1 files changed, 130 insertions, 76 deletions

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 02afc2533728..75ca78f3a8c9 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -7,6 +7,7 @@
  * Copyright (C) 2008 Jason Baron <jbaron@redhat.com>
  * By Greg Banks <gnb@melbourne.sgi.com>
  * Copyright (c) 2008 Silicon Graphics Inc.  All Rights Reserved.
+ * Copyright (C) 2011 Bart Van Assche.  All Rights Reserved.
  */
 
 #include <linux/kernel.h>
@@ -26,19 +27,13 @@
 #include <linux/dynamic_debug.h>
 #include <linux/debugfs.h>
 #include <linux/slab.h>
+#include <linux/jump_label.h>
+#include <linux/hardirq.h>
+#include <linux/sched.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;
@@ -71,15 +66,25 @@ static inline const char *basename(const char *path)
         return tail ? tail+1 : path;
 }
 
+static struct { unsigned flag:8; char opt_char; } opt_array[] = {
+        { _DPRINTK_FLAGS_PRINT, 'p' },
+        { _DPRINTK_FLAGS_INCL_MODNAME, 'm' },
+        { _DPRINTK_FLAGS_INCL_FUNCNAME, 'f' },
+        { _DPRINTK_FLAGS_INCL_LINENO, 'l' },
+        { _DPRINTK_FLAGS_INCL_TID, 't' },
+};
+
 /* format a string into buf[] which describes the _ddebug's flags */
 static char *ddebug_describe_flags(struct _ddebug *dp, char *buf,
                                     size_t maxlen)
 {
         char *p = buf;
+        int i;
 
         BUG_ON(maxlen < 4);
-        if (dp->flags & _DPRINTK_FLAGS_PRINT)
-                *p++ = 'p';
+        for (i = 0; i < ARRAY_SIZE(opt_array); ++i)
+                if (dp->flags & opt_array[i].flag)
+                        *p++ = opt_array[i].opt_char;
         if (p == buf)
                 *p++ = '-';
         *p = '\0';
@@ -88,26 +93,6 @@ 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
@@ -169,19 +154,10 @@ static void ddebug_change(const struct ddebug_query *query,
                         else if (!dp->flags)
                                 dt->num_enabled++;
                         dp->flags = newflags;
-                        if (newflags) {
-                                dynamic_debug_enabled |=
-                                                (1LL << dp->primary_hash);
-                                dynamic_debug_enabled2 |=
-                                                (1LL << dp->secondary_hash);
-                        } 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);
-                        }
+                        if (newflags)
+                                dp->enabled = 1;
+                        else
+                                dp->enabled = 0;
                         if (verbose)
                                 printk(KERN_INFO
                                         "ddebug: changed %s:%d [%s]%s %s\n",
@@ -380,7 +356,7 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
                                unsigned int *maskp)
 {
         unsigned flags = 0;
-        int op = '=';
+        int op = '=', i;
 
         switch (*str) {
         case '+':
@@ -395,13 +371,14 @@ static int ddebug_parse_flags(const char *str, unsigned int *flagsp,
                 printk(KERN_INFO "%s: op='%c'\n", __func__, op);
 
         for ( ; *str ; ++str) {
-                switch (*str) {
-                case 'p':
-                        flags |= _DPRINTK_FLAGS_PRINT;
-                        break;
-                default:
-                        return -EINVAL;
+                for (i = ARRAY_SIZE(opt_array) - 1; i >= 0; i--) {
+                        if (*str == opt_array[i].opt_char) {
+                                flags |= opt_array[i].flag;
+                                break;
+                        }
                 }
+                if (i < 0)
+                        return -EINVAL;
         }
         if (flags == 0)
                 return -EINVAL;
@@ -429,6 +406,69 @@ 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;
+}
+
+int __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...)
+{
+        va_list args;
+        int res;
+
+        BUG_ON(!descriptor);
+        BUG_ON(!fmt);
+
+        va_start(args, fmt);
+        res = printk(KERN_DEBUG);
+        if (descriptor->flags & _DPRINTK_FLAGS_INCL_TID) {
+                if (in_interrupt())
+                        res += printk(KERN_CONT "<intr> ");
+                else
+                        res += printk(KERN_CONT "[%d] ", task_pid_vnr(current));
+        }
+        if (descriptor->flags & _DPRINTK_FLAGS_INCL_MODNAME)
+                res += printk(KERN_CONT "%s:", descriptor->modname);
+        if (descriptor->flags & _DPRINTK_FLAGS_INCL_FUNCNAME)
+                res += printk(KERN_CONT "%s:", descriptor->function);
+        if (descriptor->flags & _DPRINTK_FLAGS_INCL_LINENO)
+                res += printk(KERN_CONT "%d ", descriptor->lineno);
+        res += vprintk(fmt, args);
+        va_end(args);
+
+        return res;
+}
+EXPORT_SYMBOL(__dynamic_pr_debug);
+
+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 +476,8 @@ 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 +491,9 @@ 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 +754,14 @@ 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 +772,16 @@ 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 +799,26 @@ 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);