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![Frank Rowand](/assets/img/avatar_default.png)
There is a matching of_node_put() in __of_detach_node_sysfs() Remove misleading comment from function header comment for of_detach_node(). This patch may result in memory leaks from code that directly calls the dynamic node add and delete functions directly instead of using changesets. This commit should result in powerpc systems that dynamically allocate a node, then later deallocate the node to have a memory leak when the node is deallocated. The next commit will fix the leak. Tested-by: Alan Tull <atull@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Frank Rowand <frank.rowand@sony.com>
166 lines
3.8 KiB
C
166 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/of.h>
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#include <linux/slab.h>
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#include "of_private.h"
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/* true when node is initialized */
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static int of_node_is_initialized(struct device_node *node)
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{
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return node && node->kobj.state_initialized;
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}
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/* true when node is attached (i.e. present on sysfs) */
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int of_node_is_attached(struct device_node *node)
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{
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return node && node->kobj.state_in_sysfs;
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}
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#ifndef CONFIG_OF_DYNAMIC
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static void of_node_release(struct kobject *kobj)
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{
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/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
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}
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#endif /* CONFIG_OF_DYNAMIC */
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struct kobj_type of_node_ktype = {
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.release = of_node_release,
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};
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static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf,
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loff_t offset, size_t count)
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{
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struct property *pp = container_of(bin_attr, struct property, attr);
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return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
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}
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/* always return newly allocated name, caller must free after use */
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static const char *safe_name(struct kobject *kobj, const char *orig_name)
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{
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const char *name = orig_name;
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struct kernfs_node *kn;
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int i = 0;
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/* don't be a hero. After 16 tries give up */
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while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
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sysfs_put(kn);
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if (name != orig_name)
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kfree(name);
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name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
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}
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if (name == orig_name) {
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name = kstrdup(orig_name, GFP_KERNEL);
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} else {
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pr_warn("Duplicate name in %s, renamed to \"%s\"\n",
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kobject_name(kobj), name);
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}
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return name;
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}
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int __of_add_property_sysfs(struct device_node *np, struct property *pp)
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{
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int rc;
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/* Important: Don't leak passwords */
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bool secure = strncmp(pp->name, "security-", 9) == 0;
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if (!IS_ENABLED(CONFIG_SYSFS))
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return 0;
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if (!of_kset || !of_node_is_attached(np))
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return 0;
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sysfs_bin_attr_init(&pp->attr);
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pp->attr.attr.name = safe_name(&np->kobj, pp->name);
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pp->attr.attr.mode = secure ? 0400 : 0444;
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pp->attr.size = secure ? 0 : pp->length;
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pp->attr.read = of_node_property_read;
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rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
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WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np);
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return rc;
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}
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void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
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{
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if (!IS_ENABLED(CONFIG_SYSFS))
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return;
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sysfs_remove_bin_file(&np->kobj, &prop->attr);
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kfree(prop->attr.attr.name);
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}
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void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
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{
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/* at early boot, bail here and defer setup to of_init() */
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if (of_kset && of_node_is_attached(np))
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__of_sysfs_remove_bin_file(np, prop);
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}
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void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
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struct property *oldprop)
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{
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/* At early boot, bail out and defer setup to of_init() */
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if (!of_kset)
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return;
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if (oldprop)
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__of_sysfs_remove_bin_file(np, oldprop);
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__of_add_property_sysfs(np, newprop);
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}
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int __of_attach_node_sysfs(struct device_node *np)
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{
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const char *name;
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struct kobject *parent;
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struct property *pp;
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int rc;
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if (!of_kset)
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return 0;
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np->kobj.kset = of_kset;
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if (!np->parent) {
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/* Nodes without parents are new top level trees */
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name = safe_name(&of_kset->kobj, "base");
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parent = NULL;
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} else {
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name = safe_name(&np->parent->kobj, kbasename(np->full_name));
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parent = &np->parent->kobj;
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}
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if (!name)
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return -ENOMEM;
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of_node_get(np);
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rc = kobject_add(&np->kobj, parent, "%s", name);
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kfree(name);
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if (rc)
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return rc;
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for_each_property_of_node(np, pp)
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__of_add_property_sysfs(np, pp);
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return 0;
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}
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void __of_detach_node_sysfs(struct device_node *np)
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{
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struct property *pp;
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BUG_ON(!of_node_is_initialized(np));
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if (!of_kset)
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return;
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/* only remove properties if on sysfs */
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if (of_node_is_attached(np)) {
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for_each_property_of_node(np, pp)
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__of_sysfs_remove_bin_file(np, pp);
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kobject_del(&np->kobj);
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}
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of_node_put(np);
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}
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