X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=scripts%2Fmod%2Fmodpost.c;h=d0f86ed43f7a17156953d889df8cfa00f6013b04;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=9b9f94c915d234365c14444872c5ea5e1163bd6d;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 9b9f94c91..d0f86ed43 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2,7 +2,7 @@
  *
  * Copyright 2003       Kai Germaschewski
  * Copyright 2002-2004  Rusty Russell, IBM Corporation
- *
+ * Copyright 2006       Sam Ravnborg
  * Based in part on module-init-tools/depmod.c,file2alias
  *
  * This software may be used and distributed according to the terms
@@ -20,9 +20,10 @@ int modversions = 0;
 int have_vmlinux = 0;
 /* Is CONFIG_MODULE_SRCVERSION_ALL set? */
 static int all_versions = 0;
+/* If we are modposting external module set to 1 */
+static int external_module = 0;
 
-void
-fatal(const char *fmt, ...)
+void fatal(const char *fmt, ...)
 {
 	va_list arglist;
 
@@ -35,8 +36,7 @@ fatal(const char *fmt, ...)
 	exit(1);
 }
 
-void
-warn(const char *fmt, ...)
+void warn(const char *fmt, ...)
 {
 	va_list arglist;
 
@@ -47,6 +47,18 @@ warn(const char *fmt, ...)
 	va_end(arglist);
 }
 
+static int is_vmlinux(const char *modname)
+{
+	const char *myname;
+
+	if ((myname = strrchr(modname, '/')))
+		myname++;
+	else
+		myname = modname;
+
+	return strcmp(myname, "vmlinux") == 0;
+}
+
 void *do_nofail(void *ptr, const char *expr)
 {
 	if (!ptr) {
@@ -59,8 +71,7 @@ void *do_nofail(void *ptr, const char *expr)
 
 static struct module *modules;
 
-struct module *
-find_module(char *modname)
+static struct module *find_module(char *modname)
 {
 	struct module *mod;
 
@@ -70,12 +81,11 @@ find_module(char *modname)
 	return mod;
 }
 
-struct module *
-new_module(char *modname)
+static struct module *new_module(char *modname)
 {
 	struct module *mod;
 	char *p, *s;
-	
+
 	mod = NOFAIL(malloc(sizeof(*mod)));
 	memset(mod, 0, sizeof(*mod));
 	p = NOFAIL(strdup(modname));
@@ -104,6 +114,10 @@ struct symbol {
 	unsigned int crc;
 	int crc_valid;
 	unsigned int weak:1;
+	unsigned int vmlinux:1;    /* 1 if symbol is defined in vmlinux */
+	unsigned int kernel:1;     /* 1 if symbol is from kernel
+				    *  (only for external modules) **/
+	unsigned int preloaded:1;  /* 1 if symbol from Module.symvers */
 	char name[0];
 };
 
@@ -122,11 +136,12 @@ static inline unsigned int tdb_hash(const char *name)
 	return (1103515243 * value + 12345);
 }
 
-/* Allocate a new symbols for use in the hash of exported symbols or
- * the list of unresolved symbols per module */
-
-struct symbol *
-alloc_symbol(const char *name, unsigned int weak, struct symbol *next)
+/**
+ * Allocate a new symbols for use in the hash of exported symbols or
+ * the list of unresolved symbols per module
+ **/
+static struct symbol *alloc_symbol(const char *name, unsigned int weak,
+				   struct symbol *next)
 {
 	struct symbol *s = NOFAIL(malloc(sizeof(*s) + strlen(name) + 1));
 
@@ -138,9 +153,7 @@ alloc_symbol(const char *name, unsigned int weak, struct symbol *next)
 }
 
 /* For the hash of exported symbols */
-
-void
-new_symbol(const char *name, struct module *module, unsigned int *crc)
+static struct symbol *new_symbol(const char *name, struct module *module)
 {
 	unsigned int hash;
 	struct symbol *new;
@@ -148,14 +161,10 @@ new_symbol(const char *name, struct module *module, unsigned int *crc)
 	hash = tdb_hash(name) % SYMBOL_HASH_SIZE;
 	new = symbolhash[hash] = alloc_symbol(name, 0, symbolhash[hash]);
 	new->module = module;
-	if (crc) {
-		new->crc = *crc;
-		new->crc_valid = 1;
-	}
+	return new;
 }
 
-struct symbol *
-find_symbol(const char *name)
+static struct symbol *find_symbol(const char *name)
 {
 	struct symbol *s;
 
@@ -170,25 +179,42 @@ find_symbol(const char *name)
 	return NULL;
 }
 
-/* Add an exported symbol - it may have already been added without a
- * CRC, in this case just update the CRC */
-void
-add_exported_symbol(const char *name, struct module *module, unsigned int *crc)
+/**
+ * Add an exported symbol - it may have already been added without a
+ * CRC, in this case just update the CRC
+ **/
+static struct symbol *sym_add_exported(const char *name, struct module *mod)
 {
 	struct symbol *s = find_symbol(name);
 
 	if (!s) {
-		new_symbol(name, module, crc);
-		return;
-	}
-	if (crc) {
-		s->crc = *crc;
-		s->crc_valid = 1;
+		s = new_symbol(name, mod);
+	} else {
+		if (!s->preloaded) {
+			warn("%s: '%s' exported twice. Previous export "
+			     "was in %s%s\n", mod->name, name,
+			     s->module->name,
+			     is_vmlinux(s->module->name) ?"":".ko");
+		}
 	}
+	s->preloaded = 0;
+	s->vmlinux   = is_vmlinux(mod->name);
+	s->kernel    = 0;
+	return s;
 }
 
-void *
-grab_file(const char *filename, unsigned long *size)
+static void sym_update_crc(const char *name, struct module *mod,
+			   unsigned int crc)
+{
+	struct symbol *s = find_symbol(name);
+
+	if (!s)
+		s = new_symbol(name, mod);
+	s->crc = crc;
+	s->crc_valid = 1;
+}
+
+void *grab_file(const char *filename, unsigned long *size)
 {
 	struct stat st;
 	void *map;
@@ -207,13 +233,12 @@ grab_file(const char *filename, unsigned long *size)
 	return map;
 }
 
-/*
-   Return a copy of the next line in a mmap'ed file.
-   spaces in the beginning of the line is trimmed away.
-   Return a pointer to a static buffer.
-*/
-char*
-get_next_line(unsigned long *pos, void *file, unsigned long size)
+/**
+  * Return a copy of the next line in a mmap'ed file.
+  * spaces in the beginning of the line is trimmed away.
+  * Return a pointer to a static buffer.
+  **/
+char* get_next_line(unsigned long *pos, void *file, unsigned long size)
 {
 	static char line[4096];
 	int skip = 1;
@@ -243,14 +268,12 @@ get_next_line(unsigned long *pos, void *file, unsigned long size)
 	return NULL;
 }
 
-void
-release_file(void *file, unsigned long size)
+void release_file(void *file, unsigned long size)
 {
 	munmap(file, size);
 }
 
-void
-parse_elf(struct elf_info *info, const char *filename)
+static void parse_elf(struct elf_info *info, const char *filename)
 {
 	unsigned int i;
 	Elf_Ehdr *hdr = info->hdr;
@@ -297,14 +320,13 @@ parse_elf(struct elf_info *info, const char *filename)
 			continue;
 
 		info->symtab_start = (void *)hdr + sechdrs[i].sh_offset;
-		info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset 
+		info->symtab_stop  = (void *)hdr + sechdrs[i].sh_offset
 			                         + sechdrs[i].sh_size;
-		info->strtab       = (void *)hdr + 
+		info->strtab       = (void *)hdr +
 			             sechdrs[sechdrs[i].sh_link].sh_offset;
 	}
 	if (!info->symtab_start) {
-		fprintf(stderr, "modpost: %s no symtab?\n", filename);
-		abort();
+		fatal("%s has no symtab?\n", filename);
 	}
 	/* Fix endianness in symbols */
 	for (sym = info->symtab_start; sym < info->symtab_stop; sym++) {
@@ -316,12 +338,10 @@ parse_elf(struct elf_info *info, const char *filename)
 	return;
 
  truncated:
-	fprintf(stderr, "modpost: %s is truncated.\n", filename);
-	abort();
+	fatal("%s is truncated.\n", filename);
 }
 
-void
-parse_elf_finish(struct elf_info *info)
+static void parse_elf_finish(struct elf_info *info)
 {
 	release_file(info->hdr, info->size);
 }
@@ -329,23 +349,20 @@ parse_elf_finish(struct elf_info *info)
 #define CRC_PFX     MODULE_SYMBOL_PREFIX "__crc_"
 #define KSYMTAB_PFX MODULE_SYMBOL_PREFIX "__ksymtab_"
 
-void
-handle_modversions(struct module *mod, struct elf_info *info,
-		   Elf_Sym *sym, const char *symname)
+static void handle_modversions(struct module *mod, struct elf_info *info,
+			       Elf_Sym *sym, const char *symname)
 {
 	unsigned int crc;
 
 	switch (sym->st_shndx) {
 	case SHN_COMMON:
-		fprintf(stderr, "*** Warning: \"%s\" [%s] is COMMON symbol\n",
-			symname, mod->name);
+		warn("\"%s\" [%s] is COMMON symbol\n", symname, mod->name);
 		break;
 	case SHN_ABS:
 		/* CRC'd symbol */
 		if (memcmp(symname, CRC_PFX, strlen(CRC_PFX)) == 0) {
 			crc = (unsigned int) sym->st_value;
-			add_exported_symbol(symname + strlen(CRC_PFX),
-					    mod, &crc);
+			sym_update_crc(symname + strlen(CRC_PFX), mod, crc);
 		}
 		break;
 	case SHN_UNDEF:
@@ -359,15 +376,26 @@ handle_modversions(struct module *mod, struct elf_info *info,
 		/* ignore __this_module, it will be resolved shortly */
 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "__this_module") == 0)
 			break;
-#ifdef STT_REGISTER
+/* cope with newer glibc (2.3.4 or higher) STT_ definition in elf.h */
+#if defined(STT_REGISTER) || defined(STT_SPARC_REGISTER)
+/* add compatibility with older glibc */
+#ifndef STT_SPARC_REGISTER
+#define STT_SPARC_REGISTER STT_REGISTER
+#endif
 		if (info->hdr->e_machine == EM_SPARC ||
 		    info->hdr->e_machine == EM_SPARCV9) {
 			/* Ignore register directives. */
-			if (ELF_ST_TYPE(sym->st_info) == STT_REGISTER)
+			if (ELF_ST_TYPE(sym->st_info) == STT_SPARC_REGISTER)
 				break;
+			if (symname[0] == '.') {
+				char *munged = strdup(symname);
+				munged[0] = '_';
+				munged[1] = toupper(munged[1]);
+				symname = munged;
+			}
 		}
 #endif
-		
+
 		if (memcmp(symname, MODULE_SYMBOL_PREFIX,
 			   strlen(MODULE_SYMBOL_PREFIX)) == 0)
 			mod->unres = alloc_symbol(symname +
@@ -378,8 +406,7 @@ handle_modversions(struct module *mod, struct elf_info *info,
 	default:
 		/* All exported symbols */
 		if (memcmp(symname, KSYMTAB_PFX, strlen(KSYMTAB_PFX)) == 0) {
-			add_exported_symbol(symname + strlen(KSYMTAB_PFX),
-					    mod, NULL);
+			sym_add_exported(symname + strlen(KSYMTAB_PFX), mod);
 		}
 		if (strcmp(symname, MODULE_SYMBOL_PREFIX "init_module") == 0)
 			mod->has_init = 1;
@@ -389,20 +416,9 @@ handle_modversions(struct module *mod, struct elf_info *info,
 	}
 }
 
-int
-is_vmlinux(const char *modname)
-{
-	const char *myname;
-
-	if ((myname = strrchr(modname, '/')))
-		myname++;
-	else
-		myname = modname;
-
-	return strcmp(myname, "vmlinux") == 0;
-}
-
-/* Parse tag=value strings from .modinfo section */
+/**
+ * Parse tag=value strings from .modinfo section
+ **/
 static char *next_string(char *string, unsigned long *secsize)
 {
 	/* Skip non-zero chars */
@@ -435,8 +451,473 @@ static char *get_modinfo(void *modinfo, unsigned long modinfo_len,
 	return NULL;
 }
 
-void
-read_symbols(char *modname)
+/**
+ * Test if string s ends in string sub
+ * return 0 if match
+ **/
+static int strrcmp(const char *s, const char *sub)
+{
+        int slen, sublen;
+
+	if (!s || !sub)
+		return 1;
+
+	slen = strlen(s);
+        sublen = strlen(sub);
+
+	if ((slen == 0) || (sublen == 0))
+		return 1;
+
+        if (sublen > slen)
+                return 1;
+
+        return memcmp(s + slen - sublen, sub, sublen);
+}
+
+/**
+ * Whitelist to allow certain references to pass with no warning.
+ * 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
+ *   fromsec = .data*
+ *   atsym   =__param*
+ *
+ * Pattern 2:
+ *   Many drivers utilise a *driver container with references to
+ *   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:
+ *   tosec   = .init.text | .exit.text | .init.data
+ *   fromsec = .data
+ *   atsym = *driver, *_template, *_sht, *_ops, *_probe, *probe_one
+ **/
+static int secref_whitelist(const char *tosec, const char *fromsec,
+			    const char *atsym)
+{
+	int f1 = 1, f2 = 1;
+	const char **s;
+	const char *pat2sym[] = {
+		"driver",
+		"_template", /* scsi uses *_template a lot */
+		"_sht",      /* scsi also used *_sht to some extent */
+		"_ops",
+		"_probe",
+		"_probe_one",
+		NULL
+	};
+
+	/* Check for pattern 1 */
+	if (strcmp(tosec, ".init.data") != 0)
+		f1 = 0;
+	if (strncmp(fromsec, ".data", strlen(".data")) != 0)
+		f1 = 0;
+	if (strncmp(atsym, "__param", strlen("__param")) != 0)
+		f1 = 0;
+
+	if (f1)
+		return f1;
+
+	/* Check for pattern 2 */
+	if ((strcmp(tosec, ".init.text") != 0) &&
+	    (strcmp(tosec, ".exit.text") != 0) &&
+	    (strcmp(tosec, ".init.data") != 0))
+		f2 = 0;
+	if (strcmp(fromsec, ".data") != 0)
+		f2 = 0;
+
+	for (s = pat2sym; *s; s++)
+		if (strrcmp(atsym, *s) == 0)
+			f1 = 1;
+
+	return f1 && f2;
+}
+
+/**
+ * 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.
+ *  **/
+static Elf_Sym *find_elf_symbol(struct elf_info *elf, Elf_Addr addr,
+				Elf_Sym *relsym)
+{
+	Elf_Sym *sym;
+
+	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;
+		if (sym->st_value == addr)
+			return sym;
+	}
+	return NULL;
+}
+
+/*
+ * 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.
+ **/
+static void find_symbols_between(struct elf_info *elf, Elf_Addr addr,
+				 const char *sec,
+			         Elf_Sym **before, Elf_Sym **after)
+{
+	Elf_Sym *sym;
+	Elf_Ehdr *hdr = elf->hdr;
+	Elf_Addr beforediff = ~0;
+	Elf_Addr afterdiff = ~0;
+	const char *secstrings = (void *)hdr +
+				 elf->sechdrs[hdr->e_shstrndx].sh_offset;
+
+	*before = NULL;
+	*after = NULL;
+
+	for (sym = elf->symtab_start; sym < elf->symtab_stop; sym++) {
+		const char *symsec;
+
+		if (sym->st_shndx >= SHN_LORESERVE)
+			continue;
+		symsec = secstrings + elf->sechdrs[sym->st_shndx].sh_name;
+		if (strcmp(symsec, sec) != 0)
+			continue;
+		if (sym->st_value <= addr) {
+			if ((addr - sym->st_value) < beforediff) {
+				beforediff = addr - sym->st_value;
+				*before = sym;
+			}
+			else if ((addr - sym->st_value) == beforediff) {
+				/* equal offset, valid name? */
+				const char *name = elf->strtab + sym->st_name;
+				if (name && strlen(name))
+					*before = sym;
+			}
+		}
+		else
+		{
+			if ((sym->st_value - addr) < afterdiff) {
+				afterdiff = sym->st_value - addr;
+				*after = sym;
+			}
+			else if ((sym->st_value - addr) == afterdiff) {
+				/* equal offset, valid name? */
+				const char *name = elf->strtab + sym->st_name;
+				if (name && strlen(name))
+					*after = sym;
+			}
+		}
+	}
+}
+
+/**
+ * Print a warning about a section mismatch.
+ * Try to find symbols near it so user can find it.
+ * Check whitelist before warning - it may be a false positive.
+ **/
+static void warn_sec_mismatch(const char *modname, const char *fromsec,
+			      struct elf_info *elf, Elf_Sym *sym, Elf_Rela r)
+{
+	const char *refsymname = "";
+	Elf_Sym *before, *after;
+	Elf_Sym *refsym;
+	Elf_Ehdr *hdr = elf->hdr;
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	const char *secstrings = (void *)hdr +
+				 sechdrs[hdr->e_shstrndx].sh_offset;
+	const char *secname = secstrings + sechdrs[sym->st_shndx].sh_name;
+
+	find_symbols_between(elf, r.r_offset, fromsec, &before, &after);
+
+	refsym = find_elf_symbol(elf, r.r_addend, sym);
+	if (refsym && strlen(elf->strtab + refsym->st_name))
+		refsymname = elf->strtab + refsym->st_name;
+
+	/* check whitelist - we may ignore it */
+	if (before &&
+	    secref_whitelist(secname, fromsec, elf->strtab + before->st_name))
+		return;
+
+	if (before && after) {
+		warn("%s - Section mismatch: reference to %s:%s from %s "
+		     "between '%s' (at offset 0x%llx) and '%s'\n",
+		     modname, secname, refsymname, fromsec,
+		     elf->strtab + before->st_name,
+		     (long long)r.r_offset,
+		     elf->strtab + after->st_name);
+	} else if (before) {
+		warn("%s - Section mismatch: reference to %s:%s from %s "
+		     "after '%s' (at offset 0x%llx)\n",
+		     modname, secname, refsymname, fromsec,
+		     elf->strtab + before->st_name,
+		     (long long)r.r_offset);
+	} else if (after) {
+		warn("%s - Section mismatch: reference to %s:%s from %s "
+		     "before '%s' (at offset -0x%llx)\n",
+		     modname, secname, refsymname, fromsec,
+		     elf->strtab + after->st_name,
+		     (long long)r.r_offset);
+	} else {
+		warn("%s - Section mismatch: reference to %s:%s from %s "
+		     "(offset 0x%llx)\n",
+		     modname, secname, fromsec, refsymname,
+		     (long long)r.r_offset);
+	}
+}
+
+/**
+ * A module includes a number of sections that are discarded
+ * either when loaded or when used as built-in.
+ * For loaded modules all functions marked __init and all data
+ * marked __initdata will be discarded when the module has been intialized.
+ * Likewise for modules used built-in the sections marked __exit
+ * are discarded because __exit marked function are supposed to be called
+ * only when a moduel is unloaded which never happes for built-in modules.
+ * The check_sec_ref() function traverses all relocation records
+ * to find all references to a section that reference a section that will
+ * be discarded and warns about it.
+ **/
+static void check_sec_ref(struct module *mod, const char *modname,
+			  struct elf_info *elf,
+			  int section(const char*),
+			  int section_ref_ok(const char *))
+{
+	int i;
+	Elf_Sym  *sym;
+	Elf_Ehdr *hdr = elf->hdr;
+	Elf_Shdr *sechdrs = elf->sechdrs;
+	const char *secstrings = (void *)hdr +
+				 sechdrs[hdr->e_shstrndx].sh_offset;
+
+	/* Walk through all sections */
+	for (i = 0; i < hdr->e_shnum; i++) {
+		const char *name = secstrings + sechdrs[i].sh_name;
+		const char *secname;
+		Elf_Rela r;
+		unsigned int r_sym;
+		/* We want to process only relocation sections and not .init */
+		if (sechdrs[i].sh_type == SHT_RELA) {
+			Elf_Rela *rela;
+			Elf_Rela *start = (void *)hdr + sechdrs[i].sh_offset;
+			Elf_Rela *stop  = (void*)start + sechdrs[i].sh_size;
+			name += strlen(".rela");
+			if (section_ref_ok(name))
+				continue;
+
+			for (rela = start; rela < stop; rela++) {
+				r.r_offset = TO_NATIVE(rela->r_offset);
+#if KERNEL_ELFCLASS == ELFCLASS64
+				if (hdr->e_machine == EM_MIPS) {
+					r_sym = ELF64_MIPS_R_SYM(rela->r_info);
+					r_sym = TO_NATIVE(r_sym);
+				} 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;
+
+				secname = secstrings +
+					sechdrs[sym->st_shndx].sh_name;
+				if (section(secname))
+					warn_sec_mismatch(modname, name,
+							  elf, sym, r);
+			}
+		} else if (sechdrs[i].sh_type == SHT_REL) {
+			Elf_Rel *rel;
+			Elf_Rel *start = (void *)hdr + sechdrs[i].sh_offset;
+			Elf_Rel *stop  = (void*)start + sechdrs[i].sh_size;
+			name += strlen(".rel");
+			if (section_ref_ok(name))
+				continue;
+
+			for (rel = start; rel < stop; rel++) {
+				r.r_offset = TO_NATIVE(rel->r_offset);
+#if KERNEL_ELFCLASS == ELFCLASS64
+				if (hdr->e_machine == EM_MIPS) {
+					r_sym = ELF64_MIPS_R_SYM(rel->r_info);
+					r_sym = TO_NATIVE(r_sym);
+				} 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;
+				sym = elf->symtab_start + r_sym;
+				/* Skip special sections */
+				if (sym->st_shndx >= SHN_LORESERVE)
+					continue;
+
+				secname = secstrings +
+					sechdrs[sym->st_shndx].sh_name;
+				if (section(secname))
+					warn_sec_mismatch(modname, name,
+							  elf, sym, r);
+			}
+		}
+	}
+}
+
+/**
+ * Functions used only during module init is marked __init and is stored in
+ * a .init.text section. Likewise data is marked __initdata and stored in
+ * a .init.data section.
+ * If this section is one of these sections return 1
+ * See include/linux/init.h for the details
+ **/
+static int init_section(const char *name)
+{
+	if (strcmp(name, ".init") == 0)
+		return 1;
+	if (strncmp(name, ".init.", strlen(".init.")) == 0)
+		return 1;
+	return 0;
+}
+
+/**
+ * Identify sections from which references to a .init section is OK.
+ *
+ * Unfortunately references to read only data that referenced .init
+ * sections had to be excluded. Almost all of these are false
+ * positives, they are created by gcc. The downside of excluding rodata
+ * is that there really are some user references from rodata to
+ * init code, e.g. drivers/video/vgacon.c:
+ *
+ * const struct consw vga_con = {
+ *        con_startup:            vgacon_startup,
+ *
+ * where vgacon_startup is __init.  If you want to wade through the false
+ * positives, take out the check for rodata.
+ **/
+static int init_section_ref_ok(const char *name)
+{
+	const char **s;
+	/* Absolute section names */
+	const char *namelist1[] = {
+		".init",
+		".opd",   /* see comment [OPD] at exit_section_ref_ok() */
+		".toc1",  /* used by ppc64 */
+		".stab",
+		".rodata",
+		".text.lock",
+		"__bug_table", /* used by powerpc for BUG() */
+		".pci_fixup_header",
+		".pci_fixup_final",
+		".pdr",
+		"__param",
+		NULL
+	};
+	/* Start of section names */
+	const char *namelist2[] = {
+		".init.",
+		".altinstructions",
+		".eh_frame",
+		".debug",
+		NULL
+	};
+	/* part of section name */
+	const char *namelist3 [] = {
+		".unwind",  /* sample: IA_64.unwind.init.text */
+		NULL
+	};
+
+	for (s = namelist1; *s; s++)
+		if (strcmp(*s, name) == 0)
+			return 1;
+	for (s = namelist2; *s; s++)
+		if (strncmp(*s, name, strlen(*s)) == 0)
+			return 1;
+	for (s = namelist3; *s; s++)
+		if (strstr(name, *s) != NULL)
+			return 1;
+	return 0;
+}
+
+/*
+ * Functions used only during module exit is marked __exit and is stored in
+ * a .exit.text section. Likewise data is marked __exitdata and stored in
+ * a .exit.data section.
+ * If this section is one of these sections return 1
+ * See include/linux/init.h for the details
+ **/
+static int exit_section(const char *name)
+{
+	if (strcmp(name, ".exit.text") == 0)
+		return 1;
+	if (strcmp(name, ".exit.data") == 0)
+		return 1;
+	return 0;
+
+}
+
+/*
+ * Identify sections from which references to a .exit section is OK.
+ *
+ * [OPD] Keith Ownes <kaos@sgi.com> commented:
+ * For our future {in}sanity, add a comment that this is the ppc .opd
+ * section, not the ia64 .opd section.
+ * ia64 .opd should not point to discarded sections.
+ * [.rodata] like for .init.text we ignore .rodata references -same reason
+ **/
+static int exit_section_ref_ok(const char *name)
+{
+	const char **s;
+	/* Absolute section names */
+	const char *namelist1[] = {
+		".exit.text",
+		".exit.data",
+		".init.text",
+		".rodata",
+		".opd", /* See comment [OPD] */
+		".toc1",  /* used by ppc64 */
+		".altinstructions",
+		".pdr",
+		"__bug_table", /* used by powerpc for BUG() */
+		".exitcall.exit",
+		".eh_frame",
+		".stab",
+		NULL
+	};
+	/* Start of section names */
+	const char *namelist2[] = {
+		".debug",
+		NULL
+	};
+	/* part of section name */
+	const char *namelist3 [] = {
+		".unwind",  /* Sample: IA_64.unwind.exit.text */
+		NULL
+	};
+
+	for (s = namelist1; *s; s++)
+		if (strcmp(*s, name) == 0)
+			return 1;
+	for (s = namelist2; *s; s++)
+		if (strncmp(*s, name, strlen(*s)) == 0)
+			return 1;
+	for (s = namelist3; *s; s++)
+		if (strstr(name, *s) != NULL)
+			return 1;
+	return 0;
+}
+
+static void read_symbols(char *modname)
 {
 	const char *symname;
 	char *version;
@@ -451,9 +932,7 @@ read_symbols(char *modname)
 	/* When there's no vmlinux, don't print warnings about
 	 * unresolved symbols (since there'll be too many ;) */
 	if (is_vmlinux(modname)) {
-		unsigned int fake_crc = 0;
 		have_vmlinux = 1;
-		add_exported_symbol("struct_module", mod, &fake_crc);
 		mod->skip = 1;
 	}
 
@@ -463,6 +942,8 @@ read_symbols(char *modname)
 		handle_modversions(mod, &info, sym, symname);
 		handle_moddevtable(mod, &info, sym, symname);
 	}
+	check_sec_ref(mod, modname, &info, init_section, init_section_ref_ok);
+	check_sec_ref(mod, modname, &info, exit_section, exit_section_ref_ok);
 
 	version = get_modinfo(info.modinfo, info.modinfo_len, "version");
 	if (version)
@@ -488,39 +969,33 @@ read_symbols(char *modname)
  * following helper, then compare to the file on disk and
  * only update the later if anything changed */
 
-void __attribute__((format(printf, 2, 3)))
-buf_printf(struct buffer *buf, const char *fmt, ...)
+void __attribute__((format(printf, 2, 3))) buf_printf(struct buffer *buf,
+						      const char *fmt, ...)
 {
 	char tmp[SZ];
 	int len;
 	va_list ap;
-	
+
 	va_start(ap, fmt);
 	len = vsnprintf(tmp, SZ, fmt, ap);
-	if (buf->size - buf->pos < len + 1) {
-		buf->size += 128;
-		buf->p = realloc(buf->p, buf->size);
-	}
-	strncpy(buf->p + buf->pos, tmp, len + 1);
-	buf->pos += len;
+	buf_write(buf, tmp, len);
 	va_end(ap);
 }
 
-void
-buf_write(struct buffer *buf, const char *s, int len)
+void buf_write(struct buffer *buf, const char *s, int len)
 {
 	if (buf->size - buf->pos < len) {
-		buf->size += len;
+		buf->size += len + SZ;
 		buf->p = realloc(buf->p, buf->size);
 	}
 	strncpy(buf->p + buf->pos, s, len);
 	buf->pos += len;
 }
 
-/* Header for the generated file */
-
-void
-add_header(struct buffer *b, struct module *mod)
+/**
+ * Header for the generated file
+ **/
+static void add_header(struct buffer *b, struct module *mod)
 {
 	buf_printf(b, "#include <linux/module.h>\n");
 	buf_printf(b, "#include <linux/vermagic.h>\n");
@@ -528,10 +1003,9 @@ add_header(struct buffer *b, struct module *mod)
 	buf_printf(b, "\n");
 	buf_printf(b, "MODULE_INFO(vermagic, VERMAGIC_STRING);\n");
 	buf_printf(b, "\n");
-	buf_printf(b, "#undef unix\n"); /* We have a module called "unix" */
 	buf_printf(b, "struct module __this_module\n");
 	buf_printf(b, "__attribute__((section(\".gnu.linkonce.this_module\"))) = {\n");
-	buf_printf(b, " .name = __stringify(KBUILD_MODNAME),\n");
+	buf_printf(b, " .name = KBUILD_MODNAME,\n");
 	if (mod->has_init)
 		buf_printf(b, " .init = init_module,\n");
 	if (mod->has_cleanup)
@@ -541,10 +1015,10 @@ add_header(struct buffer *b, struct module *mod)
 	buf_printf(b, "};\n");
 }
 
-/* Record CRCs for unresolved symbols */
-
-void
-add_versions(struct buffer *b, struct module *mod)
+/**
+ * Record CRCs for unresolved symbols
+ **/
+static void add_versions(struct buffer *b, struct module *mod)
 {
 	struct symbol *s, *exp;
 
@@ -552,8 +1026,8 @@ add_versions(struct buffer *b, struct module *mod)
 		exp = find_symbol(s->name);
 		if (!exp || exp->module == mod) {
 			if (have_vmlinux && !s->weak)
-				fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
-				"undefined!\n",	s->name, mod->name);
+				warn("\"%s\" [%s.ko] undefined!\n",
+				     s->name, mod->name);
 			continue;
 		}
 		s->module = exp->module;
@@ -574,8 +1048,7 @@ add_versions(struct buffer *b, struct module *mod)
 			continue;
 		}
 		if (!s->crc_valid) {
-			fprintf(stderr, "*** Warning: \"%s\" [%s.ko] "
-				"has no CRC!\n",
+			warn("\"%s\" [%s.ko] has no CRC!\n",
 				s->name, mod->name);
 			continue;
 		}
@@ -585,8 +1058,8 @@ add_versions(struct buffer *b, struct module *mod)
 	buf_printf(b, "};\n");
 }
 
-void
-add_depends(struct buffer *b, struct module *mod, struct module *modules)
+static void add_depends(struct buffer *b, struct module *mod,
+			struct module *modules)
 {
 	struct symbol *s;
 	struct module *m;
@@ -616,8 +1089,7 @@ add_depends(struct buffer *b, struct module *mod, struct module *modules)
 	buf_printf(b, "\";\n");
 }
 
-void
-add_srcversion(struct buffer *b, struct module *mod)
+static void add_srcversion(struct buffer *b, struct module *mod)
 {
 	if (mod->srcversion[0]) {
 		buf_printf(b, "\n");
@@ -626,8 +1098,7 @@ add_srcversion(struct buffer *b, struct module *mod)
 	}
 }
 
-void
-write_if_changed(struct buffer *b, const char *fname)
+static void write_if_changed(struct buffer *b, const char *fname)
 {
 	char *tmp;
 	FILE *file;
@@ -671,8 +1142,7 @@ write_if_changed(struct buffer *b, const char *fname)
 	fclose(file);
 }
 
-void
-read_dump(const char *fname)
+static void read_dump(const char *fname, unsigned int kernel)
 {
 	unsigned long size, pos = 0;
 	void *file = grab_file(fname, &size);
@@ -686,6 +1156,7 @@ read_dump(const char *fname)
 		char *symname, *modname, *d;
 		unsigned int crc;
 		struct module *mod;
+		struct symbol *s;
 
 		if (!(symname = strchr(line, '\t')))
 			goto fail;
@@ -706,15 +1177,30 @@ read_dump(const char *fname)
 			mod = new_module(NOFAIL(strdup(modname)));
 			mod->skip = 1;
 		}
-		add_exported_symbol(symname, mod, &crc);
+		s = sym_add_exported(symname, mod);
+		s->kernel    = kernel;
+		s->preloaded = 1;
+		sym_update_crc(symname, mod, crc);
 	}
 	return;
 fail:
 	fatal("parse error in symbol dump file\n");
 }
 
-void
-write_dump(const char *fname)
+/* 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;
+}
+
+static void write_dump(const char *fname)
 {
 	struct buffer buf = { };
 	struct symbol *symbol;
@@ -723,34 +1209,33 @@ write_dump(const char *fname)
 	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
 		symbol = symbolhash[n];
 		while (symbol) {
-			symbol = symbol->next;
-		}
-	}
-
-	for (n = 0; n < SYMBOL_HASH_SIZE ; n++) {
-		symbol = symbolhash[n];
-		while (symbol) {
-			buf_printf(&buf, "0x%08x\t%s\t%s\n", symbol->crc,
-				symbol->name, symbol->module->name);
+			if (dump_sym(symbol))
+				buf_printf(&buf, "0x%08x\t%s\t%s\n",
+					symbol->crc, symbol->name,
+					symbol->module->name);
 			symbol = symbol->next;
 		}
 	}
 	write_if_changed(&buf, fname);
 }
 
-int
-main(int argc, char **argv)
+int main(int argc, char **argv)
 {
 	struct module *mod;
 	struct buffer buf = { };
 	char fname[SZ];
-	char *dump_read = NULL, *dump_write = NULL;
+	char *kernel_read = NULL, *module_read = NULL;
+	char *dump_write = NULL;
 	int opt;
 
-	while ((opt = getopt(argc, argv, "i:mo:a")) != -1) {
+	while ((opt = getopt(argc, argv, "i:I:mo:a")) != -1) {
 		switch(opt) {
 			case 'i':
-				dump_read = optarg;
+				kernel_read = optarg;
+				break;
+			case 'I':
+				module_read = optarg;
+				external_module = 1;
 				break;
 			case 'm':
 				modversions = 1;
@@ -766,8 +1251,10 @@ main(int argc, char **argv)
 		}
 	}
 
-	if (dump_read)
-		read_dump(dump_read);
+	if (kernel_read)
+		read_dump(kernel_read, 1);
+	if (module_read)
+		read_dump(module_read, 0);
 
 	while (optind < argc) {
 		read_symbols(argv[optind++]);
@@ -794,4 +1281,3 @@ main(int argc, char **argv)
 
 	return 0;
 }
-