Commit fddca527 authored by James Bottomley's avatar James Bottomley Committed by Ard Biesheuvel
Browse files

efivarfs: move variable lifetime management into the inodes 



Make the inodes the default management vehicle for struct
efivar_entry, so they are now all freed automatically if the file is
removed and on unmount in kill_litter_super().  Remove the now
superfluous iterator to free the entries after kill_litter_super().

Also fixes a bug where some entry freeing was missing causing efivarfs
to leak memory.

Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 7e365c7e

fs/efivarfs/inode.c

+10 −13
Original line number Diff line number Diff line
@@ -82,26 +82,23 @@ static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir, 
	struct efivar_entry *var;

	int namelen, i = 0, err = 0;

	bool is_removable = false;

	efi_guid_t vendor;



	if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))

		return -EINVAL;



	var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);

	if (!var)

		return -ENOMEM;



	/* length of the variable name itself: remove GUID and separator */

	namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;



	err = guid_parse(dentry->d_name.name + namelen + 1, &var->var.VendorGuid);

	err = guid_parse(dentry->d_name.name + namelen + 1, &vendor);

	if (err)

		goto out;

	if (guid_equal(&var->var.VendorGuid, &LINUX_EFI_RANDOM_SEED_TABLE_GUID)) {

	if (guid_equal(&vendor, &LINUX_EFI_RANDOM_SEED_TABLE_GUID)) {

		err = -EPERM;

		goto out;

	}



	if (efivar_variable_is_removable(var->var.VendorGuid,

	if (efivar_variable_is_removable(vendor,

					 dentry->d_name.name, namelen))

		is_removable = true;
@@ -110,6 +107,9 @@ static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir, 
		err = -ENOMEM;

		goto out;

	}

	var = efivar_entry(inode);



	var->var.VendorGuid = vendor;



	for (i = 0; i < namelen; i++)

		var->var.VariableName[i] = dentry->d_name.name[i];
@@ -117,7 +117,6 @@ static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir, 
	var->var.VariableName[i] = '\0';



	inode->i_private = var;

	kmemleak_ignore(var);



	err = efivar_entry_add(var, &info->efivarfs_list);

	if (err)
@@ -126,11 +125,9 @@ static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir, 
	d_instantiate(dentry, inode);

	dget(dentry);

out:

	if (err) {

		kfree(var);

		if (inode)

	if (err && inode)

		iput(inode);

	}



	return err;

}

fs/efivarfs/internal.h

+6 −1
Original line number Diff line number Diff line
@@ -29,15 +29,20 @@ struct efi_variable { 
struct efivar_entry {

	struct efi_variable var;

	struct list_head list;

	struct inode vfs_inode;

};



static inline struct efivar_entry *efivar_entry(struct inode *inode)

{

	return container_of(inode, struct efivar_entry, vfs_inode);

}



int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *,

			    struct list_head *),

		void *data, struct list_head *head);



int efivar_entry_add(struct efivar_entry *entry, struct list_head *head);

void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head);

void efivar_entry_remove(struct efivar_entry *entry);

int efivar_entry_delete(struct efivar_entry *entry);



int efivar_entry_size(struct efivar_entry *entry, unsigned long *size);

fs/efivarfs/super.c

+29 −22
Original line number Diff line number Diff line
@@ -39,9 +39,25 @@ static int efivarfs_ops_notifier(struct notifier_block *nb, unsigned long event, 
	return NOTIFY_OK;

}



static void efivarfs_evict_inode(struct inode *inode)

static struct inode *efivarfs_alloc_inode(struct super_block *sb)

{

	clear_inode(inode);

	struct efivar_entry *entry = kzalloc(sizeof(*entry), GFP_KERNEL);



	if (!entry)

		return NULL;



	inode_init_once(&entry->vfs_inode);



	return &entry->vfs_inode;

}



static void efivarfs_free_inode(struct inode *inode)

{

	struct efivar_entry *entry = efivar_entry(inode);



	if (inode->i_private)

		list_del(&entry->list);

	kfree(entry);

}



static int efivarfs_show_options(struct seq_file *m, struct dentry *root)
@@ -106,7 +122,8 @@ static int efivarfs_statfs(struct dentry *dentry, struct kstatfs *buf) 
static const struct super_operations efivarfs_ops = {

	.statfs = efivarfs_statfs,

	.drop_inode = generic_delete_inode,

	.evict_inode = efivarfs_evict_inode,

	.alloc_inode = efivarfs_alloc_inode,

	.free_inode = efivarfs_free_inode,

	.show_options = efivarfs_show_options,

};
@@ -227,21 +244,14 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor, 
	if (guid_equal(&vendor, &LINUX_EFI_RANDOM_SEED_TABLE_GUID))

		return 0;



	entry = kzalloc(sizeof(*entry), GFP_KERNEL);

	if (!entry)

		return err;



	memcpy(entry->var.VariableName, name16, name_size);

	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));



	name = efivar_get_utf8name(name16, &vendor);

	if (!name)

		goto fail;

		return err;



	/* length of the variable name itself: remove GUID and separator */

	len = strlen(name) - EFI_VARIABLE_GUID_LEN - 1;



	if (efivar_variable_is_removable(entry->var.VendorGuid, name, len))

	if (efivar_variable_is_removable(vendor, name, len))

		is_removable = true;



	inode = efivarfs_get_inode(sb, d_inode(root), S_IFREG | 0644, 0,
@@ -249,6 +259,11 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor, 
	if (!inode)

		goto fail_name;



	entry = efivar_entry(inode);



	memcpy(entry->var.VariableName, name16, name_size);

	memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));



	dentry = efivarfs_alloc_dentry(root, name);

	if (IS_ERR(dentry)) {

		err = PTR_ERR(dentry);
@@ -273,16 +288,8 @@ static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor, 
	iput(inode);

fail_name:

	kfree(name);

fail:

	kfree(entry);

	return err;

}



static int efivarfs_destroy(struct efivar_entry *entry, void *data)

{

	efivar_entry_remove(entry);

	kfree(entry);

	return 0;

	return err;

}



enum {
@@ -407,7 +414,7 @@ static void efivarfs_kill_sb(struct super_block *sb) 
	kill_litter_super(sb);



	/* Remove all entries and destroy */

	efivar_entry_iter(efivarfs_destroy, &sfi->efivarfs_list, NULL);

	WARN_ON(!list_empty(&sfi->efivarfs_list));

	kfree(sfi);

}

fs/efivarfs/vars.c

+3 −36
Original line number Diff line number Diff line
@@ -485,34 +485,6 @@ void __efivar_entry_add(struct efivar_entry *entry, struct list_head *head) 
	list_add(&entry->list, head);

}



/**

 * efivar_entry_remove - remove entry from variable list

 * @entry: entry to remove from list

 *

 * Returns 0 on success, or a kernel error code on failure.

 */

void efivar_entry_remove(struct efivar_entry *entry)

{

	list_del(&entry->list);

}



/*

 * efivar_entry_list_del_unlock - remove entry from variable list

 * @entry: entry to remove

 *

 * Remove @entry from the variable list and release the list lock.

 *

 * NOTE: slightly weird locking semantics here - we expect to be

 * called with the efivars lock already held, and we release it before

 * returning. This is because this function is usually called after

 * set_variable() while the lock is still held.

 */

static void efivar_entry_list_del_unlock(struct efivar_entry *entry)

{

	list_del(&entry->list);

	efivar_unlock();

}



/**

 * efivar_entry_delete - delete variable and remove entry from list

 * @entry: entry containing variable to delete
@@ -536,12 +508,10 @@ int efivar_entry_delete(struct efivar_entry *entry) 
	status = efivar_set_variable_locked(entry->var.VariableName,

					    &entry->var.VendorGuid,

					    0, 0, NULL, false);

	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND)) {

	efivar_unlock();

	if (!(status == EFI_SUCCESS || status == EFI_NOT_FOUND))

		return efi_status_to_err(status);

	}



	efivar_entry_list_del_unlock(entry);

	return 0;

}
@@ -679,9 +649,6 @@ int efivar_entry_set_get_size(struct efivar_entry *entry, u32 attributes, 
				    &entry->var.VendorGuid,

				    NULL, size, NULL);



	if (status == EFI_NOT_FOUND)

		efivar_entry_list_del_unlock(entry);

	else

	efivar_unlock();



	if (status && status != EFI_BUFFER_TOO_SMALL)