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>

diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index f0cedf3395af465bc65c3cadc49f02bbc68fad48..71ab2d7410244f3bd3e1ec6615289a22f243b11d 100644 (file)
--- 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);