module: Move sysfs support into a separate file

No functional change.

This patch migrates module sysfs support out of core code into
kernel/module/sysfs.c. In addition simple code refactoring to
make this possible.

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>

1 files changed, 3 insertions, 466 deletions

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 63b98452fd7d..0cd0590dd411 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -14,9 +14,7 @@
 #include <linux/init.h>
 #include <linux/kallsyms.h>
 #include <linux/buildid.h>
-#include <linux/file.h>
 #include <linux/fs.h>
-#include <linux/sysfs.h>
 #include <linux/kernel.h>
 #include <linux/kernel_read_file.h>
 #include <linux/slab.h>
@@ -989,7 +987,7 @@ static ssize_t show_taint(struct module_attribute *mattr,
 static struct module_attribute modinfo_taint =
 	__ATTR(taint, 0444, show_taint, NULL);
 
-static struct module_attribute *modinfo_attrs[] = {
+struct module_attribute *modinfo_attrs[] = {
 	&module_uevent,
 	&modinfo_version,
 	&modinfo_srcversion,
@@ -1003,6 +1001,8 @@ static struct module_attribute *modinfo_attrs[] = {
 	NULL,
 };
 
+size_t modinfo_attrs_count = ARRAY_SIZE(modinfo_attrs);
+
 static const char vermagic[] = VERMAGIC_STRING;
 
 static int try_to_force_load(struct module *mod, const char *reason)
@@ -1254,469 +1254,6 @@ resolve_symbol_wait(struct module *mod,
 }
 
 /*
- * /sys/module/foo/sections stuff
- * J. Corbet <corbet@lwn.net>
- */
-#ifdef CONFIG_SYSFS
-
-#ifdef CONFIG_KALLSYMS
-struct module_sect_attr {
-	struct bin_attribute battr;
-	unsigned long address;
-};
-
-struct module_sect_attrs {
-	struct attribute_group grp;
-	unsigned int nsections;
-	struct module_sect_attr attrs[];
-};
-
-#define MODULE_SECT_READ_SIZE (3 /* "0x", "\n" */ + (BITS_PER_LONG / 4))
-static ssize_t module_sect_read(struct file *file, struct kobject *kobj,
-				struct bin_attribute *battr,
-				char *buf, loff_t pos, size_t count)
-{
-	struct module_sect_attr *sattr =
-		container_of(battr, struct module_sect_attr, battr);
-	char bounce[MODULE_SECT_READ_SIZE + 1];
-	size_t wrote;
-
-	if (pos != 0)
-		return -EINVAL;
-
-	/*
-	 * Since we're a binary read handler, we must account for the
-	 * trailing NUL byte that sprintf will write: if "buf" is
-	 * too small to hold the NUL, or the NUL is exactly the last
-	 * byte, the read will look like it got truncated by one byte.
-	 * Since there is no way to ask sprintf nicely to not write
-	 * the NUL, we have to use a bounce buffer.
-	 */
-	wrote = scnprintf(bounce, sizeof(bounce), "0x%px\n",
-			 kallsyms_show_value(file->f_cred)
-				? (void *)sattr->address : NULL);
-	count = min(count, wrote);
-	memcpy(buf, bounce, count);
-
-	return count;
-}
-
-static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
-{
-	unsigned int section;
-
-	for (section = 0; section < sect_attrs->nsections; section++)
-		kfree(sect_attrs->attrs[section].battr.attr.name);
-	kfree(sect_attrs);
-}
-
-static void add_sect_attrs(struct module *mod, const struct load_info *info)
-{
-	unsigned int nloaded = 0, i, size[2];
-	struct module_sect_attrs *sect_attrs;
-	struct module_sect_attr *sattr;
-	struct bin_attribute **gattr;
-
-	/* Count loaded sections and allocate structures */
-	for (i = 0; i < info->hdr->e_shnum; i++)
-		if (!sect_empty(&info->sechdrs[i]))
-			nloaded++;
-	size[0] = ALIGN(struct_size(sect_attrs, attrs, nloaded),
-			sizeof(sect_attrs->grp.bin_attrs[0]));
-	size[1] = (nloaded + 1) * sizeof(sect_attrs->grp.bin_attrs[0]);
-	sect_attrs = kzalloc(size[0] + size[1], GFP_KERNEL);
-	if (sect_attrs == NULL)
-		return;
-
-	/* Setup section attributes. */
-	sect_attrs->grp.name = "sections";
-	sect_attrs->grp.bin_attrs = (void *)sect_attrs + size[0];
-
-	sect_attrs->nsections = 0;
-	sattr = &sect_attrs->attrs[0];
-	gattr = &sect_attrs->grp.bin_attrs[0];
-	for (i = 0; i < info->hdr->e_shnum; i++) {
-		Elf_Shdr *sec = &info->sechdrs[i];
-		if (sect_empty(sec))
-			continue;
-		sysfs_bin_attr_init(&sattr->battr);
-		sattr->address = sec->sh_addr;
-		sattr->battr.attr.name =
-			kstrdup(info->secstrings + sec->sh_name, GFP_KERNEL);
-		if (sattr->battr.attr.name == NULL)
-			goto out;
-		sect_attrs->nsections++;
-		sattr->battr.read = module_sect_read;
-		sattr->battr.size = MODULE_SECT_READ_SIZE;
-		sattr->battr.attr.mode = 0400;
-		*(gattr++) = &(sattr++)->battr;
-	}
-	*gattr = NULL;
-
-	if (sysfs_create_group(&mod->mkobj.kobj, &sect_attrs->grp))
-		goto out;
-
-	mod->sect_attrs = sect_attrs;
-	return;
-  out:
-	free_sect_attrs(sect_attrs);
-}
-
-static void remove_sect_attrs(struct module *mod)
-{
-	if (mod->sect_attrs) {
-		sysfs_remove_group(&mod->mkobj.kobj,
-				   &mod->sect_attrs->grp);
-		/*
-		 * We are positive that no one is using any sect attrs
-		 * at this point.  Deallocate immediately.
-		 */
-		free_sect_attrs(mod->sect_attrs);
-		mod->sect_attrs = NULL;
-	}
-}
-
-/*
- * /sys/module/foo/notes/.section.name gives contents of SHT_NOTE sections.
- */
-
-struct module_notes_attrs {
-	struct kobject *dir;
-	unsigned int notes;
-	struct bin_attribute attrs[];
-};
-
-static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
-				 struct bin_attribute *bin_attr,
-				 char *buf, loff_t pos, size_t count)
-{
-	/*
-	 * The caller checked the pos and count against our size.
-	 */
-	memcpy(buf, bin_attr->private + pos, count);
-	return count;
-}
-
-static void free_notes_attrs(struct module_notes_attrs *notes_attrs,
-			     unsigned int i)
-{
-	if (notes_attrs->dir) {
-		while (i-- > 0)
-			sysfs_remove_bin_file(notes_attrs->dir,
-					      &notes_attrs->attrs[i]);
-		kobject_put(notes_attrs->dir);
-	}
-	kfree(notes_attrs);
-}
-
-static void add_notes_attrs(struct module *mod, const struct load_info *info)
-{
-	unsigned int notes, loaded, i;
-	struct module_notes_attrs *notes_attrs;
-	struct bin_attribute *nattr;
-
-	/* failed to create section attributes, so can't create notes */
-	if (!mod->sect_attrs)
-		return;
-
-	/* Count notes sections and allocate structures.  */
-	notes = 0;
-	for (i = 0; i < info->hdr->e_shnum; i++)
-		if (!sect_empty(&info->sechdrs[i]) &&
-		    (info->sechdrs[i].sh_type == SHT_NOTE))
-			++notes;
-
-	if (notes == 0)
-		return;
-
-	notes_attrs = kzalloc(struct_size(notes_attrs, attrs, notes),
-			      GFP_KERNEL);
-	if (notes_attrs == NULL)
-		return;
-
-	notes_attrs->notes = notes;
-	nattr = &notes_attrs->attrs[0];
-	for (loaded = i = 0; i < info->hdr->e_shnum; ++i) {
-		if (sect_empty(&info->sechdrs[i]))
-			continue;
-		if (info->sechdrs[i].sh_type == SHT_NOTE) {
-			sysfs_bin_attr_init(nattr);
-			nattr->attr.name = mod->sect_attrs->attrs[loaded].battr.attr.name;
-			nattr->attr.mode = S_IRUGO;
-			nattr->size = info->sechdrs[i].sh_size;
-			nattr->private = (void *) info->sechdrs[i].sh_addr;
-			nattr->read = module_notes_read;
-			++nattr;
-		}
-		++loaded;
-	}
-
-	notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
-	if (!notes_attrs->dir)
-		goto out;
-
-	for (i = 0; i < notes; ++i)
-		if (sysfs_create_bin_file(notes_attrs->dir,
-					  &notes_attrs->attrs[i]))
-			goto out;
-
-	mod->notes_attrs = notes_attrs;
-	return;
-
-  out:
-	free_notes_attrs(notes_attrs, i);
-}
-
-static void remove_notes_attrs(struct module *mod)
-{
-	if (mod->notes_attrs)
-		free_notes_attrs(mod->notes_attrs, mod->notes_attrs->notes);
-}
-
-#else
-
-static inline void add_sect_attrs(struct module *mod,
-				  const struct load_info *info)
-{
-}
-
-static inline void remove_sect_attrs(struct module *mod)
-{
-}
-
-static inline void add_notes_attrs(struct module *mod,
-				   const struct load_info *info)
-{
-}
-
-static inline void remove_notes_attrs(struct module *mod)
-{
-}
-#endif /* CONFIG_KALLSYMS */
-
-static void del_usage_links(struct module *mod)
-{
-#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);
-	mutex_unlock(&module_mutex);
-#endif
-}
-
-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) {
-		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 void module_remove_modinfo_attrs(struct module *mod, int end);
-
-static int module_add_modinfo_attrs(struct module *mod)
-{
-	struct module_attribute *attr;
-	struct module_attribute *temp_attr;
-	int error = 0;
-	int i;
-
-	mod->modinfo_attrs = kzalloc((sizeof(struct module_attribute) *
-					(ARRAY_SIZE(modinfo_attrs) + 1)),
-					GFP_KERNEL);
-	if (!mod->modinfo_attrs)
-		return -ENOMEM;
-
-	temp_attr = mod->modinfo_attrs;
-	for (i = 0; (attr = modinfo_attrs[i]); i++) {
-		if (!attr->test || attr->test(mod)) {
-			memcpy(temp_attr, attr, sizeof(*temp_attr));
-			sysfs_attr_init(&temp_attr->attr);
-			error = sysfs_create_file(&mod->mkobj.kobj,
-					&temp_attr->attr);
-			if (error)
-				goto error_out;
-			++temp_attr;
-		}
-	}
-
-	return 0;
-
-error_out:
-	if (i > 0)
-		module_remove_modinfo_attrs(mod, --i);
-	else
-		kfree(mod->modinfo_attrs);
-	return error;
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-	struct module_attribute *attr;
-	int i;
-
-	for (i = 0; (attr = &mod->modinfo_attrs[i]); i++) {
-		if (end >= 0 && i > end)
-			break;
-		/* pick a field to test for end of list */
-		if (!attr->attr.name)
-			break;
-		sysfs_remove_file(&mod->mkobj.kobj, &attr->attr);
-		if (attr->free)
-			attr->free(mod);
-	}
-	kfree(mod->modinfo_attrs);
-}
-
-static void mod_kobject_put(struct module *mod)
-{
-	DECLARE_COMPLETION_ONSTACK(c);
-	mod->mkobj.kobj_completion = &c;
-	kobject_put(&mod->mkobj.kobj);
-	wait_for_completion(&c);
-}
-
-static int mod_sysfs_init(struct module *mod)
-{
-	int err;
-	struct kobject *kobj;
-
-	if (!module_sysfs_initialized) {
-		pr_err("%s: module sysfs not initialized\n", mod->name);
-		err = -EINVAL;
-		goto out;
-	}
-
-	kobj = kset_find_obj(module_kset, mod->name);
-	if (kobj) {
-		pr_err("%s: module is already loaded\n", mod->name);
-		kobject_put(kobj);
-		err = -EINVAL;
-		goto out;
-	}
-
-	mod->mkobj.mod = mod;
-
-	memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
-	mod->mkobj.kobj.kset = module_kset;
-	err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
-				   "%s", mod->name);
-	if (err)
-		mod_kobject_put(mod);
-
-out:
-	return err;
-}
-
-static int mod_sysfs_setup(struct module *mod,
-			   const struct load_info *info,
-			   struct kernel_param *kparam,
-			   unsigned int num_params)
-{
-	int err;
-
-	err = mod_sysfs_init(mod);
-	if (err)
-		goto out;
-
-	mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
-	if (!mod->holders_dir) {
-		err = -ENOMEM;
-		goto out_unreg;
-	}
-
-	err = module_param_sysfs_setup(mod, kparam, num_params);
-	if (err)
-		goto out_unreg_holders;
-
-	err = module_add_modinfo_attrs(mod);
-	if (err)
-		goto out_unreg_param;
-
-	err = add_usage_links(mod);
-	if (err)
-		goto out_unreg_modinfo_attrs;
-
-	add_sect_attrs(mod, info);
-	add_notes_attrs(mod, info);
-
-	return 0;
-
-out_unreg_modinfo_attrs:
-	module_remove_modinfo_attrs(mod, -1);
-out_unreg_param:
-	module_param_sysfs_remove(mod);
-out_unreg_holders:
-	kobject_put(mod->holders_dir);
-out_unreg:
-	mod_kobject_put(mod);
-out:
-	return err;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-	remove_notes_attrs(mod);
-	remove_sect_attrs(mod);
-	mod_kobject_put(mod);
-}
-
-static void init_param_lock(struct module *mod)
-{
-	mutex_init(&mod->param_lock);
-}
-#else /* !CONFIG_SYSFS */
-
-static int mod_sysfs_setup(struct module *mod,
-			   const struct load_info *info,
-			   struct kernel_param *kparam,
-			   unsigned int num_params)
-{
-	return 0;
-}
-
-static void mod_sysfs_fini(struct module *mod)
-{
-}
-
-static void module_remove_modinfo_attrs(struct module *mod, int end)
-{
-}
-
-static void del_usage_links(struct module *mod)
-{
-}
-
-static void init_param_lock(struct module *mod)
-{
-}
-#endif /* CONFIG_SYSFS */
-
-static void mod_sysfs_teardown(struct module *mod)
-{
-	del_usage_links(mod);
-	module_remove_modinfo_attrs(mod, -1);
-	module_param_sysfs_remove(mod);
-	kobject_put(mod->mkobj.drivers_dir);
-	kobject_put(mod->holders_dir);
-	mod_sysfs_fini(mod);
-}
-
-/*
  * LKM RO/NX protection: protect module's text/ro-data
  * from modification and any data from execution.
  *