linux/scripts/mod/modpost.c at master · fabgithub/linux · GitHub

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/* Postprocess module symbol versions

* Based in part on module-init-tools/depmod.c,file2alias

* This software may be used and distributed according to the terms

* of the GNU General Public License, incorporated herein by reference.

* Usage: modpost vmlinux module1.o module2.o ...

#define _GNU_SOURCE

#include <stdio.h>

#include <ctype.h>

#include <string.h>

#include <limits.h>

#include <stdbool.h>

#include "modpost.h"

#include "../../include/generated/autoconf.h"

#include "../../include/linux/license.h"

#include "../../include/linux/export.h"

/* Are we using CONFIG_MODVERSIONS? */

int modversions = 0;

/* Warn about undefined symbols? (do so if we have vmlinux) */

int have_vmlinux = 0;

/* Is CONFIG_MODULE_SRCVERSION_ALL set? */

static int all_versions = 0;

/* If we are modposting external module set to 1 */

static int external_module = 0;

/* Warn about section mismatch in vmlinux if set to 1 */

static int vmlinux_section_warnings = 1;

/* Only warn about unresolved symbols */

static int warn_unresolved = 0;

/* How a symbol is exported */

static int sec_mismatch_count = 0;

static int sec_mismatch_verbose = 1;

enum export {

export_plain, export_unused, export_gpl,

export_unused_gpl, export_gpl_future, export_unknown

};

#define PRINTF __attribute__ ((format (printf, 1, 2)))

PRINTF void fatal(const char *fmt, ...)

{

va_list arglist;

fprintf(stderr, "FATAL: ");

va_start(arglist, fmt);

vfprintf(stderr, fmt, arglist);

va_end(arglist);

exit(1);

}

PRINTF void warn(const char *fmt, ...)

{

va_list arglist;

fprintf(stderr, "WARNING: ");

va_start(arglist, fmt);

vfprintf(stderr, fmt, arglist);

va_end(arglist);

}

PRINTF void merror(const char *fmt, ...)

{

va_list arglist;

fprintf(stderr, "ERROR: ");

va_start(arglist, fmt);

vfprintf(stderr, fmt, arglist);

va_end(arglist);

}

static inline bool strends(const char *str, const char *postfix)

{

if (strlen(str) < strlen(postfix))

return false;

return strcmp(str + strlen(str) - strlen(postfix), postfix) == 0;

}

static int is_vmlinux(const char *modname)

{

const char *myname;

myname = strrchr(modname, '/');

if (myname)

myname++;

else

myname = modname;

return (strcmp(myname, "vmlinux") == 0) ||

(strcmp(myname, "vmlinux.o") == 0);

}

void *do_nofail(void *ptr, const char *expr)

{

if (!ptr)

fatal("modpost: Memory allocation failure: %s.\n", expr);

return ptr;

}

/* A list of all modules we processed */

static struct module *modules;

static struct module *find_module(char *modname)

{

struct module *mod;

for (mod = modules; mod; mod = mod->next)

if (strcmp(mod->name, modname) == 0)

break;

return mod;

}

static struct module *new_module(const char *modname)

{

struct module *mod;

char *p;

mod = NOFAIL(malloc(sizeof(*mod)));

memset(mod, 0, sizeof(*mod));

p = NOFAIL(strdup(modname));

/* strip trailing .o */

if (strends(p, ".o")) {

p[strlen(p) - 2] = '\0';

mod->is_dot_o = 1;

}

/* add to list */

mod->name = p;

mod->gpl_compatible = -1;

mod->next = modules;

modules = mod;

return mod;

}

/* A hash of all exported symbols,

* struct symbol is also used for lists of unresolved symbols */

#define SYMBOL_HASH_SIZE 1024

struct symbol {

struct symbol *next;

struct module *module;

unsigned int crc;

int crc_valid;

unsigned int weak:1;

unsigned int vmlinux:1; /* 1 if symbol is defined in vmlinux */

unsigned int kernel:1; /* 1 if symbol is from kernel

* (only for external modules) **/

unsigned int preloaded:1; /* 1 if symbol from Module.symvers */

enum export export; /* Type of export */

char name[0];

};

static struct symbol *symbolhash[SYMBOL_HASH_SIZE];

/* This is based on the hash agorithm from gdbm, via tdb */

static inline unsigned int tdb_hash(const char *name)

{

unsigned value; /* Used to compute the hash value. */

unsigned i; /* Used to cycle through random values. */

/* Set the initial value from the key size. */

for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)

value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));

return (1103515243 * value + 12345);

}

/**

* Allocate a new symbols for use in the hash of exported symbols or

* the list of unresolved symbols per module

**/

static struct symbol *alloc_symbol(const char *name, unsigned int weak,

struct symbol *next)

{

struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));

memset(s, 0, sizeof(*s));

strcpy(s->name, name);

s->weak = weak;

s->next = next;

return s;

}

/* For the hash of exported symbols */

static struct symbol *new_symbol(const char *name, struct module *module,

enum export export)

{

unsigned int hash;

struct symbol *new;

hash = tdb_hash(name) % SYMBOL_HASH_SIZE;

new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);

new->module = module;

new->export = export;

return new;

}

static struct symbol *find_symbol(const char *name)

{

struct symbol *s;

/* For our purposes, .foo matches foo. PPC64 needs this. */

if (name[0] == '.')

name++;

for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {

if (strcmp(s->name, name) == 0)

return s;

}

return NULL;

}

static struct {

const char *str;

enum export export;

} export_list[] = {

{ .str = "EXPORT_SYMBOL", .export = export_plain },

{ .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },

{ .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },

{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },

{ .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },

{ .str = "(unknown)", .export = export_unknown },

};

static const char *export_str(enum export ex)

{

return export_list[ex].str;

}

static enum export export_no(const char *s)

{

int i;

if (!s)

return export_unknown;

for (i = 0; export_list[i].export != export_unknown; i++) {

if (strcmp(export_list[i].str, s) == 0)

return export_list[i].export;

}

return export_unknown;

}

static const char *sec_name(struct elf_info *elf, int secindex);

#define strstarts(str, prefix) (strncmp(str, prefix, strlen(prefix)) == 0)

static enum export export_from_secname(struct elf_info *elf, unsigned int sec)

{

const char *secname = sec_name(elf, sec);

if (strstarts(secname, "___ksymtab+"))

return export_plain;

else if (strstarts(secname, "___ksymtab_unused+"))

return export_unused;

else if (strstarts(secname, "___ksymtab_gpl+"))

return export_gpl;

else if (strstarts(secname, "___ksymtab_unused_gpl+"))

return export_unused_gpl;

else if (strstarts(secname, "___ksymtab_gpl_future+"))

return export_gpl_future;

else

return export_unknown;

}

static enum export export_from_sec(struct elf_info *elf, unsigned int sec)

{

if (sec == elf->export_sec)

return export_plain;

else if (sec == elf->export_unused_sec)

return export_unused;

else if (sec == elf->export_gpl_sec)

return export_gpl;

else if (sec == elf->export_unused_gpl_sec)

return export_unused_gpl;

else if (sec == elf->export_gpl_future_sec)

return export_gpl_future;

else

return export_unknown;

}

/**

* Add an exported symbol - it may have already been added without a

* CRC, in this case just update the CRC

**/

static struct symbol *sym_add_exported(const char *name, struct module *mod,

enum export export)

{

struct symbol *s = find_symbol(name);

if (!s) {

s = new_symbol(name, mod, export);

} else {

if (!s->preloaded) {

warn("%s: '%s' exported twice. Previous export "

"was in %s%s\n", mod->name, name,

s->module->name,

is_vmlinux(s->module->name) ?"":".ko");

} else {

/* In case Modules.symvers was out of date */

s->module = mod;

}

s->preloaded = 0;

s->vmlinux = is_vmlinux(mod->name);

s->kernel = 0;

s->export = export;

return s;

}

static void sym_update_crc(const char *name, struct module *mod,

unsigned int crc, enum export export)

{

struct symbol *s = find_symbol(name);

if (!s)

s = new_symbol(name, mod, export);

s->crc = crc;

s->crc_valid = 1;

}

void *grab_file(const char *filename, unsigned long *size)

{

struct stat st;

void *map = MAP_FAILED;

int fd;

fd = open(filename, O_RDONLY);

if (fd < 0)

return NULL;

if (fstat(fd, &st))

goto failed;

*size = st.st_size;

map = mmap(NULL, *size, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);

failed:

close(fd);

if (map == MAP_FAILED)

return NULL;

return map;

}

/**

* Return a copy of the next line in a mmap'ed file.

* spaces in the beginning of the line is trimmed away.

* Return a pointer to a static buffer.

**/

char *get_next_line(unsigned long *pos, void *file, unsigned long size)

{

static char line[4096];

int skip = 1;

size_t len = 0;

signed char *p = (signed char *)file + *pos;

char *s = line;

for (; *pos < size ; (*pos)++) {

if (skip && isspace(*p)) {

p++;

continue;

}

skip = 0;

if (*p != '\n' && (*pos < size)) {

len++;

*s++ = *p++;

if (len > 4095)

break; /* Too long, stop */

} else {

/* End of string */

*s = '\0';

return line;

}

/* End of buffer */

return NULL;

}

void release_file(void *file, unsigned long size)

{

munmap(file, size);

}

static int parse_elf(struct elf_info *info, const char *filename)

{

unsigned int i;

Elf_Ehdr *hdr;

Elf_Shdr *sechdrs;

Elf_Sym *sym;

const char *secstrings;

unsigned int symtab_idx = ~0U, symtab_shndx_idx = ~0U;

hdr = grab_file(filename, &info->size);

if (!hdr) {

perror(filename);

exit(1);

}

info->hdr = hdr;

if (info->size < sizeof(*hdr)) {

/* file too small, assume this is an empty .o file */

return 0;

}

/* Is this a valid ELF file? */

if ((hdr->e_ident[EI_MAG0] != ELFMAG0) ||

(hdr->e_ident[EI_MAG1] != ELFMAG1) ||

(hdr->e_ident[EI_MAG2] != ELFMAG2) ||

(hdr->e_ident[EI_MAG3] != ELFMAG3)) {

/* Not an ELF file - silently ignore it */

return 0;

}

/* Fix endianness in ELF header */

hdr->e_type = TO_NATIVE(hdr->e_type);

hdr->e_machine = TO_NATIVE(hdr->e_machine);

hdr->e_version = TO_NATIVE(hdr->e_version);

hdr->e_entry = TO_NATIVE(hdr->e_entry);

hdr->e_phoff = TO_NATIVE(hdr->e_phoff);

hdr->e_shoff = TO_NATIVE(hdr->e_shoff);

hdr->e_flags = TO_NATIVE(hdr->e_flags);

hdr->e_ehsize = TO_NATIVE(hdr->e_ehsize);

hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);

hdr->e_phnum = TO_NATIVE(hdr->e_phnum);

hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);

hdr->e_shnum = TO_NATIVE(hdr->e_shnum);

hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);

sechdrs = (void *)hdr + hdr->e_shoff;

info->sechdrs = sechdrs;

/* Check if file offset is correct */

if (hdr->e_shoff > info->size) {

fatal("section header offset=%lu in file '%s' is bigger than "

"filesize=%lu\n", (unsigned long)hdr->e_shoff,

filename, info->size);

return 0;

}

if (hdr->e_shnum == SHN_UNDEF) {

* There are more than 64k sections,

* read count from .sh_size.

info->num_sections = TO_NATIVE(sechdrs[0].sh_size);

}

else {

info->num_sections = hdr->e_shnum;

}

if (hdr->e_shstrndx == SHN_XINDEX) {

info->secindex_strings = TO_NATIVE(sechdrs[0].sh_link);

}

else {

info->secindex_strings = hdr->e_shstrndx;

}

/* Fix endianness in section headers */

for (i = 0; i < info->num_sections; i++) {

sechdrs[i].sh_name = TO_NATIVE(sechdrs[i].sh_name);

sechdrs[i].sh_type = TO_NATIVE(sechdrs[i].sh_type);

sechdrs[i].sh_flags = TO_NATIVE(sechdrs[i].sh_flags);

sechdrs[i].sh_addr = TO_NATIVE(sechdrs[i].sh_addr);

sechdrs[i].sh_offset = TO_NATIVE(sechdrs[i].sh_offset);

sechdrs[i].sh_size = TO_NATIVE(sechdrs[i].sh_size);

sechdrs[i].sh_link = TO_NATIVE(sechdrs[i].sh_link);

sechdrs[i].sh_info = TO_NATIVE(sechdrs[i].sh_info);

sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);

sechdrs[i].sh_entsize = TO_NATIVE(sechdrs[i].sh_entsize);

}

/* Find symbol table. */

secstrings = (void *)hdr + sechdrs[info->secindex_strings].sh_offset;

for (i = 1; i < info->num_sections; i++) {

const char *secname;

int nobits = sechdrs[i].sh_type == SHT_NOBITS;

if (!nobits && sechdrs[i].sh_offset > info->size) {

fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "

"sizeof(*hrd)=%zu\n", filename,

(unsigned long)sechdrs[i].sh_offset,

sizeof(*hdr));

return 0;

}

secname = secstrings + sechdrs[i].sh_name;

if (strcmp(secname, ".modinfo") == 0) {

if (nobits)

fatal("%s has NOBITS .modinfo\n", filename);

info->modinfo = (void *)hdr + sechdrs[i].sh_offset;

info->modinfo_len = sechdrs[i].sh_size;

} else if (strcmp(secname, "__ksymtab") == 0)

info->export_sec = i;

else if (strcmp(secname, "__ksymtab_unused") == 0)

info->export_unused_sec = i;

else if (strcmp(secname, "__ksymtab_gpl") == 0)

info->export_gpl_sec = i;

else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)

info->export_unused_gpl_sec = i;

else if (strcmp(secname, "__ksymtab_gpl_future") == 0)

info->export_gpl_future_sec = i;

if (sechdrs[i].sh_type == SHT_SYMTAB) {

unsigned int sh_link_idx;

symtab_idx = i;

info->symtab_start = (void *)hdr +

sechdrs[i].sh_offset;

info->symtab_stop = (void *)hdr +

sechdrs[i].sh_offset + sechdrs[i].sh_size;

sh_link_idx = sechdrs[i].sh_link;

info->strtab = (void *)hdr +

sechdrs[sh_link_idx].sh_offset;

}

/* 32bit section no. table? ("more than 64k sections") */

if (sechdrs[i].sh_type == SHT_SYMTAB_SHNDX) {

symtab_shndx_idx = i;

info->symtab_shndx_start = (void *)hdr +

sechdrs[i].sh_offset;

info->symtab_shndx_stop = (void *)hdr +

sechdrs[i].sh_offset + sechdrs[i].sh_size;

}

if (!info->symtab_start)

fatal("%s has no symtab?\n", filename);

/* Fix endianness in symbols */

for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {

sym->st_shndx = TO_NATIVE(sym->st_shndx);

sym->st_name = TO_NATIVE(sym->st_name);

sym->st_value = TO_NATIVE(sym->st_value);

sym->st_size = TO_NATIVE(sym->st_size);

}

if (symtab_shndx_idx != ~0U) {

Elf32_Word *p;

if (symtab_idx != sechdrs[symtab_shndx_idx].sh_link)

fatal("%s: SYMTAB_SHNDX has bad sh_link: %u!=%u\n",

filename, sechdrs[symtab_shndx_idx].sh_link,

symtab_idx);

/* Fix endianness */

for (p = info->symtab_shndx_start; p < info->symtab_shndx_stop;

p++)

*p = TO_NATIVE(*p);

}

return 1;

}

static void parse_elf_finish(struct elf_info *info)

{

release_file(info->hdr, info->size);

}

static int ignore_undef_symbol(struct elf_info *info, const char *symname)

{

/* ignore __this_module, it will be resolved shortly */

if (strcmp(symname, VMLINUX_SYMBOL_STR(__this_module)) == 0)

return 1;

/* ignore global offset table */

if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)

return 1;

if (info->hdr->e_machine == EM_PPC)

/* Special register function linked on all modules during final link of .ko */

if (strncmp(symname, "_restgpr_", sizeof("_restgpr_") - 1) == 0 ||

strncmp(symname, "_savegpr_", sizeof("_savegpr_") - 1) == 0 ||

strncmp(symname, "_rest32gpr_", sizeof("_rest32gpr_") - 1) == 0 ||

strncmp(symname, "_save32gpr_", sizeof("_save32gpr_") - 1) == 0)

return 1;

if (info->hdr->e_machine == EM_PPC64)

/* Special register function linked on all modules during final link of .ko */

if (strncmp(symname, "_restgpr0_", sizeof("_restgpr0_") - 1) == 0 ||

strncmp(symname, "_savegpr0_", sizeof("_savegpr0_") - 1) == 0)

return 1;

/* Do not ignore this symbol */

return 0;

}

#define CRC_PFX VMLINUX_SYMBOL_STR(__crc_)

#define KSYMTAB_PFX VMLINUX_SYMBOL_STR(__ksymtab_)

static void handle_modversions(struct module *mod, struct elf_info *info,

Elf_Sym *sym, const char *symname)

{

unsigned int crc;

enum export export;

if ((!is_vmlinux(mod->name) || mod->is_dot_o) &&

strncmp(symname, "__ksymtab", 9) == 0)

export = export_from_secname(info, get_secindex(info, sym));

else

export = export_from_sec(info, get_secindex(info, sym));

switch (sym->st_shndx) {

case SHN_COMMON:

warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);

break;

case SHN_ABS:

/* CRC'd symbol */

if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {

crc = (unsigned int) sym->st_value;

sym_update_crc(symname + strlen(CRC_PFX), mod, crc,

export);

}

break;

case SHN_UNDEF:

/* undefined symbol */

if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&

ELF_ST_BIND(sym->st_info) != STB_WEAK)

break;

if (ignore_undef_symbol(info, symname))

break;

/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */

#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)

/* add compatibility with older glibc */

#ifndef STT_SPARC_REGISTER

#define STT_SPARC_REGISTER STT_REGISTER

#endif

if (info->hdr->e_machine == EM_SPARC ||

info->hdr->e_machine == EM_SPARCV9) {

/* Ignore register directives. */

if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)

break;

if (symname[0] == '.') {

char *munged = strdup(symname);

munged[0] = '_';

munged[1] = toupper(munged[1]);

symname = munged;

}

#endif

#ifdef CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX

if (symname[0] != '_')

break;

else

symname++;

#endif

mod->unres = alloc_symbol(symname,

ELF_ST_BIND(sym->st_info) == STB_WEAK,

mod->unres);

break;

default:

/* All exported symbols */

if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {

sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,

export);

}

if (strcmp(symname, VMLINUX_SYMBOL_STR(init_module)) == 0)

mod->has_init = 1;

if (strcmp(symname, VMLINUX_SYMBOL_STR(cleanup_module)) == 0)

mod->has_cleanup = 1;

break;

}

/**

* Parse tag=value strings from .modinfo section

**/

static char *next_string(char *string, unsigned long *secsize)

{

/* Skip non-zero chars */

while (string[0]) {

string++;

if ((*secsize)-- <= 1)

return NULL;

}

/* Skip any zero padding. */

while (!string[0]) {

string++;

if ((*secsize)-- <= 1)

return NULL;

}

return string;

}

static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,

const char *tag, char *info)

{

char *p;

unsigned int taglen = strlen(tag);

unsigned long size = modinfo_len;

if (info) {

size -= info - (char *)modinfo;

modinfo = next_string(info, &size);

}

for (p = modinfo; p; p = next_string(p, &size)) {

if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')

return p + taglen + 1;

}

return NULL;

}

static char *get_modinfo(void *modinfo, unsigned long modinfo_len,

const char *tag)

{

return get_next_modinfo(modinfo, modinfo_len, tag, NULL);

}

/**

* Test if string s ends in string sub

* return 0 if match

**/

static int strrcmp(const char *s, const char *sub)

{

int slen, sublen;

if (!s || !sub)

return 1;

slen = strlen(s);

sublen = strlen(sub);

if ((slen == 0) || (sublen == 0))

return 1;

if (sublen > slen)

return 1;

return memcmp(s + slen - sublen, sub, sublen);

}

static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)

{

if (sym)

return elf->strtab + sym->st_name;

else

return "(unknown)";

}

static const char *sec_name(struct elf_info *elf, int secindex)

{

Elf_Shdr *sechdrs = elf->sechdrs;

return (void *)elf->hdr +

elf->sechdrs[elf->secindex_strings].sh_offset +

sechdrs[secindex].sh_name;

}

static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)

{

return (void *)elf->hdr +

elf->sechdrs[elf->secindex_strings].sh_offset +

sechdr->sh_name;

}

/* if sym is empty or point to a string

* like ".[0-9]+" then return 1.

* This is the optional prefix added by ld to some sections

static int number_prefix(const char *sym)

{

if (*sym++ == '\0')

return 1;

if (*sym != '.')

return 0;

do {

char c = *sym++;

if (c < '0' || c > '9')

return 0;

} while (*sym);

return 1;

}

/* The pattern is an array of simple patterns.

* "foo" will match an exact string equal to "foo"

* "*foo" will match a string that ends with "foo"

* "foo*" will match a string that begins with "foo"

* "foo$" will match a string equal to "foo" or "foo.1"

* where the '1' can be any number including several digits.

* The $ syntax is for sections where ld append a dot number

* to make section name unique.

static int match(const char *sym, const char * const pat[])

{

const char *p;

while (*pat) {

p = *pat++;

const char *endp = p + strlen(p) - 1;

/* "*foo" */

if (*p == '*') {

if (strrcmp(sym, p + 1) == 0)

return 1;

}

/* "foo*" */

else if (*endp == '*') {

if (strncmp(sym, p, strlen(p) - 1) == 0)

return 1;

}

/* "foo$" */

else if (*endp == '$') {

if (strncmp(sym, p, strlen(p) - 1) == 0) {

if (number_prefix(sym + strlen(p) - 1))

return 1;

}

/* no wildcards */

else {

if (strcmp(p, sym) == 0)

return 1;

}

/* no match */

return 0;

}

/* sections that we do not want to do full section mismatch check on */

static const char *section_white_list[] =

{

".comment*",

".debug*",

".zdebug*", /* Compressed debug sections. */

".GCC-command-line", /* mn10300 */

".GCC.command.line", /* record-gcc-switches, non mn10300 */

".mdebug*", /* alpha, score, mips etc. */

".pdr", /* alpha, score, mips etc. */

".stab*",

".note*",

".got*",

".toc*",

".xt.prop", /* xtensa */

".xt.lit", /* xtensa */

".arcextmap*", /* arc */

".gnu.linkonce.arcext*", /* arc : modules */

NULL

};

* This is used to find sections missing the SHF_ALLOC flag.

* The cause of this is often a section specified in assembler

* without "ax" / "aw".

static void check_section(const char *modname, struct elf_info *elf,

Elf_Shdr *sechdr)

{

const char *sec = sech_name(elf, sechdr);

if (sechdr->sh_type == SHT_PROGBITS &&

!(sechdr->sh_flags & SHF_ALLOC) &&

!match(sec, section_white_list)) {

warn("%s (%s): unexpected non-allocatable section.\n"

"Did you forget to use \"ax\"/\"aw\" in a .S file?\n"

"Note that for example <linux/init.h> contains\n"

"section definitions for use in .S files.\n\n",

modname, sec);

}

#define ALL_INIT_DATA_SECTIONS \

".init.setup$", ".init.rodata$", ".meminit.rodata$", \

".init.data$", ".meminit.data$"

#define ALL_EXIT_DATA_SECTIONS \

".exit.data$", ".memexit.data$"

#define ALL_INIT_TEXT_SECTIONS \

".init.text$", ".meminit.text$"

#define ALL_EXIT_TEXT_SECTIONS \

".exit.text$", ".memexit.text$"

#define ALL_PCI_INIT_SECTIONS \

".pci_fixup_early$", ".pci_fixup_header$", ".pci_fixup_final$", \

".pci_fixup_enable$", ".pci_fixup_resume$", \

".pci_fixup_resume_early$", ".pci_fixup_suspend$"

#define ALL_XXXINIT_SECTIONS MEM_INIT_SECTIONS

#define ALL_XXXEXIT_SECTIONS MEM_EXIT_SECTIONS

#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS

#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS

#define DATA_SECTIONS ".data$", ".data.rel$"

#define TEXT_SECTIONS ".text$", ".text.unlikely$"

#define INIT_SECTIONS ".init.*"

#define MEM_INIT_SECTIONS ".meminit.*"

#define EXIT_SECTIONS ".exit.*"

#define MEM_EXIT_SECTIONS ".memexit.*"

/* init data sections */

static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };

/* all init sections */

static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };

/* All init and exit sections (code + data) */

static const char *init_exit_sections[] =

{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };

/* data section */

static const char *data_sections[] = { DATA_SECTIONS, NULL };

/* symbols in .data that may refer to init/exit sections */

#define DEFAULT_SYMBOL_WHITE_LIST \

"*driver", \

"*_template", /* scsi uses *_template a lot */ \

"*_timer", /* arm uses ops structures named _timer a lot */ \

"*_sht", /* scsi also used *_sht to some extent */ \

"*_ops", \

"*_probe", \

"*_probe_one", \

"*_console"

static const char *head_sections[] = { ".head.text*", NULL };

static const char *linker_symbols[] =

{ "__init_begin", "_sinittext", "_einittext", NULL };

enum mismatch {

TEXT_TO_ANY_INIT,

DATA_TO_ANY_INIT,

TEXT_TO_ANY_EXIT,

DATA_TO_ANY_EXIT,

XXXINIT_TO_SOME_INIT,

XXXEXIT_TO_SOME_EXIT,

ANY_INIT_TO_ANY_EXIT,

ANY_EXIT_TO_ANY_INIT,

EXPORT_TO_INIT_EXIT,

};

struct sectioncheck {

const char *fromsec[20];

const char *tosec[20];

enum mismatch mismatch;

const char *symbol_white_list[20];

};

const struct sectioncheck sectioncheck[] = {

/* Do not reference init/exit code/data from

* normal code and data

{

.fromsec = { TEXT_SECTIONS, NULL },

.tosec = { ALL_INIT_SECTIONS, NULL },

.mismatch = TEXT_TO_ANY_INIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

{

.fromsec = { DATA_SECTIONS, NULL },

.tosec = { ALL_XXXINIT_SECTIONS, NULL },

.mismatch = DATA_TO_ANY_INIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

{

.fromsec = { DATA_SECTIONS, NULL },

.tosec = { INIT_SECTIONS, NULL },

.mismatch = DATA_TO_ANY_INIT,

.symbol_white_list = {

"*_template", "*_timer", "*_sht", "*_ops",

"*_probe", "*_probe_one", "*_console", NULL

{

.fromsec = { TEXT_SECTIONS, NULL },

.tosec = { ALL_EXIT_SECTIONS, NULL },

.mismatch = TEXT_TO_ANY_EXIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

{

.fromsec = { DATA_SECTIONS, NULL },

.tosec = { ALL_EXIT_SECTIONS, NULL },

.mismatch = DATA_TO_ANY_EXIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

/* Do not reference init code/data from meminit code/data */

{

.fromsec = { ALL_XXXINIT_SECTIONS, NULL },

.tosec = { INIT_SECTIONS, NULL },

.mismatch = XXXINIT_TO_SOME_INIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

/* Do not reference exit code/data from memexit code/data */

{

.fromsec = { ALL_XXXEXIT_SECTIONS, NULL },

.tosec = { EXIT_SECTIONS, NULL },

.mismatch = XXXEXIT_TO_SOME_EXIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

/* Do not use exit code/data from init code */

{

.fromsec = { ALL_INIT_SECTIONS, NULL },

.tosec = { ALL_EXIT_SECTIONS, NULL },

.mismatch = ANY_INIT_TO_ANY_EXIT,

.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },

/* Do not use init code/data from exit code */

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linux/scripts/mod/modpost.c at master · fabgithub/linux · GitHub

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