assembly

问题 I have opened a file with OpenFile, and gotten its size with GetFileSize. I wish to use ReadFile and use the stack as the buffer it requires, allocating enough room on the stack with the size of the file returned from GetFileSize. When I run this I get no output. Here is my code... extern GetStdHandle extern GetModuleFileNameA extern OpenFile extern ReadFile extern WriteFile extern CloseHandle extern GetFileSize extern ExitProcess import GetStdHandle kernel32.dll import GetModuleFileNameA

问题 I wrote a simple program in c which calls a function called while_loop with arguments 4,3,2. The function is just basically a while loop, I don't think it's really that relevant to my question since it's more of a generic question. I was told to run objdump -d, so I did. I have multiple questions so here it goes: I understand that in the leftmost column there are addresses and they increment according to the number of bytes in front. What I don't understand very well is the second column. Is

问题 I wrote a simple program in c which calls a function called while_loop with arguments 4,3,2. The function is just basically a while loop, I don't think it's really that relevant to my question since it's more of a generic question. I was told to run objdump -d, so I did. I have multiple questions so here it goes: I understand that in the leftmost column there are addresses and they increment according to the number of bytes in front. What I don't understand very well is the second column. Is

问题 I have a program that counts root of quadratic equation. And I have a problem with printing the results on the screen, because I can print only one value. This is my code below, could you please tell me what should I do to pass two result to expression "x1 = ... ". [bits 32] call getaddr format db "x1 = %lf, x2 = %lf", 0xA, 0 offset equ $ - format a dq 1.0 ; b dq -11.0 c dq 28.0 minusfour dq -4.0 getaddr: finit mov eax, [esp] lea eax, [eax+offset] ; eax = a mov edx, [esp] lea edx, [edx+offset

问题 I am working on this c program. I am compiling it with gcc on a 64 bits x64 linux: #include <stdio.h> char buffer[]={0x90,0x90,0xC3}; int main(int argc, char *argv[]) { void (*fct)(); fct=buffer; fct(); return 0; } 0x90 opcode is NOP 0xC3 opcode is RET I want to know what i should do in order to run this program. I get a segfault when running it... Thanks 回答1: TL;DR Compile with -z execstack to enable Linux's read-implies-exec feature for your executable. Despite the name, it applies to all

问题 I am working on this c program. I am compiling it with gcc on a 64 bits x64 linux: #include <stdio.h> char buffer[]={0x90,0x90,0xC3}; int main(int argc, char *argv[]) { void (*fct)(); fct=buffer; fct(); return 0; } 0x90 opcode is NOP 0xC3 opcode is RET I want to know what i should do in order to run this program. I get a segfault when running it... Thanks 回答1: TL;DR Compile with -z execstack to enable Linux's read-implies-exec feature for your executable. Despite the name, it applies to all

问题 I am a novice in assembly language programming I searched for binary search program and found this and I tried understand the program. It's working fine but I couldn't understand the success part of the code: what is ADD al,'0' and what is mov res,al ? .model small .stack 100h .data ARR DW 1000H,2000H,3000H,4000H,5000H,6000H LEN DW ($-ARR)/2 KEY EQU 2000H SUC DB "KEY IS FOUND AT$" FAILURE DB "KEY IS NOT FOUND$" RES DB "POSITION",13,10,"$" .CODE START: MOV AX,@data MOV DS,AX MOV BX,00 ;LOW MOV

问题 I am a novice in assembly language programming I searched for binary search program and found this and I tried understand the program. It's working fine but I couldn't understand the success part of the code: what is ADD al,'0' and what is mov res,al ? .model small .stack 100h .data ARR DW 1000H,2000H,3000H,4000H,5000H,6000H LEN DW ($-ARR)/2 KEY EQU 2000H SUC DB "KEY IS FOUND AT$" FAILURE DB "KEY IS NOT FOUND$" RES DB "POSITION",13,10,"$" .CODE START: MOV AX,@data MOV DS,AX MOV BX,00 ;LOW MOV

问题 I compiled .S file using command: clang-8 -c funcs.s -o funcs.o -emit-llvm I found, that .o file was generated in ELF format. I was expected to see llvm-ir format (with "BC" characters at the beginning of resulting file). Seems, Clang ignores "-emit-llvm" flag. 回答1: Your question isn't fundamentally different from Is it possible to translate an assembly language to LLVM IR, optimize it and then recompile it to a different architecture?. asm source and binary executables / object files are

问题 I have different "*.asm" files that need to be included in the "main.asm" file. The problem I'm facing is that: In many files I have declared labels like "loop", "forLoop", "whileTag" etc... in the same way ( i.e. with the same name ) And when I try to %include "file1.asm" and %include "file2.asm" it gives me a compilation error. It says that I can't declare the same label twice ( i.e. file1.asm and file2.asm, both have "loopHere" label declared ). How do I solve this ? Thanks The problem