modpost.c 52.8 KB
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/* Postprocess module symbol versions
 *
 * Copyright 2003       Kai Germaschewski
 * Copyright 2002-2004  Rusty Russell, IBM Corporation
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 * Copyright 2006-2008  Sam Ravnborg
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 * 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 ...
 */

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#define _GNU_SOURCE
#include <stdio.h>
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#include <ctype.h>
#include "modpost.h"
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#include "../../include/linux/license.h"
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/* 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;
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/* If we are modposting external module set to 1 */
static int external_module = 0;
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/* Warn about section mismatch in vmlinux if set to 1 */
static int vmlinux_section_warnings = 1;
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/* Only warn about unresolved symbols */
static int warn_unresolved = 0;
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/* How a symbol is exported */
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static int sec_mismatch_count = 0;
static int sec_mismatch_verbose = 1;

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enum export {
	export_plain,      export_unused,     export_gpl,
	export_unused_gpl, export_gpl_future, export_unknown
};
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#define PRINTF __attribute__ ((format (printf, 1, 2)))

PRINTF void fatal(const char *fmt, ...)
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{
	va_list arglist;

	fprintf(stderr, "FATAL: ");

	va_start(arglist, fmt);
	vfprintf(stderr, fmt, arglist);
	va_end(arglist);

	exit(1);
}

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PRINTF void warn(const char *fmt, ...)
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{
	va_list arglist;

	fprintf(stderr, "WARNING: ");

	va_start(arglist, fmt);
	vfprintf(stderr, fmt, arglist);
	va_end(arglist);
}

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PRINTF void merror(const char *fmt, ...)
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{
	va_list arglist;

	fprintf(stderr, "ERROR: ");

	va_start(arglist, fmt);
	vfprintf(stderr, fmt, arglist);
	va_end(arglist);
}

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static int is_vmlinux(const char *modname)
{
	const char *myname;

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	myname = strrchr(modname, '/');
	if (myname)
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		myname++;
	else
		myname = modname;

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

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void *do_nofail(void *ptr, const char *expr)
{
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	if (!ptr)
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		fatal("modpost: Memory allocation failure: %s.\n", expr);
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	return ptr;
}

/* A list of all modules we processed */
static struct module *modules;

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static struct module *find_module(char *modname)
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{
	struct module *mod;

	for (mod = modules; mod; mod = mod->next)
		if (strcmp(mod->name, modname) == 0)
			break;
	return mod;
}

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static struct module *new_module(char *modname)
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{
	struct module *mod;
	char *p, *s;
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	mod = NOFAIL(malloc(sizeof(*mod)));
	memset(mod, 0, sizeof(*mod));
	p = NOFAIL(strdup(modname));

	/* strip trailing .o */
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	s = strrchr(p, '.');
	if (s != NULL)
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		if (strcmp(s, ".o") == 0)
			*s = '\0';

	/* add to list */
	mod->name = p;
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	mod->gpl_compatible = -1;
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	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;
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	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) **/
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	unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
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	enum export  export;       /* Type of export */
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	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. */
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	for (value = 0x238F13AF * strlen(name), i = 0; name[i]; i++)
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		value = (value + (((unsigned char *)name)[i] << (i*5 % 24)));

	return (1103515243 * value + 12345);
}

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/**
 * 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)
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{
	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 */
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static struct symbol *new_symbol(const char *name, struct module *module,
				 enum export export)
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{
	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;
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	new->export = export;
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	return new;
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}

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static struct symbol *find_symbol(const char *name)
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{
	struct symbol *s;

	/* For our purposes, .foo matches foo.  PPC64 needs this. */
	if (name[0] == '.')
		name++;

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	for (s = symbolhash[tdb_hash(name) % SYMBOL_HASH_SIZE]; s; s = s->next) {
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		if (strcmp(s->name, name) == 0)
			return s;
	}
	return NULL;
}

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static struct {
	const char *str;
	enum export export;
} export_list[] = {
	{ .str = "EXPORT_SYMBOL",            .export = export_plain },
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	{ .str = "EXPORT_UNUSED_SYMBOL",     .export = export_unused },
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	{ .str = "EXPORT_SYMBOL_GPL",        .export = export_gpl },
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	{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
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	{ .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;
}

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static enum export export_no(const char *s)
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{
	int i;
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	if (!s)
		return export_unknown;
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	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 enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
{
	if (sec == elf->export_sec)
		return export_plain;
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	else if (sec == elf->export_unused_sec)
		return export_unused;
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	else if (sec == elf->export_gpl_sec)
		return export_gpl;
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	else if (sec == elf->export_unused_gpl_sec)
		return export_unused_gpl;
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	else if (sec == elf->export_gpl_future_sec)
		return export_gpl_future;
	else
		return export_unknown;
}

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/**
 * Add an exported symbol - it may have already been added without a
 * CRC, in this case just update the CRC
 **/
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static struct symbol *sym_add_exported(const char *name, struct module *mod,
				       enum export export)
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{
	struct symbol *s = find_symbol(name);

	if (!s) {
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		s = new_symbol(name, mod, export);
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	} else {
		if (!s->preloaded) {
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			warn("%s: '%s' exported twice. Previous export "
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			     "was in %s%s\n", mod->name, name,
			     s->module->name,
			     is_vmlinux(s->module->name) ?"":".ko");
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		} else {
			/* In case Modules.symvers was out of date */
			s->module = mod;
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		}
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	}
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	s->preloaded = 0;
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	s->vmlinux   = is_vmlinux(mod->name);
	s->kernel    = 0;
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	s->export    = export;
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	return s;
}

static void sym_update_crc(const char *name, struct module *mod,
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			   unsigned int crc, enum export export)
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{
	struct symbol *s = find_symbol(name);

	if (!s)
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		s = new_symbol(name, mod, export);
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	s->crc = crc;
	s->crc_valid = 1;
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}

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void *grab_file(const char *filename, unsigned long *size)
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{
	struct stat st;
	void *map;
	int fd;

	fd = open(filename, O_RDONLY);
	if (fd < 0 || fstat(fd, &st) != 0)
		return NULL;

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

	if (map == MAP_FAILED)
		return NULL;
	return map;
}

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/**
  * 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.
  **/
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char *get_next_line(unsigned long *pos, void *file, unsigned long size)
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{
	static char line[4096];
	int skip = 1;
	size_t len = 0;
	signed char *p = (signed char *)file + *pos;
	char *s = line;

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

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void release_file(void *file, unsigned long size)
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{
	munmap(file, size);
}

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static int parse_elf(struct elf_info *info, const char *filename)
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{
	unsigned int i;
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	Elf_Ehdr *hdr;
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	Elf_Shdr *sechdrs;
	Elf_Sym  *sym;

	hdr = grab_file(filename, &info->size);
	if (!hdr) {
		perror(filename);
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		exit(1);
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	}
	info->hdr = hdr;
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	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;
	}
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	/* Fix endianness in ELF header */
	hdr->e_shoff    = TO_NATIVE(hdr->e_shoff);
	hdr->e_shstrndx = TO_NATIVE(hdr->e_shstrndx);
	hdr->e_shnum    = TO_NATIVE(hdr->e_shnum);
	hdr->e_machine  = TO_NATIVE(hdr->e_machine);
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	hdr->e_type     = TO_NATIVE(hdr->e_type);
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	sechdrs = (void *)hdr + hdr->e_shoff;
	info->sechdrs = sechdrs;

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	/* Check if file offset is correct */
	if (hdr->e_shoff > info->size) {
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		fatal("section header offset=%lu in file '%s' is bigger than "
		      "filesize=%lu\n", (unsigned long)hdr->e_shoff,
		      filename, info->size);
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		return 0;
	}

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	/* Fix endianness in section headers */
	for (i = 0; i < hdr->e_shnum; i++) {
		sechdrs[i].sh_type   = TO_NATIVE(sechdrs[i].sh_type);
		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_name   = TO_NATIVE(sechdrs[i].sh_name);
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		sechdrs[i].sh_info   = TO_NATIVE(sechdrs[i].sh_info);
		sechdrs[i].sh_addr   = TO_NATIVE(sechdrs[i].sh_addr);
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	}
	/* Find symbol table. */
	for (i = 1; i < hdr->e_shnum; i++) {
		const char *secstrings
			= (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
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		const char *secname;
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		if (sechdrs[i].sh_offset > info->size) {
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			fatal("%s is truncated. sechdrs[i].sh_offset=%lu > "
			      "sizeof(*hrd)=%zu\n", filename,
			      (unsigned long)sechdrs[i].sh_offset,
			      sizeof(*hdr));
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			return 0;
		}
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		secname = secstrings + sechdrs[i].sh_name;
		if (strcmp(secname, ".modinfo") == 0) {
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			info->modinfo = (void *)hdr + sechdrs[i].sh_offset;
			info->modinfo_len = sechdrs[i].sh_size;
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		} else if (strcmp(secname, "__ksymtab") == 0)
			info->export_sec = i;
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		else if (strcmp(secname, "__ksymtab_unused") == 0)
			info->export_unused_sec = i;
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		else if (strcmp(secname, "__ksymtab_gpl") == 0)
			info->export_gpl_sec = i;
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		else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
			info->export_unused_gpl_sec = i;
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		else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
			info->export_gpl_future_sec = i;
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		else if (strcmp(secname, "__markers_strings") == 0)
			info->markers_strings_sec = i;
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		if (sechdrs[i].sh_type != SHT_SYMTAB)
			continue;

		info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
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		info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
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			                         + sechdrs[i].sh_size;
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		info->strtab       = (void *)hdr +
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			             sechdrs[sechdrs[i].sh_link].sh_offset;
	}
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	if (!info->symtab_start)
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		fatal("%s has no symtab?\n", filename);
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	/* 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);
	}
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	return 1;
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}

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static void parse_elf_finish(struct elf_info *info)
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{
	release_file(info->hdr, info->size);
}

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#define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
#define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
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static void handle_modversions(struct module *mod, struct elf_info *info,
			       Elf_Sym *sym, const char *symname)
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{
	unsigned int crc;
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	enum export export = export_from_sec(info, sym->st_shndx);
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	switch (sym->st_shndx) {
	case SHN_COMMON:
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		warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
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		break;
	case SHN_ABS:
		/* CRC'd symbol */
		if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
			crc = (unsigned int) sym->st_value;
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			sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
					export);
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		}
		break;
	case SHN_UNDEF:
		/* undefined symbol */
		if (ELF_ST_BIND(sym->st_info) != STB_GLOBAL &&
		    ELF_ST_BIND(sym->st_info) != STB_WEAK)
			break;
		/* ignore global offset table */
		if (strcmp(symname, "_GLOBAL_OFFSET_TABLE_") == 0)
			break;
		/* ignore __this_module, it will be resolved shortly */
		if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
			break;
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/* 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
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		if (info->hdr->e_machine == EM_SPARC ||
		    info->hdr->e_machine == EM_SPARCV9) {
			/* Ignore register directives. */
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			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
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				break;
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			if (symname[0] == '.') {
				char *munged = strdup(symname);
				munged[0] = '_';
				munged[1] = toupper(munged[1]);
				symname = munged;
			}
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		}
#endif
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		if (memcmp(symname, MODULE_SYMBOL_PREFIX,
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			   strlen(MODULE_SYMBOL_PREFIX)) == 0) {
			mod->unres =
			  alloc_symbol(symname +
			               strlen(MODULE_SYMBOL_PREFIX),
			               ELF_ST_BIND(sym->st_info) == STB_WEAK,
			               mod->unres);
		}
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		break;
	default:
		/* All exported symbols */
		if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
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			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod,
					export);
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		}
		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
			mod->has_init = 1;
		if (strcmp(symname, MODULE_SYMBOL_PREFIX "cleanup_module") == 0)
			mod->has_cleanup = 1;
		break;
	}
}

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/**
 * Parse tag=value strings from .modinfo section
 **/
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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;
}

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static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
			      const char *tag, char *info)
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{
	char *p;
	unsigned int taglen = strlen(tag);
	unsigned long size = modinfo_len;

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	if (info) {
		size -= info - (char *)modinfo;
		modinfo = next_string(info, &size);
	}

L
Linus Torvalds 已提交
578 579 580 581 582 583 584
	for (p = modinfo; p; p = next_string(p, &size)) {
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

585 586 587 588 589 590 591
static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
			 const char *tag)

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

592 593 594 595 596 597
/**
 * Test if string s ends in string sub
 * return 0 if match
 **/
static int strrcmp(const char *s, const char *sub)
{
S
Sam Ravnborg 已提交
598
	int slen, sublen;
599

600 601
	if (!s || !sub)
		return 1;
602

603
	slen = strlen(s);
S
Sam Ravnborg 已提交
604
	sublen = strlen(sub);
605

606 607 608
	if ((slen == 0) || (sublen == 0))
		return 1;

S
Sam Ravnborg 已提交
609 610
	if (sublen > slen)
		return 1;
611

S
Sam Ravnborg 已提交
612
	return memcmp(s + slen - sublen, sub, sublen);
613 614
}

615 616
static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
{
617 618 619
	if (sym)
		return elf->strtab + sym->st_name;
	else
620
		return "(unknown)";
621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637
}

static const char *sec_name(struct elf_info *elf, int shndx)
{
	Elf_Shdr *sechdrs = elf->sechdrs;
	return (void *)elf->hdr +
	        elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
	        sechdrs[shndx].sh_name;
}

static const char *sech_name(struct elf_info *elf, Elf_Shdr *sechdr)
{
	return (void *)elf->hdr +
	        elf->sechdrs[elf->hdr->e_shstrndx].sh_offset +
	        sechdr->sh_name;
}

638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
/* 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"
658
 * "*foo" will match a string that ends with "foo"
659 660 661 662 663 664 665 666 667 668 669 670 671
 * "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.
 */
int match(const char *sym, const char * const pat[])
{
	const char *p;
	while (*pat) {
		p = *pat++;
		const char *endp = p + strlen(p) - 1;

672 673 674 675 676
		/* "*foo" */
		if (*p == '*') {
			if (strrcmp(sym, p + 1) == 0)
				return 1;
		}
677
		/* "foo*" */
678
		else if (*endp == '*') {
679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702
			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[] =
	{ ".debug*", ".stab*", ".note*", ".got*", ".toc*", NULL };

703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739
/*
 * Is this section one we do not want to check?
 * This is often debug sections.
 * If we are going to check this section then
 * test if section name ends with a dot and a number.
 * This is used to find sections where the linker have
 * appended a dot-number to make the name unique.
 * The cause of this is often a section specified in assembler
 * without "ax" / "aw" and the same section used in .c
 * code where gcc add these.
 */
static int check_section(const char *modname, const char *sec)
{
	const char *e = sec + strlen(sec) - 1;
	if (match(sec, section_white_list))
		return 1;

	if (*e && isdigit(*e)) {
		/* consume all digits */
		while (*e && e != sec && isdigit(*e))
			e--;
		if (*e == '.') {
			warn("%s (%s): unexpected section name.\n"
			     "The (.[number]+) following section name are "
			     "ld generated and not expected.\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);
		}
	}
	return 0;
}



740 741 742 743
#define ALL_INIT_DATA_SECTIONS \
	".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
#define ALL_EXIT_DATA_SECTIONS \
	".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
744

745 746 747 748
#define ALL_INIT_TEXT_SECTIONS \
	".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
#define ALL_EXIT_TEXT_SECTIONS \
	".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
749

750 751
#define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS
#define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS
752

753
#define DATA_SECTIONS ".data$", ".data.rel$"
754 755
#define TEXT_SECTIONS ".text$"

756 757 758 759 760 761 762 763 764 765
#define INIT_SECTIONS      ".init.data$", ".init.text$"
#define DEV_INIT_SECTIONS  ".devinit.data$", ".devinit.text$"
#define CPU_INIT_SECTIONS  ".cpuinit.data$", ".cpuinit.text$"
#define MEM_INIT_SECTIONS  ".meminit.data$", ".meminit.text$"

#define EXIT_SECTIONS      ".exit.data$", ".exit.text$"
#define DEV_EXIT_SECTIONS  ".devexit.data$", ".devexit.text$"
#define CPU_EXIT_SECTIONS  ".cpuexit.data$", ".cpuexit.text$"
#define MEM_EXIT_SECTIONS  ".memexit.data$", ".memexit.text$"

766
/* init data sections */
767
static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
768 769

/* all init sections */
770
static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
771 772 773

/* All init and exit sections (code + data) */
static const char *init_exit_sections[] =
774
	{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806

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

/* sections that may refer to an init/exit section with no warning */
static const char *initref_sections[] =
{
	".text.init.refok*",
	".exit.text.refok*",
	".data.init.refok*",
	NULL
};


/* symbols in .data that may refer to init/exit sections */
static const char *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",
	NULL
};

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

807 808 809 810 811 812 813 814 815 816 817 818 819
enum mismatch {
	NO_MISMATCH,
	TEXT_TO_INIT,
	DATA_TO_INIT,
	TEXT_TO_EXIT,
	DATA_TO_EXIT,
	XXXINIT_TO_INIT,
	XXXEXIT_TO_EXIT,
	INIT_TO_EXIT,
	EXIT_TO_INIT,
	EXPORT_TO_INIT_EXIT,
};

820 821 822
struct sectioncheck {
	const char *fromsec[20];
	const char *tosec[20];
823
	enum mismatch mismatch;
824 825 826 827 828 829 830
};

const struct sectioncheck sectioncheck[] = {
/* Do not reference init/exit code/data from
 * normal code and data
 */
{
831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
	.fromsec = { TEXT_SECTIONS, NULL },
	.tosec   = { ALL_INIT_SECTIONS, NULL },
	.mismatch = TEXT_TO_INIT,
},
{
	.fromsec = { DATA_SECTIONS, NULL },
	.tosec   = { ALL_INIT_SECTIONS, NULL },
	.mismatch = DATA_TO_INIT,
},
{
	.fromsec = { TEXT_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
	.mismatch = TEXT_TO_EXIT,
},
{
	.fromsec = { DATA_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
	.mismatch = DATA_TO_EXIT,
849 850 851 852
},
/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
{
	.fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
853 854
	.tosec   = { INIT_SECTIONS, NULL },
	.mismatch = XXXINIT_TO_INIT,
855 856 857 858
},
/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
{
	.fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
859 860
	.tosec   = { EXIT_SECTIONS, NULL },
	.mismatch = XXXEXIT_TO_EXIT,
861 862 863
},
/* Do not use exit code/data from init code */
{
864 865
	.fromsec = { ALL_INIT_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
866
	.mismatch = INIT_TO_EXIT,
867 868 869
},
/* Do not use init code/data from exit code */
{
870
	.fromsec = { ALL_EXIT_SECTIONS, NULL },
871 872
	.tosec   = { ALL_INIT_SECTIONS, NULL },
	.mismatch = EXIT_TO_INIT,
873 874 875 876
},
/* Do not export init/exit functions or data */
{
	.fromsec = { "__ksymtab*", NULL },
877
	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
878
	.mismatch = EXPORT_TO_INIT_EXIT
879 880 881 882 883 884 885 886 887 888 889 890
}
};

static int section_mismatch(const char *fromsec, const char *tosec)
{
	int i;
	int elems = sizeof(sectioncheck) / sizeof(struct sectioncheck);
	const struct sectioncheck *check = &sectioncheck[0];

	for (i = 0; i < elems; i++) {
		if (match(fromsec, check->fromsec) &&
		    match(tosec, check->tosec))
891
			return check->mismatch;
892 893
		check++;
	}
894
	return NO_MISMATCH;
895 896
}

897 898
/**
 * Whitelist to allow certain references to pass with no warning.
899 900 901 902
 *
 * Pattern 0:
 *   Do not warn if funtion/data are marked with __init_refok/__initdata_refok.
 *   The pattern is identified by:
903
 *   fromsec = .text.init.refok* | .data.init.refok*
904
 *
905 906 907 908 909 910 911
 * Pattern 1:
 *   If a module parameter is declared __initdata and permissions=0
 *   then this is legal despite the warning generated.
 *   We cannot see value of permissions here, so just ignore
 *   this pattern.
 *   The pattern is identified by:
 *   tosec   = .init.data
912
 *   fromsec = .data*
913
 *   atsym   =__param*
914
 *
915
 * Pattern 2:
916
 *   Many drivers utilise a *driver container with references to
917 918 919 920
 *   add, remove, probe functions etc.
 *   These functions may often be marked __init and we do not want to
 *   warn here.
 *   the pattern is identified by:
921 922
 *   tosec   = init or exit section
 *   fromsec = data section
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Sam Ravnborg 已提交
923 924
 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
 *           *probe_one, *_console, *_timer
925 926
 *
 * Pattern 3:
927 928 929
 *   Whitelist all refereces from .text.head to .init.data
 *   Whitelist all refereces from .text.head to .init.text
 *
930
 * Pattern 4:
931 932 933 934 935 936 937
 *   Some symbols belong to init section but still it is ok to reference
 *   these from non-init sections as these symbols don't have any memory
 *   allocated for them and symbol address and value are same. So even
 *   if init section is freed, its ok to reference those symbols.
 *   For ex. symbols marking the init section boundaries.
 *   This pattern is identified by
 *   refsymname = __init_begin, _sinittext, _einittext
938
 *
939
 **/
940 941
static int secref_whitelist(const char *fromsec, const char *fromsym,
			    const char *tosec, const char *tosym)
942
{
943
	/* Check for pattern 0 */
944
	if (match(fromsec, initref_sections))
945
		return 0;
946

947
	/* Check for pattern 1 */
948 949
	if (match(tosec, init_data_sections) &&
	    match(fromsec, data_sections) &&
950 951
	    (strncmp(fromsym, "__param", strlen("__param")) == 0))
		return 0;
952 953

	/* Check for pattern 2 */
954 955
	if (match(tosec, init_exit_sections) &&
	    match(fromsec, data_sections) &&
956 957
	    match(fromsym, symbol_white_list))
		return 0;
958

959
	/* Check for pattern 3 */
960 961
	if (match(fromsec, head_sections) &&
	    match(tosec, init_sections))
962
		return 0;
963

964
	/* Check for pattern 4 */
965 966
	if (match(tosym, linker_symbols))
		return 0;
967

968
	return 1;
969 970
}

971 972 973 974 975 976 977
/**
 * Find symbol based on relocation record info.
 * In some cases the symbol supplied is a valid symbol so
 * return refsym. If st_name != 0 we assume this is a valid symbol.
 * In other cases the symbol needs to be looked up in the symbol table
 * based on section and address.
 *  **/
978
static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
979 980 981
				Elf_Sym *relsym)
{
	Elf_Sym *sym;
982 983 984
	Elf_Sym *near = NULL;
	Elf64_Sword distance = 20;
	Elf64_Sword d;
985 986 987 988 989 990

	if (relsym->st_name != 0)
		return relsym;
	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
		if (sym->st_shndx != relsym->st_shndx)
			continue;
991 992
		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
			continue;
993 994
		if (sym->st_value == addr)
			return sym;
995 996 997 998 999 1000 1001 1002
		/* Find a symbol nearby - addr are maybe negative */
		d = sym->st_value - addr;
		if (d < 0)
			d = addr - sym->st_value;
		if (d < distance) {
			distance = d;
			near = sym;
		}
1003
	}
1004 1005 1006 1007 1008
	/* We need a close match */
	if (distance < 20)
		return near;
	else
		return NULL;
1009 1010
}

1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034
static inline int is_arm_mapping_symbol(const char *str)
{
	return str[0] == '$' && strchr("atd", str[1])
	       && (str[2] == '\0' || str[2] == '.');
}

/*
 * If there's no name there, ignore it; likewise, ignore it if it's
 * one of the magic symbols emitted used by current ARM tools.
 *
 * Otherwise if find_symbols_between() returns those symbols, they'll
 * fail the whitelist tests and cause lots of false alarms ... fixable
 * only by merging __exit and __init sections into __text, bloating
 * the kernel (which is especially evil on embedded platforms).
 */
static inline int is_valid_name(struct elf_info *elf, Elf_Sym *sym)
{
	const char *name = elf->strtab + sym->st_name;

	if (!name || !strlen(name))
		return 0;
	return !is_arm_mapping_symbol(name);
}

1035
/*
1036 1037 1038 1039
 * Find symbols before or equal addr and after addr - in the section sec.
 * If we find two symbols with equal offset prefer one with a valid name.
 * The ELF format may have a better way to detect what type of symbol
 * it is, but this works for now.
1040
 **/
1041 1042
static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
				 const char *sec)
1043 1044
{
	Elf_Sym *sym;
1045 1046
	Elf_Sym *near = NULL;
	Elf_Addr distance = ~0;
1047

1048 1049 1050 1051 1052
	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
		const char *symsec;

		if (sym->st_shndx >= SHN_LORESERVE)
			continue;
1053
		symsec = sec_name(elf, sym->st_shndx);
1054 1055
		if (strcmp(symsec, sec) != 0)
			continue;
1056 1057
		if (!is_valid_name(elf, sym))
			continue;
1058
		if (sym->st_value <= addr) {
1059 1060 1061 1062 1063
			if ((addr - sym->st_value) < distance) {
				distance = addr - sym->st_value;
				near = sym;
			} else if ((addr - sym->st_value) == distance) {
				near = sym;
1064
			}
1065 1066
		}
	}
1067
	return near;
1068 1069
}

1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108
/*
 * Convert a section name to the function/data attribute
 * .init.text => __init
 * .cpuinit.data => __cpudata
 * .memexitconst => __memconst
 * etc.
*/
static char *sec2annotation(const char *s)
{
	if (match(s, init_exit_sections)) {
		char *p = malloc(20);
		char *r = p;

		*p++ = '_';
		*p++ = '_';
		if (*s == '.')
			s++;
		while (*s && *s != '.')
			*p++ = *s++;
		*p = '\0';
		if (*s == '.')
			s++;
		if (strstr(s, "rodata") != NULL)
			strcat(p, "const ");
		else if (strstr(s, "data") != NULL)
			strcat(p, "data ");
		else
			strcat(p, " ");
		return r; /* we leak her but we do not care */
	} else {
		return "";
	}
}

static int is_function(Elf_Sym *sym)
{
	if (sym)
		return ELF_ST_TYPE(sym->st_info) == STT_FUNC;
	else
1109
		return -1;
1110 1111
}

1112
/*
1113 1114
 * Print a warning about a section mismatch.
 * Try to find symbols near it so user can find it.
1115
 * Check whitelist before warning - it may be a false positive.
1116
 */
1117
static void report_sec_mismatch(const char *modname, enum mismatch mismatch,
1118 1119 1120
                                const char *fromsec,
                                unsigned long long fromaddr,
                                const char *fromsym,
1121 1122 1123 1124 1125 1126
                                int from_is_func,
                                const char *tosec, const char *tosym,
                                int to_is_func)
{
	const char *from, *from_p;
	const char *to, *to_p;
1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137

	switch (from_is_func) {
	case 0: from = "variable"; from_p = "";   break;
	case 1: from = "function"; from_p = "()"; break;
	default: from = "(unknown reference)"; from_p = ""; break;
	}
	switch (to_is_func) {
	case 0: to = "variable"; to_p = "";   break;
	case 1: to = "function"; to_p = "()"; break;
	default: to = "(unknown reference)"; to_p = ""; break;
	}
1138

1139 1140 1141 1142
	sec_mismatch_count++;
	if (!sec_mismatch_verbose)
		return;

1143 1144 1145 1146
	warn("%s(%s+0x%llx): Section mismatch in reference from the %s %s%s "
	     "to the %s %s:%s%s\n",
	     modname, fromsec, fromaddr, from, fromsym, from_p, to, tosec,
	     tosym, to_p);
1147 1148 1149 1150

	switch (mismatch) {
	case TEXT_TO_INIT:
		fprintf(stderr,
1151
		"The function %s%s() references\n"
1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171
		"the %s %s%s%s.\n"
		"This is often because %s lacks a %s\n"
		"annotation or the annotation of %s is wrong.\n",
		sec2annotation(fromsec), fromsym,
		to, sec2annotation(tosec), tosym, to_p,
		fromsym, sec2annotation(tosec), tosym);
		break;
	case DATA_TO_INIT: {
		const char **s = symbol_white_list;
		fprintf(stderr,
		"The variable %s references\n"
		"the %s %s%s%s\n"
		"If the reference is valid then annotate the\n"
		"variable with __init* (see linux/init.h) "
		"or name the variable:\n",
		fromsym, to, sec2annotation(tosec), tosym, to_p);
		while (*s)
			fprintf(stderr, "%s, ", *s++);
		fprintf(stderr, "\n");
		break;
1172
	}
1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202
	case TEXT_TO_EXIT:
		fprintf(stderr,
		"The function %s() references a %s in an exit section.\n"
		"Often the %s %s%s has valid usage outside the exit section\n"
		"and the fix is to remove the %sannotation of %s.\n",
		fromsym, to, to, tosym, to_p, sec2annotation(tosec), tosym);
		break;
	case DATA_TO_EXIT: {
		const char **s = symbol_white_list;
		fprintf(stderr,
		"The variable %s references\n"
		"the %s %s%s%s\n"
		"If the reference is valid then annotate the\n"
		"variable with __exit* (see linux/init.h) or "
		"name the variable:\n",
		fromsym, to, sec2annotation(tosec), tosym, to_p);
		while (*s)
			fprintf(stderr, "%s, ", *s++);
		fprintf(stderr, "\n");
		break;
	}
	case XXXINIT_TO_INIT:
	case XXXEXIT_TO_EXIT:
		fprintf(stderr,
		"The %s %s%s%s references\n"
		"a %s %s%s%s.\n"
		"If %s is only used by %s then\n"
		"annotate %s with a matching annotation.\n",
		from, sec2annotation(fromsec), fromsym, from_p,
		to, sec2annotation(tosec), tosym, to_p,
1203
		tosym, fromsym, tosym);
1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241
		break;
	case INIT_TO_EXIT:
		fprintf(stderr,
		"The %s %s%s%s references\n"
		"a %s %s%s%s.\n"
		"This is often seen when error handling "
		"in the init function\n"
		"uses functionality in the exit path.\n"
		"The fix is often to remove the %sannotation of\n"
		"%s%s so it may be used outside an exit section.\n",
		from, sec2annotation(fromsec), fromsym, from_p,
		to, sec2annotation(tosec), tosym, to_p,
		sec2annotation(tosec), tosym, to_p);
		break;
	case EXIT_TO_INIT:
		fprintf(stderr,
		"The %s %s%s%s references\n"
		"a %s %s%s%s.\n"
		"This is often seen when error handling "
		"in the exit function\n"
		"uses functionality in the init path.\n"
		"The fix is often to remove the %sannotation of\n"
		"%s%s so it may be used outside an init section.\n",
		from, sec2annotation(fromsec), fromsym, from_p,
		to, sec2annotation(tosec), tosym, to_p,
		sec2annotation(tosec), tosym, to_p);
		break;
	case EXPORT_TO_INIT_EXIT:
		fprintf(stderr,
		"The symbol %s is exported and annotated %s\n"
		"Fix this by removing the %sannotation of %s "
		"or drop the export.\n",
		tosym, sec2annotation(tosec), sec2annotation(tosec), tosym);
	case NO_MISMATCH:
		/* To get warnings on missing members */
		break;
	}
	fprintf(stderr, "\n");
1242 1243 1244 1245 1246 1247
}

static void check_section_mismatch(const char *modname, struct elf_info *elf,
                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
{
	const char *tosec;
1248
	enum mismatch mismatch;
1249 1250

	tosec = sec_name(elf, sym->st_shndx);
1251 1252 1253 1254
	mismatch = section_mismatch(fromsec, tosec);
	if (mismatch != NO_MISMATCH) {
		Elf_Sym *to;
		Elf_Sym *from;
1255
		const char *tosym;
1256
		const char *fromsym;
1257

1258 1259 1260 1261
		from = find_elf_symbol2(elf, r->r_offset, fromsec);
		fromsym = sym_name(elf, from);
		to = find_elf_symbol(elf, r->r_addend, sym);
		tosym = sym_name(elf, to);
1262 1263 1264

		/* check whitelist - we may ignore it */
		if (secref_whitelist(fromsec, fromsym, tosec, tosym)) {
1265 1266 1267 1268
			report_sec_mismatch(modname, mismatch,
			   fromsec, r->r_offset, fromsym,
			   is_function(from), tosec, tosym,
			   is_function(to));
1269
		}
1270 1271 1272
	}
}

1273
static unsigned int *reloc_location(struct elf_info *elf,
1274
				    Elf_Shdr *sechdr, Elf_Rela *r)
1275 1276
{
	Elf_Shdr *sechdrs = elf->sechdrs;
1277
	int section = sechdr->sh_info;
1278 1279 1280 1281 1282

	return (void *)elf->hdr + sechdrs[section].sh_offset +
		(r->r_offset - sechdrs[section].sh_addr);
}

1283
static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1284 1285
{
	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1286
	unsigned int *location = reloc_location(elf, sechdr, r);
1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301

	switch (r_typ) {
	case R_386_32:
		r->r_addend = TO_NATIVE(*location);
		break;
	case R_386_PC32:
		r->r_addend = TO_NATIVE(*location) + 4;
		/* For CONFIG_RELOCATABLE=y */
		if (elf->hdr->e_type == ET_EXEC)
			r->r_addend += r->r_offset;
		break;
	}
	return 0;
}

1302
static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1303 1304 1305 1306 1307 1308
{
	unsigned int r_typ = ELF_R_TYPE(r->r_info);

	switch (r_typ) {
	case R_ARM_ABS32:
		/* From ARM ABI: (S + A) | T */
S
Sam Ravnborg 已提交
1309 1310
		r->r_addend = (int)(long)
		              (elf->symtab_start + ELF_R_SYM(r->r_info));
1311 1312 1313
		break;
	case R_ARM_PC24:
		/* From ARM ABI: ((S + A) | T) - P */
S
Sam Ravnborg 已提交
1314
		r->r_addend = (int)(long)(elf->hdr +
1315 1316
		              sechdr->sh_offset +
		              (r->r_offset - sechdr->sh_addr));
1317 1318 1319 1320 1321 1322 1323
		break;
	default:
		return 1;
	}
	return 0;
}

1324
static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1325 1326
{
	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1327
	unsigned int *location = reloc_location(elf, sechdr, r);
1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346
	unsigned int inst;

	if (r_typ == R_MIPS_HI16)
		return 1;	/* skip this */
	inst = TO_NATIVE(*location);
	switch (r_typ) {
	case R_MIPS_LO16:
		r->r_addend = inst & 0xffff;
		break;
	case R_MIPS_26:
		r->r_addend = (inst & 0x03ffffff) << 2;
		break;
	case R_MIPS_32:
		r->r_addend = inst;
		break;
	}
	return 0;
}

1347
static void section_rela(const char *modname, struct elf_info *elf,
1348
                         Elf_Shdr *sechdr)
1349 1350 1351 1352 1353 1354 1355
{
	Elf_Sym  *sym;
	Elf_Rela *rela;
	Elf_Rela r;
	unsigned int r_sym;
	const char *fromsec;

1356
	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1357 1358
	Elf_Rela *stop  = (void *)start + sechdr->sh_size;

1359
	fromsec = sech_name(elf, sechdr);
1360 1361
	fromsec += strlen(".rela");
	/* if from section (name) is know good then skip it */
1362
	if (check_section(modname, fromsec))
1363
		return;
1364

1365 1366 1367
	for (rela = start; rela < stop; rela++) {
		r.r_offset = TO_NATIVE(rela->r_offset);
#if KERNEL_ELFCLASS == ELFCLASS64
1368
		if (elf->hdr->e_machine == EM_MIPS) {
1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386
			unsigned int r_typ;
			r_sym = ELF64_MIPS_R_SYM(rela->r_info);
			r_sym = TO_NATIVE(r_sym);
			r_typ = ELF64_MIPS_R_TYPE(rela->r_info);
			r.r_info = ELF64_R_INFO(r_sym, r_typ);
		} else {
			r.r_info = TO_NATIVE(rela->r_info);
			r_sym = ELF_R_SYM(r.r_info);
		}
#else
		r.r_info = TO_NATIVE(rela->r_info);
		r_sym = ELF_R_SYM(r.r_info);
#endif
		r.r_addend = TO_NATIVE(rela->r_addend);
		sym = elf->symtab_start + r_sym;
		/* Skip special sections */
		if (sym->st_shndx >= SHN_LORESERVE)
			continue;
1387
		check_section_mismatch(modname, elf, &r, sym, fromsec);
1388 1389 1390 1391
	}
}

static void section_rel(const char *modname, struct elf_info *elf,
1392
                        Elf_Shdr *sechdr)
1393 1394 1395 1396 1397 1398 1399
{
	Elf_Sym *sym;
	Elf_Rel *rel;
	Elf_Rela r;
	unsigned int r_sym;
	const char *fromsec;

1400
	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1401 1402
	Elf_Rel *stop  = (void *)start + sechdr->sh_size;

1403
	fromsec = sech_name(elf, sechdr);
1404 1405
	fromsec += strlen(".rel");
	/* if from section (name) is know good then skip it */
1406
	if (check_section(modname, fromsec))
1407 1408 1409 1410 1411
		return;

	for (rel = start; rel < stop; rel++) {
		r.r_offset = TO_NATIVE(rel->r_offset);
#if KERNEL_ELFCLASS == ELFCLASS64
1412
		if (elf->hdr->e_machine == EM_MIPS) {
1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426
			unsigned int r_typ;
			r_sym = ELF64_MIPS_R_SYM(rel->r_info);
			r_sym = TO_NATIVE(r_sym);
			r_typ = ELF64_MIPS_R_TYPE(rel->r_info);
			r.r_info = ELF64_R_INFO(r_sym, r_typ);
		} else {
			r.r_info = TO_NATIVE(rel->r_info);
			r_sym = ELF_R_SYM(r.r_info);
		}
#else
		r.r_info = TO_NATIVE(rel->r_info);
		r_sym = ELF_R_SYM(r.r_info);
#endif
		r.r_addend = 0;
1427
		switch (elf->hdr->e_machine) {
1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444
		case EM_386:
			if (addend_386_rel(elf, sechdr, &r))
				continue;
			break;
		case EM_ARM:
			if (addend_arm_rel(elf, sechdr, &r))
				continue;
			break;
		case EM_MIPS:
			if (addend_mips_rel(elf, sechdr, &r))
				continue;
			break;
		}
		sym = elf->symtab_start + r_sym;
		/* Skip special sections */
		if (sym->st_shndx >= SHN_LORESERVE)
			continue;
1445
		check_section_mismatch(modname, elf, &r, sym, fromsec);
1446 1447 1448
	}
}

1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461
/**
 * A module includes a number of sections that are discarded
 * either when loaded or when used as built-in.
 * For loaded modules all functions marked __init and all data
 * marked __initdata will be discarded when the module has been intialized.
 * Likewise for modules used built-in the sections marked __exit
 * are discarded because __exit marked function are supposed to be called
 * only when a moduel is unloaded which never happes for built-in modules.
 * The check_sec_ref() function traverses all relocation records
 * to find all references to a section that reference a section that will
 * be discarded and warns about it.
 **/
static void check_sec_ref(struct module *mod, const char *modname,
1462
                          struct elf_info *elf)
1463 1464 1465
{
	int i;
	Elf_Shdr *sechdrs = elf->sechdrs;
1466

1467
	/* Walk through all sections */
1468
	for (i = 0; i < elf->hdr->e_shnum; i++) {
1469
		/* We want to process only relocation sections and not .init */
1470
		if (sechdrs[i].sh_type == SHT_RELA)
1471
			section_rela(modname, elf, &elf->sechdrs[i]);
1472
		else if (sechdrs[i].sh_type == SHT_REL)
1473
			section_rel(modname, elf, &elf->sechdrs[i]);
1474 1475 1476
	}
}

1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
static void get_markers(struct elf_info *info, struct module *mod)
{
	const Elf_Shdr *sh = &info->sechdrs[info->markers_strings_sec];
	const char *strings = (const char *) info->hdr + sh->sh_offset;
	const Elf_Sym *sym, *first_sym, *last_sym;
	size_t n;

	if (!info->markers_strings_sec)
		return;

	/*
	 * First count the strings.  We look for all the symbols defined
	 * in the __markers_strings section named __mstrtab_*.  For
	 * these local names, the compiler puts a random .NNN suffix on,
	 * so the names don't correspond exactly.
	 */
	first_sym = last_sym = NULL;
	n = 0;
	for (sym = info->symtab_start; sym < info->symtab_stop; sym++)
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
		    sym->st_shndx == info->markers_strings_sec &&
		    !strncmp(info->strtab + sym->st_name,
			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
			if (first_sym == NULL)
				first_sym = sym;
			last_sym = sym;
			++n;
		}

	if (n == 0)
		return;

	/*
	 * Now collect each name and format into a line for the output.
	 * Lines look like:
	 *	marker_name	vmlinux	marker %s format %d
	 * The format string after the second \t can use whitespace.
	 */
	mod->markers = NOFAIL(malloc(sizeof mod->markers[0] * n));
	mod->nmarkers = n;

	n = 0;
	for (sym = first_sym; sym <= last_sym; sym++)
		if (ELF_ST_TYPE(sym->st_info) == STT_OBJECT &&
		    sym->st_shndx == info->markers_strings_sec &&
		    !strncmp(info->strtab + sym->st_name,
			     "__mstrtab_", sizeof "__mstrtab_" - 1)) {
			const char *name = strings + sym->st_value;
			const char *fmt = strchr(name, '\0') + 1;
			char *line = NULL;
			asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
			NOFAIL(line);
			mod->markers[n++] = line;
		}
}

1533
static void read_symbols(char *modname)
L
Linus Torvalds 已提交
1534 1535 1536
{
	const char *symname;
	char *version;
1537
	char *license;
L
Linus Torvalds 已提交
1538 1539 1540 1541
	struct module *mod;
	struct elf_info info = { };
	Elf_Sym *sym;

1542 1543
	if (!parse_elf(&info, modname))
		return;
L
Linus Torvalds 已提交
1544 1545 1546 1547 1548 1549 1550 1551 1552 1553

	mod = new_module(modname);

	/* When there's no vmlinux, don't print warnings about
	 * unresolved symbols (since there'll be too many ;) */
	if (is_vmlinux(modname)) {
		have_vmlinux = 1;
		mod->skip = 1;
	}

1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565
	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
	while (license) {
		if (license_is_gpl_compatible(license))
			mod->gpl_compatible = 1;
		else {
			mod->gpl_compatible = 0;
			break;
		}
		license = get_next_modinfo(info.modinfo, info.modinfo_len,
					   "license", license);
	}

L
Linus Torvalds 已提交
1566 1567 1568 1569 1570 1571
	for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
		symname = info.strtab + sym->st_name;

		handle_modversions(mod, &info, sym, symname);
		handle_moddevtable(mod, &info, sym, symname);
	}
1572
	if (!is_vmlinux(modname) ||
1573 1574
	     (is_vmlinux(modname) && vmlinux_section_warnings))
		check_sec_ref(mod, modname, &info);
L
Linus Torvalds 已提交
1575 1576 1577 1578 1579 1580 1581 1582 1583

	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
	if (version)
		maybe_frob_rcs_version(modname, version, info.modinfo,
				       version - (char *)info.hdr);
	if (version || (all_versions && !is_vmlinux(modname)))
		get_src_version(modname, mod->srcversion,
				sizeof(mod->srcversion)-1);

1584 1585
	get_markers(&info, mod);

L
Linus Torvalds 已提交
1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601
	parse_elf_finish(&info);

	/* Our trick to get versioning for struct_module - it's
	 * never passed as an argument to an exported function, so
	 * the automatic versioning doesn't pick it up, but it's really
	 * important anyhow */
	if (modversions)
		mod->unres = alloc_symbol("struct_module", 0, mod->unres);
}

#define SZ 500

/* We first write the generated file into memory using the
 * following helper, then compare to the file on disk and
 * only update the later if anything changed */

1602 1603
void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
						      const char *fmt, ...)
L
Linus Torvalds 已提交
1604 1605 1606 1607
{
	char tmp[SZ];
	int len;
	va_list ap;
1608

L
Linus Torvalds 已提交
1609 1610
	va_start(ap, fmt);
	len = vsnprintf(tmp, SZ, fmt, ap);
1611
	buf_write(buf, tmp, len);
L
Linus Torvalds 已提交
1612 1613 1614
	va_end(ap);
}

1615
void buf_write(struct buffer *buf, const char *s, int len)
L
Linus Torvalds 已提交
1616 1617
{
	if (buf->size - buf->pos < len) {
1618
		buf->size += len + SZ;
L
Linus Torvalds 已提交
1619 1620 1621 1622 1623 1624
		buf->p = realloc(buf->p, buf->size);
	}
	strncpy(buf->p + buf->pos, s, len);
	buf->pos += len;
}

1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
{
	const char *e = is_vmlinux(m) ?"":".ko";

	switch (exp) {
	case export_gpl:
		fatal("modpost: GPL-incompatible module %s%s "
		      "uses GPL-only symbol '%s'\n", m, e, s);
		break;
	case export_unused_gpl:
		fatal("modpost: GPL-incompatible module %s%s "
		      "uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
		break;
	case export_gpl_future:
		warn("modpost: GPL-incompatible module %s%s "
		      "uses future GPL-only symbol '%s'\n", m, e, s);
		break;
	case export_plain:
	case export_unused:
	case export_unknown:
		/* ignore */
		break;
	}
}

S
Sam Ravnborg 已提交
1650
static void check_for_unused(enum export exp, const char *m, const char *s)
1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666
{
	const char *e = is_vmlinux(m) ?"":".ko";

	switch (exp) {
	case export_unused:
	case export_unused_gpl:
		warn("modpost: module %s%s "
		      "uses symbol '%s' marked UNUSED\n", m, e, s);
		break;
	default:
		/* ignore */
		break;
	}
}

static void check_exports(struct module *mod)
1667 1668 1669 1670
{
	struct symbol *s, *exp;

	for (s = mod->unres; s; s = s->next) {
A
Andrew Morton 已提交
1671
		const char *basename;
1672 1673 1674
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod)
			continue;
A
Andrew Morton 已提交
1675
		basename = strrchr(mod->name, '/');
1676 1677
		if (basename)
			basename++;
1678 1679 1680 1681 1682
		else
			basename = mod->name;
		if (!mod->gpl_compatible)
			check_for_gpl_usage(exp->export, basename, exp->name);
		check_for_unused(exp->export, basename, exp->name);
S
Sam Ravnborg 已提交
1683
	}
1684 1685
}

1686 1687 1688 1689
/**
 * Header for the generated file
 **/
static void add_header(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1690 1691 1692 1693 1694 1695 1696 1697 1698
{
	buf_printf(b, "#include <linux/module.h>\n");
	buf_printf(b, "#include <linux/vermagic.h>\n");
	buf_printf(b, "#include <linux/compiler.h>\n");
	buf_printf(b, "\n");
	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
	buf_printf(b, "\n");
	buf_printf(b, "struct module __this_module\n");
	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
1699
	buf_printf(b, " .name = KBUILD_MODNAME,\n");
L
Linus Torvalds 已提交
1700 1701 1702 1703 1704 1705
	if (mod->has_init)
		buf_printf(b, " .init = init_module,\n");
	if (mod->has_cleanup)
		buf_printf(b, "#ifdef CONFIG_MODULE_UNLOAD\n"
			      " .exit = cleanup_module,\n"
			      "#endif\n");
1706
	buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
L
Linus Torvalds 已提交
1707 1708 1709
	buf_printf(b, "};\n");
}

1710 1711 1712
/**
 * Record CRCs for unresolved symbols
 **/
1713
static int add_versions(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1714 1715
{
	struct symbol *s, *exp;
1716
	int err = 0;
L
Linus Torvalds 已提交
1717 1718 1719 1720

	for (s = mod->unres; s; s = s->next) {
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod) {
1721
			if (have_vmlinux && !s->weak) {
1722 1723 1724 1725 1726 1727 1728 1729
				if (warn_unresolved) {
					warn("\"%s\" [%s.ko] undefined!\n",
					     s->name, mod->name);
				} else {
					merror("\"%s\" [%s.ko] undefined!\n",
					          s->name, mod->name);
					err = 1;
				}
1730
			}
L
Linus Torvalds 已提交
1731 1732 1733 1734 1735 1736 1737 1738
			continue;
		}
		s->module = exp->module;
		s->crc_valid = exp->crc_valid;
		s->crc = exp->crc;
	}

	if (!modversions)
1739
		return err;
L
Linus Torvalds 已提交
1740 1741 1742

	buf_printf(b, "\n");
	buf_printf(b, "static const struct modversion_info ____versions[]\n");
A
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1743
	buf_printf(b, "__used\n");
L
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1744 1745 1746
	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");

	for (s = mod->unres; s; s = s->next) {
S
Sam Ravnborg 已提交
1747
		if (!s->module)
L
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			continue;
		if (!s->crc_valid) {
1750
			warn("\"%s\" [%s.ko] has no CRC!\n",
L
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1751 1752 1753 1754 1755 1756 1757
				s->name, mod->name);
			continue;
		}
		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
	}

	buf_printf(b, "};\n");
1758 1759

	return err;
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}

1762 1763
static void add_depends(struct buffer *b, struct module *mod,
			struct module *modules)
L
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1764 1765 1766 1767 1768
{
	struct symbol *s;
	struct module *m;
	int first = 1;

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	for (m = modules; m; m = m->next)
L
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		m->seen = is_vmlinux(m->name);

	buf_printf(b, "\n");
	buf_printf(b, "static const char __module_depends[]\n");
A
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1774
	buf_printf(b, "__used\n");
L
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	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
	buf_printf(b, "\"depends=");
	for (s = mod->unres; s; s = s->next) {
1778
		const char *p;
L
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		if (!s->module)
			continue;

		if (s->module->seen)
			continue;

		s->module->seen = 1;
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		p = strrchr(s->module->name, '/');
		if (p)
1788 1789 1790 1791
			p++;
		else
			p = s->module->name;
		buf_printf(b, "%s%s", first ? "" : ",", p);
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		first = 0;
	}
	buf_printf(b, "\";\n");
}

1797
static void add_srcversion(struct buffer *b, struct module *mod)
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{
	if (mod->srcversion[0]) {
		buf_printf(b, "\n");
		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
			   mod->srcversion);
	}
}

1806
static void write_if_changed(struct buffer *b, const char *fname)
L
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1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849
{
	char *tmp;
	FILE *file;
	struct stat st;

	file = fopen(fname, "r");
	if (!file)
		goto write;

	if (fstat(fileno(file), &st) < 0)
		goto close_write;

	if (st.st_size != b->pos)
		goto close_write;

	tmp = NOFAIL(malloc(b->pos));
	if (fread(tmp, 1, b->pos, file) != b->pos)
		goto free_write;

	if (memcmp(tmp, b->p, b->pos) != 0)
		goto free_write;

	free(tmp);
	fclose(file);
	return;

 free_write:
	free(tmp);
 close_write:
	fclose(file);
 write:
	file = fopen(fname, "w");
	if (!file) {
		perror(fname);
		exit(1);
	}
	if (fwrite(b->p, 1, b->pos, file) != b->pos) {
		perror(fname);
		exit(1);
	}
	fclose(file);
}

1850
/* parse Module.symvers file. line format:
S
Sam Ravnborg 已提交
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 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1852
 **/
1853
static void read_dump(const char *fname, unsigned int kernel)
L
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{
	unsigned long size, pos = 0;
	void *file = grab_file(fname, &size);
	char *line;

S
Sam Ravnborg 已提交
1859
	if (!file)
L
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		/* No symbol versions, silently ignore */
		return;

	while ((line = get_next_line(&pos, file, size))) {
S
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1864
		char *symname, *modname, *d, *export, *end;
L
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1865 1866
		unsigned int crc;
		struct module *mod;
1867
		struct symbol *s;
L
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		if (!(symname = strchr(line, '\t')))
			goto fail;
		*symname++ = '\0';
		if (!(modname = strchr(symname, '\t')))
			goto fail;
		*modname++ = '\0';
1875
		if ((export = strchr(modname, '\t')) != NULL)
1876
			*export++ = '\0';
S
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1877 1878
		if (export && ((end = strchr(export, '\t')) != NULL))
			*end = '\0';
L
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		crc = strtoul(line, &d, 16);
		if (*symname == '\0' || *modname == '\0' || *d != '\0')
			goto fail;
S
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1882 1883 1884
		mod = find_module(modname);
		if (!mod) {
			if (is_vmlinux(modname))
L
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				have_vmlinux = 1;
			mod = new_module(NOFAIL(strdup(modname)));
			mod->skip = 1;
		}
1889
		s = sym_add_exported(symname, mod, export_no(export));
1890 1891
		s->kernel    = kernel;
		s->preloaded = 1;
1892
		sym_update_crc(symname, mod, crc, export_no(export));
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1893 1894 1895 1896 1897 1898
	}
	return;
fail:
	fatal("parse error in symbol dump file\n");
}

1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910
/* For normal builds always dump all symbols.
 * For external modules only dump symbols
 * that are not read from kernel Module.symvers.
 **/
static int dump_sym(struct symbol *sym)
{
	if (!external_module)
		return 1;
	if (sym->vmlinux || sym->kernel)
		return 0;
	return 1;
}
1911

1912
static void write_dump(const char *fname)
L
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{
	struct buffer buf = { };
	struct symbol *symbol;
	int n;

	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
		symbol = symbolhash[n];
		while (symbol) {
1921
			if (dump_sym(symbol))
1922
				buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1923
					symbol->crc, symbol->name,
1924 1925
					symbol->module->name,
					export_str(symbol->export));
L
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			symbol = symbol->next;
		}
	}
	write_if_changed(&buf, fname);
}

1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017
static void add_marker(struct module *mod, const char *name, const char *fmt)
{
	char *line = NULL;
	asprintf(&line, "%s\t%s\t%s\n", name, mod->name, fmt);
	NOFAIL(line);

	mod->markers = NOFAIL(realloc(mod->markers, ((mod->nmarkers + 1) *
						     sizeof mod->markers[0])));
	mod->markers[mod->nmarkers++] = line;
}

static void read_markers(const char *fname)
{
	unsigned long size, pos = 0;
	void *file = grab_file(fname, &size);
	char *line;

	if (!file)		/* No old markers, silently ignore */
		return;

	while ((line = get_next_line(&pos, file, size))) {
		char *marker, *modname, *fmt;
		struct module *mod;

		marker = line;
		modname = strchr(marker, '\t');
		if (!modname)
			goto fail;
		*modname++ = '\0';
		fmt = strchr(modname, '\t');
		if (!fmt)
			goto fail;
		*fmt++ = '\0';
		if (*marker == '\0' || *modname == '\0')
			goto fail;

		mod = find_module(modname);
		if (!mod) {
			if (is_vmlinux(modname))
				have_vmlinux = 1;
			mod = new_module(NOFAIL(strdup(modname)));
			mod->skip = 1;
		}

		add_marker(mod, marker, fmt);
	}
	return;
fail:
	fatal("parse error in markers list file\n");
}

static int compare_strings(const void *a, const void *b)
{
	return strcmp(*(const char **) a, *(const char **) b);
}

static void write_markers(const char *fname)
{
	struct buffer buf = { };
	struct module *mod;
	size_t i;

	for (mod = modules; mod; mod = mod->next)
		if ((!external_module || !mod->skip) && mod->markers != NULL) {
			/*
			 * Sort the strings so we can skip duplicates when
			 * we write them out.
			 */
			qsort(mod->markers, mod->nmarkers,
			      sizeof mod->markers[0], &compare_strings);
			for (i = 0; i < mod->nmarkers; ++i) {
				char *line = mod->markers[i];
				buf_write(&buf, line, strlen(line));
				while (i + 1 < mod->nmarkers &&
				       !strcmp(mod->markers[i],
					       mod->markers[i + 1]))
					free(mod->markers[i++]);
				free(mod->markers[i]);
			}
			free(mod->markers);
			mod->markers = NULL;
		}

	write_if_changed(&buf, fname);
}

2018
int main(int argc, char **argv)
L
Linus Torvalds 已提交
2019 2020 2021
{
	struct module *mod;
	struct buffer buf = { };
2022 2023
	char *kernel_read = NULL, *module_read = NULL;
	char *dump_write = NULL;
2024 2025
	char *markers_read = NULL;
	char *markers_write = NULL;
L
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2026
	int opt;
2027
	int err;
L
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2028

2029
	while ((opt = getopt(argc, argv, "i:I:msSo:awM:K:")) != -1) {
S
Sam Ravnborg 已提交
2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049
		switch (opt) {
		case 'i':
			kernel_read = optarg;
			break;
		case 'I':
			module_read = optarg;
			external_module = 1;
			break;
		case 'm':
			modversions = 1;
			break;
		case 'o':
			dump_write = optarg;
			break;
		case 'a':
			all_versions = 1;
			break;
		case 's':
			vmlinux_section_warnings = 0;
			break;
2050 2051 2052
		case 'S':
			sec_mismatch_verbose = 0;
			break;
S
Sam Ravnborg 已提交
2053 2054 2055
		case 'w':
			warn_unresolved = 1;
			break;
2056 2057 2058 2059 2060 2061
			case 'M':
				markers_write = optarg;
				break;
			case 'K':
				markers_read = optarg;
				break;
S
Sam Ravnborg 已提交
2062 2063
		default:
			exit(1);
L
Linus Torvalds 已提交
2064 2065 2066
		}
	}

2067 2068 2069 2070
	if (kernel_read)
		read_dump(kernel_read, 1);
	if (module_read)
		read_dump(module_read, 0);
L
Linus Torvalds 已提交
2071

S
Sam Ravnborg 已提交
2072
	while (optind < argc)
L
Linus Torvalds 已提交
2073 2074
		read_symbols(argv[optind++]);

2075 2076 2077
	for (mod = modules; mod; mod = mod->next) {
		if (mod->skip)
			continue;
2078
		check_exports(mod);
2079 2080
	}

2081 2082
	err = 0;

L
Linus Torvalds 已提交
2083
	for (mod = modules; mod; mod = mod->next) {
2084 2085
		char fname[strlen(mod->name) + 10];

L
Linus Torvalds 已提交
2086 2087 2088 2089 2090 2091
		if (mod->skip)
			continue;

		buf.pos = 0;

		add_header(&buf, mod);
2092
		err |= add_versions(&buf, mod);
L
Linus Torvalds 已提交
2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
		add_depends(&buf, mod, modules);
		add_moddevtable(&buf, mod);
		add_srcversion(&buf, mod);

		sprintf(fname, "%s.mod.c", mod->name);
		write_if_changed(&buf, fname);
	}

	if (dump_write)
		write_dump(dump_write);
2103
	if (sec_mismatch_count && !sec_mismatch_verbose)
2104 2105 2106 2107
		warn("modpost: Found %d section mismatch(es).\n"
		     "To see full details build your kernel with:\n"
		     "'make CONFIG_DEBUG_SECTION_MISMATCH=y'\n",
		     sec_mismatch_count);
L
Linus Torvalds 已提交
2108

2109 2110 2111 2112 2113 2114
	if (markers_read)
		read_markers(markers_read);

	if (markers_write)
		write_markers(markers_write);

2115
	return err;
L
Linus Torvalds 已提交
2116
}