// SPDX-License-Identifier: GPL-2.0 #include <linux/pagewalk.h>#include <linux/ptdump.h>#include <linux/kasan.h> #ifdef CONFIG_KASAN/* * This is an optimization for KASAN=y case. Since all kasan page tables * eventually point to the kasan_early_shadow_page we could call note_page() * right away without walking through lower level page tables. This saves * us dozens of seconds (minutes for 5-level config) while checking for * W+X mapping or reading kernel_page_tables debugfs file. */static inline int note_kasan_page_table(struct mm_walk *walk,					unsigned long addr){	struct ptdump_state *st = walk->private; 	st->note_page(st, addr, 4, pte_val(kasan_early_shadow_pte[0])); 	walk->action = ACTION_CONTINUE; 	return 0;}#endif static int ptdump_pgd_entry(pgd_t *pgd, unsigned long addr,			    unsigned long next, struct mm_walk *walk){	struct ptdump_state *st = walk->private;	pgd_t val = READ_ONCE(*pgd); #if CONFIG_PGTABLE_LEVELS > 4 && defined(CONFIG_KASAN)	if (pgd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_p4d)))		return note_kasan_page_table(walk, addr);#endif 	if (st->effective_prot)		st->effective_prot(st, 0, pgd_val(val)); 	if (pgd_leaf(val))		st->note_page(st, addr, 0, pgd_val(val)); 	return 0;} static int ptdump_p4d_entry(p4d_t *p4d, unsigned long addr,			    unsigned long next, struct mm_walk *walk){	struct ptdump_state *st = walk->private;	p4d_t val = READ_ONCE(*p4d); #if CONFIG_PGTABLE_LEVELS > 3 && defined(CONFIG_KASAN)	if (p4d_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pud)))		return note_kasan_page_table(walk, addr);#endif 	if (st->effective_prot)		st->effective_prot(st, 1, p4d_val(val)); 	if (p4d_leaf(val))		st->note_page(st, addr, 1, p4d_val(val)); 	return 0;} static int ptdump_pud_entry(pud_t *pud, unsigned long addr,			    unsigned long next, struct mm_walk *walk){	struct ptdump_state *st = walk->private;	pud_t val = READ_ONCE(*pud); #if CONFIG_PGTABLE_LEVELS > 2 && defined(CONFIG_KASAN)	if (pud_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pmd)))		return note_kasan_page_table(walk, addr);#endif 	if (st->effective_prot)		st->effective_prot(st, 2, pud_val(val)); 	if (pud_leaf(val))		st->note_page(st, addr, 2, pud_val(val)); 	return 0;} static int ptdump_pmd_entry(pmd_t *pmd, unsigned long addr,			    unsigned long next, struct mm_walk *walk){	struct ptdump_state *st = walk->private;	pmd_t val = READ_ONCE(*pmd); #if defined(CONFIG_KASAN)	if (pmd_page(val) == virt_to_page(lm_alias(kasan_early_shadow_pte)))		return note_kasan_page_table(walk, addr);#endif 	if (st->effective_prot)		st->effective_prot(st, 3, pmd_val(val));	if (pmd_leaf(val))		st->note_page(st, addr, 3, pmd_val(val)); 	return 0;} static int ptdump_pte_entry(pte_t *pte, unsigned long addr,			    unsigned long next, struct mm_walk *walk){	struct ptdump_state *st = walk->private;	pte_t val = READ_ONCE(*pte); 	if (st->effective_prot)		st->effective_prot(st, 4, pte_val(val)); 	st->note_page(st, addr, 4, pte_val(val)); 	return 0;} static int ptdump_hole(unsigned long addr, unsigned long next,		       int depth, struct mm_walk *walk){	struct ptdump_state *st = walk->private; 	st->note_page(st, addr, depth, 0); 	return 0;} static const struct mm_walk_ops ptdump_ops = {	.pgd_entry	= ptdump_pgd_entry,	.p4d_entry	= ptdump_p4d_entry,	.pud_entry	= ptdump_pud_entry,	.pmd_entry	= ptdump_pmd_entry,	.pte_entry	= ptdump_pte_entry,	.pte_hole	= ptdump_hole,}; void ptdump_walk_pgd(struct ptdump_state *st, struct mm_struct *mm, pgd_t *pgd){	const struct ptdump_range *range = st->range; 	mmap_read_lock(mm);	while (range->start != range->end) {		walk_page_range_novma(mm, range->start, range->end,				      &ptdump_ops, pgd, st);		range++;	}	mmap_read_unlock(mm); 	/* Flush out the last page */	st->note_page(st, 0, -1, 0);}