dynamic_debug: drop enabled field from struct _ddebug, use _DPRINTK_FLAGS_PRINT

Currently any enabled dynamic-debug flag on a pr_debug callsite will
enable printing, even if _DPRINTK_FLAGS_PRINT is off.  Checking print
flag directly allows "-p" to disable callsites without fussing with
other flags, so the following disables everything, without altering
flags user may have set:

	echo -p > $DBGFS/dynamic_debug/control
Signed-off-by: NJim Cromie <jim.cromie@gmail.com>
Signed-off-by: NJason Baron <jbaron@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

include/linux/dynamic_debug.h

@@ -28,7 +28,6 @@ struct _ddebug {
 #define _DPRINTK_FLAGS_INCL_TID		(1<<4)
 #define _DPRINTK_FLAGS_DEFAULT 0
 	unsigned int flags:8;
-	char enabled;
 } __attribute__((aligned(8)));
 
 
@@ -62,21 +61,20 @@ int __dynamic_netdev_dbg(struct _ddebug *descriptor,
 		.format = (fmt),				\
 		.lineno = __LINE__,				\
 		.flags =  _DPRINTK_FLAGS_DEFAULT,		\
-		.enabled = false,				\
 	}
 
 #define dynamic_pr_debug(fmt, ...)				\
 do {								\
 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
-	if (unlikely(descriptor.enabled))			\
+	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
 		__dynamic_pr_debug(&descriptor, pr_fmt(fmt),	\
 				   ##__VA_ARGS__);		\
 } while (0)
 
 #define dynamic_dev_dbg(dev, fmt, ...)				\
 do {								\
-	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);	\
-	if (unlikely(descriptor.enabled))			\
+	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
+	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
 		__dynamic_dev_dbg(&descriptor, dev, fmt,	\
 				  ##__VA_ARGS__);		\
 } while (0)
@@ -84,7 +82,7 @@ do {								\
 #define dynamic_netdev_dbg(dev, fmt, ...)			\
 do {								\
 	DEFINE_DYNAMIC_DEBUG_METADATA(descriptor, fmt);		\
-	if (unlikely(descriptor.enabled))			\
+	if (unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT))	\
 		__dynamic_netdev_dbg(&descriptor, dev, fmt,	\
 				     ##__VA_ARGS__);		\
 } while (0)

lib/dynamic_debug.c

@@ -151,10 +151,6 @@ static void ddebug_change(const struct ddebug_query *query,
 			if (newflags == dp->flags)
 				continue;
 			dp->flags = newflags;
-			if (newflags)
-				dp->enabled = 1;
-			else
-				dp->enabled = 0;
 			if (verbose)
 				pr_info("changed %s:%d [%s]%s %s\n",
 					dp->filename, dp->lineno,