wrapper/splice.c

   1 /*
   2  * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
   3  *
   4  * wrapper around splice_to_pipe. Using KALLSYMS to get its address when
   5  * available, else we need to have a kernel that exports this function to GPL
   6  * modules.
   7  *
   8  * Dual LGPL v2.1/GPL v2 license.
   9  */
  10
  11 #ifdef CONFIG_KALLSYMS
  12
  13 #include <linux/kallsyms.h>
  14 #include <linux/fs.h>
  15 #include <linux/splice.h>
  16 #include "kallsyms.h"
  17
  18 static
  19 ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
  20                               struct splice_pipe_desc *spd);
  21
  22 ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
  23                                struct splice_pipe_desc *spd)
  24 {
  25         if (!splice_to_pipe_sym)
  26                 splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe");
  27         if (splice_to_pipe_sym) {
  28                 return splice_to_pipe_sym(pipe, spd);
  29         } else {
  30                 printk(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
  31                 return -ENOSYS;
  32         }
  33 }
  34
  35 #else
  36
  37 #include <linux/fs.h>
  38 #include <linux/splice.h>
  39
  40 ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
  41                                struct splice_pipe_desc *spd)
  42 {
  43         return splice_to_pipe(pipe, spd);
  44 }
  45
  46 #endif