Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  module: add MODULE_STATE_GOING notifier call
  module: Enhance verify_export_symbols
  module: set unused_gpl_crcs instead of overwriting unused_crcs
  module: neaten __find_symbol, rename to find_symbol
  module: reduce module image and resident size
  module: make module_sect_attrs private to kernel/module.c

1 files changed, 171 insertions, 148 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 8d6cccc6c3cf..8674a390a2e8 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -164,131 +164,140 @@ static const struct kernel_symbol *lookup_symbol(const char *name,
 	return NULL;
 }
 
-static void printk_unused_warning(const char *name)
+static bool always_ok(bool gplok, bool warn, const char *name)
 {
-	printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
-		"however this module is using it.\n", name);
-	printk(KERN_WARNING "This symbol will go away in the future.\n");
-	printk(KERN_WARNING "Please evalute if this is the right api to use, "
-		"and if it really is, submit a report the linux kernel "
-		"mailinglist together with submitting your code for "
-		"inclusion.\n");
+	return true;
 }
 
-/* Find a symbol, return value, crc and module which owns it */
-static unsigned long __find_symbol(const char *name,
-				   struct module **owner,
-				   const unsigned long **crc,
-				   int gplok)
+static bool printk_unused_warning(bool gplok, bool warn, const char *name)
 {
-	struct module *mod;
-	const struct kernel_symbol *ks;
-
-	/* Core kernel first. */
-	*owner = NULL;
-	ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab);
-	if (ks) {
-		*crc = symversion(__start___kcrctab, (ks - __start___ksymtab));
-		return ks->value;
+	if (warn) {
+		printk(KERN_WARNING "Symbol %s is marked as UNUSED, "
+		       "however this module is using it.\n", name);
+		printk(KERN_WARNING
+		       "This symbol will go away in the future.\n");
+		printk(KERN_WARNING
+		       "Please evalute if this is the right api to use and if "
+		       "it really is, submit a report the linux kernel "
+		       "mailinglist together with submitting your code for "
+		       "inclusion.\n");
 	}
-	if (gplok) {
-		ks = lookup_symbol(name, __start___ksymtab_gpl,
-					 __stop___ksymtab_gpl);
-		if (ks) {
-			*crc = symversion(__start___kcrctab_gpl,
-					  (ks - __start___ksymtab_gpl));
-			return ks->value;
-		}
-	}
-	ks = lookup_symbol(name, __start___ksymtab_gpl_future,
-				 __stop___ksymtab_gpl_future);
-	if (ks) {
-		if (!gplok) {
-			printk(KERN_WARNING "Symbol %s is being used "
-			       "by a non-GPL module, which will not "
-			       "be allowed in the future\n", name);
-			printk(KERN_WARNING "Please see the file "
-			       "Documentation/feature-removal-schedule.txt "
-			       "in the kernel source tree for more "
-			       "details.\n");
-		}
-		*crc = symversion(__start___kcrctab_gpl_future,
-				  (ks - __start___ksymtab_gpl_future));
-		return ks->value;
+	return true;
+}
+
+static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name)
+{
+	if (!gplok)
+		return false;
+	return printk_unused_warning(gplok, warn, name);
+}
+
+static bool gpl_only(bool gplok, bool warn, const char *name)
+{
+	return gplok;
+}
+
+static bool warn_if_not_gpl(bool gplok, bool warn, const char *name)
+{
+	if (!gplok && warn) {
+		printk(KERN_WARNING "Symbol %s is being used "
+		       "by a non-GPL module, which will not "
+		       "be allowed in the future\n", name);
+		printk(KERN_WARNING "Please see the file "
+		       "Documentation/feature-removal-schedule.txt "
+		       "in the kernel source tree for more details.\n");
 	}
+	return true;
+}
 
-	ks = lookup_symbol(name, __start___ksymtab_unused,
-				 __stop___ksymtab_unused);
-	if (ks) {
-		printk_unused_warning(name);
-		*crc = symversion(__start___kcrctab_unused,
-				  (ks - __start___ksymtab_unused));
-		return ks->value;
+struct symsearch {
+	const struct kernel_symbol *start, *stop;
+	const unsigned long *crcs;
+	bool (*check)(bool gplok, bool warn, const char *name);
+};
+
+/* Look through this array of symbol tables for a symbol match which
+ * passes the check function. */
+static const struct kernel_symbol *search_symarrays(const struct symsearch *arr,
+						    unsigned int num,
+						    const char *name,
+						    bool gplok,
+						    bool warn,
+						    const unsigned long **crc)
+{
+	unsigned int i;
+	const struct kernel_symbol *ks;
+
+	for (i = 0; i < num; i++) {
+		ks = lookup_symbol(name, arr[i].start, arr[i].stop);
+		if (!ks || !arr[i].check(gplok, warn, name))
+			continue;
+
+		if (crc)
+			*crc = symversion(arr[i].crcs, ks - arr[i].start);
+		return ks;
 	}
+	return NULL;
+}
+
+/* Find a symbol, return value, (optional) crc and (optional) module
+ * which owns it */
+static unsigned long find_symbol(const char *name,
+				 struct module **owner,
+				 const unsigned long **crc,
+				 bool gplok,
+				 bool warn)
+{
+	struct module *mod;
+	const struct kernel_symbol *ks;
+	const struct symsearch arr[] = {
+		{ __start___ksymtab, __stop___ksymtab, __start___kcrctab,
+		  always_ok },
+		{ __start___ksymtab_gpl, __stop___ksymtab_gpl,
+		  __start___kcrctab_gpl, gpl_only },
+		{ __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future,
+		  __start___kcrctab_gpl_future, warn_if_not_gpl },
+		{ __start___ksymtab_unused, __stop___ksymtab_unused,
+		  __start___kcrctab_unused, printk_unused_warning },
+		{ __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl,
+		  __start___kcrctab_unused_gpl, gpl_only_unused_warning },
+	};
 
-	if (gplok)
-		ks = lookup_symbol(name, __start___ksymtab_unused_gpl,
-				 __stop___ksymtab_unused_gpl);
+	/* Core kernel first. */
+	ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc);
 	if (ks) {
-		printk_unused_warning(name);
-		*crc = symversion(__start___kcrctab_unused_gpl,
-				  (ks - __start___ksymtab_unused_gpl));
+		if (owner)
+			*owner = NULL;
 		return ks->value;
 	}
 
 	/* Now try modules. */
 	list_for_each_entry(mod, &modules, list) {
-		*owner = mod;
-		ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms);
-		if (ks) {
-			*crc = symversion(mod->crcs, (ks - mod->syms));
-			return ks->value;
-		}
-
-		if (gplok) {
-			ks = lookup_symbol(name, mod->gpl_syms,
-					   mod->gpl_syms + mod->num_gpl_syms);
-			if (ks) {
-				*crc = symversion(mod->gpl_crcs,
-						  (ks - mod->gpl_syms));
-				return ks->value;
-			}
-		}
-		ks = lookup_symbol(name, mod->unused_syms, mod->unused_syms + mod->num_unused_syms);
+		struct symsearch arr[] = {
+			{ mod->syms, mod->syms + mod->num_syms, mod->crcs,
+			  always_ok },
+			{ mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms,
+			  mod->gpl_crcs, gpl_only },
+			{ mod->gpl_future_syms,
+			  mod->gpl_future_syms + mod->num_gpl_future_syms,
+			  mod->gpl_future_crcs, warn_if_not_gpl },
+			{ mod->unused_syms,
+			  mod->unused_syms + mod->num_unused_syms,
+			  mod->unused_crcs, printk_unused_warning },
+			{ mod->unused_gpl_syms,
+			  mod->unused_gpl_syms + mod->num_unused_gpl_syms,
+			  mod->unused_gpl_crcs, gpl_only_unused_warning },
+		};
+
+		ks = search_symarrays(arr, ARRAY_SIZE(arr),
+				      name, gplok, warn, crc);
 		if (ks) {
-			printk_unused_warning(name);
-			*crc = symversion(mod->unused_crcs, (ks - mod->unused_syms));
-			return ks->value;
-		}
-
-		if (gplok) {
-			ks = lookup_symbol(name, mod->unused_gpl_syms,
-					   mod->unused_gpl_syms + mod->num_unused_gpl_syms);
-			if (ks) {
-				printk_unused_warning(name);
-				*crc = symversion(mod->unused_gpl_crcs,
-						  (ks - mod->unused_gpl_syms));
-				return ks->value;
-			}
-		}
-		ks = lookup_symbol(name, mod->gpl_future_syms,
-				   (mod->gpl_future_syms +
-				    mod->num_gpl_future_syms));
-		if (ks) {
-			if (!gplok) {
-				printk(KERN_WARNING "Symbol %s is being used "
-				       "by a non-GPL module, which will not "
-				       "be allowed in the future\n", name);
-				printk(KERN_WARNING "Please see the file "
-				       "Documentation/feature-removal-schedule.txt "
-				       "in the kernel source tree for more "
-				       "details.\n");
-			}
-			*crc = symversion(mod->gpl_future_crcs,
-					  (ks - mod->gpl_future_syms));
+			if (owner)
+				*owner = mod;
 			return ks->value;
 		}
 	}
+
 	DEBUGP("Failed to find symbol %s\n", name);
 	return -ENOENT;
 }
@@ -736,12 +745,13 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
 	if (!forced && module_refcount(mod) != 0)
 		wait_for_zero_refcount(mod);
 
+	mutex_unlock(&module_mutex);
 	/* Final destruction now noone is using it. */
-	if (mod->exit != NULL) {
-		mutex_unlock(&module_mutex);
+	if (mod->exit != NULL)
 		mod->exit();
-		mutex_lock(&module_mutex);
-	}
+	blocking_notifier_call_chain(&module_notify_list,
+				     MODULE_STATE_GOING, mod);
+	mutex_lock(&module_mutex);
 	/* Store the name of the last unloaded module for diagnostic purposes */
 	strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
 	free_module(mod);
@@ -777,10 +787,9 @@ static void print_unload_info(struct seq_file *m, struct module *mod)
 void __symbol_put(const char *symbol)
 {
 	struct module *owner;
-	const unsigned long *crc;
 
 	preempt_disable();
-	if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1)))
+	if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
 		BUG();
 	module_put(owner);
 	preempt_enable();
@@ -924,13 +933,10 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 					  struct module *mod)
 {
 	const unsigned long *crc;
-	struct module *owner;
 
-	if (IS_ERR_VALUE(__find_symbol("struct_module",
-						&owner, &crc, 1)))
+	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
 		BUG();
-	return check_version(sechdrs, versindex, "struct_module", mod,
-			     crc);
+	return check_version(sechdrs, versindex, "struct_module", mod, crc);
 }
 
 /* First part is kernel version, which we ignore. */
@@ -974,8 +980,8 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
 	unsigned long ret;
 	const unsigned long *crc;
 
-	ret = __find_symbol(name, &owner, &crc,
-			!(mod->taints & TAINT_PROPRIETARY_MODULE));
+	ret = find_symbol(name, &owner, &crc,
+			  !(mod->taints & TAINT_PROPRIETARY_MODULE), true);
 	if (!IS_ERR_VALUE(ret)) {
 		/* use_module can fail due to OOM,
 		   or module initialization or unloading */
@@ -991,6 +997,20 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
  * J. Corbet <corbet@lwn.net>
  */
 #if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+struct module_sect_attr
+{
+	struct module_attribute mattr;
+	char *name;
+	unsigned long address;
+};
+
+struct module_sect_attrs
+{
+	struct attribute_group grp;
+	unsigned int nsections;
+	struct module_sect_attr attrs[0];
+};
+
 static ssize_t module_sect_show(struct module_attribute *mattr,
 				struct module *mod, char *buf)
 {
@@ -1001,7 +1021,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
 
 static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
 {
-	int section;
+	unsigned int section;
 
 	for (section = 0; section < sect_attrs->nsections; section++)
 		kfree(sect_attrs->attrs[section].name);
@@ -1362,10 +1382,9 @@ void *__symbol_get(const char *symbol)
 {
 	struct module *owner;
 	unsigned long value;
-	const unsigned long *crc;
 
 	preempt_disable();
-	value = __find_symbol(symbol, &owner, &crc, 1);
+	value = find_symbol(symbol, &owner, NULL, true, true);
 	if (IS_ERR_VALUE(value))
 		value = 0;
 	else if (strong_try_module_get(owner))
@@ -1382,33 +1401,33 @@ EXPORT_SYMBOL_GPL(__symbol_get);
  */
 static int verify_export_symbols(struct module *mod)
 {
-	const char *name = NULL;
-	unsigned long i, ret = 0;
+	unsigned int i;
 	struct module *owner;
-	const unsigned long *crc;
-
-	for (i = 0; i < mod->num_syms; i++)
-		if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name,
-							&owner, &crc, 1))) {
-			name = mod->syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
-		}
+	const struct kernel_symbol *s;
+	struct {
+		const struct kernel_symbol *sym;
+		unsigned int num;
+	} arr[] = {
+		{ mod->syms, mod->num_syms },
+		{ mod->gpl_syms, mod->num_gpl_syms },
+		{ mod->gpl_future_syms, mod->num_gpl_future_syms },
+		{ mod->unused_syms, mod->num_unused_syms },
+		{ mod->unused_gpl_syms, mod->num_unused_gpl_syms },
+	};
 
-	for (i = 0; i < mod->num_gpl_syms; i++)
-		if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name,
-							&owner, &crc, 1))) {
-			name = mod->gpl_syms[i].name;
-			ret = -ENOEXEC;
-			goto dup;
+	for (i = 0; i < ARRAY_SIZE(arr); i++) {
+		for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
+			if (!IS_ERR_VALUE(find_symbol(s->name, &owner,
+						      NULL, true, false))) {
+				printk(KERN_ERR
+				       "%s: exports duplicate symbol %s"
+				       " (owned by %s)\n",
+				       mod->name, s->name, module_name(owner));
+				return -ENOEXEC;
+			}
 		}
-
-dup:
-	if (ret)
-		printk(KERN_ERR "%s: exports duplicate symbol %s (owned by %s)\n",
-			mod->name, name, module_name(owner));
-
-	return ret;
+	}
+	return 0;
 }
 
 /* Change all symbols so that st_value encodes the pointer directly. */
@@ -1814,8 +1833,9 @@ static struct module *load_module(void __user *umod,
 	unwindex = find_sec(hdr, sechdrs, secstrings, ARCH_UNWIND_SECTION_NAME);
 #endif
 
-	/* Don't keep modinfo section */
+	/* Don't keep modinfo and version sections. */
 	sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
+	sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
 #ifdef CONFIG_KALLSYMS
 	/* Keep symbol and string tables for decoding later. */
 	sechdrs[symindex].sh_flags |= SHF_ALLOC;
@@ -1977,7 +1997,8 @@ static struct module *load_module(void __user *umod,
 		mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr;
 	mod->unused_gpl_syms = (void *)sechdrs[unusedgplindex].sh_addr;
 	if (unusedgplcrcindex)
-		mod->unused_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr;
+		mod->unused_gpl_crcs
+			= (void *)sechdrs[unusedgplcrcindex].sh_addr;
 
 #ifdef CONFIG_MODVERSIONS
 	if ((mod->num_syms && !crcindex) ||
@@ -2171,6 +2192,8 @@ sys_init_module(void __user *umod,
 		mod->state = MODULE_STATE_GOING;
 		synchronize_sched();
 		module_put(mod);
+		blocking_notifier_call_chain(&module_notify_list,
+					     MODULE_STATE_GOING, mod);
 		mutex_lock(&module_mutex);
 		free_module(mod);
 		mutex_unlock(&module_mutex);