mirror_zfs/include/sys/zio_compress.h
Richard Yao b01615d5ac Constify structures containing function pointers
The PaX team modified the kernel's modpost to report writeable function
pointers as section mismatches because they are potential exploit
targets. We could ignore the warnings, but their presence can obscure
actual issues. Proper const correctness can also catch programming
mistakes.

Building the kernel modules against a PaX/GrSecurity patched Linux 3.4.2
kernel reports 133 section mismatches prior to this patch. This patch
eliminates 130 of them. The quantity of writeable function pointers
eliminated by constifying each structure is as follows:

vdev_opts_t             52
zil_replay_func_t       24
zio_compress_info_t     24
zio_checksum_info_t     9
space_map_ops_t         7
arc_byteswap_func_t     5

The remaining 3 writeable function pointers cannot be addressed by this
patch. 2 of them are in zpl_fs_type. The kernel's sget function requires
that this be non-const. The final writeable function pointer is created
by SPL_SHRINKER_DECLARE. The kernel's set_shrinker() and
remove_shrinker() functions also require that this be non-const.

Signed-off-by: Richard Yao <ryao@cs.stonybrook.edu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1300
2013-03-04 08:49:32 -08:00

95 lines
2.8 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifndef _SYS_ZIO_COMPRESS_H
#define _SYS_ZIO_COMPRESS_H
#include <sys/zio.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
* Common signature for all zio compress/decompress functions.
*/
typedef size_t zio_compress_func_t(void *src, void *dst,
size_t s_len, size_t d_len, int);
typedef int zio_decompress_func_t(void *src, void *dst,
size_t s_len, size_t d_len, int);
/*
* Information about each compression function.
*/
typedef const struct zio_compress_info {
zio_compress_func_t *ci_compress; /* compression function */
zio_decompress_func_t *ci_decompress; /* decompression function */
int ci_level; /* level parameter */
char *ci_name; /* algorithm name */
} zio_compress_info_t;
extern zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS];
/*
* lz4 compression init & free
*/
extern void lz4_init(void);
extern void lz4_fini(void);
/*
* Compression routines.
*/
extern size_t lzjb_compress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern int lzjb_decompress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern size_t gzip_compress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern int gzip_decompress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern size_t zle_compress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern int zle_decompress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern size_t lz4_compress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
extern int lz4_decompress(void *src, void *dst, size_t s_len, size_t d_len,
int level);
/*
* Compress and decompress data if necessary.
*/
extern size_t zio_compress_data(enum zio_compress c, void *src, void *dst,
size_t s_len);
extern int zio_decompress_data(enum zio_compress c, void *src, void *dst,
size_t s_len, size_t d_len);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_ZIO_COMPRESS_H */