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Message-Id: <1436461431-27305-3-git-send-email-toshi.kani@hp.com>
Date: Thu, 9 Jul 2015 11:03:51 -0600
From: Toshi Kani <toshi.kani@...com>
To: hpa@...or.com, tglx@...utronix.de, mingo@...hat.com
Cc: akpm@...ux-foundation.org, bp@...en8.de, linux-mm@...ck.org,
linux-kernel@...r.kernel.org, x86@...nel.org, jgross@...e.com,
konrad.wilk@...cle.com, elliott@...com,
Toshi Kani <toshi.kani@...com>
Subject: [PATCH 2/2] x86, mm: Fix page table dump to show PAT bit
/sys/kernel/debug/kernel_page_tables does not show the PAT bit
for PUD and 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 pXd_flags(),
which mask the flags properly.
Change also to show the PAT bit as "PAT" to be consistent with
other bits.
Reported-by: Robert Elliott <elliott@...com>
Signed-off-by: Toshi Kani <toshi.kani@...com>
Cc: Juergen Gross <jgross@...e.com>
Cc: Konrad Wilk <konrad.wilk@...cle.com>
Cc: Robert Elliott <elliott@...com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Ingo Molnar <mingo@...hat.com>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Andrew Morton <akpm@...ux-foundation.org>
---
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 f0cedf3..71ab2d7 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);
--
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