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1// SPDX-License-Identifier: GPL-2.02#include <linux/of.h>3#include <linux/slab.h>4 5#include "of_private.h"6 7/* true when node is initialized */8static int of_node_is_initialized(const struct device_node *node)9{10 return node && node->kobj.state_initialized;11}12 13/* true when node is attached (i.e. present on sysfs) */14int of_node_is_attached(const struct device_node *node)15{16 return node && node->kobj.state_in_sysfs;17}18 19 20#ifndef CONFIG_OF_DYNAMIC21static void of_node_release(struct kobject *kobj)22{23 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */24}25#endif /* CONFIG_OF_DYNAMIC */26 27const struct kobj_type of_node_ktype = {28 .release = of_node_release,29};30 31static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,32 struct bin_attribute *bin_attr, char *buf,33 loff_t offset, size_t count)34{35 struct property *pp = container_of(bin_attr, struct property, attr);36 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);37}38 39/* always return newly allocated name, caller must free after use */40static const char *safe_name(struct kobject *kobj, const char *orig_name)41{42 const char *name = orig_name;43 struct kernfs_node *kn;44 int i = 0;45 46 /* don't be a hero. After 16 tries give up */47 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {48 sysfs_put(kn);49 if (name != orig_name)50 kfree(name);51 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);52 }53 54 if (name == orig_name) {55 name = kstrdup(orig_name, GFP_KERNEL);56 } else {57 pr_warn("Duplicate name in %s, renamed to \"%s\"\n",58 kobject_name(kobj), name);59 }60 return name;61}62 63int __of_add_property_sysfs(struct device_node *np, struct property *pp)64{65 int rc;66 67 /* Important: Don't leak passwords */68 bool secure = strncmp(pp->name, "security-", 9) == 0;69 70 if (!IS_ENABLED(CONFIG_SYSFS))71 return 0;72 73 if (!of_kset || !of_node_is_attached(np))74 return 0;75 76 sysfs_bin_attr_init(&pp->attr);77 pp->attr.attr.name = safe_name(&np->kobj, pp->name);78 pp->attr.attr.mode = secure ? 0400 : 0444;79 pp->attr.size = secure ? 0 : pp->length;80 pp->attr.read = of_node_property_read;81 82 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);83 WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np);84 return rc;85}86 87void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)88{89 if (!IS_ENABLED(CONFIG_SYSFS))90 return;91 92 sysfs_remove_bin_file(&np->kobj, &prop->attr);93 kfree(prop->attr.attr.name);94}95 96void __of_remove_property_sysfs(struct device_node *np, struct property *prop)97{98 /* at early boot, bail here and defer setup to of_init() */99 if (of_kset && of_node_is_attached(np))100 __of_sysfs_remove_bin_file(np, prop);101}102 103void __of_update_property_sysfs(struct device_node *np, struct property *newprop,104 struct property *oldprop)105{106 /* At early boot, bail out and defer setup to of_init() */107 if (!of_kset)108 return;109 110 if (oldprop)111 __of_sysfs_remove_bin_file(np, oldprop);112 __of_add_property_sysfs(np, newprop);113}114 115int __of_attach_node_sysfs(struct device_node *np)116{117 const char *name;118 struct kobject *parent;119 struct property *pp;120 int rc;121 122 if (!IS_ENABLED(CONFIG_SYSFS) || !of_kset)123 return 0;124 125 np->kobj.kset = of_kset;126 if (!np->parent) {127 /* Nodes without parents are new top level trees */128 name = safe_name(&of_kset->kobj, "base");129 parent = NULL;130 } else {131 name = safe_name(&np->parent->kobj, kbasename(np->full_name));132 parent = &np->parent->kobj;133 }134 if (!name)135 return -ENOMEM;136 137 rc = kobject_add(&np->kobj, parent, "%s", name);138 kfree(name);139 if (rc)140 return rc;141 142 for_each_property_of_node(np, pp)143 __of_add_property_sysfs(np, pp);144 145 of_node_get(np);146 return 0;147}148 149void __of_detach_node_sysfs(struct device_node *np)150{151 struct property *pp;152 153 BUG_ON(!of_node_is_initialized(np));154 if (!of_kset)155 return;156 157 /* only remove properties if on sysfs */158 if (of_node_is_attached(np)) {159 for_each_property_of_node(np, pp)160 __of_sysfs_remove_bin_file(np, pp);161 kobject_del(&np->kobj);162 }163 164 of_node_put(np);165}166