Merge tag 'v4.13-rc1' into fixes

The fixes branch is based off a random pre-rc1 commit, because we had
some fixes that needed to go in before rc1 was released.

However we now need to fix some code that went in after that point, but
before rc1, so merge rc1 to get that code into fixes so we can fix it!

1 files changed, 55 insertions, 32 deletions

diff --git a/kernel/module.c b/kernel/module.c
index b3dbdde82e80..40f983cbea81 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -300,6 +300,7 @@ int unregister_module_notifier(struct notifier_block *nb)
 EXPORT_SYMBOL(unregister_module_notifier);
 
 struct load_info {
+	const char *name;
 	Elf_Ehdr *hdr;
 	unsigned long len;
 	Elf_Shdr *sechdrs;
@@ -600,7 +601,7 @@ static struct module *find_module_all(const char *name, size_t len,
 
 	module_assert_mutex_or_preempt();
 
-	list_for_each_entry(mod, &modules, list) {
+	list_for_each_entry_rcu(mod, &modules, list) {
 		if (!even_unformed && mod->state == MODULE_STATE_UNFORMED)
 			continue;
 		if (strlen(mod->name) == len && !memcmp(mod->name, name, len))
@@ -1273,12 +1274,13 @@ static u32 resolve_rel_crc(const s32 *crc)
 	return *(u32 *)((void *)crc + *crc);
 }
 
-static int check_version(Elf_Shdr *sechdrs,
-			 unsigned int versindex,
+static int check_version(const struct load_info *info,
 			 const char *symname,
 			 struct module *mod,
 			 const s32 *crc)
 {
+	Elf_Shdr *sechdrs = info->sechdrs;
+	unsigned int versindex = info->index.vers;
 	unsigned int i, num_versions;
 	struct modversion_info *versions;
 
@@ -1312,17 +1314,16 @@ static int check_version(Elf_Shdr *sechdrs,
 	}
 
 	/* Broken toolchain. Warn once, then let it go.. */
-	pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
+	pr_warn_once("%s: no symbol version for %s\n", info->name, symname);
 	return 1;
 
 bad_version:
 	pr_warn("%s: disagrees about version of symbol %s\n",
-	       mod->name, symname);
+	       info->name, symname);
 	return 0;
 }
 
-static inline int check_modstruct_version(Elf_Shdr *sechdrs,
-					  unsigned int versindex,
+static inline int check_modstruct_version(const struct load_info *info,
 					  struct module *mod)
 {
 	const s32 *crc;
@@ -1338,8 +1339,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs,
 		BUG();
 	}
 	preempt_enable();
-	return check_version(sechdrs, versindex,
-			     VMLINUX_SYMBOL_STR(module_layout), mod, crc);
+	return check_version(info, VMLINUX_SYMBOL_STR(module_layout),
+			     mod, crc);
 }
 
 /* First part is kernel version, which we ignore if module has crcs. */
@@ -1353,8 +1354,7 @@ static inline int same_magic(const char *amagic, const char *bmagic,
 	return strcmp(amagic, bmagic) == 0;
 }
 #else
-static inline int check_version(Elf_Shdr *sechdrs,
-				unsigned int versindex,
+static inline int check_version(const struct load_info *info,
 				const char *symname,
 				struct module *mod,
 				const s32 *crc)
@@ -1362,8 +1362,7 @@ static inline int check_version(Elf_Shdr *sechdrs,
 	return 1;
 }
 
-static inline int check_modstruct_version(Elf_Shdr *sechdrs,
-					  unsigned int versindex,
+static inline int check_modstruct_version(const struct load_info *info,
 					  struct module *mod)
 {
 	return 1;
@@ -1399,7 +1398,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
 	if (!sym)
 		goto unlock;
 
-	if (!check_version(info->sechdrs, info->index.vers, name, mod, crc)) {
+	if (!check_version(info, name, mod, crc)) {
 		sym = ERR_PTR(-EINVAL);
 		goto getname;
 	}
@@ -1662,31 +1661,36 @@ static inline void remove_notes_attrs(struct module *mod)
 }
 #endif /* CONFIG_KALLSYMS */
 
-static void add_usage_links(struct module *mod)
+static void del_usage_links(struct module *mod)
 {
 #ifdef CONFIG_MODULE_UNLOAD
 	struct module_use *use;
-	int nowarn;
 
 	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list) {
-		nowarn = sysfs_create_link(use->target->holders_dir,
-					   &mod->mkobj.kobj, mod->name);
-	}
+	list_for_each_entry(use, &mod->target_list, target_list)
+		sysfs_remove_link(use->target->holders_dir, mod->name);
 	mutex_unlock(&module_mutex);
 #endif
 }
 
-static void del_usage_links(struct module *mod)
+static int add_usage_links(struct module *mod)
 {
+	int ret = 0;
 #ifdef CONFIG_MODULE_UNLOAD
 	struct module_use *use;
 
 	mutex_lock(&module_mutex);
-	list_for_each_entry(use, &mod->target_list, target_list)
-		sysfs_remove_link(use->target->holders_dir, mod->name);
+	list_for_each_entry(use, &mod->target_list, target_list) {
+		ret = sysfs_create_link(use->target->holders_dir,
+					&mod->mkobj.kobj, mod->name);
+		if (ret)
+			break;
+	}
 	mutex_unlock(&module_mutex);
+	if (ret)
+		del_usage_links(mod);
 #endif
+	return ret;
 }
 
 static int module_add_modinfo_attrs(struct module *mod)
@@ -1797,13 +1801,18 @@ static int mod_sysfs_setup(struct module *mod,
 	if (err)
 		goto out_unreg_param;
 
-	add_usage_links(mod);
+	err = add_usage_links(mod);
+	if (err)
+		goto out_unreg_modinfo_attrs;
+
 	add_sect_attrs(mod, info);
 	add_notes_attrs(mod, info);
 
 	kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
 	return 0;
 
+out_unreg_modinfo_attrs:
+	module_remove_modinfo_attrs(mod);
 out_unreg_param:
 	module_param_sysfs_remove(mod);
 out_unreg_holders:
@@ -2910,9 +2919,15 @@ static int rewrite_section_headers(struct load_info *info, int flags)
 		info->index.vers = 0; /* Pretend no __versions section! */
 	else
 		info->index.vers = find_sec(info, "__versions");
+	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
+
 	info->index.info = find_sec(info, ".modinfo");
+	if (!info->index.info)
+		info->name = "(missing .modinfo section)";
+	else
+		info->name = get_modinfo(info, "name");
 	info->sechdrs[info->index.info].sh_flags &= ~(unsigned long)SHF_ALLOC;
-	info->sechdrs[info->index.vers].sh_flags &= ~(unsigned long)SHF_ALLOC;
+
 	return 0;
 }
 
@@ -2952,21 +2967,29 @@ static struct module *setup_load_info(struct load_info *info, int flags)
 
 	info->index.mod = find_sec(info, ".gnu.linkonce.this_module");
 	if (!info->index.mod) {
-		pr_warn("No module found in object\n");
+		pr_warn("%s: No module found in object\n",
+			info->name ?: "(missing .modinfo name field)");
 		return ERR_PTR(-ENOEXEC);
 	}
 	/* This is temporary: point mod into copy of data. */
 	mod = (void *)info->sechdrs[info->index.mod].sh_addr;
 
+	/*
+	 * If we didn't load the .modinfo 'name' field, fall back to
+	 * on-disk struct mod 'name' field.
+	 */
+	if (!info->name)
+		info->name = mod->name;
+
 	if (info->index.sym == 0) {
-		pr_warn("%s: module has no symbols (stripped?)\n", mod->name);
+		pr_warn("%s: module has no symbols (stripped?)\n", info->name);
 		return ERR_PTR(-ENOEXEC);
 	}
 
 	info->index.pcpu = find_pcpusec(info);
 
 	/* Check module struct version now, before we try to use module. */
-	if (!check_modstruct_version(info->sechdrs, info->index.vers, mod))
+	if (!check_modstruct_version(info, mod))
 		return ERR_PTR(-ENOEXEC);
 
 	return mod;
@@ -2987,7 +3010,7 @@ static int check_modinfo(struct module *mod, struct load_info *info, int flags)
 			return err;
 	} else if (!same_magic(modmagic, vermagic, info->index.vers)) {
 		pr_err("%s: version magic '%s' should be '%s'\n",
-		       mod->name, modmagic, vermagic);
+		       info->name, modmagic, vermagic);
 		return -ENOEXEC;
 	}
 
@@ -3237,7 +3260,7 @@ int __weak module_frob_arch_sections(Elf_Ehdr *hdr,
 
 /* module_blacklist is a comma-separated list of module names */
 static char *module_blacklist;
-static bool blacklisted(char *module_name)
+static bool blacklisted(const char *module_name)
 {
 	const char *p;
 	size_t len;
@@ -3267,7 +3290,7 @@ static struct module *layout_and_allocate(struct load_info *info, int flags)
 	if (IS_ERR(mod))
 		return mod;
 
-	if (blacklisted(mod->name))
+	if (blacklisted(info->name))
 		return ERR_PTR(-EPERM);
 
 	err = check_modinfo(mod, info, flags);
@@ -4196,7 +4219,7 @@ const struct exception_table_entry *search_module_extables(unsigned long addr)
 		goto out;
 
 	e = search_extable(mod->extable,
-			   mod->extable + mod->num_exentries - 1,
+			   mod->num_exentries,
 			   addr);
 out:
 	preempt_enable();