diff options
Diffstat (limited to 'fs/sysfs/group.c')
| -rw-r--r-- | fs/sysfs/group.c | 342 |
1 files changed, 283 insertions, 59 deletions
diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index ac2de0ed69ad..e1e639f515a0 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * fs/sysfs/group.c - Operations for adding/removing multiple files at once. * @@ -5,9 +6,6 @@ * Copyright (c) 2003 Open Source Development Lab * Copyright (c) 2013 Greg Kroah-Hartman * Copyright (c) 2013 The Linux Foundation - * - * This file is released undert the GPL v2. - * */ #include <linux/kobject.h> @@ -15,6 +13,7 @@ #include <linux/dcache.h> #include <linux/namei.h> #include <linux/err.h> +#include <linux/fs.h> #include "sysfs.h" @@ -22,7 +21,7 @@ static void remove_files(struct kernfs_node *parent, const struct attribute_group *grp) { struct attribute *const *attr; - struct bin_attribute *const *bin_attr; + const struct bin_attribute *const *bin_attr; if (grp->attrs) for (attr = grp->attrs; *attr; attr++) @@ -32,11 +31,26 @@ static void remove_files(struct kernfs_node *parent, kernfs_remove_by_name(parent, (*bin_attr)->attr.name); } +static umode_t __first_visible(const struct attribute_group *grp, struct kobject *kobj) +{ + if (grp->attrs && grp->attrs[0] && grp->is_visible) + return grp->is_visible(kobj, grp->attrs[0], 0); + + if (grp->attrs && grp->attrs[0] && grp->is_visible_const) + return grp->is_visible_const(kobj, grp->attrs[0], 0); + + if (grp->bin_attrs && grp->bin_attrs[0] && grp->is_bin_visible) + return grp->is_bin_visible(kobj, grp->bin_attrs[0], 0); + + return 0; +} + 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; + const struct bin_attribute *const *bin_attr; int error = 0, i; if (grp->attrs) { @@ -50,8 +64,12 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, */ if (update) kernfs_remove_by_name(parent, (*attr)->name); - if (grp->is_visible) { - mode = grp->is_visible(kobj, *attr, i); + if (grp->is_visible || grp->is_visible_const) { + if (grp->is_visible) + mode = grp->is_visible(kobj, *attr, i); + else + mode = grp->is_visible_const(kobj, *attr, i); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } @@ -61,8 +79,8 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, (*attr)->name, mode); mode &= SYSFS_PREALLOC | 0664; - error = sysfs_add_file_mode_ns(parent, *attr, false, - mode, NULL); + error = sysfs_add_file_mode_ns(parent, *attr, mode, uid, + gid, NULL); if (unlikely(error)) break; } @@ -75,24 +93,28 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, if (grp->bin_attrs) { for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { umode_t mode = (*bin_attr)->attr.mode; + size_t size = (*bin_attr)->size; 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); + mode &= ~SYSFS_GROUP_INVISIBLE; if (!mode) continue; } + if (grp->bin_size) + size = grp->bin_size(kobj, *bin_attr, i); WARN(mode & ~(SYSFS_PREALLOC | 0664), "Attribute %s: Invalid permissions 0%o\n", (*bin_attr)->attr.name, mode); mode &= SYSFS_PREALLOC | 0664; - error = sysfs_add_file_mode_ns(parent, - &(*bin_attr)->attr, true, - mode, NULL); + error = sysfs_add_bin_file_mode_ns(parent, *bin_attr, + mode, size, uid, gid, + NULL); if (error) break; } @@ -108,35 +130,72 @@ 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; - BUG_ON(!kobj || (!update && !kobj->sd)); + 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; + if (!grp->attrs && !grp->bin_attrs) { - WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n", - kobj->name, grp->name ?: ""); - return -EINVAL; + pr_debug("sysfs: (bin_)attrs not set by subsystem for group: %s/%s, skipping\n", + kobj->name, grp->name ?: ""); + return 0; } + + kobject_get_ownership(kobj, &uid, &gid); if (grp->name) { - kn = kernfs_create_dir(kobj->sd, grp->name, - S_IRWXU | S_IRUGO | S_IXUGO, kobj); - if (IS_ERR(kn)) { - if (PTR_ERR(kn) == -EEXIST) - sysfs_warn_dup(kobj->sd, grp->name); - return PTR_ERR(kn); + umode_t mode = __first_visible(grp, kobj); + + if (mode & SYSFS_GROUP_INVISIBLE) + mode = 0; + else + mode = S_IRWXU | S_IRUGO | S_IXUGO; + + if (update) { + kn = kernfs_find_and_get(kobj->sd, grp->name); + if (!kn) { + pr_debug("attr grp %s/%s not created yet\n", + kobj->name, grp->name); + /* may have been invisible prior to this update */ + update = 0; + } else if (!mode) { + sysfs_remove_group(kobj, grp); + kernfs_put(kn); + return 0; + } + } + + if (!update) { + if (!mode) + return 0; + kn = kernfs_create_dir_ns(kobj->sd, grp->name, mode, + 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 + } else { kn = kobj->sd; + } + kernfs_get(kn); - error = create_files(kn, kobj, grp, update); + 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; } @@ -157,6 +216,26 @@ int sysfs_create_group(struct kobject *kobj, } 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 @@ -173,25 +252,29 @@ EXPORT_SYMBOL_GPL(sysfs_create_group); int sysfs_create_groups(struct kobject *kobj, const struct attribute_group **groups) { - int error = 0; - int i; - - if (!groups) - return 0; - - for (i = 0; groups[i]; i++) { - error = sysfs_create_group(kobj, groups[i]); - if (error) { - while (--i >= 0) - sysfs_remove_group(kobj, groups[i]); - break; - } - } - return error; + 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 @@ -201,7 +284,8 @@ EXPORT_SYMBOL_GPL(sysfs_create_groups); * 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. + * 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. @@ -232,9 +316,8 @@ void sysfs_remove_group(struct kobject *kobj, 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)); + pr_debug("sysfs group '%s' not found for kobject '%s'\n", + grp->name, kobject_name(kobj)); return; } } else { @@ -271,18 +354,20 @@ void sysfs_remove_groups(struct kobject *kobj, EXPORT_SYMBOL_GPL(sysfs_remove_groups); /** - * sysfs_merge_group - merge files into a pre-existing attribute group. + * sysfs_merge_group - merge files into a pre-existing named 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. + * This function returns an error if the group doesn't exist, the .name field is + * NULL 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; @@ -291,8 +376,11 @@ int sysfs_merge_group(struct kobject *kobj, if (!parent) return -ENOENT; + kobject_get_ownership(kobj, &uid, &gid); + for ((i = 0, attr = grp->attrs); *attr && !error; (++i, ++attr)) - error = sysfs_add_file(parent, *attr, false); + 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); @@ -304,7 +392,7 @@ int sysfs_merge_group(struct kobject *kobj, EXPORT_SYMBOL_GPL(sysfs_merge_group); /** - * sysfs_unmerge_group - remove files from a pre-existing attribute group. + * sysfs_unmerge_group - remove files from a pre-existing named attribute group. * @kobj: The kobject containing the group. * @grp: The files to remove and the attribute group they belong to. */ @@ -367,15 +455,18 @@ void sysfs_remove_link_from_group(struct kobject *kobj, const char *group_name, EXPORT_SYMBOL_GPL(sysfs_remove_link_from_group); /** - * __compat_only_sysfs_link_entry_to_kobj - add a symlink to a kobject pointing + * 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) +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; @@ -394,18 +485,151 @@ int __compat_only_sysfs_link_entry_to_kobj(struct kobject *kobj, if (!target) return -ENOENT; - entry = kernfs_find_and_get(target_kobj->sd, target_name); + entry = kernfs_find_and_get(target, target_name); if (!entry) { kernfs_put(target); return -ENOENT; } - link = kernfs_create_link(kobj->sd, target_name, entry); - if (IS_ERR(link) && PTR_ERR(link) == -EEXIST) - sysfs_warn_dup(kobj->sd, target_name); + 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 IS_ERR(link) ? PTR_ERR(link) : 0; + return PTR_ERR_OR_ZERO(link); +} +EXPORT_SYMBOL_GPL(compat_only_sysfs_link_entry_to_kobj); + +static int sysfs_group_attrs_change_owner(struct kobject *kobj, + struct kernfs_node *grp_kn, + const struct attribute_group *grp, + struct iattr *newattrs) +{ + struct kernfs_node *kn; + int error, i; + umode_t mode; + + if (grp->attrs) { + struct attribute *const *attr; + + for (i = 0, attr = grp->attrs; *attr; i++, attr++) { + if (grp->is_visible) { + mode = grp->is_visible(kobj, *attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } + 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) { + const struct bin_attribute *const *bin_attr; + + for (i = 0, bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) { + if (grp->is_bin_visible) { + mode = grp->is_bin_visible(kobj, *bin_attr, i); + if (mode & SYSFS_GROUP_INVISIBLE) + break; + if (!mode) + continue; + } + 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(kobj, 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(__compat_only_sysfs_link_entry_to_kobj); +EXPORT_SYMBOL_GPL(sysfs_groups_change_owner); |