strcat溢出？(strcat overflow?)

 有人可以解释为什么我的strcat这样做？ 
 
 我似乎无法找出为什么我要重写源字符串的一部分。 
 
 输出如下：New String：HelloThis应该在str1中str1h 0中的反斜杠0之后 
 
    global  strcat
            extern  strlen
 
 strcat的： 
 
    push    ebp
    mov     ebp, esp
    push    ecx
    push    esi
    push    edi
    push    ebx
    push    edx
    xor     edx, edx
    xor     edi, edi
    xor     ebx, ebx
    xor     esi, esi
    xor     ecx, ecx
    mov     edi, [ebp + 8]
    mov     esi, [ebp + 12]
    push    edi
    call    strlen
    pop     edi
    mov     ecx, eax
    xor     eax, eax
    push    esi
    call    strlen
    pop     esi
    mov     ebx, eax
    xor     eax, eax
    cmp     [edi + ecx], byte 0b
    je      PUT_LINE
    jmp     FINALIZE_END
 
 PUT_LINE： 
 
    cmp     ebx, eax
    je      END
    mov     dl, [esi + eax]
    mov     [edi + ecx], dl
    xor     edx, edx
    inc     eax
    inc     ecx
    jmp     PUT_LINE
 
 结束： 
 
    mov     eax, [ebp + 8]
    jmp     FINALIZE_END
 
 FINALIZE_END： 
 
    pop     edx
    pop     ebx
    pop     edi
    pop     esi
    pop     ecx
    mov     esp, ebp
    pop     ebp
    ret
 
 〜 
 
 〜 
 
int     main(int argc, char** argv)
{
        (void)argc;
        (void)argv;
        char*   str1;   
        char*   str2;

        str1 = strdup("Hello");

        str2 = strdup("This shall be after my backslash 0 in str1");
        printf("New String : %s\n", strcat(str1, str2));
        return (0);
}
 
 〜 

Could someone explain why is my strcat doing this?
 
I can't seem to find out why I am rewriting on a part of the source string.
 
The output is like this: New String: HelloThis shall be after my backslash 0 in str1h 0 in str1
 
    global  strcat
            extern  strlen
 
strcat:
 
    push    ebp
    mov     ebp, esp
    push    ecx
    push    esi
    push    edi
    push    ebx
    push    edx
    xor     edx, edx
    xor     edi, edi
    xor     ebx, ebx
    xor     esi, esi
    xor     ecx, ecx
    mov     edi, [ebp + 8]
    mov     esi, [ebp + 12]
    push    edi
    call    strlen
    pop     edi
    mov     ecx, eax
    xor     eax, eax
    push    esi
    call    strlen
    pop     esi
    mov     ebx, eax
    xor     eax, eax
    cmp     [edi + ecx], byte 0b
    je      PUT_LINE
    jmp     FINALIZE_END
 
PUT_LINE:
 
    cmp     ebx, eax
    je      END
    mov     dl, [esi + eax]
    mov     [edi + ecx], dl
    xor     edx, edx
    inc     eax
    inc     ecx
    jmp     PUT_LINE
 
END:
 
    mov     eax, [ebp + 8]
    jmp     FINALIZE_END
 
FINALIZE_END:
 
    pop     edx
    pop     ebx
    pop     edi
    pop     esi
    pop     ecx
    mov     esp, ebp
    pop     ebp
    ret
 
~
 
~
 
int     main(int argc, char** argv)
{
        (void)argc;
        (void)argv;
        char*   str1;   
        char*   str2;

        str1 = strdup("Hello");

        str2 = strdup("This shall be after my backslash 0 in str1");
        printf("New String : %s\n", strcat(str1, str2));
        return (0);
}
 
~

原文：https://stackoverflow.com/questions/9646414