2 files changed, 112 insertions, 25 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 7bd6df781ce5..3094318bfea7 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -393,6 +393,40 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
         return 0;
 }
 
+static int ddebug_exec_query(char *query_string)
+{
+        unsigned int flags = 0, mask = 0;
+        struct ddebug_query query;
+#define MAXWORDS 9
+        int nwords;
+        char *words[MAXWORDS];
+
+        nwords = ddebug_tokenize(query_string, words, MAXWORDS);
+        if (nwords <= 0)
+                return -EINVAL;
+        if (ddebug_parse_query(words, nwords-1, &query))
+                return -EINVAL;
+        if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
+                return -EINVAL;
+
+        /* actually go and implement the change */
+        ddebug_change(&query, flags, mask);
+        return 0;
+}
+
+static __initdata char ddebug_setup_string[1024];
+static __init int ddebug_setup_query(char *str)
+{
+        if (strlen(str) >= 1024) {
+                pr_warning("ddebug boot param string too large\n");
+                return 0;
+        }
+        strcpy(ddebug_setup_string, str);
+        return 1;
+}
+
+__setup("ddebug_query=", ddebug_setup_query);
+
 /*
  * File_ops->write method for <debugfs>/dynamic_debug/conrol.  Gathers the
  * command text from userspace, parses and executes it.
@@ -400,12 +434,8 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
                                   size_t len, loff_t *offp)
 {
-        unsigned int flags = 0, mask = 0;
-        struct ddebug_query query;
-#define MAXWORDS 9
-        int nwords;
-        char *words[MAXWORDS];
         char tmpbuf[256];
+        int ret;
 
         if (len == 0)
                 return 0;
@@ -419,16 +449,9 @@ static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf,
                 printk(KERN_INFO "%s: read %d bytes from userspace\n",
                         __func__, (int)len);
 
-        nwords = ddebug_tokenize(tmpbuf, words, MAXWORDS);
-        if (nwords <= 0)
-                return -EINVAL;
-        if (ddebug_parse_query(words, nwords-1, &query))
-                return -EINVAL;
-        if (ddebug_parse_flags(words[nwords-1], &flags, &mask))
-                return -EINVAL;
-
-        /* actually go and implement the change */
-        ddebug_change(&query, flags, mask);
+        ret = ddebug_exec_query(tmpbuf);
+        if (ret)
+                return ret;
 
         *offp += len;
         return len;
@@ -689,13 +712,14 @@ static void ddebug_remove_all_tables(void)
         mutex_unlock(&ddebug_lock);
 }
 
-static int __init dynamic_debug_init(void)
+static __initdata int ddebug_init_success;
+
+static int __init dynamic_debug_init_debugfs(void)
 {
         struct dentry *dir, *file;
-        struct _ddebug *iter, *iter_start;
-        const char *modname = NULL;
-        int ret = 0;
-        int n = 0;
+
+        if (!ddebug_init_success)
+                return -ENODEV;
 
         dir = debugfs_create_dir("dynamic_debug", NULL);
         if (!dir)
@@ -706,6 +730,16 @@ static int __init dynamic_debug_init(void)
                 debugfs_remove(dir);
                 return -ENOMEM;
         }
+        return 0;
+}
+
+static int __init dynamic_debug_init(void)
+{
+        struct _ddebug *iter, *iter_start;
+        const char *modname = NULL;
+        int ret = 0;
+        int n = 0;
+
         if (__start___verbose != __stop___verbose) {
                 iter = __start___verbose;
                 modname = iter->modname;
@@ -723,12 +757,26 @@ static int __init dynamic_debug_init(void)
                 }
                 ret = ddebug_add_module(iter_start, n, modname);
         }
+
+        /* ddebug_query boot param got passed -> set it up */
+        if (ddebug_setup_string[0] != '\0') {
+                ret = ddebug_exec_query(ddebug_setup_string);
+                if (ret)
+                        pr_warning("Invalid ddebug boot param %s",
+                                   ddebug_setup_string);
+                else
+                        pr_info("ddebug initialized with string %s",
+                                ddebug_setup_string);
+        }
+
 out_free:
-        if (ret) {
+        if (ret)
                 ddebug_remove_all_tables();
-                debugfs_remove(dir);
-                debugfs_remove(file);
-        }
+        else
+                ddebug_init_success = 1;
         return 0;
 }
-module_init(dynamic_debug_init);
+/* Allow early initialization for boot messages via boot param */
+arch_initcall(dynamic_debug_init);
+/* Debugfs setup must be done later */
+module_init(dynamic_debug_init_debugfs);
diff --git a/lib/kobject.c b/lib/kobject.c
index f07c57252e82..82dc34c095c2 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -746,17 +746,56 @@ void kset_unregister(struct kset *k)
  */
 struct kobject *kset_find_obj(struct kset *kset, const char *name)
 {
+        return kset_find_obj_hinted(kset, name, NULL);
+}
+
+/**
+ * kset_find_obj_hinted - search for object in kset given a predecessor hint.
+ * @kset: kset we're looking in.
+ * @name: object's name.
+ * @hint: hint to possible object's predecessor.
+ *
+ * Check the hint's next object and if it is a match return it directly,
+ * otherwise, fall back to the behavior of kset_find_obj().  Either way
+ * a reference for the returned object is held and the reference on the
+ * hinted object is released.
+ */
+struct kobject *kset_find_obj_hinted(struct kset *kset, const char *name,
+                                     struct kobject *hint)
+{
         struct kobject *k;
         struct kobject *ret = NULL;
 
         spin_lock(&kset->list_lock);
+
+        if (!hint)
+                goto slow_search;
+
+        /* end of list detection */
+        if (hint->entry.next == kset->list.next)
+                goto slow_search;
+
+        k = container_of(hint->entry.next, struct kobject, entry);
+        if (!kobject_name(k) || strcmp(kobject_name(k), name))
+                goto slow_search;
+
+        ret = kobject_get(k);
+        goto unlock_exit;
+
+slow_search:
         list_for_each_entry(k, &kset->list, entry) {
                 if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
                         ret = kobject_get(k);
                         break;
                 }
         }
+
+unlock_exit:
         spin_unlock(&kset->list_lock);
+
+        if (hint)
+                kobject_put(hint);
+
         return ret;
 }