, &st
) != 0)
286 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
289 if (map
== MAP_FAILED
)
295 * Return a copy of the next line in a mmap'ed file.
296 * spaces in the beginning of the line is trimmed away.
297 * Return a pointer to a static buffer.
299 char* get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
301 static char line
[4096];
304 signed char *p
= (signed char *)file
+ *pos
;
307 for (; *pos
< size
; (*pos
)++)
309 if (skip
&& isspace(*p
)) {
314 if (*p
!= '\n' && (*pos
< size
)) {
318 break; /* Too long, stop */
329 void release_file(void *file
, unsigned long size
)
334 static void parse_elf(struct elf_info
*info
, const char *filename
)
337 Elf_Ehdr
*hdr
= info
->hdr
;
341 hdr
= grab_file(filename
, &info
->size
);
347 if (info
->size
< sizeof(*hdr
))
350 /* Fix endianness in ELF header */
351 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
352 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
353 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
354 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
355 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
356 info
->sechdrs
= sechdrs
;
358 /* Fix endianness in section headers */
359 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
360 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
361 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
362 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
363 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
364 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
366 /* Find symbol table. */
367 for (i
= 1; i
< hdr
->e_shnum
; i
++) {
368 const char *secstrings
369 = (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
372 if (sechdrs
[i
].sh_offset
> info
->size
)
374 secname
= secstrings
+ sechdrs
[i
].sh_name
;
375 if (strcmp(secname
, ".modinfo") == 0) {
376 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
377 info
->modinfo_len
= sechdrs
[i
].sh_size
;
378 } else if (strcmp(secname
, "__ksymtab") == 0)
379 info
->export_sec
= i
;
380 else if (strcmp(secname
, "__ksymtab_unused") == 0)
381 info
->export_unused_sec
= i
;
382 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
383 info
->export_gpl_sec
= i
;
384 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
385 info
->export_unused_gpl_sec
= i
;
386 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
387 info
->export_gpl_future_sec
= i
;
389 if (sechdrs
[i
].sh_type
!= SHT_SYMTAB
)
392 info
->symtab_start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
393 info
->symtab_stop
= (void *)hdr
+ sechdrs
[i
].sh_offset
394 + sechdrs
[i
].sh_size
;
395 info
->strtab
= (void *)hdr
+
396 sechdrs
[sechdrs
[i
].sh_link
].sh_offset
;
398 if (!info
->symtab_start
) {
399 fatal("%s has no symtab?\n", filename
);
401 /* Fix endianness in symbols */
402 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
403 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
404 sym
->st_name
= TO_NATIVE(sym
->st_name
);
405 sym
->st_value
= TO_NATIVE(sym
->st_value
);
406 sym
->st_size
= TO_NATIVE(sym
->st_size
);
411 fatal("%s is truncated.\n", filename
);
414 static void parse_elf_finish(struct elf_info
*info
)
416 release_file(info
->hdr
, info
->size
);
419 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
420 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
422 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
423 Elf_Sym
*sym
, const char *symname
)
426 enum export export
= export_from_sec(info
, sym
->st_shndx
);
428 switch (sym
->st_shndx
) {
430 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
434 if (memcmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
435 crc
= (unsigned int) sym
->st_value
;
436 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
441 /* undefined symbol */
442 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
443 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
445 /* ignore global offset table */
446 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
448 /* ignore __this_module, it will be resolved shortly */
449 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
451 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
452 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
453 /* add compatibility with older glibc */
454 #ifndef STT_SPARC_REGISTER
455 #define STT_SPARC_REGISTER STT_REGISTER
457 if (info
->hdr
->e_machine
== EM_SPARC
||
458 info
->hdr
->e_machine
== EM_SPARCV9
) {
459 /* Ignore register directives. */
460 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
462 if (symname
[0] == '.') {
463 char *munged
= strdup(symname
);
465 munged
[1] = toupper(munged
[1]);
471 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
472 strlen(MODULE_SYMBOL_PREFIX
)) == 0)
473 mod
->unres
= alloc_symbol(symname
+
474 strlen(MODULE_SYMBOL_PREFIX
),
475 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
479 /* All exported symbols */
480 if (memcmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
481 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
484 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
486 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
487 mod
->has_cleanup
= 1;
493 * Parse tag=value strings from .modinfo section
495 static char *next_string(char *string
, unsigned long *secsize
)
497 /* Skip non-zero chars */
500 if ((*secsize
)-- <= 1)
504 /* Skip any zero padding. */
507 if ((*secsize
)-- <= 1)
513 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
514 const char *tag
, char *info
)
517 unsigned int taglen
= strlen(tag
);
518 unsigned long size
= modinfo_len
;
521 size
-= info
- (char *)modinfo
;
522 modinfo
= next_string(info
, &size
);
525 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
526 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
527 return p
+ taglen
+ 1;
532 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
536 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
540 * Test if string s ends in string sub
543 static int strrcmp(const char *s
, const char *sub
)
551 sublen
= strlen(sub
);
553 if ((slen
== 0) || (sublen
== 0))
559 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
563 * Whitelist to allow certain references to pass with no warning.
565 * If a module parameter is declared __initdata and permissions=0
566 * then this is legal despite the warning generated.
567 * We cannot see value of permissions here, so just ignore
569 * The pattern is identified by:
575 * Many drivers utilise a *driver container with references to
576 * add, remove, probe functions etc.
577 * These functions may often be marked __init and we do not want to
579 * the pattern is identified by:
580 * tosec = .init.text | .exit.text | .init.data
582 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one
584 static int secref_whitelist(const char *modname
, const char *tosec
,
585 const char *fromsec
, const char *atsym
)
589 const char *pat2sym
[] = {
591 "_template", /* scsi uses *_template a lot */
592 "_sht", /* scsi also used *_sht to some extent */
599 /* Check for pattern 1 */
600 if (strcmp(tosec
, ".init.data") != 0)
602 if (strncmp(fromsec
, ".data", strlen(".data")) != 0)
604 if (strncmp(atsym
, "__param", strlen("__param")) != 0)
610 /* Check for pattern 2 */
611 if ((strcmp(tosec
, ".init.text") != 0) &&
612 (strcmp(tosec
, ".exit.text") != 0) &&
613 (strcmp(tosec
, ".init.data") != 0))
615 if (strcmp(fromsec
, ".data") != 0)
618 for (s
= pat2sym
; *s
; s
++)
619 if (strrcmp(atsym
, *s
) == 0)
624 /* Whitelist all references from .pci_fixup section if vmlinux */
625 if (is_vmlinux(modname
)) {
626 if ((strcmp(fromsec
, ".pci_fixup") == 0) &&
627 (strcmp(tosec
, ".init.text") == 0))
633 * Find symbol based on relocation record info.
634 * In some cases the symbol supplied is a valid symbol so
635 * return refsym. If st_name != 0 we assume this is a valid symbol.
636 * In other cases the symbol needs to be looked up in the symbol table
637 * based on section and address.
639 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf_Addr addr
,
644 if (relsym
->st_name
!= 0)
646 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
647 if (sym
->st_shndx
!= relsym
->st_shndx
)
649 if (sym
->st_value
== addr
)
656 * Find symbols before or equal addr and after addr - in the section sec.
657 * If we find two symbols with equal offset prefer one with a valid name.
658 * The ELF format may have a better way to detect what type of symbol
659 * it is, but this works for now.
661 static void find_symbols_between(struct elf_info
*elf
, Elf_Addr addr
,
663 Elf_Sym
**before
, Elf_Sym
**after
)
666 Elf_Ehdr
*hdr
= elf
->hdr
;
667 Elf_Addr beforediff
= ~0;
668 Elf_Addr afterdiff
= ~0;
669 const char *secstrings
= (void *)hdr
+
670 elf
->sechdrs
[hdr
->e_shstrndx
].sh_offset
;
675 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
678 if (sym
->st_shndx
>= SHN_LORESERVE
)
680 symsec
= secstrings
+ elf
->sechdrs
[sym
->st_shndx
].sh_name
;
681 if (strcmp(symsec
, sec
) != 0)
683 if (sym
->st_value
<= addr
) {
684 if ((addr
- sym
->st_value
) < beforediff
) {
685 beforediff
= addr
- sym
->st_value
;
688 else if ((addr
- sym
->st_value
) == beforediff
) {
689 /* equal offset, valid name? */
690 const char *name
= elf
->strtab
+ sym
->st_name
;
691 if (name
&& strlen(name
))
697 if ((sym
->st_value
- addr
) < afterdiff
) {
698 afterdiff
= sym
->st_value
- addr
;
701 else if ((sym
->st_value
- addr
) == afterdiff
) {
702 /* equal offset, valid name? */
703 const char *name
= elf
->strtab
+ sym
->st_name
;
704 if (name
&& strlen(name
))
712 * Print a warning about a section mismatch.
713 * Try to find symbols near it so user can find it.
714 * Check whitelist before warning - it may be a false positive.
716 static void warn_sec_mismatch(const char *modname
, const char *fromsec
,
717 struct elf_info
*elf
, Elf_Sym
*sym
, Elf_Rela r
)
719 const char *refsymname
= "";
720 Elf_Sym
*before
, *after
;
722 Elf_Ehdr
*hdr
= elf
->hdr
;
723 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
724 const char *secstrings
= (void *)hdr
+
725 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
726 const char *secname
= secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
;
728 find_symbols_between(elf
, r
.r_offset
, fromsec
, &before
, &after
);
730 refsym
= find_elf_symbol(elf
, r
.r_addend
, sym
);
731 if (refsym
&& strlen(elf
->strtab
+ refsym
->st_name
))
732 refsymname
= elf
->strtab
+ refsym
->st_name
;
734 /* check whitelist - we may ignore it */
736 secref_whitelist(modname
, secname
, fromsec
,
737 elf
->strtab
+ before
->st_name
))
740 if (before
&& after
) {
741 warn("%s - Section mismatch: reference to %s:%s from %s "
742 "between '%s' (at offset 0x%llx) and '%s'\n",
743 modname
, secname
, refsymname
, fromsec
,
744 elf
->strtab
+ before
->st_name
,
745 (long long)r
.r_offset
,
746 elf
->strtab
+ after
->st_name
);
748 warn("%s - Section mismatch: reference to %s:%s from %s "
749 "after '%s' (at offset 0x%llx)\n",
750 modname
, secname
, refsymname
, fromsec
,
751 elf
->strtab
+ before
->st_name
,
752 (long long)r
.r_offset
);
754 warn("%s - Section mismatch: reference to %s:%s from %s "
755 "before '%s' (at offset -0x%llx)\n",
756 modname
, secname
, refsymname
, fromsec
,
757 elf
->strtab
+ after
->st_name
,
758 (long long)r
.r_offset
);
760 warn("%s - Section mismatch: reference to %s:%s from %s "
762 modname
, secname
, fromsec
, refsymname
,
763 (long long)r
.r_offset
);
768 * A module includes a number of sections that are discarded
769 * either when loaded or when used as built-in.
770 * For loaded modules all functions marked __init and all data
771 * marked __initdata will be discarded when the module has been intialized.
772 * Likewise for modules used built-in the sections marked __exit
773 * are discarded because __exit marked function are supposed to be called
774 * only when a moduel is unloaded which never happes for built-in modules.
775 * The check_sec_ref() function traverses all relocation records
776 * to find all references to a section that reference a section that will
777 * be discarded and warns about it.
779 static void check_sec_ref(struct module
*mod
, const char *modname
,
780 struct elf_info
*elf
,
781 int section(const char*),
782 int section_ref_ok(const char *))
786 Elf_Ehdr
*hdr
= elf
->hdr
;
787 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
788 const char *secstrings
= (void *)hdr
+
789 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
791 /* Walk through all sections */
792 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
793 const char *name
= secstrings
+ sechdrs
[i
].sh_name
;
797 /* We want to process only relocation sections and not .init */
798 if (sechdrs
[i
].sh_type
== SHT_RELA
) {
800 Elf_Rela
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
801 Elf_Rela
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
802 name
+= strlen(".rela");
803 if (section_ref_ok(name
))
806 for (rela
= start
; rela
< stop
; rela
++) {
807 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
808 #if KERNEL_ELFCLASS == ELFCLASS64
809 if (hdr
->e_machine
== EM_MIPS
) {
810 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
811 r_sym
= TO_NATIVE(r_sym
);
813 r
.r_info
= TO_NATIVE(rela
->r_info
);
814 r_sym
= ELF_R_SYM(r
.r_info
);
817 r
.r_info
= TO_NATIVE(rela
->r_info
);
818 r_sym
= ELF_R_SYM(r
.r_info
);
820 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
821 sym
= elf
->symtab_start
+ r_sym
;
822 /* Skip special sections */
823 if (sym
->st_shndx
>= SHN_LORESERVE
)
826 secname
= secstrings
+
827 sechdrs
[sym
->st_shndx
].sh_name
;
828 if (section(secname
))
829 warn_sec_mismatch(modname
, name
,
832 } else if (sechdrs
[i
].sh_type
== SHT_REL
) {
834 Elf_Rel
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
835 Elf_Rel
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
836 name
+= strlen(".rel");
837 if (section_ref_ok(name
))
840 for (rel
= start
; rel
< stop
; rel
++) {
841 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
842 #if KERNEL_ELFCLASS == ELFCLASS64
843 if (hdr
->e_machine
== EM_MIPS
) {
844 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
845 r_sym
= TO_NATIVE(r_sym
);
847 r
.r_info
= TO_NATIVE(rel
->r_info
);
848 r_sym
= ELF_R_SYM(r
.r_info
);
851 r
.r_info
= TO_NATIVE(rel
->r_info
);
852 r_sym
= ELF_R_SYM(r
.r_info
);
855 sym
= elf
->symtab_start
+ r_sym
;
856 /* Skip special sections */
857 if (sym
->st_shndx
>= SHN_LORESERVE
)
860 secname
= secstrings
+
861 sechdrs
[sym
->st_shndx
].sh_name
;
862 if (section(secname
))
863 warn_sec_mismatch(modname
, name
,
871 * Functions used only during module init is marked __init and is stored in
872 * a .init.text section. Likewise data is marked __initdata and stored in
873 * a .init.data section.
874 * If this section is one of these sections return 1
875 * See include/linux/init.h for the details
877 static int init_section(const char *name
)
879 if (strcmp(name
, ".init") == 0)
881 if (strncmp(name
, ".init.", strlen(".init.")) == 0)
887 * Identify sections from which references to a .init section is OK.
889 * Unfortunately references to read only data that referenced .init
890 * sections had to be excluded. Almost all of these are false
891 * positives, they are created by gcc. The downside of excluding rodata
892 * is that there really are some user references from rodata to
893 * init code, e.g. drivers/video/vgacon.c:
895 * const struct consw vga_con = {
896 * con_startup: vgacon_startup,
898 * where vgacon_startup is __init. If you want to wade through the false
899 * positives, take out the check for rodata.
901 static int init_section_ref_ok(const char *name
)
904 /* Absolute section names */
905 const char *namelist1
[] = {
907 ".opd", /* see comment [OPD] at exit_section_ref_ok() */
908 ".toc1", /* used by ppc64 */
912 "__bug_table", /* used by powerpc for BUG() */
920 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
923 /* Start of section names */
924 const char *namelist2
[] = {
931 /* part of section name */
932 const char *namelist3
[] = {
933 ".unwind", /* sample: IA_64.unwind.init.text */
937 for (s
= namelist1
; *s
; s
++)
938 if (strcmp(*s
, name
) == 0)
940 for (s
= namelist2
; *s
; s
++)
941 if (strncmp(*s
, name
, strlen(*s
)) == 0)
943 for (s
= namelist3
; *s
; s
++)
944 if (strstr(name
, *s
) != NULL
)
946 if (strrcmp(name
, ".init") == 0)
952 * Functions used only during module exit is marked __exit and is stored in
953 * a .exit.text section. Likewise data is marked __exitdata and stored in
954 * a .exit.data section.
955 * If this section is one of these sections return 1
956 * See include/linux/init.h for the details
958 static int exit_section(const char *name
)
960 if (strcmp(name
, ".exit.text") == 0)
962 if (strcmp(name
, ".exit.data") == 0)
969 * Identify sections from which references to a .exit section is OK.
971 * [OPD] Keith Ownes <kaos@sgi.com> commented:
972 * For our future {in}sanity, add a comment that this is the ppc .opd
973 * section, not the ia64 .opd section.
974 * ia64 .opd should not point to discarded sections.
975 * [.rodata] like for .init.text we ignore .rodata references -same reason
977 static int exit_section_ref_ok(const char *name
)
980 /* Absolute section names */
981 const char *namelist1
[] = {
986 ".opd", /* See comment [OPD] */
987 ".toc1", /* used by ppc64 */
990 "__bug_table", /* used by powerpc for BUG() */
997 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
1000 /* Start of section names */
1001 const char *namelist2
[] = {
1005 /* part of section name */
1006 const char *namelist3
[] = {
1007 ".unwind", /* Sample: IA_64.unwind.exit.text */
1011 for (s
= namelist1
; *s
; s
++)
1012 if (strcmp(*s
, name
) == 0)
1014 for (s
= namelist2
; *s
; s
++)
1015 if (strncmp(*s
, name
, strlen(*s
)) == 0)
1017 for (s
= namelist3
; *s
; s
++)
1018 if (strstr(name
, *s
) != NULL
)
1023 static void read_symbols(char *modname
)
1025 const char *symname
;
1029 struct elf_info info
= { };
1032 parse_elf(&info
, modname
);
1034 mod
= new_module(modname
);
1036 /* When there's no vmlinux, don't print warnings about
1037 * unresolved symbols (since there'll be too many ;) */
1038 if (is_vmlinux(modname
)) {
1043 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1045 if (license_is_gpl_compatible(license
))
1046 mod
->gpl_compatible
= 1;
1048 mod
->gpl_compatible
= 0;
1051 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1052 "license", license
);
1055 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1056 symname
= info
.strtab
+ sym
->st_name
;
1058 handle_modversions(mod
, &info
, sym
, symname
);
1059 handle_moddevtable(mod
, &info
, sym
, symname
);
1061 check_sec_ref(mod
, modname
, &info
, init_section
, init_section_ref_ok
);
1062 check_sec_ref(mod
, modname
, &info
, exit_section
, exit_section_ref_ok
);
1064 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1066 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1067 version
- (char *)info
.hdr
);
1068 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1069 get_src_version(modname
, mod
->srcversion
,
1070 sizeof(mod
->srcversion
)-1);
1072 parse_elf_finish(&info
);
1074 /* Our trick to get versioning for struct_module - it's
1075 * never passed as an argument to an exported function, so
1076 * the automatic versioning doesn't pick it up, but it's really
1077 * important anyhow */
1079 mod
->unres
= alloc_symbol("struct_module", 0, mod
->unres
);
1084 /* We first write the generated file into memory using the
1085 * following helper, then compare to the file on disk and
1086 * only update the later if anything changed */
1088 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1089 const char *fmt
, ...)
1096 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1097 buf_write(buf
, tmp
, len
);
1101 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1103 if (buf
->size
- buf
->pos
< len
) {
1104 buf
->size
+= len
+ SZ
;
1105 buf
->p
= realloc(buf
->p
, buf
->size
);
1107 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1111 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1113 const char *e
= is_vmlinux(m
) ?"":".ko";
1117 fatal("modpost: GPL-incompatible module %s%s "
1118 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1120 case export_unused_gpl
:
1121 fatal("modpost: GPL-incompatible module %s%s "
1122 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1124 case export_gpl_future
:
1125 warn("modpost: GPL-incompatible module %s%s "
1126 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1130 case export_unknown
:
1136 static void check_for_unused(enum export exp
, const char* m
, const char* s
)
1138 const char *e
= is_vmlinux(m
) ?"":".ko";
1142 case export_unused_gpl
:
1143 warn("modpost: module %s%s "
1144 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1152 static void check_exports(struct module
*mod
)
1154 struct symbol
*s
, *exp
;
1156 for (s
= mod
->unres
; s
; s
= s
->next
) {
1157 const char *basename
;
1158 exp
= find_symbol(s
->name
);
1159 if (!exp
|| exp
->module
== mod
)
1161 basename
= strrchr(mod
->name
, '/');
1165 basename
= mod
->name
;
1166 if (!mod
->gpl_compatible
)
1167 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1168 check_for_unused(exp
->export
, basename
, exp
->name
);
1173 * Header for the generated file
1175 static void add_header(struct buffer
*b
, struct module
*mod
)
1177 buf_printf(b
, "#include <linux/module.h>\n");
1178 buf_printf(b
, "#include <linux/vermagic.h>\n");
1179 buf_printf(b
, "#include <linux/compiler.h>\n");
1180 buf_printf(b
, "\n");
1181 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1182 buf_printf(b
, "\n");
1183 buf_printf(b
, "struct module __this_module\n");
1184 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1185 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1187 buf_printf(b
, " .init = init_module,\n");
1188 if (mod
->has_cleanup
)
1189 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1190 " .exit = cleanup_module,\n"
1192 buf_printf(b
, "};\n");
1196 * Record CRCs for unresolved symbols
1198 static void add_versions(struct buffer
*b
, struct module
*mod
)
1200 struct symbol
*s
, *exp
;
1202 for (s
= mod
->unres
; s
; s
= s
->next
) {
1203 exp
= find_symbol(s
->name
);
1204 if (!exp
|| exp
->module
== mod
) {
1205 if (have_vmlinux
&& !s
->weak
)
1206 warn("\"%s\" [%s.ko] undefined!\n",
1207 s
->name
, mod
->name
);
1210 s
->module
= exp
->module
;
1211 s
->crc_valid
= exp
->crc_valid
;
1218 buf_printf(b
, "\n");
1219 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1220 buf_printf(b
, "__attribute_used__\n");
1221 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1223 for (s
= mod
->unres
; s
; s
= s
->next
) {
1227 if (!s
->crc_valid
) {
1228 warn("\"%s\" [%s.ko] has no CRC!\n",
1229 s
->name
, mod
->name
);
1232 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1235 buf_printf(b
, "};\n");
1238 static void add_depends(struct buffer
*b
, struct module
*mod
,
1239 struct module
*modules
)
1245 for (m
= modules
; m
; m
= m
->next
) {
1246 m
->seen
= is_vmlinux(m
->name
);
1249 buf_printf(b
, "\n");
1250 buf_printf(b
, "static const char __module_depends[]\n");
1251 buf_printf(b
, "__attribute_used__\n");
1252 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1253 buf_printf(b
, "\"depends=");
1254 for (s
= mod
->unres
; s
; s
= s
->next
) {
1258 if (s
->module
->seen
)
1261 s
->module
->seen
= 1;
1262 buf_printf(b
, "%s%s", first
? "" : ",",
1263 strrchr(s
->module
->name
, '/') + 1);
1266 buf_printf(b
, "\";\n");
1269 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1271 if (mod
->srcversion
[0]) {
1272 buf_printf(b
, "\n");
1273 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1278 static void write_if_changed(struct buffer
*b
, const char *fname
)
1284 file
= fopen(fname
, "r");
1288 if (fstat(fileno(file
), &st
) < 0)
1291 if (st
.st_size
!= b
->pos
)
1294 tmp
= NOFAIL(malloc(b
->pos
));
1295 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1298 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1310 file
= fopen(fname
, "w");
1315 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1322 /* parse Module.symvers file. line format:
1323 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1325 static void read_dump(const char *fname
, unsigned int kernel
)
1327 unsigned long size
, pos
= 0;
1328 void *file
= grab_file(fname
, &size
);
1332 /* No symbol versions, silently ignore */
1335 while ((line
= get_next_line(&pos
, file
, size
))) {
1336 char *symname
, *modname
, *d
, *export
, *end
;
1341 if (!(symname
= strchr(line
, '\t')))
1344 if (!(modname
= strchr(symname
, '\t')))
1347 if ((export
= strchr(modname
, '\t')) != NULL
)
1349 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
1351 crc
= strtoul(line
, &d
, 16);
1352 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
1355 if (!(mod
= find_module(modname
))) {
1356 if (is_vmlinux(modname
)) {
1359 mod
= new_module(NOFAIL(strdup(modname
)));
1362 s
= sym_add_exported(symname
, mod
, export_no(export
));
1365 sym_update_crc(symname
, mod
, crc
, export_no(export
));
1369 fatal("parse error in symbol dump file\n");
1372 /* For normal builds always dump all symbols.
1373 * For external modules only dump symbols
1374 * that are not read from kernel Module.symvers.
1376 static int dump_sym(struct symbol
*sym
)
1378 if (!external_module
)
1380 if (sym
->vmlinux
|| sym
->kernel
)
1385 static void write_dump(const char *fname
)
1387 struct buffer buf
= { };
1388 struct symbol
*symbol
;
1391 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
1392 symbol
= symbolhash
[n
];
1394 if (dump_sym(symbol
))
1395 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
1396 symbol
->crc
, symbol
->name
,
1397 symbol
->module
->name
,
1398 export_str(symbol
->export
));
1399 symbol
= symbol
->next
;
1402 write_if_changed(&buf
, fname
);
1405 int main(int argc
, char **argv
)
1408 struct buffer buf
= { };
1410 char *kernel_read
= NULL
, *module_read
= NULL
;
1411 char *dump_write
= NULL
;
1414 while ((opt
= getopt(argc
, argv
, "i:I:mo:a")) != -1) {
1417 kernel_read
= optarg
;
1420 module_read
= optarg
;
1421 external_module
= 1;
1427 dump_write
= optarg
;
1438 read_dump(kernel_read
, 1);
1440 read_dump(module_read
, 0);
1442 while (optind
< argc
) {
1443 read_symbols(argv
[optind
++]);
1446 for (mod
= modules
; mod
; mod
= mod
->next
) {
1452 for (mod
= modules
; mod
; mod
= mod
->next
) {
1458 add_header(&buf
, mod
);
1459 add_versions(&buf
, mod
);
1460 add_depends(&buf
, mod
, modules
);
1461 add_moddevtable(&buf
, mod
);
1462 add_srcversion(&buf
, mod
);
1464 sprintf(fname
, "%s.mod.c", mod
->name
);
1465 write_if_changed(&buf
, fname
);
1469 write_dump(dump_write
);