在Linux中在没有ptrace的情况下在C中读取另一个进程的内存

问题描述

我正在尝试读取另一个进程的内存并打印内存中的任何内容（堆和/或堆栈）。我已经使用/proc获得了内存地址范围 我提取了地址范围，例如this。现在，我想按定义读取其他进程的内存范围。

5569032d2000-5569032f3000 rw-p 00000000 00:00 0 [堆]

我被困在如何访问那些内存地址上。我尝试了如下所示的操作，但并没有太大帮助。

int main(int argc,char *argv[]) {

off_t offset = strtoul(argv[1],NULL,0);
size_t len = strtoul(argv[2],0);

// Truncate offset to a multiple of the page size,or mmap will fail.
size_t pagesize = sysconf(_SC_PAGE_SIZE);
off_t page_base = (offset / pagesize) * pagesize;
off_t page_offset = offset - page_base;

int fd = open("/dev/mem",O_SYNC);
unsigned char *mem = mmap(NULL,page_offset + len,PROT_READ | PROT_WRITE,MAP_PRIVATE,fd,page_base);
if (mem == MAP_Failed) {
    perror("Can't map memory");
    return -1;
}

size_t i;
for (i = 0; i < len; ++i)
    printf("%x ",(int)mem[page_offset + i]);
//size_t i;
return 0;}

谢谢。

我正在为嵌入式系统制作调试工具。我无法使用ptrace()，因为它会在试图窥视设备内存时暂停正在运行的进程。

解决方法

我想通读另一个过程，可以使用process_vm_readv()函数，如下所示：

pid_t pid; // Put value of pid in this
void *remotePtr; // Put starting address 
size_t bufferLength; // Put size of buffer in this,aka size to read
// Build iovec structs
    struct iovec local[1];
    local[0].iov_base = calloc(bufferLength,sizeof(char));
    local[0].iov_len = bufferLength;

    struct iovec remote[1];
    remote[0].iov_base = remotePtr;
    remote[0].iov_len = bufferLength;

/*Nread will contain amount of bytes of data read*/

nread = process_vm_readv(pid,local,2,remote,1,0); 
    if (nread < 0) {
        switch (errno) {
        case EINVAL:
            printf("ERROR: INVALID ARGUMENTS.\n");
            break;
        case EFAULT:
            printf
                ("ERROR: UNABLE TO ACCESS TARGET MEMORY ADDRESS.\n");
            break;
        case ENOMEM:
            printf("ERROR: UNABLE TO ALLOCATE MEMORY.\n");
            break;
        case EPERM:
            printf
                ("ERROR: INSUFFICIENT PRIVILEGES TO TARGET PROCESS.\n");
            break;
        case ESRCH:
            printf("ERROR: PROCESS DOES NOT EXIST.\n");
            break;
        default:
            printf("ERROR: AN UNKNOWN ERROR HAS OCCURRED.\n");
        }

        return -1;
    }
/* To print the read data */
printf("The read text is \n %s\n",local[0].iov_base);