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

/*
 * wrapper/splice.c
 *
 * 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.
 *
 * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; only
 * version 2.1 of the License.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifdef CONFIG_KALLSYMS

#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/splice.h>
#include <wrapper/kallsyms.h>

static
ssize_t (*splice_to_pipe_sym)(struct pipe_inode_info *pipe,
			      struct splice_pipe_desc *spd);

ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
			       struct splice_pipe_desc *spd)
{
	if (!splice_to_pipe_sym)
		splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe"); 
	if (splice_to_pipe_sym) {
		return splice_to_pipe_sym(pipe, spd);
	} else {
		printk_once(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
		return -ENOSYS;
	}
}

#else

#include <linux/fs.h>
#include <linux/splice.h>

ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
			       struct splice_pipe_desc *spd)
{
	return splice_to_pipe(pipe, spd);
}

#endif
Commit	Line	Data
	1	/*
	2	* wrapper/splice.c
	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	* Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	9	*
	10	* This library is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU Lesser General Public
	12	* License as published by the Free Software Foundation; only
	13	* version 2.1 of the License.
	14	*
	15	* This library is distributed in the hope that it will be useful,
	16	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	18	* Lesser General Public License for more details.
	19	*
	20	* You should have received a copy of the GNU Lesser General Public
	21	* License along with this library; if not, write to the Free Software
	22	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	23	*/
	24
	25	#ifdef CONFIG_KALLSYMS
	26
	27	#include <linux/kallsyms.h>
	28	#include <linux/fs.h>
	29	#include <linux/splice.h>
	30	#include <wrapper/kallsyms.h>
	31
	32	static
	33	ssize_t (splice_to_pipe_sym)(struct pipe_inode_info pipe,
	34	struct splice_pipe_desc *spd);
	35
	36	ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
	37	struct splice_pipe_desc *spd)
	38	{
	39	if (!splice_to_pipe_sym)
	40	splice_to_pipe_sym = (void *) kallsyms_lookup_funcptr("splice_to_pipe");
	41	if (splice_to_pipe_sym) {
	42	return splice_to_pipe_sym(pipe, spd);
	43	} else {
	44	printk_once(KERN_WARNING "LTTng: splice_to_pipe symbol lookup failed.\n");
	45	return -ENOSYS;
	46	}
	47	}
	48
	49	#else
	50
	51	#include <linux/fs.h>
	52	#include <linux/splice.h>
	53
	54	ssize_t wrapper_splice_to_pipe(struct pipe_inode_info *pipe,
	55	struct splice_pipe_desc *spd)
	56	{
	57	return splice_to_pipe(pipe, spd);
	58	}
	59
	60	#endif