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>
- Seen with Linux 4.14 kernel with error message:
In file included from ../drivers/android/kernelsu/selinux/sepolicy.c:1:
In file included from ../drivers/android/kernelsu/selinux/sepolicy.h:6:
In file included from ../security/selinux/ss/policydb.h:30: In file
included from ../security/selinux/ss/avtab.h:26:
../security/selinux/include/security.h:240:10: error: use of undeclared
identifier 'EIDRM'
return -EIDRM;
^
CC drivers/base/transport_class.o
CC kernel/rcu/update.o
../security/selinux/include/security.h:246:10: error: use of undeclared
identifier 'ENOENT'
return -ENOENT;
^
1. List KSU as a "KernelSU" menu
2. Overlayfs[1] may be disabled for some early kernels(4.4.y), so
choosing depends on OVERLAY_FS here is useless.
3. KSU_DEBUG is a bool option, it is not a module, fixed from tristate
to bool.
4. Adjust the config order
[1]: github.com/LineageOS/android_kernel_xiaomi_msm8998/commit/dcc27641
Change-Id: I49c77ba30f0a8ed00efc44afef8a12f9ad039d7e
Co-authored-by: admin <paper@localhost>
Disabled by default.
To enable/disable use terminal with root.
To enable:
echo 1 > /sys/module/ksu/parameters/global_namespace_enable
To disable:
echo 0 > /sys/module/ksu/parameters/global_namespace_enable
Value will be reset to 0 (disabled) on reboot.
For those who want to Implement KernelSU Manually with KPROBES disabled.
When KPROBES Broken and Still enabled, this will causing Loop at splash
logo even Already Manually Imported because this
https://github.com/tiann/KernelSU/blob/842c0b674feaa4f6522452c8dc2ad2837f99892c/kernel/ksu.c#L57.
And when KPROBES is disabled, KSU also will not compiled (I Know it'll
still build if obj-y is set for KSU, but it's better to remove, who
knows if someone set as obj-$(CONFIG_KSU)).
Signed-off-by: RyuujiX <saputradenny712@gmail.com>
weishu