常见函数调用约定(x86、x64、arm、arm64)
我学习逆向，整理的一些常见的函数调用约定反汇编笔记。由于我是新手，肯定有一些疏漏不完善的，我遇到了会实时更新的。
X86 函数调用约定
X86 有三种常用调用约定，cdecl(C规范)/stdcall(WinAPI默认)/fastcall 函数调用约定。
cdecl 函数调用约定
参数从右往左一次入栈，调用者实现栈平衡，返回值存放在 EAX 中。
20: int cdecl_sum = cdecl_add(1, 2, 3, 4, 5, 6, 7);
00401138 push 7
0040113A push 6
0040113C push 5
0040113E push 4
00401140 push 3
00401142 push 2
00401144 push 1
00401146 call @ILT+5(_cdecl_add) (0040100a)
0040114B add esp,1Ch # 栈平衡
0040114E mov dword ptr [ebp-4],eax # 返回值
3: int __cdecl cdecl_add(int a, int b, int c, int d, int e, int f, int g)
4: {
00401030 push ebp
00401031 mov ebp,esp
00401033 sub esp,44h
00401036 push ebx
00401037 push esi
00401038 push edi
00401039 lea edi,[ebp-44h]
0040103C mov ecx,11h
00401041 mov eax,0CCCCCCCCh
00401046 rep stos dword ptr [edi]
5: int sum = a+b+c+d+e+f+g;
00401048 mov eax,dword ptr [ebp+8]
0040104B add eax,dword ptr [ebp+0Ch]
0040104E add eax,dword ptr [ebp+10h]
00401051 add eax,dword ptr [ebp+14h]
00401054 add eax,dword ptr [ebp+18h]
00401057 add eax,dword ptr [ebp+1Ch]
0040105A add eax,dword ptr [ebp+20h]
0040105D mov dword ptr [ebp-4],eax
6: return sum;
00401060 mov eax,dword ptr [ebp-4] # 存放返回值
7: }
00401063 pop edi
00401064 pop esi
00401065 pop ebx
00401066 mov esp,ebp
00401068 pop ebp
00401069 retstdcall 函数调用约定
参数从右往左一次入栈，被调用者实现栈平衡，返回值存放在 EAX 中。
21: int stdcall_sum = stdcall_add(1, 2, 3, 4, 5, 6, 7);
00401151 push 7
00401153 push 6
00401155 push 5
00401157 push 4
00401159 push 3
0040115B push 2
0040115D push 1
0040115F call @ILT+15(_stdcall_add@28) (00401014)
00401164 mov dword ptr [ebp-8],eax # 返回值
9: int __stdcall stdcall_add(int a, int b, int c, int d, int e, int f, int g)
10: {
00401080 push ebp
00401081 mov ebp,esp
00401083 sub esp,44h
00401086 push ebx
00401087 push esi
00401088 push edi
00401089 lea edi,[ebp-44h]
0040108C mov ecx,11h
00401091 mov eax,0CCCCCCCCh
00401096 rep stos dword ptr [edi]
11: int sum = a+b+c+d+e+f+g;
00401098 mov eax,dword ptr [ebp+8]
0040109B add eax,dword ptr [ebp+0Ch]
0040109E add eax,dword ptr [ebp+10h]
004010A1 add eax,dword ptr [ebp+14h]
004010A4 add eax,dword ptr [ebp+18h]
004010A7 add eax,dword ptr [ebp+1Ch]
004010AA add eax,dword ptr [ebp+20h]
004010AD mov dword ptr [ebp-4],eax
12: return sum;
004010B0 mov eax,dword ptr [ebp-4] # 存放返回值
13: }
004010B3 pop edi
004010B4 pop esi
004010B5 pop ebx
004010B6 mov esp,ebp
004010B8 pop ebp
004010B9 ret 1Ch # 栈平衡（等价于先 add esp, 1Ch 再 ret）fastcall 函数调用约定
参数1、参数2分别保存在 ECX、EDX ，剩下的参数从右往左一次入栈，被调用者实现栈平衡，返回值存放在 EAX 中。
25: int fastcall_sum = fastcall_add(1, 2, 3, 4, 5, 6, 7);
00401167 push 7
00401169 push 6
0040116B push 5
0040116D push 4
0040116F push 3
00401171 mov edx,2
00401176 mov ecx,1
0040117B call @ILT+0(@fastcall_add@28) (00401005)
00401180 mov dword ptr [ebp-0Ch],eax # 返回值
15: int __fastcall fastcall_add(int a, int b, int c, int d, int e, int f, int g)
16: {
004010D0 push ebp
004010D1 mov ebp,esp
004010D3 sub esp,4Ch
004010D6 push ebx
004010D7 push esi
004010D8 push edi
004010D9 push ecx
004010DA lea edi,[ebp-4Ch]
004010DD mov ecx,13h
004010E2 mov eax,0CCCCCCCCh
004010E7 rep stos dword ptr [edi]
004010E9 pop ecx
004010EA mov dword ptr [ebp-8],edx
004010ED mov dword ptr [ebp-4],ecx
17: int sum = a+b+c+d+e+f+g;
004010F0 mov eax,dword ptr [ebp-4]
004010F3 add eax,dword ptr [ebp-8]
004010F6 add eax,dword ptr [ebp+8]
004010F9 add eax,dword ptr [ebp+0Ch]
004010FC add eax,dword ptr [ebp+10h]
004010FF add eax,dword ptr [ebp+14h]
00401102 add eax,dword ptr [ebp+18h]
00401105 mov dword ptr [ebp-0Ch],eax
18: return sum;
00401108 mov eax,dword ptr [ebp-0Ch] # 存放返回值
19: }
0040110B pop edi
0040110C pop esi
0040110D pop ebx
0040110E mov esp,ebp
00401110 pop ebp
00401111 ret 14h # 栈平衡（等价于先 add esp, 14h 再 ret）X64 函数调用约定
X64只有一种 fastcall 函数调用约定
fastcall 函数调用约定
参数1、参数2、参数3、参数4分别保存在 RCX、RDX、R8D、R9D ，剩下的参数从右往左一次入栈，被调用者实现栈平衡，返回值存放在 RAX 中。
# 该代码是 msvc 2017 x64 生成的汇编代码
int fastcall_sum = fastcall_add(1, 2, 3, 4, 5, 6, 7);
00007FF6577A366E mov dword ptr [rsp+30h],7
00007FF6577A3676 mov dword ptr [rsp+28h],6
00007FF6577A367E mov dword ptr [rsp+20h],5
00007FF6577A3686 mov r9d,4
00007FF6577A368C mov r8d,3
00007FF6577A3692 mov edx,2
00007FF6577A3697 mov ecx,1
00007FF6577A369C call fastcall_add (07FF6577A11C2h)
00007FF6577A36A1 mov dword ptr [fastcall_sum],eax # 返回值
int __fastcall fastcall_add(int a, int b, int c, int d, int e, int f, int g)
{
00007FF6D22D1790 mov dword ptr [rsp+20h],r9d
00007FF6D22D1795 mov dword ptr [rsp+18h],r8d
00007FF6D22D179A mov dword ptr [rsp+10h],edx
00007FF6D22D179E mov dword ptr [rsp+8],ecx
00007FF6D22D17A2 push rbp
00007FF6D22D17A3 push rdi
00007FF6D22D17A4 sub rsp,0E8h
00007FF6D22D17AB mov rbp,rsp
00007FF6D22D17AE mov rdi,rsp
00007FF6D22D17B1 mov ecx,3Ah
00007FF6D22D17B6 mov eax,0CCCCCCCCh
00007FF6D22D17BB rep stos dword ptr [rdi]
00007FF6D22D17BD mov ecx,dword ptr [rsp+108h]
int sum = a + b + c + d + e + f + g;
00007FF6D22D17C4 mov eax,dword ptr [b]
00007FF6D22D17CA mov ecx,dword ptr [a]
00007FF6D22D17D0 add ecx,eax
00007FF6D22D17D2 mov eax,ecx
00007FF6D22D17D4 add eax,dword ptr [c]
00007FF6D22D17DA add eax,dword ptr [d]
00007FF6D22D17E0 add eax,dword ptr [e]
00007FF6D22D17E6 add eax,dword ptr [f]
00007FF6D22D17EC add eax,dword ptr [g]
00007FF6D22D17F2 mov dword ptr [sum],eax
return sum;
00007FF6D22D17F5 mov eax,dword ptr [sum] # 存放返回值
}
00007FF6D22D17F8 lea rsp,[rbp+0E8h]
00007FF6D22D17FF pop rdi
00007FF6D22D1800 pop rbp
00007FF6D22D1801 ret # 没做栈平衡C++ 函数调用约定
thiscall用于C++中类成员函数（方法）的调用
thiscall 函数调用约定
暂时不懂C++，等学了C++类了再更新
ARM/ARM64 函数调用约定
ARM和ARM64使用的是ATPCS(ARM-Thumb Procedure Call Standard/ARM-Thumb过程调用标准)的函数调用约定。
ATPCS 函数调用约定
ARM
参数1~参数4 分别保存到 R0~R3 寄存器中 ，剩下的参数从右往左一次入栈，被调用者实现栈平衡，返回值存放在 R0 中。
; 该代码是 arm-linux-androideabi-gcc + IDA PRO 生成的反汇编代码
.text:00008438 MOV R3, #5
.text:0000843C STR R3, [SP,#0x1C+e] ; e
.text:00008440 MOV R3, #6
.text:00008444 STR R3, [SP,#0x1C+f] ; f
.text:00008448 MOV R3, #7
.text:0000844C STR R3, [SP,#0x1C+g] ; g
.text:00008450 MOV R0, #1 ; a
.text:00008454 MOV R1, #2 ; b
.text:00008458 MOV R2, #3 ; c
.text:0000845C MOV R3, #4 ; d
.text:00008460 BL add
.text:00008464 STR R0, [R11,#sum]
.text:000083C4 EXPORT add
.text:000083C4 STR R11, [SP,#-4+var_s0]!
.text:000083C8 ADD R11, SP, #0
.text:000083CC SUB SP, SP, #0x1C
.text:000083D0 STR R0, [R11,#a]
.text:000083D4 STR R1, [R11,#b]
.text:000083D8 STR R2, [R11,#c]
.text:000083DC STR R3, [R11,#d]
.text:000083E0 LDR R2, [R11,#a]
.text:000083E4 LDR R3, [R11,#b]
.text:000083E8 ADD R2, R2, R3
.text:000083EC LDR R3, [R11,#c]
.text:000083F0 ADD R2, R2, R3
.text:000083F4 LDR R3, [R11,#d]
.text:000083F8 ADD R2, R2, R3
.text:000083FC LDR R3, [R11,#e]
.text:00008400 ADD R2, R2, R3
.text:00008404 LDR R3, [R11,#f]
.text:00008408 ADD R2, R2, R3
.text:0000840C LDR R3, [R11,#g]
.text:00008410 ADD R3, R2, R3
.text:00008414 STR R3, [R11,#sum]
.text:00008418 LDR R3, [R11,#sum]
.text:0000841C MOV R0, R3 ; R0返回值
.text:00008420 SUB SP, R11, #0
.text:00008424 LDR R11, [SP+var_s0],#4
.text:00008428 BX LRARM64
参数1~参数8 分别保存到 X0~X7 寄存器中 ，剩下的参数从右往左一次入栈，被调用者实现栈平衡，返回值存放在 X0 中。
; 该代码是 aarch64-linux-android-gcc + IDA PRO 生成的反汇编代码
.text:0000000000400684 MOV W0, #9
.text:0000000000400688 STR W0, [SP,#0x40+i] ; i
.text:000000000040068C MOV W0, #10
.text:0000000000400690 STR W0, [SP,#0x40+j] ; j
.text:0000000000400694 MOV W0, #11
.text:0000000000400698 STR W0, [SP,#0x40+k] ; k
.text:000000000040069C MOV W0, #12
.text:00000000004006A0 STR W0, [SP,#0x40+l] ; l
.text:00000000004006A4 MOV W0, #1 ; a
.text:00000000004006A8 MOV W1, #2 ; b
.text:00000000004006AC MOV W2, #3 ; c
.text:00000000004006B0 MOV W3, #4 ; d
.text:00000000004006B4 MOV W4, #5 ; e
.text:00000000004006B8 MOV W5, #6 ; f
.text:00000000004006BC MOV W6, #7 ; g
.text:00000000004006C0 MOV W7, #8 ; h
.text:00000000004006C4 BL add
.text:00000000004006C8 STR W0, [X29,#0x20+sum]
.text:00000000004005E8 EXPORT add
.text:00000000004005E8
.text:00000000004005E8 SUB SP, SP, #0x30
.text:00000000004005EC STR W0, [SP,#0x30+a]
.text:00000000004005F0 STR W1, [SP,#0x30+b]
.text:00000000004005F4 STR W2, [SP,#0x30+c]
.text:00000000004005F8 STR W3, [SP,#0x30+d]
.text:00000000004005FC STR W4, [SP,#0x30+e]
.text:0000000000400600 STR W5, [SP,#0x30+f]
.text:0000000000400604 STR W6, [SP,#0x30+g]
.text:0000000000400608 STR W7, [SP,#0x30+h]
.text:000000000040060C LDR W1, [SP,#0x30+a]
.text:0000000000400610 LDR W0, [SP,#0x30+b]
.text:0000000000400614 ADD W1, W1, W0
.text:0000000000400618 LDR W0, [SP,#0x30+c]
.text:000000000040061C ADD W1, W1, W0
.text:0000000000400620 LDR W0, [SP,#0x30+d]
.text:0000000000400624 ADD W1, W1, W0
.text:0000000000400628 LDR W0, [SP,#0x30+e]
.text:000000000040062C ADD W1, W1, W0
.text:0000000000400630 LDR W0, [SP,#0x30+f]
.text:0000000000400634 ADD W1, W1, W0
.text:0000000000400638 LDR W0, [SP,#0x30+g]
.text:000000000040063C ADD W1, W1, W0
.text:0000000000400640 LDR W0, [SP,#0x30+h]
.text:0000000000400644 ADD W1, W1, W0
.text:0000000000400648 LDR W0, [SP,#0x30+i]
.text:000000000040064C ADD W1, W1, W0
.text:0000000000400650 LDR W0, [SP,#0x30+j]
.text:0000000000400654 ADD W1, W1, W0
.text:0000000000400658 LDR W0, [SP,#0x30+k]
.text:000000000040065C ADD W1, W1, W0
.text:0000000000400660 LDR W0, [SP,#0x30+l]
.text:0000000000400664 ADD W0, W1, W0
.text:0000000000400668 STR W0, [SP,#0x30+sum]
.text:000000000040066C LDR W0, [SP,#0x30+sum] ;X0 返回值
.text:0000000000400670 ADD SP, SP, #0x30
.text:0000000000400674 RET