mirror_zfs/module
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
..
avl Add script for builtin module building. 2012-07-26 13:45:09 -07:00
nvpair Illumos #2619 and #2747 2013-01-08 10:35:35 -08:00
unicode Add script for builtin module building. 2012-07-26 13:45:09 -07:00
zcommon Illumos #3035 LZ4 compression support in ZFS and GRUB 2013-01-29 09:28:20 -08:00
zfs Constify structures containing function pointers 2013-03-04 08:49:32 -08:00
zpios call_usermodehelper() should wait for process 2013-01-09 16:54:52 -08:00
.gitignore Add .gitignore files to exclude build products 2010-01-08 11:35:17 -08:00
Makefile.in Add script for builtin module building. 2012-07-26 13:45:09 -07:00