osandov

$ drgn
...
>>> for cpu in for_each_present_cpu():
...     task = per_cpu(prog["runqueues"], cpu).idle
...     print(task.comm, task.pid)
...
(char [16])"swapper/0" (pid_t)0
(char [16])"swapper/1" (pid_t)0
(char [16])"swapper/2" (pid_t)0
(char [16])"swapper/3" (pid_t)0

osandov

#define _GNU_SOURCE
#include <fcntl.h>
#include <sched.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/wait.h>

static const int NUM_KEEP = 5;

osandov

"""
Prototype implementation of x86-64 page table walking in drgn. Doesn't handle
huge pages or 5-level page tables. Probably wrong in other ways.
"""

from drgn import cast, reinterpret
from drgn.helpers.linux.mm import page_to_virt, pfn_to_page


def pgd_val(pgd):

osandov

#!/usr/bin/env python3

import bcc
import collections
import ctypes
import functools
import sys

bpf_text = r"""
#include <uapi/linux/ptrace.h>

osandov

#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>

osandov

.section .data
potato:
    .byte 65, 66, 10

.section .text

.globl _start
_start:
    movq $1, %rbx
    movq $potato, %rcx