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: Robert Elliott <elliott@hpe.com>
Signed-off-by: Toshi 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: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 21 insertions, 18 deletions

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index f0cedf3395af..71ab2d741024 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -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);