25 Mar
2025
25 Mar
'25
11:14 a.m.
On Mon Mar 24 15:18:34 2025 +0000, Jinoh Kang wrote:
We can probably check that the `_thread_set_tsd_base` machine code matches the expected byte sequence. We can either dynamically extract the syscall number, or hard-code it and check against the system value.
Regarding XNU syscalls, they have been historically sort of stable AFAICT and even when a new syscall gets added that supersedes the previous one (like `mach_msg_trap` vs `mach_msg2_trap`) either the previous one stops existing or returns an error value, but they are not recycled and sometimes even kept forward-compatible for a while.
Probably hard-coding and checking at compile time against `sys/syscall.h` will be sufficient here I would guess.