modpost.c 52.6 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/generated/autoconf.h"
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#include "../../include/linux/license.h"
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/* Some toolchains use a `_' prefix for all user symbols. */
#ifdef CONFIG_SYMBOL_PREFIX
#define MODULE_SYMBOL_PREFIX CONFIG_SYMBOL_PREFIX
#else
#define MODULE_SYMBOL_PREFIX ""
#endif


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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 */
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	hdr->e_type      = TO_NATIVE(hdr->e_type);
	hdr->e_machine   = TO_NATIVE(hdr->e_machine);
	hdr->e_version   = TO_NATIVE(hdr->e_version);
	hdr->e_entry     = TO_NATIVE(hdr->e_entry);
	hdr->e_phoff     = TO_NATIVE(hdr->e_phoff);
	hdr->e_shoff     = TO_NATIVE(hdr->e_shoff);
	hdr->e_flags     = TO_NATIVE(hdr->e_flags);
	hdr->e_ehsize    = TO_NATIVE(hdr->e_ehsize);
	hdr->e_phentsize = TO_NATIVE(hdr->e_phentsize);
	hdr->e_phnum     = TO_NATIVE(hdr->e_phnum);
	hdr->e_shentsize = TO_NATIVE(hdr->e_shentsize);
	hdr->e_shnum     = TO_NATIVE(hdr->e_shnum);
	hdr->e_shstrndx  = TO_NATIVE(hdr->e_shstrndx);
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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++) {
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		sechdrs[i].sh_name      = TO_NATIVE(sechdrs[i].sh_name);
		sechdrs[i].sh_type      = TO_NATIVE(sechdrs[i].sh_type);
		sechdrs[i].sh_flags     = TO_NATIVE(sechdrs[i].sh_flags);
		sechdrs[i].sh_addr      = TO_NATIVE(sechdrs[i].sh_addr);
		sechdrs[i].sh_offset    = TO_NATIVE(sechdrs[i].sh_offset);
		sechdrs[i].sh_size      = TO_NATIVE(sechdrs[i].sh_size);
		sechdrs[i].sh_link      = TO_NATIVE(sechdrs[i].sh_link);
		sechdrs[i].sh_info      = TO_NATIVE(sechdrs[i].sh_info);
		sechdrs[i].sh_addralign = TO_NATIVE(sechdrs[i].sh_addralign);
		sechdrs[i].sh_entsize   = TO_NATIVE(sechdrs[i].sh_entsize);
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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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		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 */
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		if (strncmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
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			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
557

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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 */
569
		if (strncmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
570 571
			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;
	}
}

581 582 583
/**
 * 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;
}

602 603
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;

609 610 611 612 613
	if (info) {
		size -= info - (char *)modinfo;
		modinfo = next_string(info, &size);
	}

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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;
}

621 622 623 624 625 626 627
static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
			 const char *tag)

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

628 629 630 631 632 633
/**
 * Test if string s ends in string sub
 * return 0 if match
 **/
static int strrcmp(const char *s, const char *sub)
{
S
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634
	int slen, sublen;
635

636 637
	if (!s || !sub)
		return 1;
638

639
	slen = strlen(s);
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	sublen = strlen(sub);
641

642 643 644
	if ((slen == 0) || (sublen == 0))
		return 1;

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	if (sublen > slen)
		return 1;
647

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	return memcmp(s + slen - sublen, sub, sublen);
649 650
}

651 652
static const char *sym_name(struct elf_info *elf, Elf_Sym *sym)
{
653 654 655
	if (sym)
		return elf->strtab + sym->st_name;
	else
656
		return "(unknown)";
657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673
}

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;
}

674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
/* 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"
694
 * "*foo" will match a string that ends with "foo"
695 696 697 698 699 700
 * "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.
 */
701
static int match(const char *sym, const char * const pat[])
702 703 704 705 706 707
{
	const char *p;
	while (*pat) {
		p = *pat++;
		const char *endp = p + strlen(p) - 1;

708 709 710 711 712
		/* "*foo" */
		if (*p == '*') {
			if (strrcmp(sym, p + 1) == 0)
				return 1;
		}
713
		/* "foo*" */
714
		else if (*endp == '*') {
715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736
			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[] =
737 738 739 740 741 742 743 744 745 746 747
{
	".comment*",
	".debug*",
	".mdebug*",        /* alpha, score, mips etc. */
	".pdr",            /* alpha, score, mips etc. */
	".stab*",
	".note*",
	".got*",
	".toc*",
	NULL
};
748

749
/*
750
 * This is used to find sections missing the SHF_ALLOC flag.
751
 * The cause of this is often a section specified in assembler
752
 * without "ax" / "aw".
753
 */
754 755
static void check_section(const char *modname, struct elf_info *elf,
                          Elf_Shdr *sechdr)
756
{
757 758 759 760 761 762 763 764 765 766
	const char *sec = sech_name(elf, sechdr);

	if (sechdr->sh_type == SHT_PROGBITS &&
	    !(sechdr->sh_flags & SHF_ALLOC) &&
	    !match(sec, section_white_list)) {
		warn("%s (%s): unexpected non-allocatable section.\n"
		     "Did you forget to use \"ax\"/\"aw\" in a .S file?\n"
		     "Note that for example <linux/init.h> contains\n"
		     "section definitions for use in .S files.\n\n",
		     modname, sec);
767 768 769 770 771
	}
}



772
#define ALL_INIT_DATA_SECTIONS \
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	".init.setup$", ".init.rodata$", \
	".devinit.rodata$", ".cpuinit.rodata$", ".meminit.rodata$" \
775 776 777
	".init.data$", ".devinit.data$", ".cpuinit.data$", ".meminit.data$"
#define ALL_EXIT_DATA_SECTIONS \
	".exit.data$", ".devexit.data$", ".cpuexit.data$", ".memexit.data$"
778

779 780 781 782
#define ALL_INIT_TEXT_SECTIONS \
	".init.text$", ".devinit.text$", ".cpuinit.text$", ".meminit.text$"
#define ALL_EXIT_TEXT_SECTIONS \
	".exit.text$", ".devexit.text$", ".cpuexit.text$", ".memexit.text$"
783

784 785 786 787 788 789 790
#define ALL_XXXINIT_SECTIONS DEV_INIT_SECTIONS, CPU_INIT_SECTIONS, \
	MEM_INIT_SECTIONS
#define ALL_XXXEXIT_SECTIONS DEV_EXIT_SECTIONS, CPU_EXIT_SECTIONS, \
	MEM_EXIT_SECTIONS

#define ALL_INIT_SECTIONS INIT_SECTIONS, ALL_XXXINIT_SECTIONS
#define ALL_EXIT_SECTIONS EXIT_SECTIONS, ALL_XXXEXIT_SECTIONS
791

792
#define DATA_SECTIONS ".data$", ".data.rel$"
793 794
#define TEXT_SECTIONS ".text$"

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795 796 797 798
#define INIT_SECTIONS      ".init.*"
#define DEV_INIT_SECTIONS  ".devinit.*"
#define CPU_INIT_SECTIONS  ".cpuinit.*"
#define MEM_INIT_SECTIONS  ".meminit.*"
799

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#define EXIT_SECTIONS      ".exit.*"
#define DEV_EXIT_SECTIONS  ".devexit.*"
#define CPU_EXIT_SECTIONS  ".cpuexit.*"
#define MEM_EXIT_SECTIONS  ".memexit.*"
804

805
/* init data sections */
806
static const char *init_data_sections[] = { ALL_INIT_DATA_SECTIONS, NULL };
807 808

/* all init sections */
809
static const char *init_sections[] = { ALL_INIT_SECTIONS, NULL };
810 811 812

/* All init and exit sections (code + data) */
static const char *init_exit_sections[] =
813
	{ALL_INIT_SECTIONS, ALL_EXIT_SECTIONS, NULL };
814 815 816 817 818 819

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


/* symbols in .data that may refer to init/exit sections */
820 821 822 823 824 825 826 827 828
#define DEFAULT_SYMBOL_WHITE_LIST					\
	"*driver",							\
	"*_template", /* scsi uses *_template a lot */			\
	"*_timer",    /* arm uses ops structures named _timer a lot */	\
	"*_sht",      /* scsi also used *_sht to some extent */		\
	"*_ops",							\
	"*_probe",							\
	"*_probe_one",							\
	"*_console"
829 830 831 832 833

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

834
enum mismatch {
835 836 837 838 839 840 841 842
	TEXT_TO_ANY_INIT,
	DATA_TO_ANY_INIT,
	TEXT_TO_ANY_EXIT,
	DATA_TO_ANY_EXIT,
	XXXINIT_TO_SOME_INIT,
	XXXEXIT_TO_SOME_EXIT,
	ANY_INIT_TO_ANY_EXIT,
	ANY_EXIT_TO_ANY_INIT,
843 844 845
	EXPORT_TO_INIT_EXIT,
};

846 847 848
struct sectioncheck {
	const char *fromsec[20];
	const char *tosec[20];
849
	enum mismatch mismatch;
850
	const char *symbol_white_list[20];
851 852 853 854 855 856 857
};

const struct sectioncheck sectioncheck[] = {
/* Do not reference init/exit code/data from
 * normal code and data
 */
{
858 859
	.fromsec = { TEXT_SECTIONS, NULL },
	.tosec   = { ALL_INIT_SECTIONS, NULL },
860
	.mismatch = TEXT_TO_ANY_INIT,
861
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
862 863 864
},
{
	.fromsec = { DATA_SECTIONS, NULL },
865
	.tosec   = { ALL_XXXINIT_SECTIONS, NULL },
866
	.mismatch = DATA_TO_ANY_INIT,
867
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
868
},
869 870 871 872 873 874 875 876 877
{
	.fromsec = { DATA_SECTIONS, NULL },
	.tosec   = { INIT_SECTIONS, NULL },
	.mismatch = DATA_TO_ANY_INIT,
	.symbol_white_list = {
		"*_template", "*_timer", "*_sht", "*_ops",
		"*_probe", "*_probe_one", "*_console", NULL
	},
},
878 879 880
{
	.fromsec = { TEXT_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
881
	.mismatch = TEXT_TO_ANY_EXIT,
882
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
883 884 885 886
},
{
	.fromsec = { DATA_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
887
	.mismatch = DATA_TO_ANY_EXIT,
888
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
889 890 891
},
/* Do not reference init code/data from devinit/cpuinit/meminit code/data */
{
892
	.fromsec = { ALL_XXXINIT_SECTIONS, NULL },
893
	.tosec   = { INIT_SECTIONS, NULL },
894
	.mismatch = XXXINIT_TO_SOME_INIT,
895
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
896
},
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/* Do not reference cpuinit code/data from meminit code/data */
{
	.fromsec = { MEM_INIT_SECTIONS, NULL },
	.tosec   = { CPU_INIT_SECTIONS, NULL },
901
	.mismatch = XXXINIT_TO_SOME_INIT,
902
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
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903 904 905 906 907
},
/* Do not reference meminit code/data from cpuinit code/data */
{
	.fromsec = { CPU_INIT_SECTIONS, NULL },
	.tosec   = { MEM_INIT_SECTIONS, NULL },
908
	.mismatch = XXXINIT_TO_SOME_INIT,
909
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
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910
},
911 912
/* Do not reference exit code/data from devexit/cpuexit/memexit code/data */
{
913
	.fromsec = { ALL_XXXEXIT_SECTIONS, NULL },
914
	.tosec   = { EXIT_SECTIONS, NULL },
915
	.mismatch = XXXEXIT_TO_SOME_EXIT,
916
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
917
},
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918 919 920 921
/* Do not reference cpuexit code/data from memexit code/data */
{
	.fromsec = { MEM_EXIT_SECTIONS, NULL },
	.tosec   = { CPU_EXIT_SECTIONS, NULL },
922
	.mismatch = XXXEXIT_TO_SOME_EXIT,
923
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
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924 925 926 927 928
},
/* Do not reference memexit code/data from cpuexit code/data */
{
	.fromsec = { CPU_EXIT_SECTIONS, NULL },
	.tosec   = { MEM_EXIT_SECTIONS, NULL },
929
	.mismatch = XXXEXIT_TO_SOME_EXIT,
930
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
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Jan Beulich 已提交
931
},
932 933
/* Do not use exit code/data from init code */
{
934 935
	.fromsec = { ALL_INIT_SECTIONS, NULL },
	.tosec   = { ALL_EXIT_SECTIONS, NULL },
936
	.mismatch = ANY_INIT_TO_ANY_EXIT,
937
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
938 939 940
},
/* Do not use init code/data from exit code */
{
941
	.fromsec = { ALL_EXIT_SECTIONS, NULL },
942
	.tosec   = { ALL_INIT_SECTIONS, NULL },
943
	.mismatch = ANY_EXIT_TO_ANY_INIT,
944
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
945 946 947 948
},
/* Do not export init/exit functions or data */
{
	.fromsec = { "__ksymtab*", NULL },
949
	.tosec   = { INIT_SECTIONS, EXIT_SECTIONS, NULL },
950 951
	.mismatch = EXPORT_TO_INIT_EXIT,
	.symbol_white_list = { DEFAULT_SYMBOL_WHITE_LIST, NULL },
952 953 954
}
};

955 956
static const struct sectioncheck *section_mismatch(
		const char *fromsec, const char *tosec)
957 958 959 960 961 962 963 964
{
	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))
965
			return check;
966 967
		check++;
	}
968
	return NULL;
969 970
}

971 972
/**
 * Whitelist to allow certain references to pass with no warning.
973
 *
974 975 976 977 978 979 980
 * 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
981
 *   fromsec = .data*
982
 *   atsym   =__param*
983
 *
984
 * Pattern 2:
985
 *   Many drivers utilise a *driver container with references to
986
 *   add, remove, probe functions etc.
987
 *   These functions may often be marked __devinit and we do not want to
988 989
 *   warn here.
 *   the pattern is identified by:
990 991
 *   tosec   = init or exit section
 *   fromsec = data section
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Sam Ravnborg 已提交
992 993
 *   atsym = *driver, *_template, *_sht, *_ops, *_probe,
 *           *probe_one, *_console, *_timer
994 995
 *
 * Pattern 3:
S
Sam Ravnborg 已提交
996
 *   Whitelist all references from .head.text to any init section
997
 *
998
 * Pattern 4:
999 1000 1001 1002 1003 1004 1005
 *   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
1006
 *
1007
 **/
1008 1009
static int secref_whitelist(const struct sectioncheck *mismatch,
			    const char *fromsec, const char *fromsym,
1010
			    const char *tosec, const char *tosym)
1011 1012
{
	/* Check for pattern 1 */
1013 1014
	if (match(tosec, init_data_sections) &&
	    match(fromsec, data_sections) &&
1015 1016
	    (strncmp(fromsym, "__param", strlen("__param")) == 0))
		return 0;
1017 1018

	/* Check for pattern 2 */
1019 1020
	if (match(tosec, init_exit_sections) &&
	    match(fromsec, data_sections) &&
1021
	    match(fromsym, mismatch->symbol_white_list))
1022
		return 0;
1023

1024
	/* Check for pattern 3 */
1025 1026
	if (match(fromsec, head_sections) &&
	    match(tosec, init_sections))
1027
		return 0;
1028

1029
	/* Check for pattern 4 */
1030 1031
	if (match(tosym, linker_symbols))
		return 0;
1032

1033
	return 1;
1034 1035
}

1036 1037 1038 1039 1040 1041 1042
/**
 * 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.
 *  **/
1043
static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf64_Sword addr,
1044 1045 1046
				Elf_Sym *relsym)
{
	Elf_Sym *sym;
1047 1048 1049
	Elf_Sym *near = NULL;
	Elf64_Sword distance = 20;
	Elf64_Sword d;
1050 1051 1052 1053 1054 1055

	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;
1056 1057
		if (ELF_ST_TYPE(sym->st_info) == STT_SECTION)
			continue;
1058 1059
		if (sym->st_value == addr)
			return sym;
1060 1061 1062 1063 1064 1065 1066 1067
		/* 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;
		}
1068
	}
1069 1070 1071 1072 1073
	/* We need a close match */
	if (distance < 20)
		return near;
	else
		return NULL;
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
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);
}

1100
/*
1101 1102 1103 1104
 * 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.
1105
 **/
1106 1107
static Elf_Sym *find_elf_symbol2(struct elf_info *elf, Elf_Addr addr,
				 const char *sec)
1108 1109
{
	Elf_Sym *sym;
1110 1111
	Elf_Sym *near = NULL;
	Elf_Addr distance = ~0;
1112

1113 1114 1115 1116 1117
	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
		const char *symsec;

		if (sym->st_shndx >= SHN_LORESERVE)
			continue;
1118
		symsec = sec_name(elf, sym->st_shndx);
1119 1120
		if (strcmp(symsec, sec) != 0)
			continue;
1121 1122
		if (!is_valid_name(elf, sym))
			continue;
1123
		if (sym->st_value <= addr) {
1124 1125 1126 1127 1128
			if ((addr - sym->st_value) < distance) {
				distance = addr - sym->st_value;
				near = sym;
			} else if ((addr - sym->st_value) == distance) {
				near = sym;
1129
			}
1130 1131
		}
	}
1132
	return near;
1133 1134
}

1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173
/*
 * 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
1174
		return -1;
1175 1176
}

1177
/*
1178 1179
 * Print a warning about a section mismatch.
 * Try to find symbols near it so user can find it.
1180
 * Check whitelist before warning - it may be a false positive.
1181
 */
1182 1183
static void report_sec_mismatch(const char *modname,
				const struct sectioncheck *mismatch,
1184 1185 1186
                                const char *fromsec,
                                unsigned long long fromaddr,
                                const char *fromsym,
1187 1188 1189 1190 1191 1192
                                int from_is_func,
                                const char *tosec, const char *tosym,
                                int to_is_func)
{
	const char *from, *from_p;
	const char *to, *to_p;
1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203

	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;
	}
1204

1205 1206 1207 1208
	sec_mismatch_count++;
	if (!sec_mismatch_verbose)
		return;

1209 1210 1211 1212
	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);
1213

1214
	switch (mismatch->mismatch) {
1215
	case TEXT_TO_ANY_INIT:
1216
		fprintf(stderr,
1217
		"The function %s%s() references\n"
1218 1219 1220 1221 1222 1223 1224
		"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;
1225
	case DATA_TO_ANY_INIT: {
1226
		const char *const *s = mismatch->symbol_white_list;
1227 1228 1229 1230
		fprintf(stderr,
		"The variable %s references\n"
		"the %s %s%s%s\n"
		"If the reference is valid then annotate the\n"
1231
		"variable with __init* or __refdata (see linux/init.h) "
1232 1233 1234 1235 1236 1237
		"or name the variable:\n",
		fromsym, to, sec2annotation(tosec), tosym, to_p);
		while (*s)
			fprintf(stderr, "%s, ", *s++);
		fprintf(stderr, "\n");
		break;
1238
	}
1239
	case TEXT_TO_ANY_EXIT:
1240 1241 1242 1243 1244 1245
		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;
1246
	case DATA_TO_ANY_EXIT: {
1247
		const char *const *s = mismatch->symbol_white_list;
1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
		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;
	}
1260 1261
	case XXXINIT_TO_SOME_INIT:
	case XXXEXIT_TO_SOME_EXIT:
1262 1263 1264 1265 1266 1267 1268
		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,
1269
		tosym, fromsym, tosym);
1270
		break;
1271
	case ANY_INIT_TO_ANY_EXIT:
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
		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;
1284
	case ANY_EXIT_TO_ANY_INIT:
1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305
		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);
		break;
	}
	fprintf(stderr, "\n");
1306 1307 1308 1309 1310 1311
}

static void check_section_mismatch(const char *modname, struct elf_info *elf,
                                   Elf_Rela *r, Elf_Sym *sym, const char *fromsec)
{
	const char *tosec;
1312
	const struct sectioncheck *mismatch;
1313 1314

	tosec = sec_name(elf, sym->st_shndx);
1315
	mismatch = section_mismatch(fromsec, tosec);
1316
	if (mismatch) {
1317 1318
		Elf_Sym *to;
		Elf_Sym *from;
1319
		const char *tosym;
1320
		const char *fromsym;
1321

1322 1323 1324 1325
		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);
1326 1327

		/* check whitelist - we may ignore it */
1328 1329
		if (secref_whitelist(mismatch,
					fromsec, fromsym, tosec, tosym)) {
1330 1331 1332 1333
			report_sec_mismatch(modname, mismatch,
			   fromsec, r->r_offset, fromsym,
			   is_function(from), tosec, tosym,
			   is_function(to));
1334
		}
1335 1336 1337
	}
}

1338
static unsigned int *reloc_location(struct elf_info *elf,
1339
				    Elf_Shdr *sechdr, Elf_Rela *r)
1340 1341
{
	Elf_Shdr *sechdrs = elf->sechdrs;
1342
	int section = sechdr->sh_info;
1343 1344

	return (void *)elf->hdr + sechdrs[section].sh_offset +
K
Krzysztof Halasa 已提交
1345
		r->r_offset - sechdrs[section].sh_addr;
1346 1347
}

1348
static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1349 1350
{
	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1351
	unsigned int *location = reloc_location(elf, sechdr, r);
1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366

	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;
}

1367
static int addend_arm_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1368 1369 1370 1371 1372 1373
{
	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
1374 1375
		r->r_addend = (int)(long)
		              (elf->symtab_start + ELF_R_SYM(r->r_info));
1376 1377 1378
		break;
	case R_ARM_PC24:
		/* From ARM ABI: ((S + A) | T) - P */
S
Sam Ravnborg 已提交
1379
		r->r_addend = (int)(long)(elf->hdr +
1380 1381
		              sechdr->sh_offset +
		              (r->r_offset - sechdr->sh_addr));
1382 1383 1384 1385 1386 1387 1388
		break;
	default:
		return 1;
	}
	return 0;
}

1389
static int addend_mips_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
1390 1391
{
	unsigned int r_typ = ELF_R_TYPE(r->r_info);
1392
	unsigned int *location = reloc_location(elf, sechdr, r);
1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411
	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;
}

1412
static void section_rela(const char *modname, struct elf_info *elf,
1413
                         Elf_Shdr *sechdr)
1414 1415 1416 1417 1418 1419 1420
{
	Elf_Sym  *sym;
	Elf_Rela *rela;
	Elf_Rela r;
	unsigned int r_sym;
	const char *fromsec;

1421
	Elf_Rela *start = (void *)elf->hdr + sechdr->sh_offset;
1422 1423
	Elf_Rela *stop  = (void *)start + sechdr->sh_size;

1424
	fromsec = sech_name(elf, sechdr);
1425 1426
	fromsec += strlen(".rela");
	/* if from section (name) is know good then skip it */
1427
	if (match(fromsec, section_white_list))
1428
		return;
1429

1430 1431 1432
	for (rela = start; rela < stop; rela++) {
		r.r_offset = TO_NATIVE(rela->r_offset);
#if KERNEL_ELFCLASS == ELFCLASS64
1433
		if (elf->hdr->e_machine == EM_MIPS) {
1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451
			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;
1452
		check_section_mismatch(modname, elf, &r, sym, fromsec);
1453 1454 1455 1456
	}
}

static void section_rel(const char *modname, struct elf_info *elf,
1457
                        Elf_Shdr *sechdr)
1458 1459 1460 1461 1462 1463 1464
{
	Elf_Sym *sym;
	Elf_Rel *rel;
	Elf_Rela r;
	unsigned int r_sym;
	const char *fromsec;

1465
	Elf_Rel *start = (void *)elf->hdr + sechdr->sh_offset;
1466 1467
	Elf_Rel *stop  = (void *)start + sechdr->sh_size;

1468
	fromsec = sech_name(elf, sechdr);
1469 1470
	fromsec += strlen(".rel");
	/* if from section (name) is know good then skip it */
1471
	if (match(fromsec, section_white_list))
1472 1473 1474 1475 1476
		return;

	for (rel = start; rel < stop; rel++) {
		r.r_offset = TO_NATIVE(rel->r_offset);
#if KERNEL_ELFCLASS == ELFCLASS64
1477
		if (elf->hdr->e_machine == EM_MIPS) {
1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
			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;
1492
		switch (elf->hdr->e_machine) {
1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509
		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;
1510
		check_section_mismatch(modname, elf, &r, sym, fromsec);
1511 1512 1513
	}
}

1514 1515 1516 1517 1518 1519 1520
/**
 * 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
1521
 * only when a module is unloaded which never happens for built-in modules.
1522 1523 1524 1525 1526
 * 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,
1527
                          struct elf_info *elf)
1528 1529 1530
{
	int i;
	Elf_Shdr *sechdrs = elf->sechdrs;
1531

1532
	/* Walk through all sections */
1533
	for (i = 0; i < elf->hdr->e_shnum; i++) {
1534
		check_section(modname, elf, &elf->sechdrs[i]);
1535
		/* We want to process only relocation sections and not .init */
1536
		if (sechdrs[i].sh_type == SHT_RELA)
1537
			section_rela(modname, elf, &elf->sechdrs[i]);
1538
		else if (sechdrs[i].sh_type == SHT_REL)
1539
			section_rel(modname, elf, &elf->sechdrs[i]);
1540 1541 1542
	}
}

1543
static void read_symbols(char *modname)
L
Linus Torvalds 已提交
1544 1545 1546
{
	const char *symname;
	char *version;
1547
	char *license;
L
Linus Torvalds 已提交
1548 1549 1550 1551
	struct module *mod;
	struct elf_info info = { };
	Elf_Sym *sym;

1552 1553
	if (!parse_elf(&info, modname))
		return;
L
Linus Torvalds 已提交
1554 1555 1556 1557 1558 1559 1560 1561 1562 1563

	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;
	}

1564
	license = get_modinfo(info.modinfo, info.modinfo_len, "license");
1565 1566 1567 1568
	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);
1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579
	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
1580 1581 1582 1583 1584 1585
	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);
	}
1586
	if (!is_vmlinux(modname) ||
1587 1588
	     (is_vmlinux(modname) && vmlinux_section_warnings))
		check_sec_ref(mod, modname, &info);
L
Linus Torvalds 已提交
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599

	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);

	parse_elf_finish(&info);

1600
	/* Our trick to get versioning for module struct etc. - it's
L
Linus Torvalds 已提交
1601 1602 1603 1604
	 * 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)
1605
		mod->unres = alloc_symbol("module_layout", 0, mod->unres);
L
Linus Torvalds 已提交
1606 1607 1608 1609 1610 1611 1612 1613
}

#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 */

1614 1615
void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
						      const char *fmt, ...)
L
Linus Torvalds 已提交
1616 1617 1618 1619
{
	char tmp[SZ];
	int len;
	va_list ap;
1620

L
Linus Torvalds 已提交
1621 1622
	va_start(ap, fmt);
	len = vsnprintf(tmp, SZ, fmt, ap);
1623
	buf_write(buf, tmp, len);
L
Linus Torvalds 已提交
1624 1625 1626
	va_end(ap);
}

1627
void buf_write(struct buffer *buf, const char *s, int len)
L
Linus Torvalds 已提交
1628 1629
{
	if (buf->size - buf->pos < len) {
1630
		buf->size += len + SZ;
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636
		buf->p = realloc(buf->p, buf->size);
	}
	strncpy(buf->p + buf->pos, s, len);
	buf->pos += len;
}

1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661
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
1662
static void check_for_unused(enum export exp, const char *m, const char *s)
1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678
{
	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)
1679 1680 1681 1682
{
	struct symbol *s, *exp;

	for (s = mod->unres; s; s = s->next) {
A
Andrew Morton 已提交
1683
		const char *basename;
1684 1685 1686
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod)
			continue;
A
Andrew Morton 已提交
1687
		basename = strrchr(mod->name, '/');
1688 1689
		if (basename)
			basename++;
1690 1691 1692 1693 1694
		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
1695
	}
1696 1697
}

1698 1699 1700 1701
/**
 * Header for the generated file
 **/
static void add_header(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1702 1703 1704 1705 1706 1707 1708 1709 1710
{
	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");
1711
	buf_printf(b, " .name = KBUILD_MODNAME,\n");
L
Linus Torvalds 已提交
1712 1713 1714 1715 1716 1717
	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");
1718
	buf_printf(b, " .arch = MODULE_ARCH_INIT,\n");
L
Linus Torvalds 已提交
1719 1720 1721
	buf_printf(b, "};\n");
}

1722
static void add_staging_flag(struct buffer *b, const char *name)
1723 1724 1725 1726 1727 1728 1729
{
	static const char *staging_dir = "drivers/staging";

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

1730 1731 1732
/**
 * Record CRCs for unresolved symbols
 **/
1733
static int add_versions(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1734 1735
{
	struct symbol *s, *exp;
1736
	int err = 0;
L
Linus Torvalds 已提交
1737 1738 1739 1740

	for (s = mod->unres; s; s = s->next) {
		exp = find_symbol(s->name);
		if (!exp || exp->module == mod) {
1741
			if (have_vmlinux && !s->weak) {
1742 1743 1744 1745 1746 1747 1748 1749
				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;
				}
1750
			}
L
Linus Torvalds 已提交
1751 1752 1753 1754 1755 1756 1757 1758
			continue;
		}
		s->module = exp->module;
		s->crc_valid = exp->crc_valid;
		s->crc = exp->crc;
	}

	if (!modversions)
1759
		return err;
L
Linus Torvalds 已提交
1760 1761 1762

	buf_printf(b, "\n");
	buf_printf(b, "static const struct modversion_info ____versions[]\n");
A
Adrian Bunk 已提交
1763
	buf_printf(b, "__used\n");
L
Linus Torvalds 已提交
1764 1765 1766
	buf_printf(b, "__attribute__((section(\"__versions\"))) = {\n");

	for (s = mod->unres; s; s = s->next) {
S
Sam Ravnborg 已提交
1767
		if (!s->module)
L
Linus Torvalds 已提交
1768 1769
			continue;
		if (!s->crc_valid) {
1770
			warn("\"%s\" [%s.ko] has no CRC!\n",
L
Linus Torvalds 已提交
1771 1772 1773 1774 1775 1776 1777
				s->name, mod->name);
			continue;
		}
		buf_printf(b, "\t{ %#8x, \"%s\" },\n", s->crc, s->name);
	}

	buf_printf(b, "};\n");
1778 1779

	return err;
L
Linus Torvalds 已提交
1780 1781
}

1782 1783
static void add_depends(struct buffer *b, struct module *mod,
			struct module *modules)
L
Linus Torvalds 已提交
1784 1785 1786 1787 1788
{
	struct symbol *s;
	struct module *m;
	int first = 1;

S
Sam Ravnborg 已提交
1789
	for (m = modules; m; m = m->next)
L
Linus Torvalds 已提交
1790 1791 1792 1793
		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
1794
	buf_printf(b, "__used\n");
L
Linus Torvalds 已提交
1795 1796 1797
	buf_printf(b, "__attribute__((section(\".modinfo\"))) =\n");
	buf_printf(b, "\"depends=");
	for (s = mod->unres; s; s = s->next) {
1798
		const char *p;
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803 1804 1805
		if (!s->module)
			continue;

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

		s->module->seen = 1;
S
Sam Ravnborg 已提交
1806 1807
		p = strrchr(s->module->name, '/');
		if (p)
1808 1809 1810 1811
			p++;
		else
			p = s->module->name;
		buf_printf(b, "%s%s", first ? "" : ",", p);
L
Linus Torvalds 已提交
1812 1813 1814 1815 1816
		first = 0;
	}
	buf_printf(b, "\";\n");
}

1817
static void add_srcversion(struct buffer *b, struct module *mod)
L
Linus Torvalds 已提交
1818 1819 1820 1821 1822 1823 1824 1825
{
	if (mod->srcversion[0]) {
		buf_printf(b, "\n");
		buf_printf(b, "MODULE_INFO(srcversion, \"%s\");\n",
			   mod->srcversion);
	}
}

1826
static void write_if_changed(struct buffer *b, const char *fname)
L
Linus Torvalds 已提交
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 1862 1863 1864 1865 1866 1867 1868 1869
{
	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);
}

1870
/* parse Module.symvers file. line format:
S
Sam Ravnborg 已提交
1871
 * 0x12345678<tab>symbol<tab>module[[<tab>export]<tab>something]
1872
 **/
1873
static void read_dump(const char *fname, unsigned int kernel)
L
Linus Torvalds 已提交
1874 1875 1876 1877 1878
{
	unsigned long size, pos = 0;
	void *file = grab_file(fname, &size);
	char *line;

S
Sam Ravnborg 已提交
1879
	if (!file)
L
Linus Torvalds 已提交
1880 1881 1882 1883
		/* No symbol versions, silently ignore */
		return;

	while ((line = get_next_line(&pos, file, size))) {
S
Sam Ravnborg 已提交
1884
		char *symname, *modname, *d, *export, *end;
L
Linus Torvalds 已提交
1885 1886
		unsigned int crc;
		struct module *mod;
1887
		struct symbol *s;
L
Linus Torvalds 已提交
1888 1889 1890 1891 1892 1893 1894

		if (!(symname = strchr(line, '\t')))
			goto fail;
		*symname++ = '\0';
		if (!(modname = strchr(symname, '\t')))
			goto fail;
		*modname++ = '\0';
1895
		if ((export = strchr(modname, '\t')) != NULL)
1896
			*export++ = '\0';
S
Sam Ravnborg 已提交
1897 1898
		if (export && ((end = strchr(export, '\t')) != NULL))
			*end = '\0';
L
Linus Torvalds 已提交
1899 1900 1901
		crc = strtoul(line, &d, 16);
		if (*symname == '\0' || *modname == '\0' || *d != '\0')
			goto fail;
S
Sam Ravnborg 已提交
1902 1903 1904
		mod = find_module(modname);
		if (!mod) {
			if (is_vmlinux(modname))
L
Linus Torvalds 已提交
1905
				have_vmlinux = 1;
1906
			mod = new_module(modname);
L
Linus Torvalds 已提交
1907 1908
			mod->skip = 1;
		}
1909
		s = sym_add_exported(symname, mod, export_no(export));
1910 1911
		s->kernel    = kernel;
		s->preloaded = 1;
1912
		sym_update_crc(symname, mod, crc, export_no(export));
L
Linus Torvalds 已提交
1913 1914 1915 1916 1917 1918
	}
	return;
fail:
	fatal("parse error in symbol dump file\n");
}

1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930
/* 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;
}
1931

1932
static void write_dump(const char *fname)
L
Linus Torvalds 已提交
1933 1934 1935 1936 1937 1938 1939 1940
{
	struct buffer buf = { };
	struct symbol *symbol;
	int n;

	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
		symbol = symbolhash[n];
		while (symbol) {
1941
			if (dump_sym(symbol))
1942
				buf_printf(&buf, "0x%08x\t%s\t%s\t%s\n",
1943
					symbol->crc, symbol->name,
1944 1945
					symbol->module->name,
					export_str(symbol->export));
L
Linus Torvalds 已提交
1946 1947 1948 1949 1950 1951
			symbol = symbol->next;
		}
	}
	write_if_changed(&buf, fname);
}

1952 1953 1954 1955 1956
struct ext_sym_list {
	struct ext_sym_list *next;
	const char *file;
};

1957
int main(int argc, char **argv)
L
Linus Torvalds 已提交
1958 1959 1960
{
	struct module *mod;
	struct buffer buf = { };
1961 1962
	char *kernel_read = NULL, *module_read = NULL;
	char *dump_write = NULL;
L
Linus Torvalds 已提交
1963
	int opt;
1964
	int err;
1965 1966
	struct ext_sym_list *extsym_iter;
	struct ext_sym_list *extsym_start = NULL;
L
Linus Torvalds 已提交
1967

1968
	while ((opt = getopt(argc, argv, "i:I:e:cmsSo:awM:K:")) != -1) {
S
Sam Ravnborg 已提交
1969 1970 1971 1972 1973 1974 1975 1976
		switch (opt) {
		case 'i':
			kernel_read = optarg;
			break;
		case 'I':
			module_read = optarg;
			external_module = 1;
			break;
1977 1978 1979
		case 'c':
			cross_build = 1;
			break;
1980 1981 1982 1983 1984 1985 1986 1987
		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
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
		case 'm':
			modversions = 1;
			break;
		case 'o':
			dump_write = optarg;
			break;
		case 'a':
			all_versions = 1;
			break;
		case 's':
			vmlinux_section_warnings = 0;
			break;
2000 2001 2002
		case 'S':
			sec_mismatch_verbose = 0;
			break;
S
Sam Ravnborg 已提交
2003 2004 2005 2006 2007
		case 'w':
			warn_unresolved = 1;
			break;
		default:
			exit(1);
L
Linus Torvalds 已提交
2008 2009 2010
		}
	}

2011 2012 2013 2014
	if (kernel_read)
		read_dump(kernel_read, 1);
	if (module_read)
		read_dump(module_read, 0);
2015 2016 2017 2018 2019 2020
	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
2021

S
Sam Ravnborg 已提交
2022
	while (optind < argc)
L
Linus Torvalds 已提交
2023 2024
		read_symbols(argv[optind++]);

2025 2026 2027
	for (mod = modules; mod; mod = mod->next) {
		if (mod->skip)
			continue;
2028
		check_exports(mod);
2029 2030
	}

2031 2032
	err = 0;

L
Linus Torvalds 已提交
2033
	for (mod = modules; mod; mod = mod->next) {
2034 2035
		char fname[strlen(mod->name) + 10];

L
Linus Torvalds 已提交
2036 2037 2038 2039 2040 2041
		if (mod->skip)
			continue;

		buf.pos = 0;

		add_header(&buf, mod);
2042
		add_staging_flag(&buf, mod->name);
2043
		err |= add_versions(&buf, mod);
L
Linus Torvalds 已提交
2044 2045 2046 2047 2048 2049 2050 2051 2052 2053
		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);
2054
	if (sec_mismatch_count && !sec_mismatch_verbose)
2055 2056 2057 2058
		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
2059

2060
	return err;
L
Linus Torvalds 已提交
2061
}