Files
SukiSU-Ultra/kernel/module_api.c
Juhyung Park bd8434f4f4 Hook improvements (take 2) (#563)
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>
2023-06-16 19:53:15 +08:00

34 lines
1.6 KiB
C

#include "linux/kallsyms.h"
#define RE_EXPORT_SYMBOL1(ret, func, t1, v1) \
ret ksu_##func(t1 v1) \
{ \
return func(v1); \
} \
EXPORT_SYMBOL(ksu_##func);
#define RE_EXPORT_SYMBOL2(ret, func, t1, v1, t2, v2) \
ret ksu_##func(t1 v1, t2 v2) \
{ \
return func(v1, v2); \
} \
EXPORT_SYMBOL(ksu_##func);
RE_EXPORT_SYMBOL1(unsigned long, kallsyms_lookup_name, const char *, name)
// RE_EXPORT_SYMBOL2(int, register_kprobe, struct kprobe *, p)
// RE_EXPORT_SYMBOL2(void, unregister_kprobe, struct kprobe *, p)
// RE_EXPORT_SYMBOL2(int, register_kprobe, struct kprobe *, p)
// RE_EXPORT_SYMBOL2(void, unregister_kprobe, struct kprobe *, p)
// int ksu_register_kprobe(struct kprobe *p);
// void ksu_unregister_kprobe(struct kprobe *p);
// int ksu_register_kprobes(struct kprobe **kps, int num);
// void ksu_unregister_kprobes(struct kprobe **kps, int num);
// int ksu_register_kretprobe(struct kretprobe *rp);
// void unregister_kretprobe(struct kretprobe *rp);
// int register_kretprobes(struct kretprobe **rps, int num);
// void unregister_kretprobes(struct kretprobe **rps, int num);