From e636c8d336489bf3eed5878299e6cc045bbad077 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:17:29 +0000
Subject: [PATCH] debug lk
---
kernel/fs/sysfs/group.c | 194 ++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 170 insertions(+), 24 deletions(-)
diff --git a/kernel/fs/sysfs/group.c b/kernel/fs/sysfs/group.c
index 1eb2d63..64e6a66 100644
--- a/kernel/fs/sysfs/group.c
+++ b/kernel/fs/sysfs/group.c
@@ -13,6 +13,7 @@
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/err.h>
+#include <linux/fs.h>
#include "sysfs.h"
@@ -112,7 +113,8 @@
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))
@@ -174,6 +176,26 @@
}
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
@@ -190,23 +212,27 @@
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
@@ -390,15 +416,18 @@
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;
@@ -423,12 +452,129 @@
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 PTR_ERR_OR_ZERO(link);
}
-EXPORT_SYMBOL_GPL(__compat_only_sysfs_link_entry_to_kobj);
+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);
--
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