intraxia/wp-gistpen

section .text
extern  _MessageBoxA@16
%if     __NASM_VERSION_ID__ >= 0x02030000
safeseh handler         ; register handler as "safe handler"
%endif

handler:
    push    dword 1 ; MB_OKCANCEL
    push    dword caption
    push    dword text
    push    dword 0
    call    _MessageBoxA@16
    sub     eax,1   ; incidentally suits as return value
            ; for exception handler
    ret

global  _main
_main:  push    dword handler
    push    dword [fs:0]
    mov     dword [fs:0], esp
    xor     eax,eax
    mov     eax, dword[eax]   ; cause exception
    pop     dword [fs:0]      ; disengage exception handler
    add     esp, 4
    ret

avx2:   vzeroupper
    push      rbx
    mov       rbx,   rsp
    sub       rsp,   0h20
    vmovdqa   ymm0,  [rcx]
    vpaddb    ymm0,  [rdx]
    leave
    ret

text:   db      'OK to rethrow, CANCEL to generate core dump',0
caption:db      'SEGV',0

section .drectve info
    db      '/defaultlib:user32.lib /defaultlib:msvcrt.lib '