1 /* Postprocess module symbol versions
3 * Copyright 2003 Kai Germaschewski
4 * Copyright 2002-2004 Rusty Russell, IBM Corporation
5 * Copyright 2006-2008 Sam Ravnborg
6 * Based in part on module-init-tools/depmod.c,file2alias
8 * This software may be used and distributed according to the terms
9 * of the GNU General Public License, incorporated herein by reference.
11 * Usage: modpost vmlinux module1.o module2.o ...
19 #include "../../include/generated/autoconf.h"
20 #include "../../include/linux/license.h"
22 /* Some toolchains use a `_' prefix for all user symbols. */
23 #ifdef CONFIG_SYMBOL_PREFIX
24 #define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
26 #define MODULE_SYMBOL_PREFIX ""
30 /* Are we using CONFIG_MODVERSIONS? */
32 /* Warn about undefined symbols? (do so if we have vmlinux) */
34 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
35 static int all_versions
= 0;
36 /* If we are modposting external module set to 1 */
37 static int external_module
= 0;
38 /* Warn about section mismatch in vmlinux if set to 1 */
39 static int vmlinux_section_warnings
= 1;
40 /* Only warn about unresolved symbols */
41 static int warn_unresolved
= 0;
42 /* How a symbol is exported */
43 static int sec_mismatch_count
= 0;
44 static int sec_mismatch_verbose
= 1;
47 export_plain
, export_unused
, export_gpl
,
48 export_unused_gpl
, export_gpl_future
, export_unknown
51 #define PRINTF __attribute__ ((format (printf, 1, 2)))
53 PRINTF
void fatal(const char *fmt
, ...)
57 fprintf(stderr
, "FATAL: ");
59 va_start(arglist
, fmt
);
60 vfprintf(stderr
, fmt
, arglist
);
66 PRINTF
void warn(const char *fmt
, ...)
70 fprintf(stderr
, "WARNING: ");
72 va_start(arglist
, fmt
);
73 vfprintf(stderr
, fmt
, arglist
);
77 PRINTF
void merror(const char *fmt
, ...)
81 fprintf(stderr
, "ERROR: ");
83 va_start(arglist
, fmt
);
84 vfprintf(stderr
, fmt
, arglist
);
88 static int is_vmlinux(const char *modname
)
92 myname
= strrchr(modname
, '/');
98 return (strcmp(myname
, "vmlinux") == 0) ||
99 (strcmp(myname
, "vmlinux.o") == 0);
102 void *do_nofail(void *ptr
, const char *expr
)
105 fatal("modpost: Memory allocation failure: %s.\n", expr
);
110 /* A list of all modules we processed */
111 static struct module
*modules
;
113 static struct module
*find_module(char *modname
)
117 for (mod
= modules
; mod
; mod
= mod
->next
)
118 if (strcmp(mod
->name
, modname
) == 0)
123 static struct module
*new_module(char *modname
)
128 mod
= NOFAIL(malloc(sizeof(*mod
)));
129 memset(mod
, 0, sizeof(*mod
));
130 p
= NOFAIL(strdup(modname
));
132 /* strip trailing .o */
135 if (strcmp(s
, ".o") == 0)
140 mod
->gpl_compatible
= -1;
147 /* A hash of all exported symbols,
148 * struct symbol is also used for lists of unresolved symbols */
150 #define SYMBOL_HASH_SIZE 1024
154 struct module
*module
;
158 unsigned int vmlinux
:1; /* 1 if symbol is defined in vmlinux */
159 unsigned int kernel
:1; /* 1 if symbol is from kernel
160 * (only for external modules) **/
161 unsigned int preloaded
:1; /* 1 if symbol from Module.symvers */
162 enum export export
; /* Type of export */
166 static struct symbol
*symbolhash
[SYMBOL_HASH_SIZE
];
168 /* This is based on the hash agorithm from gdbm, via tdb */
169 static inline unsigned int tdb_hash(const char *name
)
171 unsigned value
; /* Used to compute the hash value. */
172 unsigned i
; /* Used to cycle through random values. */
174 /* Set the initial value from the key size. */
175 for (value
= 0x238F13AF * strlen(name
), i
= 0; name
[i
]; i
++)
176 value
= (value
+ (((unsigned char *)name
)[i
] << (i
*5 % 24)));
178 return (1103515243 * value
+ 12345);
182 * Allocate a new symbols for use in the hash of exported symbols or
183 * the list of unresolved symbols per module
185 static struct symbol
*alloc_symbol(const char *name
, unsigned int weak
,
188 struct symbol
*s
= NOFAIL(malloc(sizeof(*s
) + strlen(name
) + 1));
190 memset(s
, 0, sizeof(*s
));
191 strcpy(s
->name
, name
);
197 /* For the hash of exported symbols */
198 static struct symbol
*new_symbol(const char *name
, struct module
*module
,
204 hash
= tdb_hash(name
) % SYMBOL_HASH_SIZE
;
205 new = symbolhash
[hash
] = alloc_symbol(name
, 0, symbolhash
[hash
]);
206 new->module
= module
;
207 new->export
= export
;
211 static struct symbol
*find_symbol(const char *name
)
215 /* For our purposes, .foo matches foo. PPC64 needs this. */
219 for (s
= symbolhash
[tdb_hash(name
) % SYMBOL_HASH_SIZE
]; s
; s
= s
->next
) {
220 if (strcmp(s
->name
, name
) == 0)
230 { .str
= "EXPORT_SYMBOL", .export
= export_plain
},
231 { .str
= "EXPORT_UNUSED_SYMBOL", .export
= export_unused
},
232 { .str
= "EXPORT_SYMBOL_GPL", .export
= export_gpl
},
233 { .str
= "EXPORT_UNUSED_SYMBOL_GPL", .export
= export_unused_gpl
},
234 { .str
= "EXPORT_SYMBOL_GPL_FUTURE", .export
= export_gpl_future
},
235 { .str
= "(unknown)", .export
= export_unknown
},
239 static const char *export_str(enum export ex
)
241 return export_list
[ex
].str
;
244 static enum export
export_no(const char *s
)
249 return export_unknown
;
250 for (i
= 0; export_list
[i
].export
!= export_unknown
; i
++) {
251 if (strcmp(export_list
[i
].str
, s
) == 0)
252 return export_list
[i
].export
;
254 return export_unknown
;
257 static enum export
export_from_sec(struct elf_info
*elf
, unsigned int sec
)
259 if (sec
== elf
->export_sec
)
261 else if (sec
== elf
->export_unused_sec
)
262 return export_unused
;
263 else if (sec
== elf
->export_gpl_sec
)
265 else if (sec
== elf
->export_unused_gpl_sec
)
266 return export_unused_gpl
;
267 else if (sec
== elf
->export_gpl_future_sec
)
268 return export_gpl_future
;
270 return export_unknown
;
274 * Add an exported symbol - it may have already been added without a
275 * CRC, in this case just update the CRC
277 static struct symbol
*sym_add_exported(const char *name
, struct module
*mod
,
280 struct symbol
*s
= find_symbol(name
);
283 s
= new_symbol(name
, mod
, export
);
286 warn("%s: '%s' exported twice. Previous export "
287 "was in %s%s\n", mod
->name
, name
,
289 is_vmlinux(s
->module
->name
) ?"":".ko");
291 /* In case Modules.symvers was out of date */
296 s
->vmlinux
= is_vmlinux(mod
->name
);
302 static void sym_update_crc(const char *name
, struct module
*mod
,
303 unsigned int crc
, enum export export
)
305 struct symbol
*s
= find_symbol(name
);
308 s
= new_symbol(name
, mod
, export
);
313 void *grab_file(const char *filename
, unsigned long *size
)
319 fd
= open(filename
, O_RDONLY
);
320 if (fd
< 0 || fstat(fd
, &st
) != 0)
324 map
= mmap(NULL
, *size
, PROT_READ
|PROT_WRITE
, MAP_PRIVATE
, fd
, 0);
327 if (map
== MAP_FAILED
)
333 * Return a copy of the next line in a mmap'ed file.
334 * spaces in the beginning of the line is trimmed away.
335 * Return a pointer to a static buffer.
337 char *get_next_line(unsigned long *pos
, void *file
, unsigned long size
)
339 static char line
[4096];
342 signed char *p
= (signed char *)file
+ *pos
;
345 for (; *pos
< size
; (*pos
)++) {
346 if (skip
&& isspace(*p
)) {
351 if (*p
!= '\n' && (*pos
< size
)) {
355 break; /* Too long, stop */
366 void release_file(void *file
, unsigned long size
)
371 static int parse_elf(struct elf_info
*info
, const char *filename
)
377 const char *secstrings
;
378 unsigned int symtab_idx
= ~0U, symtab_shndx_idx
= ~0U;
380 hdr
= grab_file(filename
, &info
->size
);
386 if (info
->size
< sizeof(*hdr
)) {
387 /* file too small, assume this is an empty .o file */
390 /* Is this a valid ELF file? */
391 if ((hdr
->e_ident
[EI_MAG0
] != ELFMAG0
) ||
392 (hdr
->e_ident
[EI_MAG1
] != ELFMAG1
) ||
393 (hdr
->e_ident
[EI_MAG2
] != ELFMAG2
) ||
394 (hdr
->e_ident
[EI_MAG3
] != ELFMAG3
)) {
395 /* Not an ELF file - silently ignore it */
398 /* Fix endianness in ELF header */
399 hdr
->e_type
= TO_NATIVE(hdr
->e_type
);
400 hdr
->e_machine
= TO_NATIVE(hdr
->e_machine
);
401 hdr
->e_version
= TO_NATIVE(hdr
->e_version
);
402 hdr
->e_entry
= TO_NATIVE(hdr
->e_entry
);
403 hdr
->e_phoff
= TO_NATIVE(hdr
->e_phoff
);
404 hdr
->e_shoff
= TO_NATIVE(hdr
->e_shoff
);
405 hdr
->e_flags
= TO_NATIVE(hdr
->e_flags
);
406 hdr
->e_ehsize
= TO_NATIVE(hdr
->e_ehsize
);
407 hdr
->e_phentsize
= TO_NATIVE(hdr
->e_phentsize
);
408 hdr
->e_phnum
= TO_NATIVE(hdr
->e_phnum
);
409 hdr
->e_shentsize
= TO_NATIVE(hdr
->e_shentsize
);
410 hdr
->e_shnum
= TO_NATIVE(hdr
->e_shnum
);
411 hdr
->e_shstrndx
= TO_NATIVE(hdr
->e_shstrndx
);
412 sechdrs
= (void *)hdr
+ hdr
->e_shoff
;
413 info
->sechdrs
= sechdrs
;
415 /* Check if file offset is correct */
416 if (hdr
->e_shoff
> info
->size
) {
417 fatal("section header offset=%lu in file '%s' is bigger than "
418 "filesize=%lu\n", (unsigned long)hdr
->e_shoff
,
419 filename
, info
->size
);
423 if (hdr
->e_shnum
== SHN_UNDEF
) {
425 * There are more than 64k sections,
426 * read count from .sh_size.
428 info
->num_sections
= TO_NATIVE(sechdrs
[0].sh_size
);
431 info
->num_sections
= hdr
->e_shnum
;
433 if (hdr
->e_shstrndx
== SHN_XINDEX
) {
434 info
->secindex_strings
= TO_NATIVE(sechdrs
[0].sh_link
);
437 info
->secindex_strings
= hdr
->e_shstrndx
;
440 /* Fix endianness in section headers */
441 for (i
= 0; i
< info
->num_sections
; i
++) {
442 sechdrs
[i
].sh_name
= TO_NATIVE(sechdrs
[i
].sh_name
);
443 sechdrs
[i
].sh_type
= TO_NATIVE(sechdrs
[i
].sh_type
);
444 sechdrs
[i
].sh_flags
= TO_NATIVE(sechdrs
[i
].sh_flags
);
445 sechdrs
[i
].sh_addr
= TO_NATIVE(sechdrs
[i
].sh_addr
);
446 sechdrs
[i
].sh_offset
= TO_NATIVE(sechdrs
[i
].sh_offset
);
447 sechdrs
[i
].sh_size
= TO_NATIVE(sechdrs
[i
].sh_size
);
448 sechdrs
[i
].sh_link
= TO_NATIVE(sechdrs
[i
].sh_link
);
449 sechdrs
[i
].sh_info
= TO_NATIVE(sechdrs
[i
].sh_info
);
450 sechdrs
[i
].sh_addralign
= TO_NATIVE(sechdrs
[i
].sh_addralign
);
451 sechdrs
[i
].sh_entsize
= TO_NATIVE(sechdrs
[i
].sh_entsize
);
453 /* Find symbol table. */
454 secstrings
= (void *)hdr
+ sechdrs
[info
->secindex_strings
].sh_offset
;
455 for (i
= 1; i
< info
->num_sections
; i
++) {
457 int nobits
= sechdrs
[i
].sh_type
== SHT_NOBITS
;
459 if (!nobits
&& sechdrs
[i
].sh_offset
> info
->size
) {
460 fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
461 "sizeof(*hrd)=%zu\n", filename
,
462 (unsigned long)sechdrs
[i
].sh_offset
,
466 secname
= secstrings
+ sechdrs
[i
].sh_name
;
467 if (strcmp(secname
, ".modinfo") == 0) {
469 fatal("%s has NOBITS .modinfo\n", filename
);
470 info
->modinfo
= (void *)hdr
+ sechdrs
[i
].sh_offset
;
471 info
->modinfo_len
= sechdrs
[i
].sh_size
;
472 } else if (strcmp(secname
, "__ksymtab") == 0)
473 info
->export_sec
= i
;
474 else if (strcmp(secname
, "__ksymtab_unused") == 0)
475 info
->export_unused_sec
= i
;
476 else if (strcmp(secname
, "__ksymtab_gpl") == 0)
477 info
->export_gpl_sec
= i
;
478 else if (strcmp(secname
, "__ksymtab_unused_gpl") == 0)
479 info
->export_unused_gpl_sec
= i
;
480 else if (strcmp(secname
, "__ksymtab_gpl_future") == 0)
481 info
->export_gpl_future_sec
= i
;
483 if (sechdrs
[i
].sh_type
== SHT_SYMTAB
) {
484 unsigned int sh_link_idx
;
486 info
->symtab_start
= (void *)hdr
+
487 sechdrs
[i
].sh_offset
;
488 info
->symtab_stop
= (void *)hdr
+
489 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
490 sh_link_idx
= sechdrs
[i
].sh_link
;
491 info
->strtab
= (void *)hdr
+
492 sechdrs
[sh_link_idx
].sh_offset
;
495 /* 32bit section no. table? ("more than 64k sections") */
496 if (sechdrs
[i
].sh_type
== SHT_SYMTAB_SHNDX
) {
497 symtab_shndx_idx
= i
;
498 info
->symtab_shndx_start
= (void *)hdr
+
499 sechdrs
[i
].sh_offset
;
500 info
->symtab_shndx_stop
= (void *)hdr
+
501 sechdrs
[i
].sh_offset
+ sechdrs
[i
].sh_size
;
504 if (!info
->symtab_start
)
505 fatal("%s has no symtab?\n", filename
);
507 /* Fix endianness in symbols */
508 for (sym
= info
->symtab_start
; sym
< info
->symtab_stop
; sym
++) {
509 sym
->st_shndx
= TO_NATIVE(sym
->st_shndx
);
510 sym
->st_name
= TO_NATIVE(sym
->st_name
);
511 sym
->st_value
= TO_NATIVE(sym
->st_value
);
512 sym
->st_size
= TO_NATIVE(sym
->st_size
);
515 if (symtab_shndx_idx
!= ~0U) {
517 if (symtab_idx
!= sechdrs
[symtab_shndx_idx
].sh_link
)
518 fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",
519 filename
, sechdrs
[symtab_shndx_idx
].sh_link
,
522 for (p
= info
->symtab_shndx_start
; p
< info
->symtab_shndx_stop
;
530 static void parse_elf_finish(struct elf_info
*info
)
532 release_file(info
->hdr
, info
->size
);
535 static int ignore_undef_symbol(struct elf_info
*info
, const char *symname
)
537 /* ignore __this_module, it will be resolved shortly */
538 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"__this_module") == 0)
540 /* ignore global offset table */
541 if (strcmp(symname
, "_GLOBAL_OFFSET_TABLE_") == 0)
543 if (info
->hdr
->e_machine
== EM_PPC
)
544 /* Special register function linked on all modules during final link of .ko */
545 if (strncmp(symname
, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||
546 strncmp(symname
, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||
547 strncmp(symname
, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||
548 strncmp(symname
, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)
550 if (info
->hdr
->e_machine
== EM_PPC64
)
551 /* Special register function linked on all modules during final link of .ko */
552 if (strncmp(symname
, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||
553 strncmp(symname
, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)
555 /* Do not ignore this symbol */
559 #define CRC_PFX MODULE_SYMBOL_PREFIX "__crc_"
560 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
562 static void handle_modversions(struct module
*mod
, struct elf_info
*info
,
563 Elf_Sym
*sym
, const char *symname
)
566 enum export export
= export_from_sec(info
, get_secindex(info
, sym
));
568 switch (sym
->st_shndx
) {
570 warn("\"%s\" [%s] is COMMON symbol\n", symname
, mod
->name
);
574 if (strncmp(symname
, CRC_PFX
, strlen(CRC_PFX
)) == 0) {
575 crc
= (unsigned int) sym
->st_value
;
576 sym_update_crc(symname
+ strlen(CRC_PFX
), mod
, crc
,
581 /* undefined symbol */
582 if (ELF_ST_BIND(sym
->st_info
) != STB_GLOBAL
&&
583 ELF_ST_BIND(sym
->st_info
) != STB_WEAK
)
585 if (ignore_undef_symbol(info
, symname
))
587 /* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
588 #if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
589 /* add compatibility with older glibc */
590 #ifndef STT_SPARC_REGISTER
591 #define STT_SPARC_REGISTER STT_REGISTER
593 if (info
->hdr
->e_machine
== EM_SPARC
||
594 info
->hdr
->e_machine
== EM_SPARCV9
) {
595 /* Ignore register directives. */
596 if (ELF_ST_TYPE(sym
->st_info
) == STT_SPARC_REGISTER
)
598 if (symname
[0] == '.') {
599 char *munged
= strdup(symname
);
601 munged
[1] = toupper(munged
[1]);
607 if (memcmp(symname
, MODULE_SYMBOL_PREFIX
,
608 strlen(MODULE_SYMBOL_PREFIX
)) == 0) {
610 alloc_symbol(symname
+
611 strlen(MODULE_SYMBOL_PREFIX
),
612 ELF_ST_BIND(sym
->st_info
) == STB_WEAK
,
617 /* All exported symbols */
618 if (strncmp(symname
, KSYMTAB_PFX
, strlen(KSYMTAB_PFX
)) == 0) {
619 sym_add_exported(symname
+ strlen(KSYMTAB_PFX
), mod
,
622 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"init_module") == 0)
624 if (strcmp(symname
, MODULE_SYMBOL_PREFIX
"cleanup_module") == 0)
625 mod
->has_cleanup
= 1;
631 * Parse tag=value strings from .modinfo section
633 static char *next_string(char *string
, unsigned long *secsize
)
635 /* Skip non-zero chars */
638 if ((*secsize
)-- <= 1)
642 /* Skip any zero padding. */
645 if ((*secsize
)-- <= 1)
651 static char *get_next_modinfo(void *modinfo
, unsigned long modinfo_len
,
652 const char *tag
, char *info
)
655 unsigned int taglen
= strlen(tag
);
656 unsigned long size
= modinfo_len
;
659 size
-= info
- (char *)modinfo
;
660 modinfo
= next_string(info
, &size
);
663 for (p
= modinfo
; p
; p
= next_string(p
, &size
)) {
664 if (strncmp(p
, tag
, taglen
) == 0 && p
[taglen
] == '=')
665 return p
+ taglen
+ 1;
670 static char *get_modinfo(void *modinfo
, unsigned long modinfo_len
,
674 return get_next_modinfo(modinfo
, modinfo_len
, tag
, NULL
);
678 * Test if string s ends in string sub
681 static int strrcmp(const char *s
, const char *sub
)
689 sublen
= strlen(sub
);
691 if ((slen
== 0) || (sublen
== 0))
697 return memcmp(s
+ slen
- sublen
, sub
, sublen
);
700 static const char *sym_name(struct elf_info
*elf
, Elf_Sym
*sym
)
703 return elf
->strtab
+ sym
->st_name
;
708 static const char *sec_name(struct elf_info
*elf
, int secindex
)
710 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
711 return (void *)elf
->hdr
+
712 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
713 sechdrs
[secindex
].sh_name
;
716 static const char *sech_name(struct elf_info
*elf
, Elf_Shdr
*sechdr
)
718 return (void *)elf
->hdr
+
719 elf
->sechdrs
[elf
->secindex_strings
].sh_offset
+
723 /* if sym is empty or point to a string
724 * like ".[0-9]+" then return 1.
725 * This is the optional prefix added by ld to some sections
727 static int number_prefix(const char *sym
)
735 if (c
< '0' || c
> '9')
741 /* The pattern is an array of simple patterns.
742 * "foo" will match an exact string equal to "foo"
743 * "*foo" will match a string that ends with "foo"
744 * "foo*" will match a string that begins with "foo"
745 * "foo$" will match a string equal to "foo" or "foo.1"
746 * where the '1' can be any number including several digits.
747 * The $ syntax is for sections where ld append a dot number
748 * to make section name unique.
750 static int match(const char *sym
, const char * const pat
[])
755 const char *endp
= p
+ strlen(p
) - 1;
759 if (strrcmp(sym
, p
+ 1) == 0)
763 else if (*endp
== '*') {
764 if (strncmp(sym
, p
, strlen(p
) - 1) == 0)
768 else if (*endp
== '$') {
769 if (strncmp(sym
, p
, strlen(p
) - 1) == 0) {
770 if (number_prefix(sym
+ strlen(p
) - 1))
776 if (strcmp(p
, sym
) == 0)
784 /* sections that we do not want to do full section mismatch check on */
785 static const char *section_white_list
[] =
789 ".zdebug*", /* Compressed debug sections. */
790 ".GCC-command-line", /* mn10300 */
791 ".mdebug*", /* alpha, score, mips etc. */
792 ".pdr", /* alpha, score, mips etc. */
801 * This is used to find sections missing the SHF_ALLOC flag.
802 * The cause of this is often a section specified in assembler
803 * without "ax" / "aw".
805 static void check_section(const char *modname
, struct elf_info
*elf
,
808 const char *sec
= sech_name(elf
, sechdr
);
810 if (sechdr
->sh_type
== SHT_PROGBITS
&&
811 !(sechdr
->sh_flags
& SHF_ALLOC
) &&
812 !match(sec
, section_white_list
)) {
813 warn("%s (%s): unexpected non-allocatable section.\n"
814 "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
815 "Note that for example <linux/init.h> contains\n"
816 "section definitions for use in .S files.\n\n",
823 #define ALL_INIT_DATA_SECTIONS \
824 ".init.setup$", ".init.rodata$", \
825 ".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
826 ".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
827 #define ALL_EXIT_DATA_SECTIONS \
828 ".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
830 #define ALL_INIT_TEXT_SECTIONS \
831 ".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
832 #define ALL_EXIT_TEXT_SECTIONS \
833 ".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
835 #define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
837 #define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
840 #define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
841 #define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
843 #define DATA_SECTIONS ".data$", ".data.rel$"
844 #define TEXT_SECTIONS ".text$"
846 #define INIT_SECTIONS ".init.*"
847 #define DEV_INIT_SECTIONS ".devinit.*"
848 #define CPU_INIT_SECTIONS ".cpuinit.*"
849 #define MEM_INIT_SECTIONS ".meminit.*"
851 #define EXIT_SECTIONS ".exit.*"
852 #define DEV_EXIT_SECTIONS ".devexit.*"
853 #define CPU_EXIT_SECTIONS ".cpuexit.*"
854 #define MEM_EXIT_SECTIONS ".memexit.*"
856 /* init data sections */
857 static const char *init_data_sections
[] = { ALL_INIT_DATA_SECTIONS
, NULL
};
859 /* all init sections */
860 static const char *init_sections
[] = { ALL_INIT_SECTIONS
, NULL
};
862 /* All init and exit sections (code + data) */
863 static const char *init_exit_sections
[] =
864 {ALL_INIT_SECTIONS
, ALL_EXIT_SECTIONS
, NULL
};
867 static const char *data_sections
[] = { DATA_SECTIONS
, NULL
};
870 /* symbols in .data that may refer to init/exit sections */
871 #define DEFAULT_SYMBOL_WHITE_LIST \
873 "*_template", /* scsi uses *_template a lot */ \
874 "*_timer", /* arm uses ops structures named _timer a lot */ \
875 "*_sht", /* scsi also used *_sht to some extent */ \
881 static const char *head_sections
[] = { ".head.text*", NULL
};
882 static const char *linker_symbols
[] =
883 { "__init_begin", "_sinittext", "_einittext", NULL
};
890 XXXINIT_TO_SOME_INIT
,
891 XXXEXIT_TO_SOME_EXIT
,
892 ANY_INIT_TO_ANY_EXIT
,
893 ANY_EXIT_TO_ANY_INIT
,
897 struct sectioncheck
{
898 const char *fromsec
[20];
899 const char *tosec
[20];
900 enum mismatch mismatch
;
901 const char *symbol_white_list
[20];
904 const struct sectioncheck sectioncheck
[] = {
905 /* Do not reference init/exit code/data from
906 * normal code and data
909 .fromsec
= { TEXT_SECTIONS
, NULL
},
910 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
911 .mismatch
= TEXT_TO_ANY_INIT
,
912 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
915 .fromsec
= { DATA_SECTIONS
, NULL
},
916 .tosec
= { ALL_XXXINIT_SECTIONS
, NULL
},
917 .mismatch
= DATA_TO_ANY_INIT
,
918 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
921 .fromsec
= { DATA_SECTIONS
, NULL
},
922 .tosec
= { INIT_SECTIONS
, NULL
},
923 .mismatch
= DATA_TO_ANY_INIT
,
924 .symbol_white_list
= {
925 "*_template", "*_timer", "*_sht", "*_ops",
926 "*_probe", "*_probe_one", "*_console", NULL
930 .fromsec
= { TEXT_SECTIONS
, NULL
},
931 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
932 .mismatch
= TEXT_TO_ANY_EXIT
,
933 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
936 .fromsec
= { DATA_SECTIONS
, NULL
},
937 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
938 .mismatch
= DATA_TO_ANY_EXIT
,
939 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
941 /* Do not reference init code/data from devinit/cpuinit/meminit code/data */
943 .fromsec
= { ALL_XXXINIT_SECTIONS
, NULL
},
944 .tosec
= { INIT_SECTIONS
, NULL
},
945 .mismatch
= XXXINIT_TO_SOME_INIT
,
946 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
948 /* Do not reference cpuinit code/data from meminit code/data */
950 .fromsec
= { MEM_INIT_SECTIONS
, NULL
},
951 .tosec
= { CPU_INIT_SECTIONS
, NULL
},
952 .mismatch
= XXXINIT_TO_SOME_INIT
,
953 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
955 /* Do not reference meminit code/data from cpuinit code/data */
957 .fromsec
= { CPU_INIT_SECTIONS
, NULL
},
958 .tosec
= { MEM_INIT_SECTIONS
, NULL
},
959 .mismatch
= XXXINIT_TO_SOME_INIT
,
960 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
962 /* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
964 .fromsec
= { ALL_XXXEXIT_SECTIONS
, NULL
},
965 .tosec
= { EXIT_SECTIONS
, NULL
},
966 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
967 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
969 /* Do not reference cpuexit code/data from memexit code/data */
971 .fromsec
= { MEM_EXIT_SECTIONS
, NULL
},
972 .tosec
= { CPU_EXIT_SECTIONS
, NULL
},
973 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
974 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
976 /* Do not reference memexit code/data from cpuexit code/data */
978 .fromsec
= { CPU_EXIT_SECTIONS
, NULL
},
979 .tosec
= { MEM_EXIT_SECTIONS
, NULL
},
980 .mismatch
= XXXEXIT_TO_SOME_EXIT
,
981 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
983 /* Do not use exit code/data from init code */
985 .fromsec
= { ALL_INIT_SECTIONS
, NULL
},
986 .tosec
= { ALL_EXIT_SECTIONS
, NULL
},
987 .mismatch
= ANY_INIT_TO_ANY_EXIT
,
988 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
990 /* Do not use init code/data from exit code */
992 .fromsec
= { ALL_EXIT_SECTIONS
, NULL
},
993 .tosec
= { ALL_INIT_SECTIONS
, NULL
},
994 .mismatch
= ANY_EXIT_TO_ANY_INIT
,
995 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
997 /* Do not export init/exit functions or data */
999 .fromsec
= { "__ksymtab*", NULL
},
1000 .tosec
= { INIT_SECTIONS
, EXIT_SECTIONS
, NULL
},
1001 .mismatch
= EXPORT_TO_INIT_EXIT
,
1002 .symbol_white_list
= { DEFAULT_SYMBOL_WHITE_LIST
, NULL
},
1006 static const struct sectioncheck
*section_mismatch(
1007 const char *fromsec
, const char *tosec
)
1010 int elems
= sizeof(sectioncheck
) / sizeof(struct sectioncheck
);
1011 const struct sectioncheck
*check
= §ioncheck
[0];
1013 for (i
= 0; i
< elems
; i
++) {
1014 if (match(fromsec
, check
->fromsec
) &&
1015 match(tosec
, check
->tosec
))
1023 * Whitelist to allow certain references to pass with no warning.
1026 * If a module parameter is declared __initdata and permissions=0
1027 * then this is legal despite the warning generated.
1028 * We cannot see value of permissions here, so just ignore
1030 * The pattern is identified by:
1031 * tosec = .init.data
1036 * module_param_call() ops can refer to __init set function if permissions=0
1037 * The pattern is identified by:
1038 * tosec = .init.text
1040 * atsym = __param_ops_*
1043 * Many drivers utilise a *driver container with references to
1044 * add, remove, probe functions etc.
1045 * These functions may often be marked __devinit and we do not want to
1047 * the pattern is identified by:
1048 * tosec = init or exit section
1049 * fromsec = data section
1050 * atsym = *driver, *_template, *_sht, *_ops, *_probe,
1051 * *probe_one, *_console, *_timer
1054 * Whitelist all references from .head.text to any init section
1057 * Some symbols belong to init section but still it is ok to reference
1058 * these from non-init sections as these symbols don't have any memory
1059 * allocated for them and symbol address and value are same. So even
1060 * if init section is freed, its ok to reference those symbols.
1061 * For ex. symbols marking the init section boundaries.
1062 * This pattern is identified by
1063 * refsymname = __init_begin, _sinittext, _einittext
1066 static int secref_whitelist(const struct sectioncheck
*mismatch
,
1067 const char *fromsec
, const char *fromsym
,
1068 const char *tosec
, const char *tosym
)
1070 /* Check for pattern 1 */
1071 if (match(tosec
, init_data_sections
) &&
1072 match(fromsec
, data_sections
) &&
1073 (strncmp(fromsym
, "__param", strlen("__param")) == 0))
1076 /* Check for pattern 1a */
1077 if (strcmp(tosec
, ".init.text") == 0 &&
1078 match(fromsec
, data_sections
) &&
1079 (strncmp(fromsym
, "__param_ops_", strlen("__param_ops_")) == 0))
1082 /* Check for pattern 2 */
1083 if (match(tosec
, init_exit_sections
) &&
1084 match(fromsec
, data_sections
) &&
1085 match(fromsym
, mismatch
->symbol_white_list
))
1088 /* Check for pattern 3 */
1089 if (match(fromsec
, head_sections
) &&
1090 match(tosec
, init_sections
))
1093 /* Check for pattern 4 */
1094 if (match(tosym
, linker_symbols
))
1101 * Find symbol based on relocation record info.
1102 * In some cases the symbol supplied is a valid symbol so
1103 * return refsym. If st_name != 0 we assume this is a valid symbol.
1104 * In other cases the symbol needs to be looked up in the symbol table
1105 * based on section and address.
1107 static Elf_Sym
*find_elf_symbol(struct elf_info
*elf
, Elf64_Sword addr
,
1111 Elf_Sym
*near
= NULL
;
1112 Elf64_Sword distance
= 20;
1114 unsigned int relsym_secindex
;
1116 if (relsym
->st_name
!= 0)
1119 relsym_secindex
= get_secindex(elf
, relsym
);
1120 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1121 if (get_secindex(elf
, sym
) != relsym_secindex
)
1123 if (ELF_ST_TYPE(sym
->st_info
) == STT_SECTION
)
1125 if (sym
->st_value
== addr
)
1127 /* Find a symbol nearby - addr are maybe negative */
1128 d
= sym
->st_value
- addr
;
1130 d
= addr
- sym
->st_value
;
1136 /* We need a close match */
1143 static inline int is_arm_mapping_symbol(const char *str
)
1145 return str
[0] == '$' && strchr("atd", str
[1])
1146 && (str
[2] == '\0' || str
[2] == '.');
1150 * If there's no name there, ignore it; likewise, ignore it if it's
1151 * one of the magic symbols emitted used by current ARM tools.
1153 * Otherwise if find_symbols_between() returns those symbols, they'll
1154 * fail the whitelist tests and cause lots of false alarms ... fixable
1155 * only by merging __exit and __init sections into __text, bloating
1156 * the kernel (which is especially evil on embedded platforms).
1158 static inline int is_valid_name(struct elf_info
*elf
, Elf_Sym
*sym
)
1160 const char *name
= elf
->strtab
+ sym
->st_name
;
1162 if (!name
|| !strlen(name
))
1164 return !is_arm_mapping_symbol(name
);
1168 * Find symbols before or equal addr and after addr - in the section sec.
1169 * If we find two symbols with equal offset prefer one with a valid name.
1170 * The ELF format may have a better way to detect what type of symbol
1171 * it is, but this works for now.
1173 static Elf_Sym
*find_elf_symbol2(struct elf_info
*elf
, Elf_Addr addr
,
1177 Elf_Sym
*near
= NULL
;
1178 Elf_Addr distance
= ~0;
1180 for (sym
= elf
->symtab_start
; sym
< elf
->symtab_stop
; sym
++) {
1183 if (is_shndx_special(sym
->st_shndx
))
1185 symsec
= sec_name(elf
, get_secindex(elf
, sym
));
1186 if (strcmp(symsec
, sec
) != 0)
1188 if (!is_valid_name(elf
, sym
))
1190 if (sym
->st_value
<= addr
) {
1191 if ((addr
- sym
->st_value
) < distance
) {
1192 distance
= addr
- sym
->st_value
;
1194 } else if ((addr
- sym
->st_value
) == distance
) {
1203 * Convert a section name to the function/data attribute
1204 * .init.text => __init
1205 * .cpuinit.data => __cpudata
1206 * .memexitconst => __memconst
1209 * The memory of returned value has been allocated on a heap. The user of this
1210 * method should free it after usage.
1212 static char *sec2annotation(const char *s
)
1214 if (match(s
, init_exit_sections
)) {
1215 char *p
= malloc(20);
1222 while (*s
&& *s
!= '.')
1227 if (strstr(s
, "rodata") != NULL
)
1228 strcat(p
, "const ");
1229 else if (strstr(s
, "data") != NULL
)
1239 static int is_function(Elf_Sym
*sym
)
1242 return ELF_ST_TYPE(sym
->st_info
) == STT_FUNC
;
1247 static void print_section_list(const char * const list
[20])
1249 const char *const *s
= list
;
1252 fprintf(stderr
, "%s", *s
);
1255 fprintf(stderr
, ", ");
1257 fprintf(stderr
, "\n");
1261 * Print a warning about a section mismatch.
1262 * Try to find symbols near it so user can find it.
1263 * Check whitelist before warning - it may be a false positive.
1265 static void report_sec_mismatch(const char *modname
,
1266 const struct sectioncheck
*mismatch
,
1267 const char *fromsec
,
1268 unsigned long long fromaddr
,
1269 const char *fromsym
,
1271 const char *tosec
, const char *tosym
,
1274 const char *from
, *from_p
;
1275 const char *to
, *to_p
;
1279 switch (from_is_func
) {
1280 case 0: from
= "variable"; from_p
= ""; break;
1281 case 1: from
= "function"; from_p
= "()"; break;
1282 default: from
= "(unknown reference)"; from_p
= ""; break;
1284 switch (to_is_func
) {
1285 case 0: to
= "variable"; to_p
= ""; break;
1286 case 1: to
= "function"; to_p
= "()"; break;
1287 default: to
= "(unknown reference)"; to_p
= ""; break;
1290 sec_mismatch_count
++;
1291 if (!sec_mismatch_verbose
)
1294 warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
1295 "to the %s %s:%s%s\n",
1296 modname
, fromsec
, fromaddr
, from
, fromsym
, from_p
, to
, tosec
,
1299 switch (mismatch
->mismatch
) {
1300 case TEXT_TO_ANY_INIT
:
1301 prl_from
= sec2annotation(fromsec
);
1302 prl_to
= sec2annotation(tosec
);
1304 "The function %s%s() references\n"
1306 "This is often because %s lacks a %s\n"
1307 "annotation or the annotation of %s is wrong.\n",
1309 to
, prl_to
, tosym
, to_p
,
1310 fromsym
, prl_to
, tosym
);
1314 case DATA_TO_ANY_INIT
: {
1315 prl_to
= sec2annotation(tosec
);
1317 "The variable %s references\n"
1319 "If the reference is valid then annotate the\n"
1320 "variable with __init* or __refdata (see linux/init.h) "
1321 "or name the variable:\n",
1322 fromsym
, to
, prl_to
, tosym
, to_p
);
1323 print_section_list(mismatch
->symbol_white_list
);
1327 case TEXT_TO_ANY_EXIT
:
1328 prl_to
= sec2annotation(tosec
);
1330 "The function %s() references a %s in an exit section.\n"
1331 "Often the %s %s%s has valid usage outside the exit section\n"
1332 "and the fix is to remove the %sannotation of %s.\n",
1333 fromsym
, to
, to
, tosym
, to_p
, prl_to
, tosym
);
1336 case DATA_TO_ANY_EXIT
: {
1337 prl_to
= sec2annotation(tosec
);
1339 "The variable %s references\n"
1341 "If the reference is valid then annotate the\n"
1342 "variable with __exit* (see linux/init.h) or "
1343 "name the variable:\n",
1344 fromsym
, to
, prl_to
, tosym
, to_p
);
1345 print_section_list(mismatch
->symbol_white_list
);
1349 case XXXINIT_TO_SOME_INIT
:
1350 case XXXEXIT_TO_SOME_EXIT
:
1351 prl_from
= sec2annotation(fromsec
);
1352 prl_to
= sec2annotation(tosec
);
1354 "The %s %s%s%s references\n"
1356 "If %s is only used by %s then\n"
1357 "annotate %s with a matching annotation.\n",
1358 from
, prl_from
, fromsym
, from_p
,
1359 to
, prl_to
, tosym
, to_p
,
1360 tosym
, fromsym
, tosym
);
1364 case ANY_INIT_TO_ANY_EXIT
:
1365 prl_from
= sec2annotation(fromsec
);
1366 prl_to
= sec2annotation(tosec
);
1368 "The %s %s%s%s references\n"
1370 "This is often seen when error handling "
1371 "in the init function\n"
1372 "uses functionality in the exit path.\n"
1373 "The fix is often to remove the %sannotation of\n"
1374 "%s%s so it may be used outside an exit section.\n",
1375 from
, prl_from
, fromsym
, from_p
,
1376 to
, prl_to
, tosym
, to_p
,
1377 prl_to
, tosym
, to_p
);
1381 case ANY_EXIT_TO_ANY_INIT
:
1382 prl_from
= sec2annotation(fromsec
);
1383 prl_to
= sec2annotation(tosec
);
1385 "The %s %s%s%s references\n"
1387 "This is often seen when error handling "
1388 "in the exit function\n"
1389 "uses functionality in the init path.\n"
1390 "The fix is often to remove the %sannotation of\n"
1391 "%s%s so it may be used outside an init section.\n",
1392 from
, prl_from
, fromsym
, from_p
,
1393 to
, prl_to
, tosym
, to_p
,
1394 prl_to
, tosym
, to_p
);
1398 case EXPORT_TO_INIT_EXIT
:
1399 prl_to
= sec2annotation(tosec
);
1401 "The symbol %s is exported and annotated %s\n"
1402 "Fix this by removing the %sannotation of %s "
1403 "or drop the export.\n",
1404 tosym
, prl_to
, prl_to
, tosym
);
1408 fprintf(stderr
, "\n");
1411 static void check_section_mismatch(const char *modname
, struct elf_info
*elf
,
1412 Elf_Rela
*r
, Elf_Sym
*sym
, const char *fromsec
)
1415 const struct sectioncheck
*mismatch
;
1417 tosec
= sec_name(elf
, get_secindex(elf
, sym
));
1418 mismatch
= section_mismatch(fromsec
, tosec
);
1423 const char *fromsym
;
1425 from
= find_elf_symbol2(elf
, r
->r_offset
, fromsec
);
1426 fromsym
= sym_name(elf
, from
);
1427 to
= find_elf_symbol(elf
, r
->r_addend
, sym
);
1428 tosym
= sym_name(elf
, to
);
1430 /* check whitelist - we may ignore it */
1431 if (secref_whitelist(mismatch
,
1432 fromsec
, fromsym
, tosec
, tosym
)) {
1433 report_sec_mismatch(modname
, mismatch
,
1434 fromsec
, r
->r_offset
, fromsym
,
1435 is_function(from
), tosec
, tosym
,
1441 static unsigned int *reloc_location(struct elf_info
*elf
,
1442 Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1444 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1445 int section
= sechdr
->sh_info
;
1447 return (void *)elf
->hdr
+ sechdrs
[section
].sh_offset
+
1451 static int addend_386_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1453 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1454 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1458 r
->r_addend
= TO_NATIVE(*location
);
1461 r
->r_addend
= TO_NATIVE(*location
) + 4;
1462 /* For CONFIG_RELOCATABLE=y */
1463 if (elf
->hdr
->e_type
== ET_EXEC
)
1464 r
->r_addend
+= r
->r_offset
;
1470 static int addend_arm_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1472 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1476 /* From ARM ABI: (S + A) | T */
1477 r
->r_addend
= (int)(long)
1478 (elf
->symtab_start
+ ELF_R_SYM(r
->r_info
));
1481 /* From ARM ABI: ((S + A) | T) - P */
1482 r
->r_addend
= (int)(long)(elf
->hdr
+
1484 (r
->r_offset
- sechdr
->sh_addr
));
1492 static int addend_mips_rel(struct elf_info
*elf
, Elf_Shdr
*sechdr
, Elf_Rela
*r
)
1494 unsigned int r_typ
= ELF_R_TYPE(r
->r_info
);
1495 unsigned int *location
= reloc_location(elf
, sechdr
, r
);
1498 if (r_typ
== R_MIPS_HI16
)
1499 return 1; /* skip this */
1500 inst
= TO_NATIVE(*location
);
1503 r
->r_addend
= inst
& 0xffff;
1506 r
->r_addend
= (inst
& 0x03ffffff) << 2;
1515 static void section_rela(const char *modname
, struct elf_info
*elf
,
1522 const char *fromsec
;
1524 Elf_Rela
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1525 Elf_Rela
*stop
= (void *)start
+ sechdr
->sh_size
;
1527 fromsec
= sech_name(elf
, sechdr
);
1528 fromsec
+= strlen(".rela");
1529 /* if from section (name) is know good then skip it */
1530 if (match(fromsec
, section_white_list
))
1533 for (rela
= start
; rela
< stop
; rela
++) {
1534 r
.r_offset
= TO_NATIVE(rela
->r_offset
);
1535 #if KERNEL_ELFCLASS == ELFCLASS64
1536 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1538 r_sym
= ELF64_MIPS_R_SYM(rela
->r_info
);
1539 r_sym
= TO_NATIVE(r_sym
);
1540 r_typ
= ELF64_MIPS_R_TYPE(rela
->r_info
);
1541 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1543 r
.r_info
= TO_NATIVE(rela
->r_info
);
1544 r_sym
= ELF_R_SYM(r
.r_info
);
1547 r
.r_info
= TO_NATIVE(rela
->r_info
);
1548 r_sym
= ELF_R_SYM(r
.r_info
);
1550 r
.r_addend
= TO_NATIVE(rela
->r_addend
);
1551 sym
= elf
->symtab_start
+ r_sym
;
1552 /* Skip special sections */
1553 if (is_shndx_special(sym
->st_shndx
))
1555 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1559 static void section_rel(const char *modname
, struct elf_info
*elf
,
1566 const char *fromsec
;
1568 Elf_Rel
*start
= (void *)elf
->hdr
+ sechdr
->sh_offset
;
1569 Elf_Rel
*stop
= (void *)start
+ sechdr
->sh_size
;
1571 fromsec
= sech_name(elf
, sechdr
);
1572 fromsec
+= strlen(".rel");
1573 /* if from section (name) is know good then skip it */
1574 if (match(fromsec
, section_white_list
))
1577 for (rel
= start
; rel
< stop
; rel
++) {
1578 r
.r_offset
= TO_NATIVE(rel
->r_offset
);
1579 #if KERNEL_ELFCLASS == ELFCLASS64
1580 if (elf
->hdr
->e_machine
== EM_MIPS
) {
1582 r_sym
= ELF64_MIPS_R_SYM(rel
->r_info
);
1583 r_sym
= TO_NATIVE(r_sym
);
1584 r_typ
= ELF64_MIPS_R_TYPE(rel
->r_info
);
1585 r
.r_info
= ELF64_R_INFO(r_sym
, r_typ
);
1587 r
.r_info
= TO_NATIVE(rel
->r_info
);
1588 r_sym
= ELF_R_SYM(r
.r_info
);
1591 r
.r_info
= TO_NATIVE(rel
->r_info
);
1592 r_sym
= ELF_R_SYM(r
.r_info
);
1595 switch (elf
->hdr
->e_machine
) {
1597 if (addend_386_rel(elf
, sechdr
, &r
))
1601 if (addend_arm_rel(elf
, sechdr
, &r
))
1605 if (addend_mips_rel(elf
, sechdr
, &r
))
1609 sym
= elf
->symtab_start
+ r_sym
;
1610 /* Skip special sections */
1611 if (is_shndx_special(sym
->st_shndx
))
1613 check_section_mismatch(modname
, elf
, &r
, sym
, fromsec
);
1618 * A module includes a number of sections that are discarded
1619 * either when loaded or when used as built-in.
1620 * For loaded modules all functions marked __init and all data
1621 * marked __initdata will be discarded when the module has been initialized.
1622 * Likewise for modules used built-in the sections marked __exit
1623 * are discarded because __exit marked function are supposed to be called
1624 * only when a module is unloaded which never happens for built-in modules.
1625 * The check_sec_ref() function traverses all relocation records
1626 * to find all references to a section that reference a section that will
1627 * be discarded and warns about it.
1629 static void check_sec_ref(struct module
*mod
, const char *modname
,
1630 struct elf_info
*elf
)
1633 Elf_Shdr
*sechdrs
= elf
->sechdrs
;
1635 /* Walk through all sections */
1636 for (i
= 0; i
< elf
->num_sections
; i
++) {
1637 check_section(modname
, elf
, &elf
->sechdrs
[i
]);
1638 /* We want to process only relocation sections and not .init */
1639 if (sechdrs
[i
].sh_type
== SHT_RELA
)
1640 section_rela(modname
, elf
, &elf
->sechdrs
[i
]);
1641 else if (sechdrs
[i
].sh_type
== SHT_REL
)
1642 section_rel(modname
, elf
, &elf
->sechdrs
[i
]);
1646 static void read_symbols(char *modname
)
1648 const char *symname
;
1652 struct elf_info info
= { };
1655 if (!parse_elf(&info
, modname
))
1658 mod
= new_module(modname
);
1660 /* When there's no vmlinux, don't print warnings about
1661 * unresolved symbols (since there'll be too many ;) */
1662 if (is_vmlinux(modname
)) {
1667 license
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "license");
1668 if (info
.modinfo
&& !license
&& !is_vmlinux(modname
))
1669 warn("modpost: missing MODULE_LICENSE() in %s\n"
1670 "see include/linux/module.h for "
1671 "more information\n", modname
);
1673 if (license_is_gpl_compatible(license
))
1674 mod
->gpl_compatible
= 1;
1676 mod
->gpl_compatible
= 0;
1679 license
= get_next_modinfo(info
.modinfo
, info
.modinfo_len
,
1680 "license", license
);
1683 for (sym
= info
.symtab_start
; sym
< info
.symtab_stop
; sym
++) {
1684 symname
= info
.strtab
+ sym
->st_name
;
1686 handle_modversions(mod
, &info
, sym
, symname
);
1687 handle_moddevtable(mod
, &info
, sym
, symname
);
1689 if (!is_vmlinux(modname
) ||
1690 (is_vmlinux(modname
) && vmlinux_section_warnings
))
1691 check_sec_ref(mod
, modname
, &info
);
1693 version
= get_modinfo(info
.modinfo
, info
.modinfo_len
, "version");
1695 maybe_frob_rcs_version(modname
, version
, info
.modinfo
,
1696 version
- (char *)info
.hdr
);
1697 if (version
|| (all_versions
&& !is_vmlinux(modname
)))
1698 get_src_version(modname
, mod
->srcversion
,
1699 sizeof(mod
->srcversion
)-1);
1701 parse_elf_finish(&info
);
1703 /* Our trick to get versioning for module struct etc. - it's
1704 * never passed as an argument to an exported function, so
1705 * the automatic versioning doesn't pick it up, but it's really
1706 * important anyhow */
1708 mod
->unres
= alloc_symbol("module_layout", 0, mod
->unres
);
1713 /* We first write the generated file into memory using the
1714 * following helper, then compare to the file on disk and
1715 * only update the later if anything changed */
1717 void __attribute__((format(printf
, 2, 3))) buf_printf(struct buffer
*buf
,
1718 const char *fmt
, ...)
1725 len
= vsnprintf(tmp
, SZ
, fmt
, ap
);
1726 buf_write(buf
, tmp
, len
);
1730 void buf_write(struct buffer
*buf
, const char *s
, int len
)
1732 if (buf
->size
- buf
->pos
< len
) {
1733 buf
->size
+= len
+ SZ
;
1734 buf
->p
= realloc(buf
->p
, buf
->size
);
1736 strncpy(buf
->p
+ buf
->pos
, s
, len
);
1740 static void check_for_gpl_usage(enum export exp
, const char *m
, const char *s
)
1742 const char *e
= is_vmlinux(m
) ?"":".ko";
1746 fatal("modpost: GPL-incompatible module %s%s "
1747 "uses GPL-only symbol '%s'\n", m
, e
, s
);
1749 case export_unused_gpl
:
1750 fatal("modpost: GPL-incompatible module %s%s "
1751 "uses GPL-only symbol marked UNUSED '%s'\n", m
, e
, s
);
1753 case export_gpl_future
:
1754 warn("modpost: GPL-incompatible module %s%s "
1755 "uses future GPL-only symbol '%s'\n", m
, e
, s
);
1759 case export_unknown
:
1765 static void check_for_unused(enum export exp
, const char *m
, const char *s
)
1767 const char *e
= is_vmlinux(m
) ?"":".ko";
1771 case export_unused_gpl
:
1772 warn("modpost: module %s%s "
1773 "uses symbol '%s' marked UNUSED\n", m
, e
, s
);
1781 static void check_exports(struct module
*mod
)
1783 struct symbol
*s
, *exp
;
1785 for (s
= mod
->unres
; s
; s
= s
->next
) {
1786 const char *basename
;
1787 exp
= find_symbol(s
->name
);
1788 if (!exp
|| exp
->module
== mod
)
1790 basename
= strrchr(mod
->name
, '/');
1794 basename
= mod
->name
;
1795 if (!mod
->gpl_compatible
)
1796 check_for_gpl_usage(exp
->export
, basename
, exp
->name
);
1797 check_for_unused(exp
->export
, basename
, exp
->name
);
1802 * Header for the generated file
1804 static void add_header(struct buffer
*b
, struct module
*mod
)
1806 buf_printf(b
, "#include <linux/module.h>\n");
1807 buf_printf(b
, "#include <linux/vermagic.h>\n");
1808 buf_printf(b
, "#include <linux/compiler.h>\n");
1809 buf_printf(b
, "\n");
1810 buf_printf(b
, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
1811 buf_printf(b
, "\n");
1812 buf_printf(b
, "struct module __this_module\n");
1813 buf_printf(b
, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1814 buf_printf(b
, " .name = KBUILD_MODNAME,\n");
1816 buf_printf(b
, " .init = init_module,\n");
1817 if (mod
->has_cleanup
)
1818 buf_printf(b
, "#ifdef CONFIG_MODULE_UNLOAD\n"
1819 " .exit = cleanup_module,\n"
1821 buf_printf(b
, " .arch = MODULE_ARCH_INIT,\n");
1822 buf_printf(b
, "};\n");
1825 static void add_staging_flag(struct buffer
*b
, const char *name
)
1827 static const char *staging_dir
= "drivers/staging";
1829 if (strncmp(staging_dir
, name
, strlen(staging_dir
)) == 0)
1830 buf_printf(b
, "\nMODULE_INFO(staging, \"Y\");\n");
1834 * Record CRCs for unresolved symbols
1836 static int add_versions(struct buffer
*b
, struct module
*mod
)
1838 struct symbol
*s
, *exp
;
1841 for (s
= mod
->unres
; s
; s
= s
->next
) {
1842 exp
= find_symbol(s
->name
);
1843 if (!exp
|| exp
->module
== mod
) {
1844 if (have_vmlinux
&& !s
->weak
) {
1845 if (warn_unresolved
) {
1846 warn("\"%s\" [%s.ko] undefined!\n",
1847 s
->name
, mod
->name
);
1849 merror("\"%s\" [%s.ko] undefined!\n",
1850 s
->name
, mod
->name
);
1856 s
->module
= exp
->module
;
1857 s
->crc_valid
= exp
->crc_valid
;
1864 buf_printf(b
, "\n");
1865 buf_printf(b
, "static const struct modversion_info ____versions[]\n");
1866 buf_printf(b
, "__used\n");
1867 buf_printf(b
, "__attribute__((section(\"__versions\"))) = {\n");
1869 for (s
= mod
->unres
; s
; s
= s
->next
) {
1872 if (!s
->crc_valid
) {
1873 warn("\"%s\" [%s.ko] has no CRC!\n",
1874 s
->name
, mod
->name
);
1877 buf_printf(b
, "\t{ %#8x, \"%s\" },\n", s
->crc
, s
->name
);
1880 buf_printf(b
, "};\n");
1885 static void add_depends(struct buffer
*b
, struct module
*mod
,
1886 struct module
*modules
)
1892 for (m
= modules
; m
; m
= m
->next
)
1893 m
->seen
= is_vmlinux(m
->name
);
1895 buf_printf(b
, "\n");
1896 buf_printf(b
, "static const char __module_depends[]\n");
1897 buf_printf(b
, "__used\n");
1898 buf_printf(b
, "__attribute__((section(\".modinfo\"))) =\n");
1899 buf_printf(b
, "\"depends=");
1900 for (s
= mod
->unres
; s
; s
= s
->next
) {
1905 if (s
->module
->seen
)
1908 s
->module
->seen
= 1;
1909 p
= strrchr(s
->module
->name
, '/');
1913 p
= s
->module
->name
;
1914 buf_printf(b
, "%s%s", first
? "" : ",", p
);
1917 buf_printf(b
, "\";\n");
1920 static void add_srcversion(struct buffer
*b
, struct module
*mod
)
1922 if (mod
->srcversion
[0]) {
1923 buf_printf(b
, "\n");
1924 buf_printf(b
, "MODULE_INFO(srcversion, \"%s\");\n",
1929 static void write_if_changed(struct buffer
*b
, const char *fname
)
1935 file
= fopen(fname
, "r");
1939 if (fstat(fileno(file
), &st
) < 0)
1942 if (st
.st_size
!= b
->pos
)
1945 tmp
= NOFAIL(malloc(b
->pos
));
1946 if (fread(tmp
, 1, b
->pos
, file
) != b
->pos
)
1949 if (memcmp(tmp
, b
->p
, b
->pos
) != 0)
1961 file
= fopen(fname
, "w");
1966 if (fwrite(b
->p
, 1, b
->pos
, file
) != b
->pos
) {
1973 /* parse Module.symvers file. line format:
1974 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1976 static void read_dump(const char *fname
, unsigned int kernel
)
1978 unsigned long size
, pos
= 0;
1979 void *file
= grab_file(fname
, &size
);
1983 /* No symbol versions, silently ignore */
1986 while ((line
= get_next_line(&pos
, file
, size
))) {
1987 char *symname
, *modname
, *d
, *export
, *end
;
1992 if (!(symname
= strchr(line
, '\t')))
1995 if (!(modname
= strchr(symname
, '\t')))
1998 if ((export
= strchr(modname
, '\t')) != NULL
)
2000 if (export
&& ((end
= strchr(export
, '\t')) != NULL
))
2002 crc
= strtoul(line
, &d
, 16);
2003 if (*symname
== '\0' || *modname
== '\0' || *d
!= '\0')
2005 mod
= find_module(modname
);
2007 if (is_vmlinux(modname
))
2009 mod
= new_module(modname
);
2012 s
= sym_add_exported(symname
, mod
, export_no(export
));
2015 sym_update_crc(symname
, mod
, crc
, export_no(export
));
2019 fatal("parse error in symbol dump file\n");
2022 /* For normal builds always dump all symbols.
2023 * For external modules only dump symbols
2024 * that are not read from kernel Module.symvers.
2026 static int dump_sym(struct symbol
*sym
)
2028 if (!external_module
)
2030 if (sym
->vmlinux
|| sym
->kernel
)
2035 static void write_dump(const char *fname
)
2037 struct buffer buf
= { };
2038 struct symbol
*symbol
;
2041 for (n
= 0; n
< SYMBOL_HASH_SIZE
; n
++) {
2042 symbol
= symbolhash
[n
];
2044 if (dump_sym(symbol
))
2045 buf_printf(&buf
, "0x%08x\t%s\t%s\t%s\n",
2046 symbol
->crc
, symbol
->name
,
2047 symbol
->module
->name
,
2048 export_str(symbol
->export
));
2049 symbol
= symbol
->next
;
2052 write_if_changed(&buf
, fname
);
2055 struct ext_sym_list
{
2056 struct ext_sym_list
*next
;
2060 int main(int argc
, char **argv
)
2063 struct buffer buf
= { };
2064 char *kernel_read
= NULL
, *module_read
= NULL
;
2065 char *dump_write
= NULL
;
2068 struct ext_sym_list
*extsym_iter
;
2069 struct ext_sym_list
*extsym_start
= NULL
;
2071 while ((opt
= getopt(argc
, argv
, "i:I:e:cmsSo:awM:K:")) != -1) {
2074 kernel_read
= optarg
;
2077 module_read
= optarg
;
2078 external_module
= 1;
2084 external_module
= 1;
2086 NOFAIL(malloc(sizeof(*extsym_iter
)));
2087 extsym_iter
->next
= extsym_start
;
2088 extsym_iter
->file
= optarg
;
2089 extsym_start
= extsym_iter
;
2095 dump_write
= optarg
;
2101 vmlinux_section_warnings
= 0;
2104 sec_mismatch_verbose
= 0;
2107 warn_unresolved
= 1;
2115 read_dump(kernel_read
, 1);
2117 read_dump(module_read
, 0);
2118 while (extsym_start
) {
2119 read_dump(extsym_start
->file
, 0);
2120 extsym_iter
= extsym_start
->next
;
2122 extsym_start
= extsym_iter
;
2125 while (optind
< argc
)
2126 read_symbols(argv
[optind
++]);
2128 for (mod
= modules
; mod
; mod
= mod
->next
) {
2136 for (mod
= modules
; mod
; mod
= mod
->next
) {
2137 char fname
[strlen(mod
->name
) + 10];
2144 add_header(&buf
, mod
);
2145 add_staging_flag(&buf
, mod
->name
);
2146 err
|= add_versions(&buf
, mod
);
2147 add_depends(&buf
, mod
, modules
);
2148 add_moddevtable(&buf
, mod
);
2149 add_srcversion(&buf
, mod
);
2151 sprintf(fname
, "%s.mod.c", mod
->name
);
2152 write_if_changed(&buf
, fname
);
2156 write_dump(dump_write
);
2157 if (sec_mismatch_count
&& !sec_mismatch_verbose
)
2158 warn("modpost: Found %d section mismatch(es).\n"
2159 "To see full details build your kernel with:\n"
2160 "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
2161 sec_mismatch_count
);