linux/fs/sysfs/group.c

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// SPDX-License-Identifier: GPL-2.0
/*
* fs/sysfs/group.c - Operations for adding/removing multiple files at once.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2013 Greg Kroah-Hartman
* Copyright (c) 2013 The Linux Foundation
*/
#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/err.h>
#include <linux/fs.h>
#include "sysfs.h"
static void remove_files(struct kernfs_node *parent,
const struct attribute_group *grp)
{
struct attribute *const *attr;
struct bin_attribute *const *bin_attr;
if (grp->attrs)
for (attr = grp->attrs; *attr; attr++)
kernfs_remove_by_name(parent, (*attr)->name);
if (grp->bin_attrs)
for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++)
kernfs_remove_by_name(parent, (*bin_attr)->attr.name);
}
static int create_files(struct kernfs_node *parent, struct kobject *kobj,
kuid_t uid, kgid_t gid,
const struct attribute_group *grp, int update)
{
struct attribute *const *attr;
struct bin_attribute *const *bin_attr;
int error = 0, i;
if (grp->attrs) {
for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
umode_t mode = (*attr)->mode;
/*
* In update mode, we're changing the permissions or
* visibility. Do this by first removing then
* re-adding (if required) the file.
*/
if (update)
kernfs_remove_by_name(parent, (*attr)->name);
if (grp->is_visible) {
mode = grp->is_visible(kobj, *attr, i);
if (!mode)
continue;
}
WARN(mode & ~(SYSFS_PREALLOC | 0664),
"Attribute %s: Invalid permissions 0%o\n",
(*attr)->name, mode);
mode &= SYSFS_PREALLOC | 0664;
error = sysfs_add_file_mode_ns(parent, *attr, mode, uid,
gid, NULL);
if (unlikely(error))
break;
}
if (error) {
remove_files(parent, grp);
goto exit;
}
}
if (grp->bin_attrs) {
for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
umode_t mode = (*bin_attr)->attr.mode;
if (update)
kernfs_remove_by_name(parent,
(*bin_attr)->attr.name);
if (grp->is_bin_visible) {
mode = grp->is_bin_visible(kobj, *bin_attr, i);
if (!mode)
continue;
}
WARN(mode & ~(SYSFS_PREALLOC | 0664),
"Attribute %s: Invalid permissions 0%o\n",
(*bin_attr)->attr.name, mode);
mode &= SYSFS_PREALLOC | 0664;
error = sysfs_add_bin_file_mode_ns(parent, *bin_attr,
mode, uid, gid,
NULL);
if (error)
break;
}
if (error)
remove_files(parent, grp);
}
exit:
return error;
}
static int internal_create_group(struct kobject *kobj, int update,
const struct attribute_group *grp)
{
struct kernfs_node *kn;
kuid_t uid;
kgid_t gid;
int error;
if (WARN_ON(!kobj || (!update && !kobj->sd)))
return -EINVAL;
/* Updates may happen before the object has been instantiated */
if (unlikely(update && !kobj->sd))
return -EINVAL;
sysfs: Skip empty folders creation Most sysfs attributes are statically defined, the goal with this design being to be able to move all the filesystem description into read-only memory. Anyway, it may be relevant in some cases to populate attributes at run time. This leads to situation where an attribute may or may not be present depending on conditions which are not known at compile time, up to the point where no attribute at all gets added in a folder which then becomes "sometimes" empty. Problem is, providing an attribute group with a name and without .[bin_]attrs members will be loudly refused by the core, leading in most cases to a device registration failure. The simple way to support such situation right now is to dynamically allocate an empty attribute array, which is: * a (small) waste of space * a waste of time * disturbing, to say the least, as an empty sysfs folder will be created anyway. Another (even worse) possibility would be to dynamically overwrite a member of the attribute_group list, hopefully the last, which is also supposed to remain in the read-only section. In order to avoid these hackish situations, while still giving a little bit of flexibility, we might just check the validity of the .[bin_]attrs list and, if empty, just skip the attribute group creation instead of failing. This way, developers will not be tempted to workaround the core with useless allocations or strange writes on supposedly read-only structures. The content of the WARN() message is kept but turned into a debug message in order to help developers understanding why their sysfs folders might now silently fail to be created. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Message-ID: <20230614063018.2419043-3-miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 06:30:16 +00:00
if (!grp->attrs && !grp->bin_attrs) {
sysfs: Skip empty folders creation Most sysfs attributes are statically defined, the goal with this design being to be able to move all the filesystem description into read-only memory. Anyway, it may be relevant in some cases to populate attributes at run time. This leads to situation where an attribute may or may not be present depending on conditions which are not known at compile time, up to the point where no attribute at all gets added in a folder which then becomes "sometimes" empty. Problem is, providing an attribute group with a name and without .[bin_]attrs members will be loudly refused by the core, leading in most cases to a device registration failure. The simple way to support such situation right now is to dynamically allocate an empty attribute array, which is: * a (small) waste of space * a waste of time * disturbing, to say the least, as an empty sysfs folder will be created anyway. Another (even worse) possibility would be to dynamically overwrite a member of the attribute_group list, hopefully the last, which is also supposed to remain in the read-only section. In order to avoid these hackish situations, while still giving a little bit of flexibility, we might just check the validity of the .[bin_]attrs list and, if empty, just skip the attribute group creation instead of failing. This way, developers will not be tempted to workaround the core with useless allocations or strange writes on supposedly read-only structures. The content of the WARN() message is kept but turned into a debug message in order to help developers understanding why their sysfs folders might now silently fail to be created. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Message-ID: <20230614063018.2419043-3-miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 06:30:16 +00:00
pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n",
kobj->name, grp->name ?: "");
return 0;
sysfs: Prevent crash on unset sysfs group attributes Do not let the kernel crash when a device is registered with sysfs while group attributes are not set (aka NULL). Warn about the offender with some information about the offending device. This would warn instead of trying NULL pointer deref like: BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81152673>] internal_create_group+0x83/0x1a0 PGD 0 Oops: 0000 [#1] SMP CPU 0 Modules linked in: Pid: 1, comm: swapper/0 Not tainted 3.4.0-rc1-x86_64 #3 HP ProLiant DL360 G4 RIP: 0010:[<ffffffff81152673>] [<ffffffff81152673>] internal_create_group+0x83/0x1a0 RSP: 0018:ffff88019485fd70 EFLAGS: 00010202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000001 RDX: ffff880192e99908 RSI: ffff880192e99630 RDI: ffffffff81a26c60 RBP: ffff88019485fdc0 R08: 0000000000000000 R09: 0000000000000000 R10: ffff880192e99908 R11: 0000000000000000 R12: ffffffff81a16a00 R13: ffff880192e99908 R14: ffffffff81a16900 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88019bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001a0c000 CR4: 00000000000007f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process swapper/0 (pid: 1, threadinfo ffff88019485e000, task ffff880194878000) Stack: ffff88019485fdd0 ffff880192da9d60 0000000000000000 ffff880192e99908 ffff880192e995d8 0000000000000001 ffffffff81a16a00 ffff880192da9d60 0000000000000000 0000000000000000 ffff88019485fdd0 ffffffff811527be Call Trace: [<ffffffff811527be>] sysfs_create_group+0xe/0x10 [<ffffffff81376ca6>] device_add_groups+0x46/0x80 [<ffffffff81377d3d>] device_add+0x46d/0x6a0 ... Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-03 07:59:48 +00:00
}
sysfs: Skip empty folders creation Most sysfs attributes are statically defined, the goal with this design being to be able to move all the filesystem description into read-only memory. Anyway, it may be relevant in some cases to populate attributes at run time. This leads to situation where an attribute may or may not be present depending on conditions which are not known at compile time, up to the point where no attribute at all gets added in a folder which then becomes "sometimes" empty. Problem is, providing an attribute group with a name and without .[bin_]attrs members will be loudly refused by the core, leading in most cases to a device registration failure. The simple way to support such situation right now is to dynamically allocate an empty attribute array, which is: * a (small) waste of space * a waste of time * disturbing, to say the least, as an empty sysfs folder will be created anyway. Another (even worse) possibility would be to dynamically overwrite a member of the attribute_group list, hopefully the last, which is also supposed to remain in the read-only section. In order to avoid these hackish situations, while still giving a little bit of flexibility, we might just check the validity of the .[bin_]attrs list and, if empty, just skip the attribute group creation instead of failing. This way, developers will not be tempted to workaround the core with useless allocations or strange writes on supposedly read-only structures. The content of the WARN() message is kept but turned into a debug message in order to help developers understanding why their sysfs folders might now silently fail to be created. Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Message-ID: <20230614063018.2419043-3-miquel.raynal@bootlin.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-14 06:30:16 +00:00
kobject_get_ownership(kobj, &uid, &gid);
if (grp->name) {
if (update) {
kn = kernfs_find_and_get(kobj->sd, grp->name);
if (!kn) {
pr_warn("Can't update unknown attr grp name: %s/%s\n",
kobj->name, grp->name);
return -EINVAL;
}
} else {
Driver core patches for 4.19-rc1 Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported. That merge issue is in fs/sysfs/group.c and Stephen has posted the diff of what it should be to resolve this. I'll follow up with that diff to this pull request. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -----BEGIN PGP SIGNATURE----- iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCW3g86Q8cZ3JlZ0Brcm9h aC5jb20ACgkQMUfUDdst+ynyXQCePaZSW8wft4b7nLN8RdZ98ATBru0Ani10lrJa HQeQJRNbWU1AZ0ym7695 =tOaH -----END PGP SIGNATURE----- Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...
2018-08-18 18:44:53 +00:00
kn = kernfs_create_dir_ns(kobj->sd, grp->name,
S_IRWXU | S_IRUGO | S_IXUGO,
uid, gid, kobj, NULL);
if (IS_ERR(kn)) {
if (PTR_ERR(kn) == -EEXIST)
sysfs_warn_dup(kobj->sd, grp->name);
return PTR_ERR(kn);
}
}
} else {
kn = kobj->sd;
}
kernfs_get(kn);
error = create_files(kn, kobj, uid, gid, grp, update);
if (error) {
if (grp->name)
kernfs_remove(kn);
}
kernfs_put(kn);
if (grp->name && update)
kernfs_put(kn);
return error;
}
/**
* sysfs_create_group - given a directory kobject, create an attribute group
* @kobj: The kobject to create the group on
* @grp: The attribute group to create
*
* This function creates a group for the first time. It will explicitly
* warn and error if any of the attribute files being created already exist.
*
* Returns 0 on success or error code on failure.
*/
int sysfs_create_group(struct kobject *kobj,
const struct attribute_group *grp)
{
return internal_create_group(kobj, 0, grp);
}
EXPORT_SYMBOL_GPL(sysfs_create_group);
static int internal_create_groups(struct kobject *kobj, int update,
const struct attribute_group **groups)
{
int error = 0;
int i;
if (!groups)
return 0;
for (i = 0; groups[i]; i++) {
error = internal_create_group(kobj, update, groups[i]);
if (error) {
while (--i >= 0)
sysfs_remove_group(kobj, groups[i]);
break;
}
}
return error;
}
/**
* sysfs_create_groups - given a directory kobject, create a bunch of attribute groups
* @kobj: The kobject to create the group on
* @groups: The attribute groups to create, NULL terminated
*
* This function creates a bunch of attribute groups. If an error occurs when
* creating a group, all previously created groups will be removed, unwinding
* everything back to the original state when this function was called.
* It will explicitly warn and error if any of the attribute files being
* created already exist.
*
* Returns 0 on success or error code from sysfs_create_group on failure.
*/
int sysfs_create_groups(struct kobject *kobj,
const struct attribute_group **groups)
{
return internal_create_groups(kobj, 0, groups);
}
EXPORT_SYMBOL_GPL(sysfs_create_groups);
/**
* sysfs_update_groups - given a directory kobject, create a bunch of attribute groups
* @kobj: The kobject to update the group on
* @groups: The attribute groups to update, NULL terminated
*
* This function update a bunch of attribute groups. If an error occurs when
* updating a group, all previously updated groups will be removed together
* with already existing (not updated) attributes.
*
* Returns 0 on success or error code from sysfs_update_group on failure.
*/
int sysfs_update_groups(struct kobject *kobj,
const struct attribute_group **groups)
{
return internal_create_groups(kobj, 1, groups);
}
EXPORT_SYMBOL_GPL(sysfs_update_groups);
/**
* sysfs_update_group - given a directory kobject, update an attribute group
* @kobj: The kobject to update the group on
* @grp: The attribute group to update
*
* This function updates an attribute group. Unlike
* sysfs_create_group(), it will explicitly not warn or error if any
* of the attribute files being created already exist. Furthermore,
* if the visibility of the files has changed through the is_visible()
* callback, it will update the permissions and add or remove the
* relevant files. Changing a group's name (subdirectory name under
* kobj's directory in sysfs) is not allowed.
*
* The primary use for this function is to call it after making a change
* that affects group visibility.
*
* Returns 0 on success or error code on failure.
*/
int sysfs_update_group(struct kobject *kobj,
const struct attribute_group *grp)
{
return internal_create_group(kobj, 1, grp);
}
EXPORT_SYMBOL_GPL(sysfs_update_group);
/**
* sysfs_remove_group: remove a group from a kobject
* @kobj: kobject to remove the group from
* @grp: group to remove
*
* This function removes a group of attributes from a kobject. The attributes
* previously have to have been created for this group, otherwise it will fail.
*/
void sysfs_remove_group(struct kobject *kobj,
const struct attribute_group *grp)
{
struct kernfs_node *parent = kobj->sd;
struct kernfs_node *kn;
if (grp->name) {
kn = kernfs_find_and_get(parent, grp->name);
if (!kn) {
WARN(!kn, KERN_WARNING
"sysfs group '%s' not found for kobject '%s'\n",
grp->name, kobject_name(kobj));
return;
}
} else {
kn = parent;
kernfs_get(kn);
}
remove_files(kn, grp);
if (grp->name)
kernfs_remove(kn);
kernfs_put(kn);
}
EXPORT_SYMBOL_GPL(sysfs_remove_group);
/**
* sysfs_remove_groups - remove a list of groups
*
* @kobj: The kobject for the groups to be removed from
* @groups: NULL terminated list of groups to be removed
*
* If groups is not NULL, remove the specified groups from the kobject.
*/
void sysfs_remove_groups(struct kobject *kobj,
const struct attribute_group **groups)
{
int i;
if (!groups)
return;
for (i = 0; groups[i]; i++)
sysfs_remove_group(kobj, groups[i]);
}
EXPORT_SYMBOL_GPL(sysfs_remove_groups);
/**
* sysfs_merge_group - merge files into a pre-existing attribute group.
* @kobj: The kobject containing the group.
* @grp: The files to create and the attribute group they belong to.
*
* This function returns an error if the group doesn't exist or any of the
* files already exist in that group, in which case none of the new files
* are created.
*/
int sysfs_merge_group(struct kobject *kobj,
const struct attribute_group *grp)
{
struct kernfs_node *parent;
kuid_t uid;
kgid_t gid;
int error = 0;
struct attribute *const *attr;
int i;
parent = kernfs_find_and_get(kobj->sd, grp->name);
if (!parent)
return -ENOENT;
kobject_get_ownership(kobj, &uid, &gid);
for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr))
error = sysfs_add_file_mode_ns(parent, *attr, (*attr)->mode,
uid, gid, NULL);
if (error) {
while (--i >= 0)
kernfs_remove_by_name(parent, (*--attr)->name);
}
kernfs_put(parent);
return error;
}
EXPORT_SYMBOL_GPL(sysfs_merge_group);
/**
* sysfs_unmerge_group - remove files from a pre-existing attribute group.
* @kobj: The kobject containing the group.
* @grp: The files to remove and the attribute group they belong to.
*/
void sysfs_unmerge_group(struct kobject *kobj,
const struct attribute_group *grp)
{
struct kernfs_node *parent;
struct attribute *const *attr;
parent = kernfs_find_and_get(kobj->sd, grp->name);
if (parent) {
for (attr = grp->attrs; *attr; ++attr)
kernfs_remove_by_name(parent, (*attr)->name);
kernfs_put(parent);
}
}
EXPORT_SYMBOL_GPL(sysfs_unmerge_group);
/**
* sysfs_add_link_to_group - add a symlink to an attribute group.
* @kobj: The kobject containing the group.
* @group_name: The name of the group.
* @target: The target kobject of the symlink to create.
* @link_name: The name of the symlink to create.
*/
int sysfs_add_link_to_group(struct kobject *kobj, const char *group_name,
struct kobject *target, const char *link_name)
{
struct kernfs_node *parent;
int error = 0;
parent = kernfs_find_and_get(kobj->sd, group_name);
if (!parent)
return -ENOENT;
error = sysfs_create_link_sd(parent, target, link_name);
kernfs_put(parent);
return error;
}
EXPORT_SYMBOL_GPL(sysfs_add_link_to_group);
/**
* sysfs_remove_link_from_group - remove a symlink from an attribute group.
* @kobj: The kobject containing the group.
* @group_name: The name of the group.
* @link_name: The name of the symlink to remove.
*/
void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name,
const char *link_name)
{
struct kernfs_node *parent;
parent = kernfs_find_and_get(kobj->sd, group_name);
if (parent) {
kernfs_remove_by_name(parent, link_name);
kernfs_put(parent);
}
}
EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group);
/**
* compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing
* to a group or an attribute
* @kobj: The kobject containing the group.
* @target_kobj: The target kobject.
* @target_name: The name of the target group or attribute.
* @symlink_name: The name of the symlink file (target_name will be
* considered if symlink_name is NULL).
*/
int compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj,
struct kobject *target_kobj,
const char *target_name,
const char *symlink_name)
{
struct kernfs_node *target;
struct kernfs_node *entry;
struct kernfs_node *link;
/*
* We don't own @target_kobj and it may be removed at any time.
* Synchronize using sysfs_symlink_target_lock. See sysfs_remove_dir()
* for details.
*/
spin_lock(&sysfs_symlink_target_lock);
target = target_kobj->sd;
if (target)
kernfs_get(target);
spin_unlock(&sysfs_symlink_target_lock);
if (!target)
return -ENOENT;
entry = kernfs_find_and_get(target, target_name);
if (!entry) {
kernfs_put(target);
return -ENOENT;
}
if (!symlink_name)
symlink_name = target_name;
link = kernfs_create_link(kobj->sd, symlink_name, entry);
if (PTR_ERR(link) == -EEXIST)
sysfs_warn_dup(kobj->sd, symlink_name);
kernfs_put(entry);
kernfs_put(target);
return PTR_ERR_OR_ZERO(link);
}
EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj);
static int sysfs_group_attrs_change_owner(struct kernfs_node *grp_kn,
const struct attribute_group *grp,
struct iattr *newattrs)
{
struct kernfs_node *kn;
int error;
if (grp->attrs) {
struct attribute *const *attr;
for (attr = grp->attrs; *attr; attr++) {
kn = kernfs_find_and_get(grp_kn, (*attr)->name);
if (!kn)
return -ENOENT;
error = kernfs_setattr(kn, newattrs);
kernfs_put(kn);
if (error)
return error;
}
}
if (grp->bin_attrs) {
struct bin_attribute *const *bin_attr;
for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
kn = kernfs_find_and_get(grp_kn, (*bin_attr)->attr.name);
if (!kn)
return -ENOENT;
error = kernfs_setattr(kn, newattrs);
kernfs_put(kn);
if (error)
return error;
}
}
return 0;
}
/**
* sysfs_group_change_owner - change owner of an attribute group.
* @kobj: The kobject containing the group.
* @grp: The attribute group.
* @kuid: new owner's kuid
* @kgid: new owner's kgid
*
* Returns 0 on success or error code on failure.
*/
int sysfs_group_change_owner(struct kobject *kobj,
const struct attribute_group *grp, kuid_t kuid,
kgid_t kgid)
{
struct kernfs_node *grp_kn;
int error;
struct iattr newattrs = {
.ia_valid = ATTR_UID | ATTR_GID,
.ia_uid = kuid,
.ia_gid = kgid,
};
if (!kobj->state_in_sysfs)
return -EINVAL;
if (grp->name) {
grp_kn = kernfs_find_and_get(kobj->sd, grp->name);
} else {
kernfs_get(kobj->sd);
grp_kn = kobj->sd;
}
if (!grp_kn)
return -ENOENT;
error = kernfs_setattr(grp_kn, &newattrs);
if (!error)
error = sysfs_group_attrs_change_owner(grp_kn, grp, &newattrs);
kernfs_put(grp_kn);
return error;
}
EXPORT_SYMBOL_GPL(sysfs_group_change_owner);
/**
* sysfs_groups_change_owner - change owner of a set of attribute groups.
* @kobj: The kobject containing the groups.
* @groups: The attribute groups.
* @kuid: new owner's kuid
* @kgid: new owner's kgid
*
* Returns 0 on success or error code on failure.
*/
int sysfs_groups_change_owner(struct kobject *kobj,
const struct attribute_group **groups,
kuid_t kuid, kgid_t kgid)
{
int error = 0, i;
if (!kobj->state_in_sysfs)
return -EINVAL;
if (!groups)
return 0;
for (i = 0; groups[i]; i++) {
error = sysfs_group_change_owner(kobj, groups[i], kuid, kgid);
if (error)
break;
}
return error;
}
EXPORT_SYMBOL_GPL(sysfs_groups_change_owner);