X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_backend.c;h=e8ad4c521cfb66440e51eb4ae9ca0930ea6528d6;hb=886d51a3d7ed5fa6b41d7f19b3e14ae6c535a44c;hp=bfe63d7b34b913c8307ba4ae7cb17221a18287f1;hpb=863497faa1facd29322a990accfd911c8c55b2cc;p=lttng-modules.git

diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c
index bfe63d7b..e8ad4c52 100644
--- a/lib/ringbuffer/ring_buffer_backend.c
+++ b/lib/ringbuffer/ring_buffer_backend.c
@@ -1,9 +1,21 @@
 /*
  * ring_buffer_backend.c
  *
- * Copyright (C) 2005-2010 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2005-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  *
- * Dual LGPL v2.1/GPL v2 license.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; only
+ * version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <linux/stddef.h>
@@ -307,19 +319,17 @@ int channel_backend_init(struct channel_backend *chanb,
 	if (!name)
 		return -EPERM;
 
-	if (!(subbuf_size && num_subbuf))
-		return -EPERM;
-
 	/* Check that the subbuffer size is larger than a page. */
 	if (subbuf_size < PAGE_SIZE)
 		return -EINVAL;
 
 	/*
-	 * Make sure the number of subbuffers and subbuffer size are power of 2.
+	 * Make sure the number of subbuffers and subbuffer size are
+	 * power of 2 and nonzero.
 	 */
-	if (hweight32(subbuf_size) != 1)
+	if (!subbuf_size || (subbuf_size & (subbuf_size - 1)))
 		return -EINVAL;
-	if (hweight32(num_subbuf) != 1)
+	if (!num_subbuf || (num_subbuf & (num_subbuf - 1)))
 		return -EINVAL;
 
 	ret = subbuffer_id_check_index(config, num_subbuf);