为什么我的第5个参数没有通过？

问题描述

因此，我试图在x64中实现，以在运行时确定参数数量和类型的函数来实现该功能，但由于未通过测试用例，因此我似乎未处理堆栈参数。这是masm中的代码：

PUBLIC makeuniquecall

.data

makeuniquecall_jmp_table    dq  zero_zero,one_zero,two_zero,three_zero ; ordinary

makeuniquecall_jmp_table_one    dq  zero_one,one_one,two_one,three_one ; single precision

makeuniquecall_jmp_table_two    dq  zero_two,one_two,two_two,three_two ; double precision

.code

makeuniquecall PROC
;rcx - function pointer
;rdx - raw argument data
;r8 - a byte array specifying each register parameter if it's float and the last qword is the size of the rest
push    r12
push    r13
push    r14

mov r12,rcx
mov r13,rdx
mov r14,r8

; first store the stack vars

mov rax,[r14 + 4] ; retrieve size of stack

sub rsp,rax

mov rdi,rsp
xor rdx,rdx
mov r8,8
div r8
mov rcx,rax
mov rsi,r13
add rsi,32

rep movs qword ptr [rdi],qword ptr [rsi] ; here somehow the 5th parameter is not correctly trasnfered

xor r10,r10
cycle:
mov rax,r14
add rax,r10
movzx rax,byte ptr [rax]
test rax,rax
jnz jmp_one
lea rax,makeuniquecall_jmp_table
jmp qword ptr[rax + r10 * 8]
jmp_one:
cmp rax,1
jnz jmp_two
lea rax,makeuniquecall_jmp_table_one
jmp qword ptr[rax + r10 * 8]
jmp_two:
lea rax,makeuniquecall_jmp_table_two
jmp qword ptr[rax + r10 * 8]

zero_zero::
mov rcx,qword ptr[r13+r10*8]
jmp continue
one_zero::
mov rdx,qword ptr[r13+r10*8]
jmp continue
two_zero::
mov r8,qword ptr[r13+r10*8]
jmp continue
three_zero::
mov r9,qword ptr[r13+r10*8]
jmp continue
zero_one::
movss xmm0,dword ptr[r13+r10*8]
jmp continue
one_one::
movss xmm1,dword ptr[r13+r10*8]
jmp continue
two_one::
movss xmm2,dword ptr[r13+r10*8]
jmp continue
three_one::
movss xmm3,dword ptr[r13+r10*8]
jmp continue
zero_two::
movsd xmm0,qword ptr[r13+r10*8]
jmp continue
one_two::
movsd xmm1,qword ptr[r13+r10*8]
jmp continue
two_two::
movsd xmm2,qword ptr[r13+r10*8]
jmp continue
three_two::
movsd xmm3,qword ptr[r13+r10*8]
continue:
inc r10
cmp r10,4
jb  cycle

mov r14,[r14 + 4] ; retrieve size of stack

call    r12

add rsp,r14

pop r14
pop r13
pop r12

ret

makeuniquecall ENDP

END

这是我的测试用例：

int functiontest(double a0,float a1,char* a2,wchar_t* a3,double a4)
{
    printf("%d %f %s %ls %d",a0,a1,a2,a3,a4);
}

main()
{
#pragma pack(push,1)
    struct { char data[4]; size_t stack; } footprint = { {2,1,0},sizeof (double) };
#pragma pack(pop)

    makeuniquecall(functiontest,(struct { double m0; float m1; char* m2,* m3; double m4; }) {
        3.66,3.66,"3.66",L"3.66",3.77
    },& footprint);
}

似乎第五个参数（a4）不是我最初传递的-3.77-为什么有任何想法？

解决方法

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