wrapper/splice.c

   1 /*
   2  * Copyright (C) 2011 Mathieu Desnoyers (mathieu.desnoyers@efficios.com)
   3  *
   4  * wrapper around vmalloc_sync_all. 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
  17 static
  18 ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
  19                               struct splice_pipe_desc *spd);
  20
  21 ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
  22                                struct splice_pipe_desc *spd)
  23 {
  24         if (!splice_to_pipe_sym)
  25                 splice_to_pipe_sym = (void *) kallsyms_lookup_name("splice_to_pipe");
  26         if (splice_to_pipe_sym) {
  27                 return splice_to_pipe_sym(pipe, spd);
  28         } else {
  29                 printk(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
  30                 return -ENOSYS;
  31         }
  32 }
  33
  34 #else
  35
  36 #include <linux/fs.h>
  37 #include <linux/splice.h>
  38
  39 ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
  40                                struct splice_pipe_desc *spd)
  41 {
  42         return splice_to_pipe(pipe, spd);
  43 }
  44
  45 #endif