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 <asm/pgtable.h>
 7
 8static int ptdump_show(struct seq_file *m, void *v)
 9{
10	ptdump_walk_pgd_level_debugfs(m, NULL, 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		down_read(&current->mm->mmap_sem);
20		ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false);
21		up_read(&current->mm->mmap_sem);
22	}
23	return 0;
24}
25
26DEFINE_SHOW_ATTRIBUTE(ptdump_curknl);
27
28#ifdef CONFIG_PAGE_TABLE_ISOLATION
29static int ptdump_curusr_show(struct seq_file *m, void *v)
30{
31	if (current->mm->pgd) {
32		down_read(&current->mm->mmap_sem);
33		ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true);
34		up_read(&current->mm->mmap_sem);
35	}
36	return 0;
37}
38
39DEFINE_SHOW_ATTRIBUTE(ptdump_curusr);
40#endif
41
42#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
43static int ptdump_efi_show(struct seq_file *m, void *v)
44{
45	if (efi_mm.pgd)
46		ptdump_walk_pgd_level_debugfs(m, efi_mm.pgd, false);
47	return 0;
48}
49
50DEFINE_SHOW_ATTRIBUTE(ptdump_efi);
51#endif
52
53static struct dentry *dir;
54
55static int __init pt_dump_debug_init(void)
56{
57	dir = debugfs_create_dir("page_tables", NULL);
58
59	debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops);
60	debugfs_create_file("current_kernel", 0400, dir, NULL,
61			    &ptdump_curknl_fops);
62
63#ifdef CONFIG_PAGE_TABLE_ISOLATION
64	debugfs_create_file("current_user", 0400, dir, NULL,
65			    &ptdump_curusr_fops);
66#endif
67#if defined(CONFIG_EFI) && defined(CONFIG_X86_64)
68	debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops);
69#endif
70	return 0;
71}
72
73static void __exit pt_dump_debug_exit(void)
74{
75	debugfs_remove_recursive(dir);
76}
77
78module_init(pt_dump_debug_init);
79module_exit(pt_dump_debug_exit);
80MODULE_LICENSE("GPL");
81MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>");
82MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");