1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/debugfs.h>
3#include <linux/efi.h>
4#include <linux/module.h>
5#include <linux/seq_file.h>
6#include <linux/pgtable.h>
7
8static int ptdump_show(struct seq_file *m, void *v)
9{
10 ptdump_walk_pgd_level_debugfs(m, mm: &init_mm, user: false);
11 return 0;
12}
13
14DEFINE_SHOW_ATTRIBUTE(ptdump);
15
16static int ptdump_curknl_show(struct seq_file *m, void *v)
17{
18 if (current->mm->pgd)
19 ptdump_walk_pgd_level_debugfs(m, current->mm, user: false);
20 return 0;
21}
22
23DEFINE_SHOW_ATTRIBUTE(ptdump_curknl);
24
25#ifdef CONFIG_PAGE_TABLE_ISOLATION
26static int ptdump_curusr_show(struct seq_file *m, void *v)
27{
28 if (current->mm->pgd)
29 ptdump_walk_pgd_level_debugfs(m, current->mm, user: true);
30 return 0;
31}
32
33DEFINE_SHOW_ATTRIBUTE(ptdump_curusr);
34#endif
35
36#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
37static int ptdump_efi_show(struct seq_file *m, void *v)
38{
39 if (efi_mm.pgd)
40 ptdump_walk_pgd_level_debugfs(m, mm: &efi_mm, user: false);
41 return 0;
42}
43
44DEFINE_SHOW_ATTRIBUTE(ptdump_efi);
45#endif
46
47static struct dentry *dir;
48
49static int __init pt_dump_debug_init(void)
50{
51 dir = debugfs_create_dir(name: "page_tables", NULL);
52
53 debugfs_create_file(name: "kernel", mode: 0400, parent: dir, NULL, fops: &ptdump_fops);
54 debugfs_create_file(name: "current_kernel", mode: 0400, parent: dir, NULL,
55 fops: &ptdump_curknl_fops);
56
57#ifdef CONFIG_PAGE_TABLE_ISOLATION
58 debugfs_create_file(name: "current_user", mode: 0400, parent: dir, NULL,
59 fops: &ptdump_curusr_fops);
60#endif
61#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
62 debugfs_create_file(name: "efi", mode: 0400, parent: dir, NULL, fops: &ptdump_efi_fops);
63#endif
64 return 0;
65}
66
67static void __exit pt_dump_debug_exit(void)
68{
69 debugfs_remove_recursive(dentry: dir);
70}
71
72module_init(pt_dump_debug_init);
73module_exit(pt_dump_debug_exit);
74MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
75MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");
76

source code of linux/arch/x86/mm/debug_pagetables.c