dynamic debug: combine dprintk and dynamic printk

This patch combines Greg Bank's dprintk() work with the existing dynamic
printk patchset, we are now calling it 'dynamic debug'.

The new feature of this patchset is a richer /debugfs control file interface,
(an example output from my system is at the bottom), which allows fined grained
control over the the debug output. The output can be controlled by function,
file, module, format string, and line number.

for example, enabled all debug messages in module 'nf_conntrack':

echo -n 'module nf_conntrack +p' > /mnt/debugfs/dynamic_debug/control

to disable them:

echo -n 'module nf_conntrack -p' > /mnt/debugfs/dynamic_debug/control

A further explanation can be found in the documentation patch.

Signed-off-by: Greg Banks <gnb@sgi.com>
Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 10 insertions, 15 deletions

diff --git a/kernel/module.c b/kernel/module.c
index 1196f5d11700..77672233387f 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -822,7 +822,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
         mutex_lock(&module_mutex);
         /* Store the name of the last unloaded module for diagnostic purposes */
         strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
-        unregister_dynamic_debug_module(mod->name);
+        ddebug_remove_module(mod->name);
         free_module(mod);
 
  out:
@@ -1827,19 +1827,13 @@ static inline void add_kallsyms(struct module *mod,
 }
 #endif /* CONFIG_KALLSYMS */
 
-static void dynamic_printk_setup(struct mod_debug *debug, unsigned int num)
+static void dynamic_debug_setup(struct _ddebug *debug, unsigned int num)
 {
-#ifdef CONFIG_DYNAMIC_PRINTK_DEBUG
-        unsigned int i;
-
-        for (i = 0; i < num; i++) {
-                register_dynamic_debug_module(debug[i].modname,
-                                              debug[i].type,
-                                              debug[i].logical_modname,
-                                              debug[i].flag_names,
-                                              debug[i].hash, debug[i].hash2);
-        }
-#endif /* CONFIG_DYNAMIC_PRINTK_DEBUG */
+#ifdef CONFIG_DYNAMIC_DEBUG
+        if (ddebug_add_module(debug, num, debug->modname))
+                printk(KERN_ERR "dynamic debug error adding module: %s\n",
+                                        debug->modname);
+#endif
 }
 
 static void *module_alloc_update_bounds(unsigned long size)
@@ -2213,12 +2207,13 @@ static noinline struct module *load_module(void __user *umod,
         add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
 
         if (!mod->taints) {
-                struct mod_debug *debug;
+                struct _ddebug *debug;
                 unsigned int num_debug;
 
                 debug = section_objs(hdr, sechdrs, secstrings, "__verbose",
                                      sizeof(*debug), &num_debug);
-                dynamic_printk_setup(debug, num_debug);
+                if (debug)
+                        dynamic_debug_setup(debug, num_debug);
         }
 
         /* sechdrs[0].sh_size is always zero */