NASM ReadConsoleA 或 WriteConsoleA 缓冲区调试问题
NASM ReadConsoleA or WriteConsoleA Buffer Debugging Issue
我正在 Windows 上编写一个 NASM 汇编程序，让用户输入两个单位数字，将它们相加，然后输出结果。我正在尝试使用 Windows API 作为输入和输出。
不幸的是，虽然我可以让它在程序循环后立即读取一个数字以获得第二个数字，但程序结束而不是要求第二个数字。
程序的输出如下所示：
有趣的是，如果我输入 1，那么显示的值会大一个，所以它正在添加一些东西！
这也适用于输入的其他个位数 (2-9)。
我很确定这与我使用 ReadConsoleA 函数的方式有关，但我在尝试寻找解决方案时遇到了一些困难。我安装了gdb调试程序，组装如下：
nasm -f win64 -g -o task9.obj task9.asmGoLink /console /entry _main task9.obj kernel32.dllgdb task9
但我得到以下错误：
"C:\Users\Administrator\Desktop/task9.exe": not in executable format: File format not recognized
我后来读到 NASM 不输出 Win64 格式所需的调试信息，但我对此不是 100% 确定。我相当确定我安装了 64 位版本的 GDB：
我的程序如下：
extern ExitProcess ;windows API function to exit process
extern WriteConsoleA ;windows API function to write to the console window (ANSI version)
extern ReadConsoleA ;windows API function to read from the console window (ANSI version)
extern GetStdHandle ;windows API to get the for the console handle for input/output
section .data ;the .data section is where variables and constants are defined
STD_OUTPUT_HANDLE equ -11
STD_INPUT_HANDLE equ -10
digits db '0123456789' ;list of digits
input_message db 'Please enter your next number: '
length equ $-input_message
section .bss ;the .bss section is where space is reserved for additional variables
input_buffer: resb 2 ;reserve 64 bits for user input
char_written: resb 4
chars: resb 1 ;reversed for use with write operation
section .text ;the .text section is where the program code goes
global _main ;tells the machine which label to start program execution from
_num_to_str:
cmp rax, 0 ;compare value in rax to 0
jne .convert ;if not equal then jump to label
jmp .output
.convert:
;get next digit value
inc r15 ;increment the counter for next digit
mov rcx, 10
xor rdx, rdx ;clear previous remainder result
div rcx ;divide value in rax by value in rcx
;quotient (result) stored in rax
;remainder stored in rdx
push rdx ;store remainder on the stack
jmp _num_to_str
.output:
pop rdx ;get the last digit from the stack
;convert digit value to ascii character
mov r10, digits ;load the address of the digits into rsi
add r10, rdx ;get the character of the digits string to display
mov rdx, r10 ;digit to print
mov r8, 1 ;one byte to be output
call _print
;decide whether to loop
dec r15 ;reduce remaining digits (having printed one)
cmp r15, 0 ;are there digits left to print?
jne .output ;if not equal then jump to label output
ret
_print:
;get the output handle
mov rcx, STD_OUTPUT_HANDLE ;specifies that the output handle is required
call GetStdHandle ;returns value for handle to rax
mov rcx, rax
mov r9, char_written
call WriteConsoleA
ret
_read:
;get the input handle
mov rcx, STD_INPUT_HANDLE ;specifies that the input handle is required
call GetStdHandle
;get value from keyboard
mov rcx, rax ;place the handle for operation
mov rdx, input_buffer ;set name to receive input from keyboard
mov r8, 2 ;max number of characters to read
mov r9, chars ;stores the number of characters actually read
call ReadConsoleA
movzx r12, byte[input_buffer]
ret
_get_value:
mov rdx, input_message ;move the input message into rdx for function call
mov r8, length ;load the length of the message for function call
call _print
xor r8, r8
xor r9, r9
call _read
.end:
ret
_main:
mov r13, 0 ;counter for values input
mov r14, 0 ;total for calculation
.loop:
xor r12, r12
call _get_value ;get value from user
sub r12, '0' ;convert char to integer
add r14, r12 ;add value to total
;decide whether to loop for another character or not
inc r13
cmp r13, 2
jne .loop
;convert total to ASCII value
mov rax, r14 ;num_to_str expects total in rax
mov r15, 0 ;num_to_str uses r15 as a counter - must be initialised
call _num_to_str
;exit the program
mov rcx, 0 ;exit code
call ExitProcess
如果您能提供解决问题或如何使用 gdb 解决问题的任何帮助，我将不胜感激。
我发现您的代码存在以下问题：
- Microsoft x86-64 convention 要求
rsp 16 字节对齐。
- 您必须为堆栈中的参数保留 space，即使您在寄存器中传递它们也是如此。
- 您的
chars 变量需要 4 个字节而不是 1 个字节。
ReadConsole 需要 5 个参数。- 你应该读取 3 个字节，因为
ReadConsole returns CR LF。或者你可以忽略领先的白色space.
- 如果输入
0，你的 _num_to_str 就坏了。
根据 Jester 的 建议，这是最终程序：
extern ExitProcess ;windows API function to exit process
extern WriteConsoleA ;windows API function to write to the console window (ANSI version)
extern ReadConsoleA ;windows API function to read from the console window (ANSI version)
extern GetStdHandle ;windows API to get the for the console handle for input/output
section .data ;the .data section is where variables and constants are defined
STD_OUTPUT_HANDLE equ -11
STD_INPUT_HANDLE equ -10
digits db '0123456789' ;list of digits
input_message db 'Please enter your next number: '
length equ $-input_message
NULL equ 0
section .bss ;the .bss section is where space is reserved for additional variables
input_buffer: resb 3 ;reserve 64 bits for user input
char_written: resb 4
chars: resb 4 ;reversed for use with write operation
section .text ;the .text section is where the program code goes
global _main ;tells the machine which label to start program execution from
_num_to_str:
sub rsp, 32
cmp rax, 0
jne .next_digit
push rax
inc r15
jmp .output
.next_digit:
cmp rax, 0 ;compare value in rax to 0
jne .convert ;if not equal then jump to label
jmp .output
.convert:
;get next digit value
inc r15 ;increment the counter for next digit
mov rcx, 10
xor rdx, rdx ;clear previous remainder result
div rcx ;divide value in rax by value in rcx
;quotient (result) stored in rax
;remainder stored in rdx
sub rsp, 8 ;add space on stack for value
push rdx ;store remainder on the stack
jmp .next_digit
.output:
pop rdx ;get the last digit from the stack
add rsp, 8 ;remove space from stack for popped value
;convert digit value to ascii character
mov r10, digits ;load the address of the digits into rsi
add r10, rdx ;get the character of the digits string to display
mov rdx, r10 ;digit to print
mov r8, 1 ;one byte to be output
call _print
;decide whether to loop
dec r15 ;reduce remaining digits (having printed one)
cmp r15, 0 ;are there digits left to print?
jne .output ;if not equal then jump to label output
add rsp, 32
ret
_print:
sub rsp, 40
;get the output handle
mov rcx, STD_OUTPUT_HANDLE ;specifies that the output handle is required
call GetStdHandle ;returns value for handle to rax
mov rcx, rax
mov r9, char_written
mov rax, qword 0 ;fifth argument
mov qword [rsp+0x20], rax
call WriteConsoleA
add rsp, 40
ret
_read:
sub rsp, 40
;get the input handle
mov rcx, STD_INPUT_HANDLE ;specifies that the input handle is required
call GetStdHandle
;get value from keyboard
mov rcx, rax ;place the handle for operation
xor rdx, rdx
mov rdx, input_buffer ;set name to receive input from keyboard
mov r8, 3 ;max number of characters to read
mov r9, chars ;stores the number of characters actually read
mov rax, qword 0 ;fifth argument
mov qword [rsp+0x20], rax
call ReadConsoleA
movzx r12, byte[input_buffer]
add rsp, 40
ret
_get_value:
sub rsp, 40
mov rdx, input_message ;move the input message into rdx for function call
mov r8, length ;load the length of the message for function call
call _print
call _read
.end:
add rsp, 40
ret
_main:
sub rsp, 40
mov r13, 0 ;counter for values input
mov r14, 0 ;total for calculation
.loop:
call _get_value ;get value from user
sub r12, '0' ;convert char to integer
add r14, r12 ;add value to total
;decide whether to loop for another character or not
inc r13
cmp r13, 2
jne .loop
;convert total to ASCII value
mov rax, r14 ;num_to_str expects total in rax
mov r15, 0 ;num_to_str uses r15 as a counter - must be initialised
call _num_to_str
;exit the program
mov rcx, 0 ;exit code
call ExitProcess
add rsp, 40
ret
事实证明，我实际上也遗漏了 WriteConsole 函数中的第 5 个参数。
我正在 Windows 上编写一个 NASM 汇编程序，让用户输入两个单位数字，将它们相加，然后输出结果。我正在尝试使用 Windows API 作为输入和输出。
不幸的是，虽然我可以让它在程序循环后立即读取一个数字以获得第二个数字，但程序结束而不是要求第二个数字。
程序的输出如下所示：
有趣的是，如果我输入 1，那么显示的值会大一个，所以它正在添加一些东西！
这也适用于输入的其他个位数 (2-9)。
我很确定这与我使用 ReadConsoleA 函数的方式有关，但我在尝试寻找解决方案时遇到了一些困难。我安装了gdb调试程序，组装如下：
nasm -f win64 -g -o task9.obj task9.asmGoLink /console /entry _main task9.obj kernel32.dllgdb task9
但我得到以下错误：
"C:\Users\Administrator\Desktop/task9.exe": not in executable format: File format not recognized
我后来读到 NASM 不输出 Win64 格式所需的调试信息，但我对此不是 100% 确定。我相当确定我安装了 64 位版本的 GDB：
我的程序如下：
extern ExitProcess ;windows API function to exit process
extern WriteConsoleA ;windows API function to write to the console window (ANSI version)
extern ReadConsoleA ;windows API function to read from the console window (ANSI version)
extern GetStdHandle ;windows API to get the for the console handle for input/output
section .data ;the .data section is where variables and constants are defined
STD_OUTPUT_HANDLE equ -11
STD_INPUT_HANDLE equ -10
digits db '0123456789' ;list of digits
input_message db 'Please enter your next number: '
length equ $-input_message
section .bss ;the .bss section is where space is reserved for additional variables
input_buffer: resb 2 ;reserve 64 bits for user input
char_written: resb 4
chars: resb 1 ;reversed for use with write operation
section .text ;the .text section is where the program code goes
global _main ;tells the machine which label to start program execution from
_num_to_str:
cmp rax, 0 ;compare value in rax to 0
jne .convert ;if not equal then jump to label
jmp .output
.convert:
;get next digit value
inc r15 ;increment the counter for next digit
mov rcx, 10
xor rdx, rdx ;clear previous remainder result
div rcx ;divide value in rax by value in rcx
;quotient (result) stored in rax
;remainder stored in rdx
push rdx ;store remainder on the stack
jmp _num_to_str
.output:
pop rdx ;get the last digit from the stack
;convert digit value to ascii character
mov r10, digits ;load the address of the digits into rsi
add r10, rdx ;get the character of the digits string to display
mov rdx, r10 ;digit to print
mov r8, 1 ;one byte to be output
call _print
;decide whether to loop
dec r15 ;reduce remaining digits (having printed one)
cmp r15, 0 ;are there digits left to print?
jne .output ;if not equal then jump to label output
ret
_print:
;get the output handle
mov rcx, STD_OUTPUT_HANDLE ;specifies that the output handle is required
call GetStdHandle ;returns value for handle to rax
mov rcx, rax
mov r9, char_written
call WriteConsoleA
ret
_read:
;get the input handle
mov rcx, STD_INPUT_HANDLE ;specifies that the input handle is required
call GetStdHandle
;get value from keyboard
mov rcx, rax ;place the handle for operation
mov rdx, input_buffer ;set name to receive input from keyboard
mov r8, 2 ;max number of characters to read
mov r9, chars ;stores the number of characters actually read
call ReadConsoleA
movzx r12, byte[input_buffer]
ret
_get_value:
mov rdx, input_message ;move the input message into rdx for function call
mov r8, length ;load the length of the message for function call
call _print
xor r8, r8
xor r9, r9
call _read
.end:
ret
_main:
mov r13, 0 ;counter for values input
mov r14, 0 ;total for calculation
.loop:
xor r12, r12
call _get_value ;get value from user
sub r12, '0' ;convert char to integer
add r14, r12 ;add value to total
;decide whether to loop for another character or not
inc r13
cmp r13, 2
jne .loop
;convert total to ASCII value
mov rax, r14 ;num_to_str expects total in rax
mov r15, 0 ;num_to_str uses r15 as a counter - must be initialised
call _num_to_str
;exit the program
mov rcx, 0 ;exit code
call ExitProcess
如果您能提供解决问题或如何使用 gdb 解决问题的任何帮助，我将不胜感激。
我发现您的代码存在以下问题：
- Microsoft x86-64 convention 要求
rsp16 字节对齐。 - 您必须为堆栈中的参数保留 space，即使您在寄存器中传递它们也是如此。
- 您的
chars变量需要 4 个字节而不是 1 个字节。 ReadConsole需要 5 个参数。- 你应该读取 3 个字节，因为
ReadConsolereturnsCR LF。或者你可以忽略领先的白色space. - 如果输入
0，你的_num_to_str就坏了。
根据 Jester 的 建议，这是最终程序：
extern ExitProcess ;windows API function to exit process
extern WriteConsoleA ;windows API function to write to the console window (ANSI version)
extern ReadConsoleA ;windows API function to read from the console window (ANSI version)
extern GetStdHandle ;windows API to get the for the console handle for input/output
section .data ;the .data section is where variables and constants are defined
STD_OUTPUT_HANDLE equ -11
STD_INPUT_HANDLE equ -10
digits db '0123456789' ;list of digits
input_message db 'Please enter your next number: '
length equ $-input_message
NULL equ 0
section .bss ;the .bss section is where space is reserved for additional variables
input_buffer: resb 3 ;reserve 64 bits for user input
char_written: resb 4
chars: resb 4 ;reversed for use with write operation
section .text ;the .text section is where the program code goes
global _main ;tells the machine which label to start program execution from
_num_to_str:
sub rsp, 32
cmp rax, 0
jne .next_digit
push rax
inc r15
jmp .output
.next_digit:
cmp rax, 0 ;compare value in rax to 0
jne .convert ;if not equal then jump to label
jmp .output
.convert:
;get next digit value
inc r15 ;increment the counter for next digit
mov rcx, 10
xor rdx, rdx ;clear previous remainder result
div rcx ;divide value in rax by value in rcx
;quotient (result) stored in rax
;remainder stored in rdx
sub rsp, 8 ;add space on stack for value
push rdx ;store remainder on the stack
jmp .next_digit
.output:
pop rdx ;get the last digit from the stack
add rsp, 8 ;remove space from stack for popped value
;convert digit value to ascii character
mov r10, digits ;load the address of the digits into rsi
add r10, rdx ;get the character of the digits string to display
mov rdx, r10 ;digit to print
mov r8, 1 ;one byte to be output
call _print
;decide whether to loop
dec r15 ;reduce remaining digits (having printed one)
cmp r15, 0 ;are there digits left to print?
jne .output ;if not equal then jump to label output
add rsp, 32
ret
_print:
sub rsp, 40
;get the output handle
mov rcx, STD_OUTPUT_HANDLE ;specifies that the output handle is required
call GetStdHandle ;returns value for handle to rax
mov rcx, rax
mov r9, char_written
mov rax, qword 0 ;fifth argument
mov qword [rsp+0x20], rax
call WriteConsoleA
add rsp, 40
ret
_read:
sub rsp, 40
;get the input handle
mov rcx, STD_INPUT_HANDLE ;specifies that the input handle is required
call GetStdHandle
;get value from keyboard
mov rcx, rax ;place the handle for operation
xor rdx, rdx
mov rdx, input_buffer ;set name to receive input from keyboard
mov r8, 3 ;max number of characters to read
mov r9, chars ;stores the number of characters actually read
mov rax, qword 0 ;fifth argument
mov qword [rsp+0x20], rax
call ReadConsoleA
movzx r12, byte[input_buffer]
add rsp, 40
ret
_get_value:
sub rsp, 40
mov rdx, input_message ;move the input message into rdx for function call
mov r8, length ;load the length of the message for function call
call _print
call _read
.end:
add rsp, 40
ret
_main:
sub rsp, 40
mov r13, 0 ;counter for values input
mov r14, 0 ;total for calculation
.loop:
call _get_value ;get value from user
sub r12, '0' ;convert char to integer
add r14, r12 ;add value to total
;decide whether to loop for another character or not
inc r13
cmp r13, 2
jne .loop
;convert total to ASCII value
mov rax, r14 ;num_to_str expects total in rax
mov r15, 0 ;num_to_str uses r15 as a counter - must be initialised
call _num_to_str
;exit the program
mov rcx, 0 ;exit code
call ExitProcess
add rsp, 40
ret
事实证明，我实际上也遗漏了 WriteConsole 函数中的第 5 个参数。