1 files changed, 76 insertions, 64 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 02afc2533728..3094318bfea7 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -26,19 +26,11 @@
 #include <linux/dynamic_debug.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
+#include <linux/jump_label.h>
 
 extern struct _ddebug __start___verbose[];
 extern struct _ddebug __stop___verbose[];
 
-/* dynamic_debug_enabled, and dynamic_debug_enabled2 are bitmasks in which
- * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They
- * use independent hash functions, to reduce the chance of false positives.
- */
-long long dynamic_debug_enabled;
-EXPORT_SYMBOL_GPL(dynamic_debug_enabled);
-long long dynamic_debug_enabled2;
-EXPORT_SYMBOL_GPL(dynamic_debug_enabled2);
-
 struct ddebug_table {
         struct list_head link;
         char *mod_name;
@@ -88,26 +80,6 @@ static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
 }
 
 /*
- * must be called with ddebug_lock held
- */
-
-static int disabled_hash(char hash, bool first_table)
-{
-        struct ddebug_table *dt;
-        char table_hash_value;
-
-        list_for_each_entry(dt, &ddebug_tables, link) {
-                if (first_table)
-                        table_hash_value = dt->ddebugs->primary_hash;
-                else
-                        table_hash_value = dt->ddebugs->secondary_hash;
-                if (dt->num_enabled && (hash == table_hash_value))
-                        return 0;
-        }
-        return 1;
-}
-
-/*
  * Search the tables for _ddebug's which match the given
  * `query' and apply the `flags' and `mask' to them.  Tells
  * the user which ddebug's were changed, or whether none
@@ -170,17 +142,9 @@ static void ddebug_change(const struct ddebug_query *query,
                                 dt->num_enabled++;
                         dp->flags = newflags;
                         if (newflags) {
-                                dynamic_debug_enabled |=
-                                                (1LL << dp->primary_hash);
-                                dynamic_debug_enabled2 |=
-                                                (1LL << dp->secondary_hash);
+                                jump_label_enable(&dp->enabled);
                         } else {
-                                if (disabled_hash(dp->primary_hash, true))
-                                        dynamic_debug_enabled &=
-                                                ~(1LL << dp->primary_hash);
-                                if (disabled_hash(dp->secondary_hash, false))
-                                        dynamic_debug_enabled2 &=
-                                                ~(1LL << dp->secondary_hash);
+                                jump_label_disable(&dp->enabled);
                         }
                         if (verbose)
                                 printk(KERN_INFO
@@ -429,6 +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.
@@ -436,12 +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;
@@ -455,16 +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;
@@ -725,13 +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)
@@ -742,6 +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;
@@ -759,12 +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);