Merge branch 'master' into next

1 files changed, 161 insertions, 113 deletions

diff --git a/kernel/module.c b/kernel/module.c
index ee7ab61..cb3887e 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -68,7 +68,8 @@
 
 /* List of modules, protected by module_mutex or preempt_disable
  * (delete uses stop_machine/add uses RCU list operations). */
-static DEFINE_MUTEX(module_mutex);
+DEFINE_MUTEX(module_mutex);
+EXPORT_SYMBOL_GPL(module_mutex);
 static LIST_HEAD(modules);
 
 /* Block module loading/unloading? */
@@ -79,7 +80,7 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq);
 
 static BLOCKING_NOTIFIER_HEAD(module_notify_list);
 
-/* Bounds of module allocation, for speeding __module_text_address */
+/* Bounds of module allocation, for speeding __module_address */
 static unsigned long module_addr_min = -1UL, module_addr_max = 0;
 
 int register_module_notifier(struct notifier_block * nb)
@@ -189,17 +190,6 @@ extern const unsigned long __start___kcrctab_unused_gpl[];
 #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL)
 #endif
 
-struct symsearch {
-	const struct kernel_symbol *start, *stop;
-	const unsigned long *crcs;
-	enum {
-		NOT_GPL_ONLY,
-		GPL_ONLY,
-		WILL_BE_GPL_ONLY,
-	} licence;
-	bool unused;
-};
-
 static bool each_symbol_in_section(const struct symsearch *arr,
 				   unsigned int arrsize,
 				   struct module *owner,
@@ -220,10 +210,8 @@ static bool each_symbol_in_section(const struct symsearch *arr,
 }
 
 /* Returns true as soon as fn returns true, otherwise false. */
-static bool each_symbol(bool (*fn)(const struct symsearch *arr,
-				   struct module *owner,
-				   unsigned int symnum, void *data),
-			void *data)
+bool each_symbol(bool (*fn)(const struct symsearch *arr, struct module *owner,
+			    unsigned int symnum, void *data), void *data)
 {
 	struct module *mod;
 	const struct symsearch arr[] = {
@@ -276,6 +264,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr,
 	}
 	return false;
 }
+EXPORT_SYMBOL_GPL(each_symbol);
 
 struct find_symbol_arg {
 	/* Input */
@@ -286,7 +275,7 @@ struct find_symbol_arg {
 	/* Output */
 	struct module *owner;
 	const unsigned long *crc;
-	unsigned long value;
+	const struct kernel_symbol *sym;
 };
 
 static bool find_symbol_in_section(const struct symsearch *syms,
@@ -327,17 +316,17 @@ static bool find_symbol_in_section(const struct symsearch *syms,
 
 	fsa->owner = owner;
 	fsa->crc = symversion(syms->crcs, symnum);
-	fsa->value = syms->start[symnum].value;
+	fsa->sym = &syms->start[symnum];
 	return true;
 }
 
-/* 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)
+/* Find a symbol and return it, along with, (optional) crc and
+ * (optional) module which owns it */
+const struct kernel_symbol *find_symbol(const char *name,
+					struct module **owner,
+					const unsigned long **crc,
+					bool gplok,
+					bool warn)
 {
 	struct find_symbol_arg fsa;
 
@@ -350,15 +339,16 @@ static unsigned long find_symbol(const char *name,
 			*owner = fsa.owner;
 		if (crc)
 			*crc = fsa.crc;
-		return fsa.value;
+		return fsa.sym;
 	}
 
 	DEBUGP("Failed to find symbol %s\n", name);
-	return -ENOENT;
+	return NULL;
 }
+EXPORT_SYMBOL_GPL(find_symbol);
 
 /* Search for module by name: must hold module_mutex. */
-static struct module *find_module(const char *name)
+struct module *find_module(const char *name)
 {
 	struct module *mod;
 
@@ -368,6 +358,7 @@ static struct module *find_module(const char *name)
 	}
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(find_module);
 
 #ifdef CONFIG_SMP
 
@@ -644,7 +635,7 @@ static int already_uses(struct module *a, struct module *b)
 }
 
 /* Module a uses b */
-static int use_module(struct module *a, struct module *b)
+int use_module(struct module *a, struct module *b)
 {
 	struct module_use *use;
 	int no_warn, err;
@@ -677,6 +668,7 @@ static int use_module(struct module *a, struct module *b)
 	no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
 	return 1;
 }
+EXPORT_SYMBOL_GPL(use_module);
 
 /* Clear the unload stuff of the module. */
 static void module_unload_free(struct module *mod)
@@ -897,7 +889,7 @@ void __symbol_put(const char *symbol)
 	struct module *owner;
 
 	preempt_disable();
-	if (IS_ERR_VALUE(find_symbol(symbol, &owner, NULL, true, false)))
+	if (!find_symbol(symbol, &owner, NULL, true, false))
 		BUG();
 	module_put(owner);
 	preempt_enable();
@@ -911,8 +903,10 @@ void symbol_put_addr(void *addr)
 	if (core_kernel_text((unsigned long)addr))
 		return;
 
-	if (!(modaddr = module_text_address((unsigned long)addr)))
-		BUG();
+	/* module_text_address is safe here: we're supposed to have reference
+	 * to module from symbol_get, so it can't go away. */
+	modaddr = __module_text_address((unsigned long)addr);
+	BUG_ON(!modaddr);
 	module_put(modaddr);
 }
 EXPORT_SYMBOL_GPL(symbol_put_addr);
@@ -952,10 +946,11 @@ static inline void module_unload_free(struct module *mod)
 {
 }
 
-static inline int use_module(struct module *a, struct module *b)
+int use_module(struct module *a, struct module *b)
 {
 	return strong_try_module_get(b) == 0;
 }
+EXPORT_SYMBOL_GPL(use_module);
 
 static inline void module_unload_init(struct module *mod)
 {
@@ -998,12 +993,12 @@ static struct module_attribute *modinfo_attrs[] = {
 
 static const char vermagic[] = VERMAGIC_STRING;
 
-static int try_to_force_load(struct module *mod, const char *symname)
+static int try_to_force_load(struct module *mod, const char *reason)
 {
 #ifdef CONFIG_MODULE_FORCE_LOAD
 	if (!test_taint(TAINT_FORCED_MODULE))
-		printk("%s: no version for \"%s\" found: kernel tainted.\n",
-		       mod->name, symname);
+		printk(KERN_WARNING "%s: %s: kernel tainted.\n",
+		       mod->name, reason);
 	add_taint_module(mod, TAINT_FORCED_MODULE);
 	return 0;
 #else
@@ -1060,9 +1055,9 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 {
 	const unsigned long *crc;
 
-	if (IS_ERR_VALUE(find_symbol("struct_module", NULL, &crc, true, false)))
+	if (!find_symbol("module_layout", NULL, &crc, true, false))
 		BUG();
-	return check_version(sechdrs, versindex, "struct_module", mod, crc);
+	return check_version(sechdrs, versindex, "module_layout", mod, crc);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -1101,25 +1096,25 @@ static inline int same_magic(const char *amagic, const char *bmagic,
 
 /* Resolve a symbol for this module.  I.e. if we find one, record usage.
    Must be holding module_mutex. */
-static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
-				    unsigned int versindex,
-				    const char *name,
-				    struct module *mod)
+static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
+						  unsigned int versindex,
+						  const char *name,
+						  struct module *mod)
 {
 	struct module *owner;
-	unsigned long ret;
+	const struct kernel_symbol *sym;
 	const unsigned long *crc;
 
-	ret = find_symbol(name, &owner, &crc,
+	sym = find_symbol(name, &owner, &crc,
 			  !(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
-	if (!IS_ERR_VALUE(ret)) {
-		/* use_module can fail due to OOM,
-		   or module initialization or unloading */
+	/* use_module can fail due to OOM,
+	   or module initialization or unloading */
+	if (sym) {
 		if (!check_version(sechdrs, versindex, name, mod, crc) ||
 		    !use_module(mod, owner))
-			ret = -EINVAL;
+			sym = NULL;
 	}
-	return ret;
+	return sym;
 }
 
 /*
@@ -1494,6 +1489,9 @@ static void free_module(struct module *mod)
 	/* Module unload stuff */
 	module_unload_free(mod);
 
+	/* Free any allocated parameters. */
+	destroy_params(mod->kp, mod->num_kp);
+
 	/* release any pointers to mcount in this module */
 	ftrace_release(mod->module_core, mod->core_size);
 
@@ -1516,17 +1514,15 @@ static void free_module(struct module *mod)
 void *__symbol_get(const char *symbol)
 {
 	struct module *owner;
-	unsigned long value;
+	const struct kernel_symbol *sym;
 
 	preempt_disable();
-	value = find_symbol(symbol, &owner, NULL, true, true);
-	if (IS_ERR_VALUE(value))
-		value = 0;
-	else if (strong_try_module_get(owner))
-		value = 0;
+	sym = find_symbol(symbol, &owner, NULL, true, true);
+	if (sym && strong_try_module_get(owner))
+		sym = NULL;
 	preempt_enable();
 
-	return (void *)value;
+	return sym ? (void *)sym->value : NULL;
 }
 EXPORT_SYMBOL_GPL(__symbol_get);
 
@@ -1554,8 +1550,7 @@ static int verify_export_symbols(struct module *mod)
 
 	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))) {
+			if (find_symbol(s->name, &owner, NULL, true, false)) {
 				printk(KERN_ERR
 				       "%s: exports duplicate symbol %s"
 				       " (owned by %s)\n",
@@ -1579,6 +1574,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
 	unsigned long secbase;
 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
 	int ret = 0;
+	const struct kernel_symbol *ksym;
 
 	for (i = 1; i < n; i++) {
 		switch (sym[i].st_shndx) {
@@ -1598,13 +1594,14 @@ static int simplify_symbols(Elf_Shdr *sechdrs,
 			break;
 
 		case SHN_UNDEF:
-			sym[i].st_value
-			  = resolve_symbol(sechdrs, versindex,
-					   strtab + sym[i].st_name, mod);
-
+			ksym = resolve_symbol(sechdrs, versindex,
+					      strtab + sym[i].st_name, mod);
 			/* Ok if resolved.  */
-			if (!IS_ERR_VALUE(sym[i].st_value))
+			if (ksym) {
+				sym[i].st_value = ksym->value;
 				break;
+			}
+
 			/* Ok if weak.  */
 			if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
 				break;
@@ -1679,8 +1676,7 @@ static void layout_sections(struct module *mod,
 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
 			    || (s->sh_flags & masks[m][1])
 			    || s->sh_entsize != ~0UL
-			    || strncmp(secstrings + s->sh_name,
-				       ".init", 5) == 0)
+			    || strstarts(secstrings + s->sh_name, ".init"))
 				continue;
 			s->sh_entsize = get_offset(mod, &mod->core_size, s, i);
 			DEBUGP("\t%s\n", secstrings + s->sh_name);
@@ -1697,8 +1693,7 @@ static void layout_sections(struct module *mod,
 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
 			    || (s->sh_flags & masks[m][1])
 			    || s->sh_entsize != ~0UL
-			    || strncmp(secstrings + s->sh_name,
-				       ".init", 5) != 0)
+			    || !strstarts(secstrings + s->sh_name, ".init"))
 				continue;
 			s->sh_entsize = (get_offset(mod, &mod->init_size, s, i)
 					 | INIT_OFFSET_MASK);
@@ -1831,8 +1826,7 @@ static char elf_type(const Elf_Sym *sym,
 		else
 			return 'b';
 	}
-	if (strncmp(secstrings + sechdrs[sym->st_shndx].sh_name,
-		    ".debug", strlen(".debug")) == 0)
+	if (strstarts(secstrings + sechdrs[sym->st_shndx].sh_name, ".debug"))
 		return 'n';
 	return '?';
 }
@@ -1901,8 +1895,7 @@ static noinline struct module *load_module(void __user *umod,
 	unsigned int symindex = 0;
 	unsigned int strindex = 0;
 	unsigned int modindex, versindex, infoindex, pcpuindex;
-	unsigned int num_kp, num_mcount;
-	struct kernel_param *kp;
+	unsigned int num_mcount;
 	struct module *mod;
 	long err = 0;
 	void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
@@ -1919,12 +1912,6 @@ static noinline struct module *load_module(void __user *umod,
 	if (len > 64 * 1024 * 1024 || (hdr = vmalloc(len)) == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	/* Create stop_machine threads since the error path relies on
-	 * a non-failing stop_machine call. */
-	err = stop_machine_create();
-	if (err)
-		goto free_hdr;
-
 	if (copy_from_user(hdr, umod, len) != 0) {
 		err = -EFAULT;
 		goto free_hdr;
@@ -1965,7 +1952,7 @@ static noinline struct module *load_module(void __user *umod,
 		}
 #ifndef CONFIG_MODULE_UNLOAD
 		/* Don't load .exit sections */
-		if (strncmp(secstrings+sechdrs[i].sh_name, ".exit", 5) == 0)
+		if (strstarts(secstrings+sechdrs[i].sh_name, ".exit"))
 			sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
 #endif
 	}
@@ -2009,7 +1996,7 @@ static noinline struct module *load_module(void __user *umod,
 	modmagic = get_modinfo(sechdrs, infoindex, "vermagic");
 	/* This is allowed: modprobe --force will invalidate it. */
 	if (!modmagic) {
-		err = try_to_force_load(mod, "magic");
+		err = try_to_force_load(mod, "bad vermagic");
 		if (err)
 			goto free_hdr;
 	} else if (!same_magic(modmagic, vermagic, versindex)) {
@@ -2147,8 +2134,8 @@ static noinline struct module *load_module(void __user *umod,
 
 	/* Now we've got everything in the final locations, we can
 	 * find optional sections. */
-	kp = section_objs(hdr, sechdrs, secstrings, "__param", sizeof(*kp),
-			  &num_kp);
+	mod->kp = section_objs(hdr, sechdrs, secstrings, "__param",
+			       sizeof(*mod->kp), &mod->num_kp);
 	mod->syms = section_objs(hdr, sechdrs, secstrings, "__ksymtab",
 				 sizeof(*mod->syms), &mod->num_syms);
 	mod->crcs = section_addr(hdr, sechdrs, secstrings, "__kcrctab");
@@ -2198,8 +2185,8 @@ static noinline struct module *load_module(void __user *umod,
 	    || (mod->num_unused_gpl_syms && !mod->unused_gpl_crcs)
 #endif
 		) {
-		printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name);
-		err = try_to_force_load(mod, "nocrc");
+		err = try_to_force_load(mod,
+					"no versions for exported symbols");
 		if (err)
 			goto cleanup;
 	}
@@ -2294,11 +2281,11 @@ static noinline struct module *load_module(void __user *umod,
 	 */
 	list_add_rcu(&mod->list, &modules);
 
-	err = parse_args(mod->name, mod->args, kp, num_kp, NULL);
+	err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
 	if (err < 0)
 		goto unlink;
 
-	err = mod_sysfs_setup(mod, kp, num_kp);
+	err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
 	if (err < 0)
 		goto unlink;
 	add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
@@ -2307,12 +2294,13 @@ static noinline struct module *load_module(void __user *umod,
 	/* Get rid of temporary copy */
 	vfree(hdr);
 
-	stop_machine_destroy();
 	/* Done! */
 	return mod;
 
  unlink:
-	stop_machine(__unlink_module, mod, NULL);
+	/* Unlink carefully: kallsyms could be walking list. */
+	list_del_rcu(&mod->list);
+	synchronize_sched();
 	module_arch_cleanup(mod);
  cleanup:
 	kobject_del(&mod->mkobj.kobj);
@@ -2320,8 +2308,8 @@ static noinline struct module *load_module(void __user *umod,
 	ftrace_release(mod->module_core, mod->core_size);
  free_unload:
 	module_unload_free(mod);
- free_init:
 #if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ free_init:
 	percpu_modfree(mod->refptr);
 #endif
 	module_free(mod, mod->module_init);
@@ -2335,7 +2323,6 @@ static noinline struct module *load_module(void __user *umod,
 	kfree(args);
  free_hdr:
 	vfree(hdr);
-	stop_machine_destroy();
 	return ERR_PTR(err);
 
  truncated:
@@ -2404,6 +2391,9 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
 	blocking_notifier_call_chain(&module_notify_list,
 				     MODULE_STATE_LIVE, mod);
 
+	/* We need to finish all async code before the module init sequence is done */
+	async_synchronize_full();
+
 	mutex_lock(&module_mutex);
 	/* Drop initial reference. */
 	module_put(mod);
@@ -2612,6 +2602,25 @@ unsigned long module_kallsyms_lookup_name(const char *name)
 	preempt_enable();
 	return ret;
 }
+
+int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
+					     struct module *, unsigned long),
+				   void *data)
+{
+	struct module *mod;
+	unsigned int i;
+	int ret;
+
+	list_for_each_entry(mod, &modules, list) {
+		for (i = 0; i < mod->num_symtab; i++) {
+			ret = fn(data, mod->strtab + mod->symtab[i].st_name,
+				 mod, mod->symtab[i].st_value);
+			if (ret != 0)
+				return ret;
+		}
+	}
+	return 0;
+}
 #endif /* CONFIG_KALLSYMS */
 
 static char *module_flags(struct module *mod, char *buf)
@@ -2747,29 +2756,31 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
 }
 
 /*
- * Is this a valid module address?
+ * is_module_address - is this address inside a module?
+ * @addr: the address to check.
+ *
+ * See is_module_text_address() if you simply want to see if the address
+ * is code (not data).
  */
-int is_module_address(unsigned long addr)
+bool is_module_address(unsigned long addr)
 {
-	struct module *mod;
+	bool ret;
 
 	preempt_disable();
-
-	list_for_each_entry_rcu(mod, &modules, list) {
-		if (within_module_core(addr, mod)) {
-			preempt_enable();
-			return 1;
-		}
-	}
-
+	ret = __module_address(addr) != NULL;
 	preempt_enable();
 
-	return 0;
+	return ret;
 }
 
-
-/* Is this a valid kernel address? */
-__notrace_funcgraph struct module *__module_text_address(unsigned long addr)
+/*
+ * __module_address - get the module which contains an address.
+ * @addr: the address.
+ *
+ * Must be called with preempt disabled or module mutex held so that
+ * module doesn't get freed during this.
+ */
+struct module *__module_address(unsigned long addr)
 {
 	struct module *mod;
 
@@ -2777,22 +2788,51 @@ __notrace_funcgraph struct module *__module_text_address(unsigned long addr)
 		return NULL;
 
 	list_for_each_entry_rcu(mod, &modules, list)
-		if (within(addr, mod->module_init, mod->init_text_size)
-		    || within(addr, mod->module_core, mod->core_text_size))
+		if (within_module_core(addr, mod)
+		    || within_module_init(addr, mod))
 			return mod;
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(__module_address);
 
-struct module *module_text_address(unsigned long addr)
+/*
+ * is_module_text_address - is this address inside module code?
+ * @addr: the address to check.
+ *
+ * See is_module_address() if you simply want to see if the address is
+ * anywhere in a module.  See kernel_text_address() for testing if an
+ * address corresponds to kernel or module code.
+ */
+bool is_module_text_address(unsigned long addr)
 {
-	struct module *mod;
+	bool ret;
 
 	preempt_disable();
-	mod = __module_text_address(addr);
+	ret = __module_text_address(addr) != NULL;
 	preempt_enable();
 
+	return ret;
+}
+
+/*
+ * __module_text_address - get the module whose code contains an address.
+ * @addr: the address.
+ *
+ * Must be called with preempt disabled or module mutex held so that
+ * module doesn't get freed during this.
+ */
+struct module *__module_text_address(unsigned long addr)
+{
+	struct module *mod = __module_address(addr);
+	if (mod) {
+		/* Make sure it's within the text section. */
+		if (!within(addr, mod->module_init, mod->init_text_size)
+		    && !within(addr, mod->module_core, mod->core_text_size))
+			mod = NULL;
+	}
 	return mod;
 }
+EXPORT_SYMBOL_GPL(__module_text_address);
 
 /* Don't grab lock, we're oopsing. */
 void print_modules(void)
@@ -2812,9 +2852,17 @@ void print_modules(void)
 }
 
 #ifdef CONFIG_MODVERSIONS
-/* Generate the signature for struct module here, too, for modversions. */
-void struct_module(struct module *mod) { return; }
-EXPORT_SYMBOL(struct_module);
+/* Generate the signature for all relevant module structures here.
+ * If these change, we don't want to try to parse the module. */
+void module_layout(struct module *mod,
+		   struct modversion_info *ver,
+		   struct kernel_param *kp,
+		   struct kernel_symbol *ks,
+		   struct marker *marker,
+		   struct tracepoint *tp)
+{
+}
+EXPORT_SYMBOL(module_layout);
 #endif
 
 #ifdef CONFIG_MARKERS