linux get process name from pid within kernel

Question

hi i have used sys_getpid() from within kernel to get process id how can I find out process name from kernel struct? does it exist in kernel??

thanks very much

Answer 1

My kernel module loads with "modprobe -v my_module --allow-unsupported -o some-data" and I extract the "some-data" parameter. The following code gave me the entire command line, and here is how I parsed out the parameter of interest:

struct mm_struct *mm;
unsigned char x, cmdlen;

mm = get_task_mm(current);
down_read(&mm->mmap_sem);

cmdlen = mm->arg_end - mm->arg_start;
for(x=0; xarg_start + x) == '-' && *(unsigned char *)(mm->arg_start + (x+1)) == 'o') {
        break;
    }
}
up_read(&mm->mmap_sem);

if(x == cmdlen) {
    printk(KERN_ERR "inject: ERROR - no target specified\n");
    return -EINVAL;
}

strcpy(target,(unsigned char *)(mm->arg_start + (x+3)));

"target" holds the string after the -o parameter. You can compress this somewhat - the caller (in this case, modprobe) will be the first string in mm->arg_start - to suit your needs.