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 /* Warn about section mismatch in vmlinux if set to 1 */
27 static int vmlinux_section_warnings
= 1;
28 /* Only warn about unresolved symbols */
29 static int warn_unresolved
= 0;
30 /* How a symbol is exported */
32 export_plain
, export_unused
, export_gpl
,
33 export_unused_gpl
, export_gpl_future
, export_unknown
36 #define PRINTF __attribute__ ((format (printf, 1, 2)))
38 PRINTF
void fatal(const char *fmt
, ...)
42 fprintf(stderr
, "FATAL: ");
44 va_start(arglist
, fmt
);
45 vfprintf(stderr
, fmt
, arglist
);
51 PRINTF
void warn(const char *fmt
, ...)
55 fprintf(stderr
, "WARNING: ");
57 va_start(arglist
, fmt
);
58 vfprintf(stderr
, fmt
, arglist
);
62 PRINTF
void merror(const char *fmt
, ...)
66 fprintf(stderr
, "ERROR: ");
68 va_start(arglist
, fmt
);
69 vfprintf(stderr
, fmt
, arglist
);
73 static int is_vmlinux(const char *modname
)
77 if ((myname
= strrchr(modname
, '/')))
82 return (strcmp(myname
, "vmlinux") == 0) ||
83 (strcmp(myname
, "vmlinux.o") == 0);
86 void *do_nofail(void *ptr
, const char *expr
)
89 fatal("modpost: Memory allocation failure: %s.\n", expr
);
94 /* A list of all modules we processed */
96 static struct module
*modules
;
98 static struct module
*find_module(char *modname
)
102 for (mod
= modules
; mod
; mod
= mod
->next
)
103 if (strcmp(mod
->name
, modname
) == 0)
108 static struct module
*new_module(char *modname
)
113 mod
= NOFAIL(malloc(sizeof(*mod
)));
114 memset(mod
, 0, sizeof(*mod
));
115 p
= NOFAIL(strdup(modname
));
117 /* strip trailing .o */
118 if ((s
= strrchr(p
, '.')) != NULL
)
119 if (strcmp(s
, ".o") == 0)
124 mod
->gpl_compatible
= -1;
131 /* A hash of all exported symbols,
132 * struct symbol is also used for lists of unresolved symbols */
134 #define SYMBOL_HASH_SIZE 1024
138 struct module
*module
;
142 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
143 unsigned int kernel
:1; /* 1 if symbol is from kernel
144 * (only for external modules) **/
145 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
146 enum export export
; /* Type of export */
150 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
152 /* This is based on the hash agorithm from gdbm, via tdb */
153 static inline unsigned int tdb_hash(const char *name
)
155 unsigned value
; /* Used to compute the hash value. */
156 unsigned i
; /* Used to cycle through random values. */
158 /* Set the initial value from the key size. */
159 for (value
= 0x238F13AF * strlen(name
), i
=0; name
[i
]; i
++)
160 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
162 return (1103515243 * value
+ 12345);
166 * Allocate a new symbols for use in the hash of exported symbols or
167 * the list of unresolved symbols per module
169 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
172 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
174 memset(s
, 0, sizeof(*s
));
175 strcpy(s
->name
, name
);
181 /* For the hash of exported symbols */
182 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
188 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
189 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
190 new->module
= module
;
191 new->export
= export
;
195 static struct symbol
*find_symbol(const char *name
)
199 /* For our purposes, .foo matches foo. PPC64 needs this. */
203 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
=s
->next
) {
204 if (strcmp(s
->name
, name
) == 0)
214 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
215 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
216 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
217 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
218 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
219 { .str
= "(unknown)", .export
= export_unknown
},
223 static const char *export_str(enum export ex
)
225 return export_list
[ex
].str
;
228 static enum export
export_no(const char * s
)
232 return export_unknown
;
233 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
234 if (strcmp(export_list
[i
].str
, s
) == 0)
235 return export_list
[i
].export
;
237 return export_unknown
;
240 static enum export
export_from_sec(struct elf_info
*elf
, Elf_Section sec
)
242 if (sec
== elf
->export_sec
)
244 else if (sec
== elf
->export_unused_sec
)
245 return export_unused
;
246 else if (sec
== elf
->export_gpl_sec
)
248 else if (sec
== elf
->export_unused_gpl_sec
)
249 return export_unused_gpl
;
250 else if (sec
== elf
->export_gpl_future_sec
)
251 return export_gpl_future
;
253 return export_unknown
;
257 * Add an exported symbol - it may have already been added without a
258 * CRC, in this case just update the CRC
260 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
263 struct symbol
*s
= find_symbol(name
);
266 s
= new_symbol(name
, mod
, export
);
269 warn("%s: '%s' exported twice. Previous export "
270 "was in %s%s\n", mod
->name
, name
,
272 is_vmlinux(s
->module
->name
) ?"":".ko");
274 /* In case Modules.symvers was out of date */
279 s
->vmlinux
= is_vmlinux(mod
->name
);
285 static void sym_update_crc(const char *name
, struct module
*mod
,
286 unsigned int crc
, enum export export
)
288 struct symbol
*s
= find_symbol(name
);
291 s
= new_symbol(name
, mod
, export
);
296 void *grab_file(const char *filename
, unsigned long *size
)
302 fd
= open(filename
, O_RDONLY
);
303 if (fd
< 0 || fstat(fd
, &st
) != 0)
307 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
310 if (map
== MAP_FAILED
)
316 * Return a copy of the next line in a mmap'ed file.
317 * spaces in the beginning of the line is trimmed away.
318 * Return a pointer to a static buffer.
320 char* get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
322 static char line
[4096];
325 signed char *p
= (signed char *)file
+ *pos
;
328 for (; *pos
< size
; (*pos
)++)
330 if (skip
&& isspace(*p
)) {
335 if (*p
!= '\n' && (*pos
< size
)) {
339 break; /* Too long, stop */
350 void release_file(void *file
, unsigned long size
)
355 static int parse_elf(struct elf_info
*info
, const char *filename
)
362 hdr
= grab_file(filename
, &info
->size
);
368 if (info
->size
< sizeof(*hdr
)) {
369 /* file too small, assume this is an empty .o file */
372 /* Is this a valid ELF file? */
373 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
374 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
375 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
376 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
377 /* Not an ELF file - silently ignore it */
380 /* Fix endianness in ELF header */
381 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
382 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
383 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
384 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
385 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
386 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
387 info
->sechdrs
= sechdrs
;
389 /* Check if file offset is correct */
390 if (hdr
->e_shoff
> info
->size
) {
391 fatal("section header offset=%u in file '%s' is bigger then filesize=%lu\n", hdr
->e_shoff
, filename
, info
->size
);
395 /* Fix endianness in section headers */
396 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
397 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
398 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
399 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
400 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
401 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
402 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
403 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
405 /* Find symbol table. */
406 for (i
= 1; i
< hdr
->e_shnum
; i
++) {
407 const char *secstrings
408 = (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
411 if (sechdrs
[i
].sh_offset
> info
->size
) {
412 fatal("%s is truncated. sechdrs[i].sh_offset=%u > sizeof(*hrd)=%ul\n", filename
, (unsigned int)sechdrs
[i
].sh_offset
, sizeof(*hdr
));
415 secname
= secstrings
+ sechdrs
[i
].sh_name
;
416 if (strcmp(secname
, ".modinfo") == 0) {
417 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
418 info
->modinfo_len
= sechdrs
[i
].sh_size
;
419 } else if (strcmp(secname
, "__ksymtab") == 0)
420 info
->export_sec
= i
;
421 else if (strcmp(secname
, "__ksymtab_unused") == 0)
422 info
->export_unused_sec
= i
;
423 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
424 info
->export_gpl_sec
= i
;
425 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
426 info
->export_unused_gpl_sec
= i
;
427 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
428 info
->export_gpl_future_sec
= i
;
430 if (sechdrs
[i
].sh_type
!= SHT_SYMTAB
)
433 info
->symtab_start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
434 info
->symtab_stop
= (void *)hdr
+ sechdrs
[i
].sh_offset
435 + sechdrs
[i
].sh_size
;
436 info
->strtab
= (void *)hdr
+
437 sechdrs
[sechdrs
[i
].sh_link
].sh_offset
;
439 if (!info
->symtab_start
) {
440 fatal("%s has no symtab?\n", filename
);
442 /* Fix endianness in symbols */
443 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
444 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
445 sym
->st_name
= TO_NATIVE(sym
->st_name
);
446 sym
->st_value
= TO_NATIVE(sym
->st_value
);
447 sym
->st_size
= TO_NATIVE(sym
->st_size
);
452 static void parse_elf_finish(struct elf_info
*info
)
454 release_file(info
->hdr
, info
->size
);
457 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
458 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
460 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
461 Elf_Sym
*sym
, const char *symname
)
464 enum export export
= export_from_sec(info
, sym
->st_shndx
);
466 switch (sym
->st_shndx
) {
468 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
472 if (memcmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
473 crc
= (unsigned int) sym
->st_value
;
474 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
479 /* undefined symbol */
480 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
481 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
483 /* ignore global offset table */
484 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
486 /* ignore __this_module, it will be resolved shortly */
487 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
489 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
490 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
491 /* add compatibility with older glibc */
492 #ifndef STT_SPARC_REGISTER
493 #define STT_SPARC_REGISTER STT_REGISTER
495 if (info
->hdr
->e_machine
== EM_SPARC
||
496 info
->hdr
->e_machine
== EM_SPARCV9
) {
497 /* Ignore register directives. */
498 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
500 if (symname
[0] == '.') {
501 char *munged
= strdup(symname
);
503 munged
[1] = toupper(munged
[1]);
509 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
510 strlen(MODULE_SYMBOL_PREFIX
)) == 0)
511 mod
->unres
= alloc_symbol(symname
+
512 strlen(MODULE_SYMBOL_PREFIX
),
513 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
517 /* All exported symbols */
518 if (memcmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
519 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
522 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
524 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
525 mod
->has_cleanup
= 1;
531 * Parse tag=value strings from .modinfo section
533 static char *next_string(char *string
, unsigned long *secsize
)
535 /* Skip non-zero chars */
538 if ((*secsize
)-- <= 1)
542 /* Skip any zero padding. */
545 if ((*secsize
)-- <= 1)
551 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
552 const char *tag
, char *info
)
555 unsigned int taglen
= strlen(tag
);
556 unsigned long size
= modinfo_len
;
559 size
-= info
- (char *)modinfo
;
560 modinfo
= next_string(info
, &size
);
563 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
564 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
565 return p
+ taglen
+ 1;
570 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
574 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
578 * Test if string s ends in string sub
581 static int strrcmp(const char *s
, const char *sub
)
589 sublen
= strlen(sub
);
591 if ((slen
== 0) || (sublen
== 0))
597 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
601 * Functions used only during module init is marked __init and is stored in
602 * a .init.text section. Likewise data is marked __initdata and stored in
603 * a .init.data section.
604 * If this section is one of these sections return 1
605 * See include/linux/init.h for the details
607 static int init_section(const char *name
)
609 if (strcmp(name
, ".init") == 0)
611 if (strncmp(name
, ".init.", strlen(".init.")) == 0)
617 * Functions used only during module exit is marked __exit and is stored in
618 * a .exit.text section. Likewise data is marked __exitdata and stored in
619 * a .exit.data section.
620 * If this section is one of these sections return 1
621 * See include/linux/init.h for the details
623 static int exit_section(const char *name
)
625 if (strcmp(name
, ".exit.text") == 0)
627 if (strcmp(name
, ".exit.data") == 0)
634 * Data sections are named like this:
635 * .data | .data.rel | .data.rel.*
636 * Return 1 if the specified section is a data section
638 static int data_section(const char *name
)
640 if ((strcmp(name
, ".data") == 0) ||
641 (strcmp(name
, ".data.rel") == 0) ||
642 (strncmp(name
, ".data.rel.", strlen(".data.rel.")) == 0))
649 * Whitelist to allow certain references to pass with no warning.
652 * Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
653 * The pattern is identified by:
654 * fromsec = .text.init.refok* | .data.init.refok*
657 * If a module parameter is declared __initdata and permissions=0
658 * then this is legal despite the warning generated.
659 * We cannot see value of permissions here, so just ignore
661 * The pattern is identified by:
667 * Many drivers utilise a *driver container with references to
668 * add, remove, probe functions etc.
669 * These functions may often be marked __init and we do not want to
671 * the pattern is identified by:
672 * tosec = init or exit section
673 * fromsec = data section
674 * atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one, *_console, *_timer
677 * Whitelist all refereces from .text.head to .init.data
678 * Whitelist all refereces from .text.head to .init.text
681 * Some symbols belong to init section but still it is ok to reference
682 * these from non-init sections as these symbols don't have any memory
683 * allocated for them and symbol address and value are same. So even
684 * if init section is freed, its ok to reference those symbols.
685 * For ex. symbols marking the init section boundaries.
686 * This pattern is identified by
687 * refsymname = __init_begin, _sinittext, _einittext
690 * Xtensa uses literal sections for constants that are accessed PC-relative.
691 * Literal sections may safely reference their text sections.
692 * (Note that the name for the literal section omits any trailing '.text')
693 * tosec = <section>[.text]
694 * fromsec = <section>.literal
696 static int secref_whitelist(const char *modname
, const char *tosec
,
697 const char *fromsec
, const char *atsym
,
698 const char *refsymname
)
702 const char *pat2sym
[] = {
704 "_template", /* scsi uses *_template a lot */
705 "_timer", /* arm uses ops structures named _timer a lot */
706 "_sht", /* scsi also used *_sht to some extent */
714 const char *pat3refsym
[] = {
721 /* Check for pattern 0 */
722 if ((strncmp(fromsec
, ".text.init.refok", strlen(".text.init.refok")) == 0) ||
723 (strncmp(fromsec
, ".exit.text.refok", strlen(".exit.text.refok")) == 0) ||
724 (strncmp(fromsec
, ".data.init.refok", strlen(".data.init.refok")) == 0))
727 /* Check for pattern 1 */
728 if ((strcmp(tosec
, ".init.data") == 0) &&
729 (strncmp(fromsec
, ".data", strlen(".data")) == 0) &&
730 (strncmp(atsym
, "__param", strlen("__param")) == 0))
733 /* Check for pattern 2 */
734 if ((init_section(tosec
) || exit_section(tosec
)) && data_section(fromsec
))
735 for (s
= pat2sym
; *s
; s
++)
736 if (strrcmp(atsym
, *s
) == 0)
739 /* Check for pattern 3 */
740 if ((strcmp(fromsec
, ".text.head") == 0) &&
741 ((strcmp(tosec
, ".init.data") == 0) ||
742 (strcmp(tosec
, ".init.text") == 0)))
745 /* Check for pattern 4 */
746 for (s
= pat3refsym
; *s
; s
++)
747 if (strcmp(refsymname
, *s
) == 0)
750 /* Check for pattern 5 */
751 if (strrcmp(tosec
, ".text") == 0)
752 len
= strlen(tosec
) - strlen(".text");
755 if ((strncmp(tosec
, fromsec
, len
) == 0) && (strlen(fromsec
) > len
) &&
756 (strcmp(fromsec
+ len
, ".literal") == 0))
763 * Find symbol based on relocation record info.
764 * In some cases the symbol supplied is a valid symbol so
765 * return refsym. If st_name != 0 we assume this is a valid symbol.
766 * In other cases the symbol needs to be looked up in the symbol table
767 * based on section and address.
769 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf_Addr addr
,
774 if (relsym
->st_name
!= 0)
776 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
777 if (sym
->st_shndx
!= relsym
->st_shndx
)
779 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
781 if (sym
->st_value
== addr
)
787 static inline int is_arm_mapping_symbol(const char *str
)
789 return str
[0] == '$' && strchr("atd", str
[1])
790 && (str
[2] == '\0' || str
[2] == '.');
794 * If there's no name there, ignore it; likewise, ignore it if it's
795 * one of the magic symbols emitted used by current ARM tools.
797 * Otherwise if find_symbols_between() returns those symbols, they'll
798 * fail the whitelist tests and cause lots of false alarms ... fixable
799 * only by merging __exit and __init sections into __text, bloating
800 * the kernel (which is especially evil on embedded platforms).
802 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
804 const char *name
= elf
->strtab
+ sym
->st_name
;
806 if (!name
|| !strlen(name
))
808 return !is_arm_mapping_symbol(name
);
812 * Find symbols before or equal addr and after addr - in the section sec.
813 * If we find two symbols with equal offset prefer one with a valid name.
814 * The ELF format may have a better way to detect what type of symbol
815 * it is, but this works for now.
817 static void find_symbols_between(struct elf_info
*elf
, Elf_Addr addr
,
819 Elf_Sym
**before
, Elf_Sym
**after
)
822 Elf_Ehdr
*hdr
= elf
->hdr
;
823 Elf_Addr beforediff
= ~0;
824 Elf_Addr afterdiff
= ~0;
825 const char *secstrings
= (void *)hdr
+
826 elf
->sechdrs
[hdr
->e_shstrndx
].sh_offset
;
831 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
834 if (sym
->st_shndx
>= SHN_LORESERVE
)
836 symsec
= secstrings
+ elf
->sechdrs
[sym
->st_shndx
].sh_name
;
837 if (strcmp(symsec
, sec
) != 0)
839 if (!is_valid_name(elf
, sym
))
841 if (sym
->st_value
<= addr
) {
842 if ((addr
- sym
->st_value
) < beforediff
) {
843 beforediff
= addr
- sym
->st_value
;
846 else if ((addr
- sym
->st_value
) == beforediff
) {
852 if ((sym
->st_value
- addr
) < afterdiff
) {
853 afterdiff
= sym
->st_value
- addr
;
856 else if ((sym
->st_value
- addr
) == afterdiff
) {
864 * Print a warning about a section mismatch.
865 * Try to find symbols near it so user can find it.
866 * Check whitelist before warning - it may be a false positive.
868 static void warn_sec_mismatch(const char *modname
, const char *fromsec
,
869 struct elf_info
*elf
, Elf_Sym
*sym
, Elf_Rela r
)
871 const char *refsymname
= "";
872 Elf_Sym
*before
, *after
;
874 Elf_Ehdr
*hdr
= elf
->hdr
;
875 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
876 const char *secstrings
= (void *)hdr
+
877 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
878 const char *secname
= secstrings
+ sechdrs
[sym
->st_shndx
].sh_name
;
880 find_symbols_between(elf
, r
.r_offset
, fromsec
, &before
, &after
);
882 refsym
= find_elf_symbol(elf
, r
.r_addend
, sym
);
883 if (refsym
&& strlen(elf
->strtab
+ refsym
->st_name
))
884 refsymname
= elf
->strtab
+ refsym
->st_name
;
886 /* check whitelist - we may ignore it */
887 if (secref_whitelist(modname
, secname
, fromsec
,
888 before
? elf
->strtab
+ before
->st_name
: "",
892 if (before
&& after
) {
893 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
894 "(between '%s' and '%s')\n",
895 modname
, fromsec
, (unsigned long long)r
.r_offset
,
897 elf
->strtab
+ before
->st_name
,
898 elf
->strtab
+ after
->st_name
);
900 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
902 modname
, fromsec
, (unsigned long long)r
.r_offset
,
904 elf
->strtab
+ before
->st_name
);
906 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s "
907 "before '%s' (at offset -0x%llx)\n",
908 modname
, fromsec
, (unsigned long long)r
.r_offset
,
910 elf
->strtab
+ after
->st_name
);
912 warn("%s(%s+0x%llx): Section mismatch: reference to %s:%s\n",
913 modname
, fromsec
, (unsigned long long)r
.r_offset
,
914 secname
, refsymname
);
918 static unsigned int *reloc_location(struct elf_info
*elf
,
919 int rsection
, Elf_Rela
*r
)
921 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
922 int section
= sechdrs
[rsection
].sh_info
;
924 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
925 (r
->r_offset
- sechdrs
[section
].sh_addr
);
928 static int addend_386_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
930 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
931 unsigned int *location
= reloc_location(elf
, rsection
, r
);
935 r
->r_addend
= TO_NATIVE(*location
);
938 r
->r_addend
= TO_NATIVE(*location
) + 4;
939 /* For CONFIG_RELOCATABLE=y */
940 if (elf
->hdr
->e_type
== ET_EXEC
)
941 r
->r_addend
+= r
->r_offset
;
947 static int addend_arm_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
949 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
953 /* From ARM ABI: (S + A) | T */
954 r
->r_addend
= (int)(long)(elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
957 /* From ARM ABI: ((S + A) | T) - P */
958 r
->r_addend
= (int)(long)(elf
->hdr
+ elf
->sechdrs
[rsection
].sh_offset
+
959 (r
->r_offset
- elf
->sechdrs
[rsection
].sh_addr
));
967 static int addend_mips_rel(struct elf_info
*elf
, int rsection
, Elf_Rela
*r
)
969 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
970 unsigned int *location
= reloc_location(elf
, rsection
, r
);
973 if (r_typ
== R_MIPS_HI16
)
974 return 1; /* skip this */
975 inst
= TO_NATIVE(*location
);
978 r
->r_addend
= inst
& 0xffff;
981 r
->r_addend
= (inst
& 0x03ffffff) << 2;
991 * A module includes a number of sections that are discarded
992 * either when loaded or when used as built-in.
993 * For loaded modules all functions marked __init and all data
994 * marked __initdata will be discarded when the module has been intialized.
995 * Likewise for modules used built-in the sections marked __exit
996 * are discarded because __exit marked function are supposed to be called
997 * only when a moduel is unloaded which never happes for built-in modules.
998 * The check_sec_ref() function traverses all relocation records
999 * to find all references to a section that reference a section that will
1000 * be discarded and warns about it.
1002 static void check_sec_ref(struct module
*mod
, const char *modname
,
1003 struct elf_info
*elf
,
1004 int section(const char*),
1005 int section_ref_ok(const char *))
1009 Elf_Ehdr
*hdr
= elf
->hdr
;
1010 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1011 const char *secstrings
= (void *)hdr
+
1012 sechdrs
[hdr
->e_shstrndx
].sh_offset
;
1014 /* Walk through all sections */
1015 for (i
= 0; i
< hdr
->e_shnum
; i
++) {
1016 const char *name
= secstrings
+ sechdrs
[i
].sh_name
;
1017 const char *secname
;
1020 /* We want to process only relocation sections and not .init */
1021 if (sechdrs
[i
].sh_type
== SHT_RELA
) {
1023 Elf_Rela
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
1024 Elf_Rela
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
1025 name
+= strlen(".rela");
1026 if (section_ref_ok(name
))
1029 for (rela
= start
; rela
< stop
; rela
++) {
1030 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1031 #if KERNEL_ELFCLASS == ELFCLASS64
1032 if (hdr
->e_machine
== EM_MIPS
) {
1034 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1035 r_sym
= TO_NATIVE(r_sym
);
1036 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1037 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1039 r
.r_info
= TO_NATIVE(rela
->r_info
);
1040 r_sym
= ELF_R_SYM(r
.r_info
);
1043 r
.r_info
= TO_NATIVE(rela
->r_info
);
1044 r_sym
= ELF_R_SYM(r
.r_info
);
1046 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1047 sym
= elf
->symtab_start
+ r_sym
;
1048 /* Skip special sections */
1049 if (sym
->st_shndx
>= SHN_LORESERVE
)
1052 secname
= secstrings
+
1053 sechdrs
[sym
->st_shndx
].sh_name
;
1054 if (section(secname
))
1055 warn_sec_mismatch(modname
, name
,
1058 } else if (sechdrs
[i
].sh_type
== SHT_REL
) {
1060 Elf_Rel
*start
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
1061 Elf_Rel
*stop
= (void*)start
+ sechdrs
[i
].sh_size
;
1062 name
+= strlen(".rel");
1063 if (section_ref_ok(name
))
1066 for (rel
= start
; rel
< stop
; rel
++) {
1067 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1068 #if KERNEL_ELFCLASS == ELFCLASS64
1069 if (hdr
->e_machine
== EM_MIPS
) {
1071 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1072 r_sym
= TO_NATIVE(r_sym
);
1073 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1074 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1076 r
.r_info
= TO_NATIVE(rel
->r_info
);
1077 r_sym
= ELF_R_SYM(r
.r_info
);
1080 r
.r_info
= TO_NATIVE(rel
->r_info
);
1081 r_sym
= ELF_R_SYM(r
.r_info
);
1084 switch (hdr
->e_machine
) {
1086 if (addend_386_rel(elf
, i
, &r
))
1090 if(addend_arm_rel(elf
, i
, &r
))
1094 if (addend_mips_rel(elf
, i
, &r
))
1098 sym
= elf
->symtab_start
+ r_sym
;
1099 /* Skip special sections */
1100 if (sym
->st_shndx
>= SHN_LORESERVE
)
1103 secname
= secstrings
+
1104 sechdrs
[sym
->st_shndx
].sh_name
;
1105 if (section(secname
))
1106 warn_sec_mismatch(modname
, name
,
1114 * Identify sections from which references to either a
1115 * .init or a .exit section is OK.
1117 * [OPD] Keith Ownes <kaos@sgi.com> commented:
1118 * For our future {in}sanity, add a comment that this is the ppc .opd
1119 * section, not the ia64 .opd section.
1120 * ia64 .opd should not point to discarded sections.
1121 * [.rodata] like for .init.text we ignore .rodata references -same reason
1123 static int initexit_section_ref_ok(const char *name
)
1126 /* Absolute section names */
1127 const char *namelist1
[] = {
1128 "__bug_table", /* used by powerpc for BUG() */
1131 ".cranges", /* used by sh64 */
1133 ".machvec", /* ia64 + powerpc uses these */
1135 ".opd", /* See comment [OPD] */
1137 ".parainstructions",
1139 ".plt", /* seen on ARCH=um build on x86_64. Harmless */
1143 ".xt.prop", /* xtensa informational section */
1144 ".xt.lit", /* xtensa informational section */
1147 /* Start of section names */
1148 const char *namelist2
[] = {
1151 ".note", /* ignore ELF notes - may contain anything */
1152 ".got", /* powerpc - global offset table */
1153 ".toc", /* powerpc - table of contents */
1156 /* part of section name */
1157 const char *namelist3
[] = {
1158 ".unwind", /* Sample: IA_64.unwind.exit.text */
1162 for (s
= namelist1
; *s
; s
++)
1163 if (strcmp(*s
, name
) == 0)
1165 for (s
= namelist2
; *s
; s
++)
1166 if (strncmp(*s
, name
, strlen(*s
)) == 0)
1168 for (s
= namelist3
; *s
; s
++)
1169 if (strstr(name
, *s
) != NULL
)
1176 * Identify sections from which references to a .init section is OK.
1178 * Unfortunately references to read only data that referenced .init
1179 * sections had to be excluded. Almost all of these are false
1180 * positives, they are created by gcc. The downside of excluding rodata
1181 * is that there really are some user references from rodata to
1182 * init code, e.g. drivers/video/vgacon.c:
1184 * const struct consw vga_con = {
1185 * con_startup: vgacon_startup,
1187 * where vgacon_startup is __init. If you want to wade through the false
1188 * positives, take out the check for rodata.
1190 static int init_section_ref_ok(const char *name
)
1193 /* Absolute section names */
1194 const char *namelist1
[] = {
1195 "__dbe_table", /* MIPS generate these */
1196 "__ftr_fixup", /* powerpc cpu feature fixup */
1197 "__fw_ftr_fixup", /* powerpc firmware feature fixup */
1199 ".data.rel.ro", /* used by parisc64 */
1204 /* Start of section names */
1205 const char *namelist2
[] = {
1212 if (initexit_section_ref_ok(name
))
1215 for (s
= namelist1
; *s
; s
++)
1216 if (strcmp(*s
, name
) == 0)
1218 for (s
= namelist2
; *s
; s
++)
1219 if (strncmp(*s
, name
, strlen(*s
)) == 0)
1222 /* If section name ends with ".init" we allow references
1223 * as is the case with .initcallN.init, .early_param.init, .taglist.init etc
1225 if (strrcmp(name
, ".init") == 0)
1231 * Identify sections from which references to a .exit section is OK.
1233 static int exit_section_ref_ok(const char *name
)
1236 /* Absolute section names */
1237 const char *namelist1
[] = {
1245 if (initexit_section_ref_ok(name
))
1248 for (s
= namelist1
; *s
; s
++)
1249 if (strcmp(*s
, name
) == 0)
1254 static void read_symbols(char *modname
)
1256 const char *symname
;
1260 struct elf_info info
= { };
1263 if (!parse_elf(&info
, modname
))
1266 mod
= new_module(modname
);
1268 /* When there's no vmlinux, don't print warnings about
1269 * unresolved symbols (since there'll be too many ;) */
1270 if (is_vmlinux(modname
)) {
1275 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1277 if (license_is_gpl_compatible(license
))
1278 mod
->gpl_compatible
= 1;
1280 mod
->gpl_compatible
= 0;
1283 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1284 "license", license
);
1287 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1288 symname
= info
.strtab
+ sym
->st_name
;
1290 handle_modversions(mod
, &info
, sym
, symname
);
1291 handle_moddevtable(mod
, &info
, sym
, symname
);
1293 if (is_vmlinux(modname
) && vmlinux_section_warnings
) {
1294 check_sec_ref(mod
, modname
, &info
, init_section
, init_section_ref_ok
);
1295 check_sec_ref(mod
, modname
, &info
, exit_section
, exit_section_ref_ok
);
1298 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1300 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1301 version
- (char *)info
.hdr
);
1302 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1303 get_src_version(modname
, mod
->srcversion
,
1304 sizeof(mod
->srcversion
)-1);
1306 parse_elf_finish(&info
);
1308 /* Our trick to get versioning for struct_module - it's
1309 * never passed as an argument to an exported function, so
1310 * the automatic versioning doesn't pick it up, but it's really
1311 * important anyhow */
1313 mod
->unres
= alloc_symbol("struct_module", 0, mod
->unres
);
1318 /* We first write the generated file into memory using the
1319 * following helper, then compare to the file on disk and
1320 * only update the later if anything changed */
1322 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1323 const char *fmt
, ...)
1330 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1331 buf_write(buf
, tmp
, len
);
1335 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1337 if (buf
->size
- buf
->pos
< len
) {
1338 buf
->size
+= len
+ SZ
;
1339 buf
->p
= realloc(buf
->p
, buf
->size
);
1341 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1345 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1347 const char *e
= is_vmlinux(m
) ?"":".ko";
1351 fatal("modpost: GPL-incompatible module %s%s "
1352 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1354 case export_unused_gpl
:
1355 fatal("modpost: GPL-incompatible module %s%s "
1356 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1358 case export_gpl_future
:
1359 warn("modpost: GPL-incompatible module %s%s "
1360 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1364 case export_unknown
:
1370 static void check_for_unused(enum export exp
, const char* m
, const char* s
)
1372 const char *e
= is_vmlinux(m
) ?"":".ko";
1376 case export_unused_gpl
:
1377 warn("modpost: module %s%s "
1378 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1386 static void check_exports(struct module
*mod
)
1388 struct symbol
*s
, *exp
;
1390 for (s
= mod
->unres
; s
; s
= s
->next
) {
1391 const char *basename
;
1392 exp
= find_symbol(s
->name
);
1393 if (!exp
|| exp
->module
== mod
)
1395 basename
= strrchr(mod
->name
, '/');
1399 basename
= mod
->name
;
1400 if (!mod
->gpl_compatible
)
1401 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1402 check_for_unused(exp
->export
, basename
, exp
->name
);
1407 * Header for the generated file
1409 static void add_header(struct buffer
*b
, struct module
*mod
)
1411 buf_printf(b
, "#include <linux/module.h>\n");
1412 buf_printf(b
, "#include <linux/vermagic.h>\n");
1413 buf_printf(b
, "#include <linux/compiler.h>\n");
1414 buf_printf(b
, "\n");
1415 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1416 buf_printf(b
, "\n");
1417 buf_printf(b
, "struct module __this_module\n");
1418 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1419 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1421 buf_printf(b
, " .init = init_module,\n");
1422 if (mod
->has_cleanup
)
1423 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1424 " .exit = cleanup_module,\n"
1426 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1427 buf_printf(b
, "};\n");
1431 * Record CRCs for unresolved symbols
1433 static int add_versions(struct buffer
*b
, struct module
*mod
)
1435 struct symbol
*s
, *exp
;
1438 for (s
= mod
->unres
; s
; s
= s
->next
) {
1439 exp
= find_symbol(s
->name
);
1440 if (!exp
|| exp
->module
== mod
) {
1441 if (have_vmlinux
&& !s
->weak
) {
1442 if (warn_unresolved
) {
1443 warn("\"%s\" [%s.ko] undefined!\n",
1444 s
->name
, mod
->name
);
1446 merror("\"%s\" [%s.ko] undefined!\n",
1447 s
->name
, mod
->name
);
1453 s
->module
= exp
->module
;
1454 s
->crc_valid
= exp
->crc_valid
;
1461 buf_printf(b
, "\n");
1462 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1463 buf_printf(b
, "__attribute_used__\n");
1464 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1466 for (s
= mod
->unres
; s
; s
= s
->next
) {
1470 if (!s
->crc_valid
) {
1471 warn("\"%s\" [%s.ko] has no CRC!\n",
1472 s
->name
, mod
->name
);
1475 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1478 buf_printf(b
, "};\n");
1483 static void add_depends(struct buffer
*b
, struct module
*mod
,
1484 struct module
*modules
)
1490 for (m
= modules
; m
; m
= m
->next
) {
1491 m
->seen
= is_vmlinux(m
->name
);
1494 buf_printf(b
, "\n");
1495 buf_printf(b
, "static const char __module_depends[]\n");
1496 buf_printf(b
, "__attribute_used__\n");
1497 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1498 buf_printf(b
, "\"depends=");
1499 for (s
= mod
->unres
; s
; s
= s
->next
) {
1504 if (s
->module
->seen
)
1507 s
->module
->seen
= 1;
1508 if ((p
= strrchr(s
->module
->name
, '/')) != NULL
)
1511 p
= s
->module
->name
;
1512 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1515 buf_printf(b
, "\";\n");
1518 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1520 if (mod
->srcversion
[0]) {
1521 buf_printf(b
, "\n");
1522 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1527 static void write_if_changed(struct buffer
*b
, const char *fname
)
1533 file
= fopen(fname
, "r");
1537 if (fstat(fileno(file
), &st
) < 0)
1540 if (st
.st_size
!= b
->pos
)
1543 tmp
= NOFAIL(malloc(b
->pos
));
1544 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1547 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1559 file
= fopen(fname
, "w");
1564 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1571 /* parse Module.symvers file. line format:
1572 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1574 static void read_dump(const char *fname
, unsigned int kernel
)
1576 unsigned long size
, pos
= 0;
1577 void *file
= grab_file(fname
, &size
);
1581 /* No symbol versions, silently ignore */
1584 while ((line
= get_next_line(&pos
, file
, size
))) {
1585 char *symname
, *modname
, *d
, *export
, *end
;
1590 if (!(symname
= strchr(line
, '\t')))
1593 if (!(modname
= strchr(symname
, '\t')))
1596 if ((export
= strchr(modname
, '\t')) != NULL
)
1598 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
1600 crc
= strtoul(line
, &d
, 16);
1601 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
1604 if (!(mod
= find_module(modname
))) {
1605 if (is_vmlinux(modname
)) {
1608 mod
= new_module(NOFAIL(strdup(modname
)));
1611 s
= sym_add_exported(symname
, mod
, export_no(export
));
1614 sym_update_crc(symname
, mod
, crc
, export_no(export
));
1618 fatal("parse error in symbol dump file\n");
1621 /* For normal builds always dump all symbols.
1622 * For external modules only dump symbols
1623 * that are not read from kernel Module.symvers.
1625 static int dump_sym(struct symbol
*sym
)
1627 if (!external_module
)
1629 if (sym
->vmlinux
|| sym
->kernel
)
1634 static void write_dump(const char *fname
)
1636 struct buffer buf
= { };
1637 struct symbol
*symbol
;
1640 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
1641 symbol
= symbolhash
[n
];
1643 if (dump_sym(symbol
))
1644 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
1645 symbol
->crc
, symbol
->name
,
1646 symbol
->module
->name
,
1647 export_str(symbol
->export
));
1648 symbol
= symbol
->next
;
1651 write_if_changed(&buf
, fname
);
1654 int main(int argc
, char **argv
)
1657 struct buffer buf
= { };
1659 char *kernel_read
= NULL
, *module_read
= NULL
;
1660 char *dump_write
= NULL
;
1664 while ((opt
= getopt(argc
, argv
, "i:I:mso:aw")) != -1) {
1667 kernel_read
= optarg
;
1670 module_read
= optarg
;
1671 external_module
= 1;
1677 dump_write
= optarg
;
1683 vmlinux_section_warnings
= 0;
1686 warn_unresolved
= 1;
1694 read_dump(kernel_read
, 1);
1696 read_dump(module_read
, 0);
1698 while (optind
< argc
) {
1699 read_symbols(argv
[optind
++]);
1702 for (mod
= modules
; mod
; mod
= mod
->next
) {
1710 for (mod
= modules
; mod
; mod
= mod
->next
) {
1716 add_header(&buf
, mod
);
1717 err
|= add_versions(&buf
, mod
);
1718 add_depends(&buf
, mod
, modules
);
1719 add_moddevtable(&buf
, mod
);
1720 add_srcversion(&buf
, mod
);
1722 sprintf(fname
, "%s.mod.c", mod
->name
);
1723 write_if_changed(&buf
, fname
);
1727 write_dump(dump_write
);