mirror of https://github.com/flysand7/ciabatta.git
43 lines
1.1 KiB
NASM
43 lines
1.1 KiB
NASM
|
|
||
|
|
bits 64
|
||
|
|
|
||
|
|
section .text
|
||
|
|
global _cia_clone
|
||
|
|
|
||
|
|
; flags, &stack[-2], &parent_tid, &child_tid, 0
|
||
|
|
|
||
|
|
; DESCRIPTION:
|
||
|
|
; Function to be called when using the _clone syscall
|
||
|
|
; We don't just call the _clone syscall directly because
|
||
|
|
; if we call the clone syscall wrapper that's defined in
|
||
|
|
; linux/sys, our stack will be bad and we won't be able
|
||
|
|
; to return from the syscall wrapper
|
||
|
|
; PARAMETERS:
|
||
|
|
; rdi - flags
|
||
|
|
; rsi - stack_base
|
||
|
|
; rdx - parent_tid_ptr
|
||
|
|
; rcx - child_tid_ptr
|
||
|
|
; r8 - tls
|
||
|
|
; RETURNS:
|
||
|
|
; i64 value
|
||
|
|
; 0 if returning as a parent
|
||
|
|
; 1 if returning as a child
|
||
|
|
; negative value if there was an error making the thread
|
||
|
|
_cia_clone:
|
||
|
|
mov r10, rcx
|
||
|
|
sub rsi, 8
|
||
|
|
; As a child thread we wanna return to the same place as the parent
|
||
|
|
mov rax, qword [rsp]
|
||
|
|
mov qword [rsi], rax
|
||
|
|
; ; Copy child tid ptr
|
||
|
|
; mov qword [rsi + 0], rcx
|
||
|
|
; Call syscall right away, since the order of the first 5 arguments
|
||
|
|
; matches with the argument order of the function
|
||
|
|
mov rax, 56 ; SYS_CLONE
|
||
|
|
syscall
|
||
|
|
; Check to see if we're child
|
||
|
|
test eax, eax
|
||
|
|
jnz .exit
|
||
|
|
.exit:
|
||
|
|
ret
|