On 11/29/05, Stephen Smalley <sds(a)tycho.nsa.gov> wrote:
On Tue, 2005-11-29 at 11:51 -0500, Stephen Smalley wrote:
> Random thought: As udev only manages devices, why not run file_contexts
> through a filter to extract /dev entries at policy build time, saving
> the result as a file_contexts.dev file, and have udev use
> matchpathcon_init() to select that file for its matching. That would
> then avoid having to process the entire file contexts configuration for
> udev.
An unscientific experiment, with a slightly modified matchpathcon util
that lets me specify the file_contexts path:
$ grep '^/dev' file_contexts > file_contexts.dev
$ time ./matchpathcon -f file_contexts.dev /dev/ttyS0
/dev/ttyS0 system_u:object_r:tty_device_t
real 0m0.023s
user 0m0.012s
sys 0m0.008s
$ time ./matchpathcon -f file_contexts /dev/ttyS0
/dev/ttyS0 system_u:object_r:tty_device_t
real 0m0.216s
user 0m0.152s
sys 0m0.064s
Quite the difference, no?
Cool. I take it matchpathcon() is called approx. once per created
entry in /dev, etc. If so, 'du -a /dev | wc' reports about 310 entries
on my system.
If so, that would be noticable. ;)
tom
--
Tom London