modpost.c 54.1 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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		int nobits = sechdrs[i].sh_type == SHT_NOBITS;
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		if (!nobits && 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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			if (nobits)
				fatal("%s has NOBITS .modinfo\n", filename);
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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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static int ignore_undef_symbol(struct elf_info *info, const char *symname)
{
	/* ignore __this_module, it will be resolved shortly */
	if (strcmp(symname, MODULE_SYMBOL_PREFIX "__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;
	/* Do not ignore this symbol */
	return 0;
}

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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;
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		if (ignore_undef_symbol(info, symname))
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			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;
	}
}

563 564 565
/**
 * Parse tag=value strings from .modinfo section
 **/
L
Linus Torvalds 已提交
566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583
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;
}

584 585
static char *get_next_modinfo(void *modinfo, unsigned long modinfo_len,
			      const char *tag, char *info)
L
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586 587 588 589 590
{
	char *p;
	unsigned int taglen = strlen(tag);
	unsigned long size = modinfo_len;

591 592 593 594 595
	if (info) {
		size -= info - (char *)modinfo;
		modinfo = next_string(info, &size);
	}

L
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	for (p = modinfo; p; p = next_string(p, &size)) {
		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
			return p + taglen + 1;
	}
	return NULL;
}

603 604 605 606 607 608 609
static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
			 const char *tag)

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

610 611 612 613 614 615
/**
 * 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
616
	int slen, sublen;
617

618 619
	if (!s || !sub)
		return 1;
620

621
	slen = strlen(s);
S
Sam Ravnborg 已提交
622
	sublen = strlen(sub);
623

624 625 626
	if ((slen == 0) || (sublen == 0))
		return 1;

S
Sam Ravnborg 已提交
627 628
	if (sublen > slen)
		return 1;
629

S
Sam Ravnborg 已提交
630
	return memcmp(s + slen - sublen, sub, sublen);
631 632
}

633 634
static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
{
635 636 637
	if (sym)
		return elf->strtab + sym->st_name;
	else
638
		return "(unknown)";
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
}

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;
}

656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675
/* 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"
676
 * "*foo" will match a string that ends with "foo"
677 678 679 680 681 682 683 684 685 686 687 688 689
 * "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;

690 691 692 693 694
		/* "*foo" */
		if (*p == '*') {
			if (strrcmp(sym, p + 1) == 0)
				return 1;
		}
695
		/* "foo*" */
696
		else if (*endp == '*') {
697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720
			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 };

721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741
/*
 * 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--;
742
		if (*e == '.' && !strstr(sec, ".linkonce")) {
743 744 745 746 747 748 749 750 751 752 753 754 755 756 757
			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;
}



758 759 760 761
#define ALL_INIT_DATA_SECTIONS \
	".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
#define ALL_EXIT_DATA_SECTIONS \
	".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
762

763 764 765 766
#define ALL_INIT_TEXT_SECTIONS \
	".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
#define ALL_EXIT_TEXT_SECTIONS \
	".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
767

768 769
#define ALL_INIT_SECTIONS ALL_INIT_DATA_SECTIONS, ALL_INIT_TEXT_SECTIONS
#define ALL_EXIT_SECTIONS ALL_EXIT_DATA_SECTIONS, ALL_EXIT_TEXT_SECTIONS
770

771
#define DATA_SECTIONS ".data$", ".data.rel$"
772 773
#define TEXT_SECTIONS ".text$"

774 775 776 777 778 779 780 781 782 783
#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$", ".memexit.text$"

784
/* init data sections */
785
static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
786 787

/* all init sections */
788
static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
789 790 791

/* All init and exit sections (code + data) */
static const char *init_exit_sections[] =
792
	{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815

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

816 817 818 819 820 821 822 823 824 825 826 827 828
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,
};

829 830 831
struct sectioncheck {
	const char *fromsec[20];
	const char *tosec[20];
832
	enum mismatch mismatch;
833 834 835 836 837 838 839
};

const struct sectioncheck sectioncheck[] = {
/* Do not reference init/exit code/data from
 * normal code and data
 */
{
840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857
	.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,
858 859 860 861
},
/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
{
	.fromsec = { DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, MEM_INIT_SECTIONS, NULL },
862 863
	.tosec   = { INIT_SECTIONS, NULL },
	.mismatch = XXXINIT_TO_INIT,
864 865 866 867
},
/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
{
	.fromsec = { DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, MEM_EXIT_SECTIONS, NULL },
868 869
	.tosec   = { EXIT_SECTIONS, NULL },
	.mismatch = XXXEXIT_TO_EXIT,
870 871 872
},
/* Do not use exit code/data from init code */
{
873 874
	.fromsec = { ALL_INIT_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
875
	.mismatch = INIT_TO_EXIT,
876 877 878
},
/* Do not use init code/data from exit code */
{
879
	.fromsec = { ALL_EXIT_SECTIONS, NULL },
880 881
	.tosec   = { ALL_INIT_SECTIONS, NULL },
	.mismatch = EXIT_TO_INIT,
882 883 884 885
},
/* Do not export init/exit functions or data */
{
	.fromsec = { "__ksymtab*", NULL },
886
	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
887
	.mismatch = EXPORT_TO_INIT_EXIT
888 889 890 891 892 893 894 895 896 897 898 899
}
};

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))
900
			return check->mismatch;
901 902
		check++;
	}
903
	return NO_MISMATCH;
904 905
}

906 907
/**
 * Whitelist to allow certain references to pass with no warning.
908
 *
909 910 911 912 913 914 915
 * 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
916
 *   fromsec = .data*
917
 *   atsym   =__param*
918
 *
919
 * Pattern 2:
920
 *   Many drivers utilise a *driver container with references to
921 922 923 924
 *   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:
925 926
 *   tosec   = init or exit section
 *   fromsec = data section
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Sam Ravnborg 已提交
927 928
 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
 *           *probe_one, *_console, *_timer
929 930
 *
 * Pattern 3:
931 932 933
 *   Whitelist all refereces from .text.head to .init.data
 *   Whitelist all refereces from .text.head to .init.text
 *
934
 * Pattern 4:
935 936 937 938 939 940 941
 *   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
942
 *
943
 **/
944 945
static int secref_whitelist(const char *fromsec, const char *fromsym,
			    const char *tosec, const char *tosym)
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
/**
 * 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
1456
 * only when a module is unloaded which never happens for built-in modules.
1457 1458 1459 1460 1461
 * 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
	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1555 1556 1557 1558
	if (info.modinfo && !license && !is_vmlinux(modname))
		warn("modpost: missing MODULE_LICENSE() in %s\n"
		     "see include/linux/module.h for "
		     "more information\n", modname);
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569
	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
1570 1571 1572 1573 1574 1575
	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);
	}
1576
	if (!is_vmlinux(modname) ||
1577 1578
	     (is_vmlinux(modname) && vmlinux_section_warnings))
		check_sec_ref(mod, modname, &info);
L
Linus Torvalds 已提交
1579 1580 1581 1582 1583 1584 1585 1586 1587

	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);

1588 1589
	get_markers(&info, mod);

L
Linus Torvalds 已提交
1590 1591
	parse_elf_finish(&info);

1592
	/* Our trick to get versioning for module struct etc. - it's
L
Linus Torvalds 已提交
1593 1594 1595 1596
	 * 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)
1597
		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
L
Linus Torvalds 已提交
1598 1599 1600 1601 1602 1603 1604 1605
}

#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 */

1606 1607
void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
						      const char *fmt, ...)
L
Linus Torvalds 已提交
1608 1609 1610 1611
{
	char tmp[SZ];
	int len;
	va_list ap;
1612

L
Linus Torvalds 已提交
1613 1614
	va_start(ap, fmt);
	len = vsnprintf(tmp, SZ, fmt, ap);
1615
	buf_write(buf, tmp, len);
L
Linus Torvalds 已提交
1616 1617 1618
	va_end(ap);
}

1619
void buf_write(struct buffer *buf, const char *s, int len)
L
Linus Torvalds 已提交
1620 1621
{
	if (buf->size - buf->pos < len) {
1622
		buf->size += len + SZ;
L
Linus Torvalds 已提交
1623 1624 1625 1626 1627 1628
		buf->p = realloc(buf->p, buf->size);
	}
	strncpy(buf->p + buf->pos, s, len);
	buf->pos += len;
}

1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653
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
1654
static void check_for_unused(enum export exp, const char *m, const char *s)
1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670
{
	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)
1671 1672 1673 1674
{
	struct symbol *s, *exp;

	for (s = mod->unres; s; s = s->next) {
A
Andrew Morton 已提交
1675
		const char *basename;
1676 1677 1678
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod)
			continue;
A
Andrew Morton 已提交
1679
		basename = strrchr(mod->name, '/');
1680 1681
		if (basename)
			basename++;
1682 1683 1684 1685 1686
		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
1687
	}
1688 1689
}

1690 1691 1692 1693
/**
 * Header for the generated file
 **/
static void add_header(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1694 1695 1696 1697 1698 1699 1700 1701 1702
{
	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");
1703
	buf_printf(b, " .name = KBUILD_MODNAME,\n");
L
Linus Torvalds 已提交
1704 1705 1706 1707 1708 1709
	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");
1710
	buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
L
Linus Torvalds 已提交
1711 1712 1713
	buf_printf(b, "};\n");
}

1714 1715 1716 1717 1718 1719 1720 1721
void add_staging_flag(struct buffer *b, const char *name)
{
	static const char *staging_dir = "drivers/staging";

	if (strncmp(staging_dir, name, strlen(staging_dir)) == 0)
		buf_printf(b, "\nMODULE_INFO(staging, \"Y\");\n");
}

1722 1723 1724
/**
 * Record CRCs for unresolved symbols
 **/
1725
static int add_versions(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1726 1727
{
	struct symbol *s, *exp;
1728
	int err = 0;
L
Linus Torvalds 已提交
1729 1730 1731 1732

	for (s = mod->unres; s; s = s->next) {
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod) {
1733
			if (have_vmlinux && !s->weak) {
1734 1735 1736 1737 1738 1739 1740 1741
				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;
				}
1742
			}
L
Linus Torvalds 已提交
1743 1744 1745 1746 1747 1748 1749 1750
			continue;
		}
		s->module = exp->module;
		s->crc_valid = exp->crc_valid;
		s->crc = exp->crc;
	}

	if (!modversions)
1751
		return err;
L
Linus Torvalds 已提交
1752 1753 1754

	buf_printf(b, "\n");
	buf_printf(b, "static const struct modversion_info ____versions[]\n");
A
Adrian Bunk 已提交
1755
	buf_printf(b, "__used\n");
L
Linus Torvalds 已提交
1756 1757 1758
	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");

	for (s = mod->unres; s; s = s->next) {
S
Sam Ravnborg 已提交
1759
		if (!s->module)
L
Linus Torvalds 已提交
1760 1761
			continue;
		if (!s->crc_valid) {
1762
			warn("\"%s\" [%s.ko] has no CRC!\n",
L
Linus Torvalds 已提交
1763 1764 1765 1766 1767 1768 1769
				s->name, mod->name);
			continue;
		}
		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
	}

	buf_printf(b, "};\n");
1770 1771

	return err;
L
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1772 1773
}

1774 1775
static void add_depends(struct buffer *b, struct module *mod,
			struct module *modules)
L
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1776 1777 1778 1779 1780
{
	struct symbol *s;
	struct module *m;
	int first = 1;

S
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1781
	for (m = modules; m; m = m->next)
L
Linus Torvalds 已提交
1782 1783 1784 1785
		m->seen = is_vmlinux(m->name);

	buf_printf(b, "\n");
	buf_printf(b, "static const char __module_depends[]\n");
A
Adrian Bunk 已提交
1786
	buf_printf(b, "__used\n");
L
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1787 1788 1789
	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
	buf_printf(b, "\"depends=");
	for (s = mod->unres; s; s = s->next) {
1790
		const char *p;
L
Linus Torvalds 已提交
1791 1792 1793 1794 1795 1796 1797
		if (!s->module)
			continue;

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

		s->module->seen = 1;
S
Sam Ravnborg 已提交
1798 1799
		p = strrchr(s->module->name, '/');
		if (p)
1800 1801 1802 1803
			p++;
		else
			p = s->module->name;
		buf_printf(b, "%s%s", first ? "" : ",", p);
L
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1804 1805 1806 1807 1808
		first = 0;
	}
	buf_printf(b, "\";\n");
}

1809
static void add_srcversion(struct buffer *b, struct module *mod)
L
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1810 1811 1812 1813 1814 1815 1816 1817
{
	if (mod->srcversion[0]) {
		buf_printf(b, "\n");
		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
			   mod->srcversion);
	}
}

1818
static void write_if_changed(struct buffer *b, const char *fname)
L
Linus Torvalds 已提交
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 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861
{
	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);
}

1862
/* 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]
1864
 **/
1865
static void read_dump(const char *fname, unsigned int kernel)
L
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1866 1867 1868 1869 1870
{
	unsigned long size, pos = 0;
	void *file = grab_file(fname, &size);
	char *line;

S
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1871
	if (!file)
L
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1872 1873 1874 1875
		/* No symbol versions, silently ignore */
		return;

	while ((line = get_next_line(&pos, file, size))) {
S
Sam Ravnborg 已提交
1876
		char *symname, *modname, *d, *export, *end;
L
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1877 1878
		unsigned int crc;
		struct module *mod;
1879
		struct symbol *s;
L
Linus Torvalds 已提交
1880 1881 1882 1883 1884 1885 1886

		if (!(symname = strchr(line, '\t')))
			goto fail;
		*symname++ = '\0';
		if (!(modname = strchr(symname, '\t')))
			goto fail;
		*modname++ = '\0';
1887
		if ((export = strchr(modname, '\t')) != NULL)
1888
			*export++ = '\0';
S
Sam Ravnborg 已提交
1889 1890
		if (export && ((end = strchr(export, '\t')) != NULL))
			*end = '\0';
L
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1891 1892 1893
		crc = strtoul(line, &d, 16);
		if (*symname == '\0' || *modname == '\0' || *d != '\0')
			goto fail;
S
Sam Ravnborg 已提交
1894 1895 1896
		mod = find_module(modname);
		if (!mod) {
			if (is_vmlinux(modname))
L
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1897
				have_vmlinux = 1;
1898
			mod = new_module(modname);
L
Linus Torvalds 已提交
1899 1900
			mod->skip = 1;
		}
1901
		s = sym_add_exported(symname, mod, export_no(export));
1902 1903
		s->kernel    = kernel;
		s->preloaded = 1;
1904
		sym_update_crc(symname, mod, crc, export_no(export));
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909 1910
	}
	return;
fail:
	fatal("parse error in symbol dump file\n");
}

1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922
/* 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;
}
1923

1924
static void write_dump(const char *fname)
L
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1925 1926 1927 1928 1929 1930 1931 1932
{
	struct buffer buf = { };
	struct symbol *symbol;
	int n;

	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
		symbol = symbolhash[n];
		while (symbol) {
1933
			if (dump_sym(symbol))
1934
				buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1935
					symbol->crc, symbol->name,
1936 1937
					symbol->module->name,
					export_str(symbol->export));
L
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1938 1939 1940 1941 1942 1943
			symbol = symbol->next;
		}
	}
	write_if_changed(&buf, fname);
}

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
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) {
1982
			mod = new_module(modname);
1983 1984
			mod->skip = 1;
		}
1985 1986 1987 1988
		if (is_vmlinux(modname)) {
			have_vmlinux = 1;
			mod->skip = 0;
		}
1989

1990 1991
		if (!mod->skip)
			add_marker(mod, marker, fmt);
1992
	}
1993
	release_file(file, size);
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033
	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);
}

2034 2035 2036 2037 2038
struct ext_sym_list {
	struct ext_sym_list *next;
	const char *file;
};

2039
int main(int argc, char **argv)
L
Linus Torvalds 已提交
2040 2041 2042
{
	struct module *mod;
	struct buffer buf = { };
2043 2044
	char *kernel_read = NULL, *module_read = NULL;
	char *dump_write = NULL;
2045 2046
	char *markers_read = NULL;
	char *markers_write = NULL;
L
Linus Torvalds 已提交
2047
	int opt;
2048
	int err;
2049 2050
	struct ext_sym_list *extsym_iter;
	struct ext_sym_list *extsym_start = NULL;
L
Linus Torvalds 已提交
2051

2052
	while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
S
Sam Ravnborg 已提交
2053 2054 2055 2056 2057 2058 2059 2060
		switch (opt) {
		case 'i':
			kernel_read = optarg;
			break;
		case 'I':
			module_read = optarg;
			external_module = 1;
			break;
2061 2062 2063
		case 'c':
			cross_build = 1;
			break;
2064 2065 2066 2067 2068 2069 2070 2071
		case 'e':
			external_module = 1;
			extsym_iter =
			   NOFAIL(malloc(sizeof(*extsym_iter)));
			extsym_iter->next = extsym_start;
			extsym_iter->file = optarg;
			extsym_start = extsym_iter;
			break;
S
Sam Ravnborg 已提交
2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083
		case 'm':
			modversions = 1;
			break;
		case 'o':
			dump_write = optarg;
			break;
		case 'a':
			all_versions = 1;
			break;
		case 's':
			vmlinux_section_warnings = 0;
			break;
2084 2085 2086
		case 'S':
			sec_mismatch_verbose = 0;
			break;
S
Sam Ravnborg 已提交
2087 2088 2089
		case 'w':
			warn_unresolved = 1;
			break;
2090 2091 2092 2093 2094 2095
			case 'M':
				markers_write = optarg;
				break;
			case 'K':
				markers_read = optarg;
				break;
S
Sam Ravnborg 已提交
2096 2097
		default:
			exit(1);
L
Linus Torvalds 已提交
2098 2099 2100
		}
	}

2101 2102 2103 2104
	if (kernel_read)
		read_dump(kernel_read, 1);
	if (module_read)
		read_dump(module_read, 0);
2105 2106 2107 2108 2109 2110
	while (extsym_start) {
		read_dump(extsym_start->file, 0);
		extsym_iter = extsym_start->next;
		free(extsym_start);
		extsym_start = extsym_iter;
	}
L
Linus Torvalds 已提交
2111

S
Sam Ravnborg 已提交
2112
	while (optind < argc)
L
Linus Torvalds 已提交
2113 2114
		read_symbols(argv[optind++]);

2115 2116 2117
	for (mod = modules; mod; mod = mod->next) {
		if (mod->skip)
			continue;
2118
		check_exports(mod);
2119 2120
	}

2121 2122
	err = 0;

L
Linus Torvalds 已提交
2123
	for (mod = modules; mod; mod = mod->next) {
2124 2125
		char fname[strlen(mod->name) + 10];

L
Linus Torvalds 已提交
2126 2127 2128 2129 2130 2131
		if (mod->skip)
			continue;

		buf.pos = 0;

		add_header(&buf, mod);
2132
		add_staging_flag(&buf, mod->name);
2133
		err |= add_versions(&buf, mod);
L
Linus Torvalds 已提交
2134 2135 2136 2137 2138 2139 2140 2141 2142 2143
		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);
2144
	if (sec_mismatch_count && !sec_mismatch_verbose)
2145 2146 2147 2148
		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
2149

2150 2151 2152 2153 2154 2155
	if (markers_read)
		read_markers(markers_read);

	if (markers_write)
		write_markers(markers_write);

2156
	return err;
L
Linus Torvalds 已提交
2157
}