[PATCH] powerpc: Cope with duplicate node & property names in /proc/device-tree
Various dodgy firmware might give us nodes and/or properties in the device
tree with conflicting names. That's generally ok, except for when we export
the device tree via /proc, so check when we're creating the proc device tree
and munge names accordingly.
Tested on a faked device tree with kexec, would be good if someone with
actual bogus firmware could try it, but just for completeness.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/fs/proc/proc_devtree.c b/fs/proc/proc_devtree.c
index 596b4b4..abdf068 100644
--- a/fs/proc/proc_devtree.c
+++ b/fs/proc/proc_devtree.c
@@ -52,7 +52,8 @@
* Add a property to a node
*/
static struct proc_dir_entry *
-__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp)
+__proc_device_tree_add_prop(struct proc_dir_entry *de, struct property *pp,
+ const char *name)
{
struct proc_dir_entry *ent;
@@ -60,14 +61,14 @@
* Unfortunately proc_register puts each new entry
* at the beginning of the list. So we rearrange them.
*/
- ent = create_proc_read_entry(pp->name,
- strncmp(pp->name, "security-", 9)
+ ent = create_proc_read_entry(name,
+ strncmp(name, "security-", 9)
? S_IRUGO : S_IRUSR, de,
property_read_proc, pp);
if (ent == NULL)
return NULL;
- if (!strncmp(pp->name, "security-", 9))
+ if (!strncmp(name, "security-", 9))
ent->size = 0; /* don't leak number of password chars */
else
ent->size = pp->length;
@@ -78,7 +79,7 @@
void proc_device_tree_add_prop(struct proc_dir_entry *pde, struct property *prop)
{
- __proc_device_tree_add_prop(pde, prop);
+ __proc_device_tree_add_prop(pde, prop, prop->name);
}
void proc_device_tree_remove_prop(struct proc_dir_entry *pde,
@@ -106,6 +107,69 @@
}
/*
+ * Various dodgy firmware might give us nodes and/or properties with
+ * conflicting names. That's generally ok, except for exporting via /proc,
+ * so munge names here to ensure they're unique.
+ */
+
+static int duplicate_name(struct proc_dir_entry *de, const char *name)
+{
+ struct proc_dir_entry *ent;
+ int found = 0;
+
+ spin_lock(&proc_subdir_lock);
+
+ for (ent = de->subdir; ent != NULL; ent = ent->next) {
+ if (strcmp(ent->name, name) == 0) {
+ found = 1;
+ break;
+ }
+ }
+
+ spin_unlock(&proc_subdir_lock);
+
+ return found;
+}
+
+static const char *fixup_name(struct device_node *np, struct proc_dir_entry *de,
+ const char *name)
+{
+ char *fixed_name;
+ int fixup_len = strlen(name) + 2 + 1; /* name + #x + \0 */
+ int i = 1, size;
+
+realloc:
+ fixed_name = kmalloc(fixup_len, GFP_KERNEL);
+ if (fixed_name == NULL) {
+ printk(KERN_ERR "device-tree: Out of memory trying to fixup "
+ "name \"%s\"\n", name);
+ return name;
+ }
+
+retry:
+ size = snprintf(fixed_name, fixup_len, "%s#%d", name, i);
+ size++; /* account for NULL */
+
+ if (size > fixup_len) {
+ /* We ran out of space, free and reallocate. */
+ kfree(fixed_name);
+ fixup_len = size;
+ goto realloc;
+ }
+
+ if (duplicate_name(de, fixed_name)) {
+ /* Multiple duplicates. Retry with a different offset. */
+ i++;
+ goto retry;
+ }
+
+ printk(KERN_WARNING "device-tree: Duplicate name in %s, "
+ "renamed to \"%s\"\n", np->full_name, fixed_name);
+
+ return fixed_name;
+}
+
+/*
* Process a node, adding entries for its children and its properties.
*/
void proc_device_tree_add_node(struct device_node *np,
@@ -118,37 +182,30 @@
set_node_proc_entry(np, de);
for (child = NULL; (child = of_get_next_child(np, child));) {
+ /* Use everything after the last slash, or the full name */
p = strrchr(child->full_name, '/');
if (!p)
p = child->full_name;
else
++p;
+
+ if (duplicate_name(de, p))
+ p = fixup_name(np, de, p);
+
ent = proc_mkdir(p, de);
if (ent == 0)
break;
proc_device_tree_add_node(child, ent);
}
of_node_put(child);
- for (pp = np->properties; pp != 0; pp = pp->next) {
- /*
- * Yet another Apple device-tree bogosity: on some machines,
- * they have properties & nodes with the same name. Those
- * properties are quite unimportant for us though, thus we
- * simply "skip" them here, but we do have to check.
- */
- spin_lock(&proc_subdir_lock);
- for (ent = de->subdir; ent != NULL; ent = ent->next)
- if (!strcmp(ent->name, pp->name))
- break;
- spin_unlock(&proc_subdir_lock);
- if (ent != NULL) {
- printk(KERN_WARNING "device-tree: property \"%s\" name"
- " conflicts with node in %s\n", pp->name,
- np->full_name);
- continue;
- }
- ent = __proc_device_tree_add_prop(de, pp);
+ for (pp = np->properties; pp != 0; pp = pp->next) {
+ p = pp->name;
+
+ if (duplicate_name(de, p))
+ p = fixup_name(np, de, p);
+
+ ent = __proc_device_tree_add_prop(de, pp, p);
if (ent == 0)
break;
}