Question

我正在尝试使用带有以下代码的程序集插入在屏幕上打印单个字符：

output:
           keywords  search_volume  loan  mortgage  accounts  cards
0             loans         132000     10        0         0      0
1    funding circle          81000     0         0         0      0
2        government          36000     0         0         0      0
3  short term loans          30000     10        0         0      0
4           company          27000     0         0         0      0

但是我不知道如何在此c ++代码中插入80h函数调用。

asm（“ int 80h”）和asm（“ int 80h”：）无效。我正在使用clang ++

好的，我实际上用以下代码成功解决了这个问题：

char z[]="x";
int result;

asm( "mov 4, %%eax" : );
asm( "mov 1, %%ebx" : );
asm( "mov %%edx, %%ecx" : : "d"(&z) );
asm( "mov 2, %%edx" : );
//int 80h

但是执行后，我收到了分段错误错误。我还收到带有-fsanitize = undefined，address标志的消息：

char z[]="x";
int result;

asm( "mov 4, %%eax" : : : "eax" );
asm( "mov 1, %%ebx" : : : "ebx" );
asm( "mov %%edx, %%ecx" : : "d"(&z) : "ecx" );
asm( "mov 2, %%edx" : : : "edx" );
asm( "int $0x80" : );

我也用gdb调试了它，所以我知道该程序在此行上崩溃了：

AddressSanitizer:DEADLYSIGNAL
=================================================================
==6068==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000004   (pc 0x558c9691bb24 bp 0x7ffde7b2e180 sp 0x7ffde7b2e0c0 T0)
==6068==The signal is caused by a READ memory access.
==6068==Hint: address points to the zero page.
#0 0x558c9691bb23  (/notroot/Documents/asmcheckcpp.e+0x137b23)
#1 0x7faa9eb49ce2  (/usr/lib/libc.so.6+0x23ce2)
#2 0x558c9680311d  (/notroot/Documents/asmcheckcpp.e+0x1f11d)

AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/notroot/Documents/asmcheckcpp.e+0x137b23) 
==6068==ABORTING

但是我不知道为什么。 -我已经解决了这个问题，所以这段代码：

asm( "mov 4, %%eax" : : : "eax" );

有效但显示

cout << 'a' << endl;

char z[]="x";

asm( "mov $4, %%eax \n"
   "mov $1, %%ebx \n"
   "mov $2, %%edx \n"
   "int $0x80"
   :
   : "ecx"(&z)
   : "eax", "ebx", "edx" );

cout << 'a' << endl;

不是

a
a

在屏幕上

是否可以在装配件中执行80h系统功能？

0 个答案: