Hello,
4. I know there should be yet another way.
The way is to load a saved register in the delay slot of jalr. The saved
register shall not be s0, of course, because it's saved by the first
instruction in save_static_function. So the proposed patch is
arch/mips/kernel/scall32-o32.S:
syscall_trace_entry:
SAVE_STATIC
- move s0, t2
+ move s1, t2
move a0, sp
li a1, 0
jal do_syscall_trace
lw a0, PT_R4(sp) # Restore argument registers
lw a1, PT_R5(sp)
lw a2, PT_R6(sp)
lw a3, PT_R7(sp)
- jalr s0
+ .set push
+ .set noreorder
+ jalr s1
+ lw s1, PT_R17(sp)
+ .set pop
The rest of ABIs shall be implemented in the same way.
Regards,
Gleb.
