LXR linux/tools/testing/selftests/bpf/progs/bpf_iter_task

   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c) 2020 Facebook */
   3#include "bpf_iter.h"
   4#include <bpf/bpf_helpers.h>
   5
   6char _license[] SEC("license") = "GPL";
   7
   8/* Copied from mm.h */
   9#define VM_READ         0x00000001
  10#define VM_WRITE        0x00000002
  11#define VM_EXEC         0x00000004
  12#define VM_MAYSHARE     0x00000080
  13
  14/* Copied from kdev_t.h */
  15#define MINORBITS       20
  16#define MINORMASK       ((1U << MINORBITS) - 1)
  17#define MAJOR(dev)      ((unsigned int) ((dev) >> MINORBITS))
  18#define MINOR(dev)      ((unsigned int) ((dev) & MINORMASK))
  19
  20#define D_PATH_BUF_SIZE 1024
  21char d_path_buf[D_PATH_BUF_SIZE] = {};
  22__u32 pid = 0;
  23
  24SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx)
  25{
  26        struct vm_area_struct *vma = ctx->vma;
  27        struct seq_file *seq = ctx->meta->seq;
  28        struct task_struct *task = ctx->task;
  29        struct file *file;
  30        char perm_str[] = "----";
  31
  32        if (task == (void *)0 || vma == (void *)0)
  33                return 0;
  34
  35        file = vma->vm_file;
  36        if (task->tgid != pid)
  37                return 0;
  38        perm_str[0] = (vma->vm_flags & VM_READ) ? 'r' : '-';
  39        perm_str[1] = (vma->vm_flags & VM_WRITE) ? 'w' : '-';
  40        perm_str[2] = (vma->vm_flags & VM_EXEC) ? 'x' : '-';
  41        perm_str[3] = (vma->vm_flags & VM_MAYSHARE) ? 's' : 'p';
  42        BPF_SEQ_PRINTF(seq, "%08llx-%08llx %s ", vma->vm_start, vma->vm_end, perm_str);
  43
  44        if (file) {
  45                __u32 dev = file->f_inode->i_sb->s_dev;
  46
  47                bpf_d_path(&file->f_path, d_path_buf, D_PATH_BUF_SIZE);
  48
  49                BPF_SEQ_PRINTF(seq, "%08llx ", vma->vm_pgoff << 12);
  50                BPF_SEQ_PRINTF(seq, "%02x:%02x %u", MAJOR(dev), MINOR(dev),
  51                               file->f_inode->i_ino);
  52                BPF_SEQ_PRINTF(seq, "\t%s\n", d_path_buf);
  53        } else {
  54                BPF_SEQ_PRINTF(seq, "%08llx 00:00 0\n", 0ULL);
  55        }
  56        return 0;
  57}
  58