Remove dependency on kallsyms for splice_to_pipe (kernel 4.2+)

[lttng-modules.git] / wrapper / splice.c

diff --git a/wrapper/splice.c b/wrapper/splice.c
index 0ef8dd99653a4c976e701749ba0ae97fc48b1ded..b0f8738b03b3cf5c06dd918af49cada27e6919fb 100644 (file)
--- a/wrapper/splice.c
+++ b/wrapper/splice.c
@@ -1,33 +1,23 @@
-/*
+/* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1)
+ *
  * wrapper/splice.c
  *
  * wrapper around splice_to_pipe. Using KALLSYMS to get its address when
  * available, else we need to have a kernel that exports this function to GPL
- * modules.
+ * modules. The export was introduced in kernel 4.2.
  *
  * Copyright (C) 2011-2012 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
  */
 
-#ifdef CONFIG_KALLSYMS
+#include <lttng-kernel-version.h>
+
+#if (defined(CONFIG_KALLSYMS) \
+       && (LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)))
 
 #include <linux/kallsyms.h>
 #include <linux/fs.h>
 #include <linux/splice.h>
-#include "kallsyms.h"
+#include <wrapper/kallsyms.h>
 
 static
 ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
@@ -37,11 +27,11 @@ ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
                               struct splice_pipe_desc *spd)
 {
        if (!splice_to_pipe_sym)
-               splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe"); 
+               splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe");
        if (splice_to_pipe_sym) {
                return splice_to_pipe_sym(pipe, spd);
        } else {
-               printk(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
+               printk_once(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
                return -ENOSYS;
        }
 }