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Commit da25e628 authored by Toshi Kani's avatar Toshi Kani Committed by Thomas Gleixner
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x86/mm: Fix page table dump to show PAT bit 



/sys/kernel/debug/kernel_page_tables does not show the PAT bit for
PUD/PMD mappings.  This is because walk_pud_level(), walk_pmd_level()
and note_page() mask the flags with PTE_FLAGS_MASK, which does not
cover their PAT bit, _PAGE_PAT_LARGE.

Fix it by replacing the use of PTE_FLAGS_MASK with p?d_flags(),
which masks the flags properly.

Also change to show the PAT bit as "PAT" to be consistent with
other bits.

Reported-by: default avatarRobert Elliott <elliott@hpe.com>
Signed-off-by: default avatarToshi Kani <toshi.kani@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Konrad Wilk <konrad.wilk@oracle.com>
Cc: Robert Elliot <elliott@hpe.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/1442514264-12475-7-git-send-email-toshi.kani@hpe.com


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent bbac8c6d

arch/x86/mm/dump_pagetables.c

+21 −18
Original line number Diff line number Diff line
@@ -155,7 +155,7 @@ static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg) 
			pt_dump_cont_printf(m, dmsg, "    ");

		if ((level == 4 && pr & _PAGE_PAT) ||

		    ((level == 3 || level == 2) && pr & _PAGE_PAT_LARGE))

			pt_dump_cont_printf(m, dmsg, "pat ");

			pt_dump_cont_printf(m, dmsg, "PAT ");

		else

			pt_dump_cont_printf(m, dmsg, "    ");

		if (pr & _PAGE_GLOBAL)
@@ -198,8 +198,8 @@ static void note_page(struct seq_file *m, struct pg_state *st, 
	 * we have now. "break" is either changing perms, levels or

	 * address space marker.

	 */

	prot = pgprot_val(new_prot) & PTE_FLAGS_MASK;

	cur = pgprot_val(st->current_prot) & PTE_FLAGS_MASK;

	prot = pgprot_val(new_prot);

	cur = pgprot_val(st->current_prot);



	if (!st->level) {

		/* First entry */
@@ -269,13 +269,13 @@ static void walk_pte_level(struct seq_file *m, struct pg_state *st, pmd_t addr, 
{

	int i;

	pte_t *start;

	pgprotval_t prot;



	start = (pte_t *) pmd_page_vaddr(addr);

	for (i = 0; i < PTRS_PER_PTE; i++) {

		pgprot_t prot = pte_pgprot(*start);



		prot = pte_flags(*start);

		st->current_address = normalize_addr(P + i * PTE_LEVEL_MULT);

		note_page(m, st, prot, 4);

		note_page(m, st, __pgprot(prot), 4);

		start++;

	}

}
@@ -287,18 +287,19 @@ static void walk_pmd_level(struct seq_file *m, struct pg_state *st, pud_t addr, 
{

	int i;

	pmd_t *start;

	pgprotval_t prot;



	start = (pmd_t *) pud_page_vaddr(addr);

	for (i = 0; i < PTRS_PER_PMD; i++) {

		st->current_address = normalize_addr(P + i * PMD_LEVEL_MULT);

		if (!pmd_none(*start)) {

			pgprotval_t prot = pmd_val(*start) & PTE_FLAGS_MASK;



			if (pmd_large(*start) || !pmd_present(*start))

			if (pmd_large(*start) || !pmd_present(*start)) {

				prot = pmd_flags(*start);

				note_page(m, st, __pgprot(prot), 3);

			else

			} else {

				walk_pte_level(m, st, *start,

					       P + i * PMD_LEVEL_MULT);

			}

		} else

			note_page(m, st, __pgprot(0), 3);

		start++;
@@ -318,19 +319,20 @@ static void walk_pud_level(struct seq_file *m, struct pg_state *st, pgd_t addr, 
{

	int i;

	pud_t *start;

	pgprotval_t prot;



	start = (pud_t *) pgd_page_vaddr(addr);



	for (i = 0; i < PTRS_PER_PUD; i++) {

		st->current_address = normalize_addr(P + i * PUD_LEVEL_MULT);

		if (!pud_none(*start)) {

			pgprotval_t prot = pud_val(*start) & PTE_FLAGS_MASK;



			if (pud_large(*start) || !pud_present(*start))

			if (pud_large(*start) || !pud_present(*start)) {

				prot = pud_flags(*start);

				note_page(m, st, __pgprot(prot), 2);

			else

			} else {

				walk_pmd_level(m, st, *start,

					       P + i * PUD_LEVEL_MULT);

			}

		} else

			note_page(m, st, __pgprot(0), 2);
@@ -351,6 +353,7 @@ void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd) 
#else

	pgd_t *start = swapper_pg_dir;

#endif

	pgprotval_t prot;

	int i;

	struct pg_state st = {};
@@ -362,13 +365,13 @@ void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd) 
	for (i = 0; i < PTRS_PER_PGD; i++) {

		st.current_address = normalize_addr(i * PGD_LEVEL_MULT);

		if (!pgd_none(*start)) {

			pgprotval_t prot = pgd_val(*start) & PTE_FLAGS_MASK;



			if (pgd_large(*start) || !pgd_present(*start))

			if (pgd_large(*start) || !pgd_present(*start)) {

				prot = pgd_flags(*start);

				note_page(m, &st, __pgprot(prot), 1);

			else

			} else {

				walk_pud_level(m, &st, *start,

					       i * PGD_LEVEL_MULT);

			}

		} else

			note_page(m, &st, __pgprot(0), 1);