From da25e628c4c231a281b1c1de3168a36ab9bfe473 Mon Sep 17 00:00:00 2001 From: Toshi Kani Date: Thu, 17 Sep 2015 12:24:19 -0600 Subject: [PATCH] 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 Signed-off-by: Toshi Kani Cc: Andrew Morton Cc: Juergen Gross Cc: H. Peter Anvin Cc: Ingo Molnar Cc: Borislav Petkov Cc: Konrad Wilk Cc: Robert Elliot 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 --- arch/x86/mm/dump_pagetables.c | 39 +++++++++++++++++++---------------- 1 file 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); -- 2.39.2