디버거

#define _GNU_SOURCE
#include <stdio.h>
#include <stdio.h>
#include <dlfcn.h>
#include <capstone/capstone.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>

char* bp_addr;
char saved_bp;
csh handle;
cs_insn* insn;

void disass(void* addr){
    cs_disasm(handle, addr, 15, addr, 0, &insn);
    printf("Disassembly : %s %s\n", insn[0].mnemonic, insn[0].op_str);
}

void handler(int sig, siginfo_t *info, void *ucontext)
{
    ucontext_t *uc = (ucontext_t *)ucontext;
    char command[0x100];
    if (info->si_addr == NULL){
        //int3
        puts("BP Hit");
        printf("RIP : %p\n", uc->uc_mcontext.gregs[16] - 1);
        *bp_addr = saved_bp;
        disass(uc->uc_mcontext.gregs[16] - 1);
        uc->uc_mcontext.gregs[16] = bp_addr;
        scanf("%s", command);
        //continue
        if (!strcmp(command, "c")){
            size_t eflags = uc->uc_mcontext.gregs[17];
            eflags &= ~0x100; //single step disable
            uc->uc_mcontext.gregs[17] = eflags;
        }
        else if(!strcmp(command, "si")){
            size_t eflags = uc->uc_mcontext.gregs[17];
            eflags |= 0x100; //single step enable
            uc->uc_mcontext.gregs[17] = eflags;
        }
    }
    else{
        //single step
        printf("RIP : %p\n", info->si_addr);
        disass(info->si_addr);
        scanf("%s", command);
        //continue
        if (!strcmp(command, "c")){
            size_t eflags = uc->uc_mcontext.gregs[17];
            eflags &= ~0x100; //single step disable
            uc->uc_mcontext.gregs[17] = eflags;
        }
        else if(!strcmp(command, "si")){
            size_t eflags = uc->uc_mcontext.gregs[17];
            eflags |= 0x100; //single step enable
            uc->uc_mcontext.gregs[17] = eflags;
        }
    }
}



void __attribute__((constructor)) my_init() {
    cs_open(CS_ARCH_X86, CS_MODE_64, &handle);
    printf("debugger start!\n");
    struct sigaction sa;
    sa.sa_sigaction = handler;
    sa.sa_flags = SA_SIGINFO;
    if (sigaction(SIGTRAP, &sa, NULL) == -1) {
        perror("sigaction");
        return 1;
    }
    printf("bp > ");
    scanf("%llx", &bp_addr);  //bp_addr = bp 걸 주소
    printf("%llx\n", ((size_t)bp_addr >> 12) << 12);
    mprotect(((size_t)bp_addr >> 12) << 12, 0x1000, 7);
    saved_bp = *bp_addr;
    *bp_addr = 0xCC;
    getchar(); //개행제거
}