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; TAKEN FROM https://github.com/davidad/asm_concurrency/blob/master/os_dependent_stuff.asm
; syscalls
%ifidn __OUTPUT_FORMAT__,elf64
; http://lxr.linux.no/linux+v3.13.5/arch/x86/syscalls/syscall_64.tbl
%define SYS_READ 0
%define SYS_OPEN 2
%define SYS_WRITE 1
%define SYS_MMAP 9
%define SYS_FTRUNCATE 77
%define SYS_PWRITE 18
%define SYS_FORK 57
%define SYS_WAITID 247
%define SYS_EXIT 60
%elifidn __OUTPUT_FORMAT__,macho64
; http://www.opensource.apple.com/source/xnu/xnu-1456.1.26/bsd/kern/syscalls.master
%define SYS_READ 0x2000003
%define SYS_OPEN 0x2000005
%define SYS_WRITE 0x2000004
%define SYS_MMAP 0x20000C5
%define SYS_FTRUNCATE 0x20000C9
%define SYS_PWRITE 0x200009A
%define SYS_FORK 0x2000002
%define SYS_WAITID 0x20000AD
%define SYS_EXIT 0x2000001
%endif
; mmap() and mprotect() flags
%ifidn __OUTPUT_FORMAT__,elf64
; http://lxr.linux.no/linux+v3.13.5/include/uapi/asm-generic/mman-common.h
%define MAP_SHARED 0x01
%define MAP_PRIVATE 0x02
%define MAP_FIXED 0x10
%define MAP_ANON 0x20
%define PROT_NONE 0x0
%define PROT_READ 0x1
%define PROT_WRITE 0x2
%define PROT_EXEC 0x4
%define PROT_SEM 0x8
%define PROT_GROWSDOWN 0x01000000
%define PROT_GROWSUP 0x02000000
%elifidn __OUTPUT_FORMAT__,macho64
; http://www.opensource.apple.com/source/xnu/xnu-2050.18.24/bsd/sys/mman.h
%define MAP_SHARED 0x001
%define MAP_PRIVATE 0x002
%define MAP_FIXED 0x010
%define MAP_RENAME 0x020
%define MAP_NORESERVE 0x040
%define MAP_INHERIT 0x080
%define MAP_NOEXTEND 0x100
%define MAP_SEMAPHORE 0x200
%define MAP_NOCACHE 0x400
%define MAP_JIT 0x800
%define MAP_FILE 0x0000
%define MAP_ANON 0x1000
%define PROT_NONE 0x0
%define PROT_READ 0x1
%define PROT_WRITE 0x2
%define PROT_EXEC 0x4
%endif
%define STDIN_FILENO 0
%define STDOUT_FILENO 1
%define STDERR_FILENO 2
global start, _start, putc, putint, getc, exit, _builtin_malloc, _builtin_outofbounds
default rel
extern main
section .text
start:
_start:
and rsp, -16 ; make stack 16-byte aligned
call main
mov rdi, rax
mov eax, SYS_EXIT
syscall
jmp $
putc:
push rax
push rdi
push rsi
push rdx
push rcx
push r11
mov eax, SYS_WRITE
mov edi, STDOUT_FILENO
lea rsi, [rsp+56]
mov edx, edi
syscall
pop r11
pop rcx
pop rdx
pop rsi
pop rdi
pop rax
ret
putint:
push rdi
push rsi
push rax
push rbx
push rcx
push rdx
push r11
mov rax, [rsp+64]
mov ebx, 18
test rax, rax
jz .numzero
mov ecx, 10
.strlp:
xor edx, edx
div rcx
add dl, '0'
dec rbx
mov [rsp+rbx], dl
test rax, rax
jnz .strlp
jmp .strdone
.numzero:
dec rbx
mov byte [rsp+rbx], '0'
jmp .strdone
.strdone:
mov eax, SYS_WRITE
mov edi, 1
lea rsi, [rsp+rbx]
mov edx, 18
sub rdx, rbx
syscall
pop r11
pop rdx
pop rcx
pop rbx
pop rax
pop rsi
pop rdi
ret
getc:
push rdi
push rsi
push rdx
push rcx
push r11
mov eax, SYS_READ
mov edi, STDIN_FILENO
lea rsi, [rsp-1]
mov edx, 1
syscall
cmp rax, 1
jne .fail
xor eax, eax
mov al, [rsp-1]
.finish:
pop r11
pop rcx
pop rdx
pop rsi
pop rdi
ret
.fail:
mov rax, -1
jmp .finish
exit:
mov rdi, [rsp+8]
mov eax, SYS_EXIT
syscall
jmp $
strlen:
push rbx
push rcx
push rdx
push rdi
push rsi
mov rsi, [rsp+8] ; string data pointer
mov rcx, [rsi-8] ; array size
xor edx, edx ; string walker
cmp rcx, 16
jb .short
movdqa [rsp], xmm1
movdqa [rsp-16], xmm2
mov rax, rcx ; now array size
lea rbx, [rax-16]
pxor xmm2, xmm2
.lp:
movdqu xmm1, [rsi+rdx]
pcmpistri xmm1, xmm2, 0x08
js .nullfound
add rdx, 16
cmp rdx, rbx
jbe .lp
movdqa xmm2, [rsp-16]
movdqa xmm1, [rsp]
cmp rdx, rax
je .nonull
mov rcx, rax
sub rcx, rdx
.short:
mov al, [rsi+rdx]
inc rdx
test al, al
loopnz .short
jnz .nonull
lea rax, [rdx-1]
pop rsi
pop rdi
pop rdx
pop rcx
pop rbx
ret
.nullfound:
add rdx, rcx
mov rax, rdx
pop rsi
pop rdi
pop rdx
pop rcx
pop rbx
ret
.nonull:
mov edi, STDERR_FILENO
lea rsi, [nonull_msg]
mov edx, nonull_msg.len
mov eax, SYS_WRITE
syscall
jmp exit255
_builtin_malloc:
push rdi
push rsi
push rdx
push r8
push r9
push r10
push r11
push rcx
xor edi, edi
mov rsi, [rsp+72]
mov edx, PROT_READ | PROT_WRITE
mov r10d, MAP_ANON | MAP_PRIVATE
mov r8d, -1
xor r9d, r9d
mov eax, SYS_MMAP
syscall
pop rcx
pop r11
pop r10
pop r9
pop r8
pop rdx
pop rsi
pop rdi
ret
_builtin_outofbounds:
mov edi, STDERR_FILENO
lea rsi, [outofbounds_msg]
mov rdx, outofbounds_msg.len
mov eax, SYS_WRITE
syscall
exit255:
mov edi, 255
mov eax, SYS_EXIT
syscall
jmp $
section .data
outofbounds_msg: db "Runtime Error: Out-of-bounds array access detected", 10
.len: equ $ - outofbounds_msg
nonull_msg: db "Runtime Error: No null byte found in string", 10
.len: equ $ - nonull_msg
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