Add splice_to_pipe wrapper

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

diff --git a/lib/ringbuffer/ring_buffer_splice.c b/lib/ringbuffer/ring_buffer_splice.c
index 531914a4ef04a9b205564ddba1cc0df6e9de1522..5fa779f5a63e1038ad477abea8d7807a335fbf2c 100644 (file)
--- a/lib/ringbuffer/ring_buffer_splice.c
+++ b/lib/ringbuffer/ring_buffer_splice.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 
+#include "../../wrapper/splice.h"
 #include "../../wrapper/ringbuffer/backend.h"
 #include "../../wrapper/ringbuffer/frontend.h"
 #include "../../wrapper/ringbuffer/vfs.h"
@@ -142,7 +143,7 @@ static int subbuf_splice_actor(struct file *in,
        if (!spd.nr_pages)
                return 0;
 
-       return splice_to_pipe(pipe, &spd);
+       return wrapper_splice_to_pipe(pipe, &spd);
 }
 
 ssize_t lib_ring_buffer_splice_read(struct file *in, loff_t *ppos,

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 */