* The coding format is too messy, reformat to improve readability
and get closer to Linux kernel coding style.
* While at it, update .clang-format file to linux-mainline state.
* Much cleaner code, although setenforce is not used anymore
* Guard is_ksu_transition only for 4.19 and under.
Signed-off-by: rsuntk <rsuntk@yukiprjkt.my.id>
Hi @tiann.
Thanks for the great project, I had great fun playing around with it.
This PR mainly tries to further minimize the possible delays caused by
KernelSU hooking.
There are 3 major changes:
- Processes with 0 < UID < 2000 are blocked straight-up before going
through the allow_list.
I don't see any need for such processes to be interested in root, and
this allows returning early before going through a more expensive
lookup.
If there's an expected breakage due to this change, I'll remove it. Let
me know.
- A page-sized (4K) bitmap is added.
This allows O(1) lookup for UID <= 32767.
This speeds up `ksu_is_allow_uid()` by about 4.8x by sacrificing a 4K
memory. IMHO, a good trade-off.
Most notably, this reduces the 99.999% result previously from worrying
milliseconds scale to microseconds scale.
For UID > 32767, another page-sized (4K) sequential array is used to
cache allow_list.
Compared to the previous PR #557, this new approach gives another nice
25% performance boost in average, 63-96% boost in worst cases.
Benchmark results are available at
https://docs.google.com/spreadsheets/d/1w_tO1zRLPNMFRer49pL1TQfL6ndEhilRrDU1XFIcWXY/edit?usp=sharing
Thanks!
---------
Signed-off-by: Juhyung Park <qkrwngud825@gmail.com>
This checks `selinux_state` and `current_sid` supports in a raw way.
Feels more reliable than the version checks.
Supersedes #401, fixes#280, fixes#400.
