// SPDX-License-Identifier: GPL-2.0-only #include <linux/debugfs.h> #include <linux/efi.h> #include <linux/module.h> #include <linux/seq_file.h> #include <asm/pgtable.h> static int ptdump_show(struct seq_file *m, void *v) { ptdump_walk_pgd_level_debugfs(m, NULL, false); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump); static int ptdump_curknl_show(struct seq_file *m, void *v) { if (current->mm->pgd) { down_read(¤t->mm->mmap_sem); ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false); up_read(¤t->mm->mmap_sem); } return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump_curknl); #ifdef CONFIG_PAGE_TABLE_ISOLATION static int ptdump_curusr_show(struct seq_file *m, void *v) { if (current->mm->pgd) { down_read(¤t->mm->mmap_sem); ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true); up_read(¤t->mm->mmap_sem); } return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump_curusr); #endif #if defined(CONFIG_EFI) && defined(CONFIG_X86_64) static int ptdump_efi_show(struct seq_file *m, void *v) { if (efi_mm.pgd) ptdump_walk_pgd_level_debugfs(m, efi_mm.pgd, false); return 0; } DEFINE_SHOW_ATTRIBUTE(ptdump_efi); #endif static struct dentry *dir; static int __init pt_dump_debug_init(void) { dir = debugfs_create_dir("page_tables", NULL); debugfs_create_file("kernel", 0400, dir, NULL, &ptdump_fops); debugfs_create_file("current_kernel", 0400, dir, NULL, &ptdump_curknl_fops); #ifdef CONFIG_PAGE_TABLE_ISOLATION debugfs_create_file("current_user", 0400, dir, NULL, &ptdump_curusr_fops); #endif #if defined(CONFIG_EFI) && defined(CONFIG_X86_64) debugfs_create_file("efi", 0400, dir, NULL, &ptdump_efi_fops); #endif return 0; } static void __exit pt_dump_debug_exit(void) { debugfs_remove_recursive(dir); } module_init(pt_dump_debug_init); module_exit(pt_dump_debug_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Arjan van de Ven <arjan@linux.intel.com>"); MODULE_DESCRIPTION("Kernel debugging helper that dumps pagetables");