X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=wrapper%2Fgenhd.h;h=98feb57bebde635fb11781209ca2871a8faafa0c;hb=3bd6ac3e83874adf006a1bc46d94d8880fc197c8;hp=5bb390b6f9f98255052311fd1493ba364e1c2e30;hpb=f0dbdefbdbc26a000ed546180b22144c5b48857d;p=lttng-modules.git

diff --git a/wrapper/genhd.h b/wrapper/genhd.h
index 5bb390b6..98feb57b 100644
--- a/wrapper/genhd.h
+++ b/wrapper/genhd.h
@@ -1,7 +1,5 @@
-#ifndef _LTTNG_WRAPPER_GENHD_H
-#define _LTTNG_WRAPPER_GENHD_H
-
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * wrapper/genhd.h
  *
  * wrapper around block layer functions and data structures. Using
@@ -9,54 +7,17 @@
  * kernel that exports this function to GPL modules.
  *
  * Copyright (C) 2011-2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- *
- * 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
  */
 
+#ifndef _LTTNG_WRAPPER_GENHD_H
+#define _LTTNG_WRAPPER_GENHD_H
+
 #include <linux/genhd.h>
 
-#ifdef CONFIG_KALLSYMS
+#ifdef CONFIG_KALLSYMS_ALL
 
 #include <linux/kallsyms.h>
-#include "kallsyms.h"
-
-static inline
-char *wrapper_disk_name(struct gendisk *hd, int partno, char *buf)
-{
-	char *(*disk_name_sym)(struct gendisk *hd, int partno, char *buf);
-
-	disk_name_sym = (void *) kallsyms_lookup_funcptr("disk_name");
-	if (disk_name_sym) {
-		return disk_name_sym(hd, partno, buf);
-	} else {
-		printk(KERN_WARNING "LTTng: disk_name symbol lookup failed.\n");
-		return NULL;
-	}
-}
-
-#else
-
-static inline
-char *wrapper_disk_name(struct gendisk *hd, int partno, char *buf)
-{
-	return disk_name(hd, partno, buf);
-}
-
-#endif
-
-#ifdef CONFIG_KALLSYMS_ALL
+#include <wrapper/kallsyms.h>
 
 static inline
 struct class *wrapper_get_block_class(void)
@@ -65,12 +26,25 @@ struct class *wrapper_get_block_class(void)
 
 	ptr_block_class = (struct class *) kallsyms_lookup_dataptr("block_class");
 	if (!ptr_block_class) {
-		printk(KERN_WARNING "LTTng: block_class symbol lookup failed.\n");
+		printk_once(KERN_WARNING "LTTng: block_class symbol lookup failed.\n");
 		return NULL;
 	}
 	return ptr_block_class;
 }
 
+/*
+ * Canary function to check for 'block_class' at compile time.
+ *
+ * From 'include/linux/genhd.h':
+ *
+ *   extern struct class block_class;
+ */
+static inline
+struct class *__canary__get_block_class(void)
+{
+	return &block_class;
+}
+
 static inline
 struct device_type *wrapper_get_disk_type(void)
 {
@@ -78,12 +52,22 @@ struct device_type *wrapper_get_disk_type(void)
 
 	ptr_disk_type = (struct device_type *) kallsyms_lookup_dataptr("disk_type");
 	if (!ptr_disk_type) {
-		printk(KERN_WARNING "LTTng: disk_type symbol lookup failed.\n");
+		printk_once(KERN_WARNING "LTTng: disk_type symbol lookup failed.\n");
 		return NULL;
 	}
 	return ptr_disk_type;
 }
 
+/*
+ * No canary for 'disk_type', it's only defined in 'block/genhd.c'.
+ *
+ * static inline
+ * struct device_type *__canary__get_disk_type(void)
+ * {
+ * 	return &disk_type;
+ * }
+ */
+
 #else
 
 static inline