From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 2 Mar 2020 16:03:19 +0000 (-0500)
Subject: Remove dependency on kallsyms for splice_to_pipe (kernel 4.2+)
X-Git-Tag: before-upstreaming~23
X-Git-Url: http://git.liburcu.org/?p=lttng-modules.git;a=commitdiff_plain;h=d072dbc6353855937ca51f2c3746ad25ad21d978

Remove dependency on kallsyms for splice_to_pipe (kernel 4.2+)

Upstream commit 2b514574f7e88 "net: af_unix: implement splice for stream
af_unix sockets" exported the "splice_to_pipe" symbol, so use it to
remove a dependency on kallsyms_lookup_name().

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
---

diff --git a/wrapper/splice.c b/wrapper/splice.c
index d7ef83d8..b0f8738b 100644
--- a/wrapper/splice.c
+++ b/wrapper/splice.c
@@ -4,12 +4,15 @@
  *
  * 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>
  */
 
-#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>