1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2020 Facebook */
3 #include "bpf_iter.h"
4 #include <bpf/bpf_helpers.h>
5
6 char _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
21 char d_path_buf[D_PATH_BUF_SIZE] = {};
22 __u32 pid = 0;
23 __u32 one_task = 0;
24 __u32 one_task_error = 0;
25
26 SEC("iter/task_vma") int proc_maps(struct bpf_iter__task_vma *ctx)
27 {
28 struct vm_area_struct *vma = ctx->vma;
29 struct seq_file *seq = ctx->meta->seq;
30 struct task_struct *task = ctx->task;
31 struct file *file;
32 char perm_str[] = "----";
33
34 if (task == (void *)0 || vma == (void *)0)
35 return 0;
36
37 file = vma->vm_file;
38 if (task->tgid != (pid_t)pid) {
39 if (one_task)
40 one_task_error = 1;
41 return 0;
42 }
43 perm_str[0] = (vma->vm_flags & VM_READ) ? 'r' : '-';
44 perm_str[1] = (vma->vm_flags & VM_WRITE) ? 'w' : '-';
45 perm_str[2] = (vma->vm_flags & VM_EXEC) ? 'x' : '-';
46 perm_str[3] = (vma->vm_flags & VM_MAYSHARE) ? 's' : 'p';
47 BPF_SEQ_PRINTF(seq, "%08llx-%08llx %s ", vma->vm_start, vma->vm_end, perm_str);
48
49 if (file) {
50 __u32 dev = file->f_inode->i_sb->s_dev;
51
52 bpf_d_path(&file->f_path, d_path_buf, D_PATH_BUF_SIZE);
53
54 BPF_SEQ_PRINTF(seq, "%08llx ", vma->vm_pgoff << 12);
55 BPF_SEQ_PRINTF(seq, "%02x:%02x %u", MAJOR(dev), MINOR(dev),
56 file->f_inode->i_ino);
57 BPF_SEQ_PRINTF(seq, "\t%s\n", d_path_buf);
58 } else {
59 BPF_SEQ_PRINTF(seq, "%08llx 00:00 0\n", 0ULL);
60 }
61 return 0;
62 }
63
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