Add splice_to_pipe wrapper

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

diff --git a/wrapper/splice.h b/wrapper/splice.h
new file mode 100644 (file)
index 0000000..5f40074
--- /dev/null
+++ b/wrapper/splice.h
@@ -0,0 +1,46 @@
+#ifndef _LTT_WRAPPER_SPLICE_H
+#define _LTT_WRAPPER_SPLICE_H
+
+/*
+ * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
+ *
+ * wrapper around vmalloc_sync_all. Using KALLSYMS to get its address when
+ * available, else we need to have a kernel that exports this function to GPL
+ * modules.
+ *
+ * Dual LGPL v2.1/GPL v2 license.
+ */
+
+#ifdef CONFIG_KALLSYMS
+
+#include <linux/kallsyms.h>
+#include <linux/splice.h>
+
+static inline
+ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
+                              struct splice_pipe_desc *spd)
+{
+       ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
+                                     struct splice_pipe_desc *spd);
+
+       splice_to_pipe_sym = (void *) kallsyms_lookup_name("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");
+               return -ENOSYS;
+       }
+}
+#else
+
+#include <linux/splice.h>
+
+static inline
+ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
+                              struct splice_pipe_desc *spd)
+{
+       return splice_to_pipe(pipe, spd);
+}
+#endif
+
+#endif /* _LTT_WRAPPER_SPLICE_H */