From: Steven Price <steven.price@arm.com>
To: linux-mm@kvack.org
Cc: "Steven Price" <steven.price@arm.com>,
"Andy Lutomirski" <luto@kernel.org>,
"Ard Biesheuvel" <ard.biesheuvel@linaro.org>,
"Arnd Bergmann" <arnd@arndb.de>, "Borislav Petkov" <bp@alien8.de>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"Ingo Molnar" <mingo@redhat.com>,
"James Morse" <james.morse@arm.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Will Deacon" <will.deacon@arm.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
"Mark Rutland" <Mark.Rutland@arm.com>,
"Liang, Kan" <kan.liang@linux.intel.com>
Subject: [PATCH v5 11/19] mm: pagewalk: Allow walking without vma
Date: Thu, 21 Mar 2019 14:19:45 +0000 [thread overview]
Message-ID: <20190321141953.31960-12-steven.price@arm.com> (raw)
In-Reply-To: <20190321141953.31960-1-steven.price@arm.com>
Since 48684a65b4e3: "mm: pagewalk: fix misbehavior of walk_page_range
for vma(VM_PFNMAP)", page_table_walk() will report any kernel area as
a hole, because it lacks a vma.
This means each arch has re-implemented page table walking when needed,
for example in the per-arch ptdump walker.
Remove the requirement to have a vma except when trying to split huge
pages.
Signed-off-by: Steven Price <steven.price@arm.com>
---
mm/pagewalk.c | 25 +++++++++++++++++--------
1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 98373a9f88b8..dac0c848b458 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -36,7 +36,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
do {
again:
next = pmd_addr_end(addr, end);
- if (pmd_none(*pmd) || !walk->vma) {
+ if (pmd_none(*pmd)) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, walk);
if (err)
@@ -59,9 +59,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
if (!walk->pte_entry)
continue;
- split_huge_pmd(walk->vma, pmd, addr);
- if (pmd_trans_unstable(pmd))
- goto again;
+ if (walk->vma) {
+ split_huge_pmd(walk->vma, pmd, addr);
+ if (pmd_trans_unstable(pmd))
+ goto again;
+ } else if (pmd_large(*pmd)) {
+ continue;
+ }
+
err = walk_pte_range(pmd, addr, next, walk);
if (err)
break;
@@ -81,7 +86,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
do {
again:
next = pud_addr_end(addr, end);
- if (pud_none(*pud) || !walk->vma) {
+ if (pud_none(*pud)) {
if (walk->pte_hole)
err = walk->pte_hole(addr, next, walk);
if (err)
@@ -95,9 +100,13 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
break;
}
- split_huge_pud(walk->vma, pud, addr);
- if (pud_none(*pud))
- goto again;
+ if (walk->vma) {
+ split_huge_pud(walk->vma, pud, addr);
+ if (pud_none(*pud))
+ goto again;
+ } else if (pud_large(*pud)) {
+ continue;
+ }
if (walk->pmd_entry || walk->pte_entry)
err = walk_pmd_range(pud, addr, next, walk);
--
2.20.1
next prev parent reply other threads:[~2019-03-21 14:20 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-21 14:19 [PATCH v5 00/19] Convert x86 & arm64 to use generic page walk Steven Price
2019-03-21 14:19 ` [PATCH v5 01/19] arc: mm: Add p?d_large() definitions Steven Price
2019-03-21 14:19 ` [PATCH v5 02/19] arm64: " Steven Price
2019-03-21 14:19 ` [PATCH v5 03/19] mips: " Steven Price
2019-03-21 14:19 ` [PATCH v5 04/19] powerpc: " Steven Price
2019-03-21 14:19 ` [PATCH v5 05/19] riscv: " Steven Price
2019-03-21 14:19 ` [PATCH v5 06/19] s390: " Steven Price
2019-03-21 14:19 ` [PATCH v5 07/19] sparc: " Steven Price
2019-03-21 14:19 ` [PATCH v5 08/19] x86: " Steven Price
2019-03-21 14:19 ` [PATCH v5 09/19] mm: Add generic p?d_large() macros Steven Price
2019-03-21 14:19 ` [PATCH v5 10/19] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-03-21 21:15 ` Mike Rapoport
2019-03-22 10:11 ` Steven Price
2019-03-22 10:29 ` Mike Rapoport
2019-03-22 10:37 ` Steven Price
2019-03-21 14:19 ` Steven Price [this message]
2019-03-21 14:19 ` [PATCH v5 12/19] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-03-21 14:19 ` [PATCH v5 13/19] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-03-21 14:19 ` [PATCH v5 14/19] x86: mm: Don't display pages which aren't present in debugfs Steven Price
2019-03-21 14:19 ` [PATCH v5 15/19] x86: mm: Point to struct seq_file from struct pg_state Steven Price
2019-03-21 14:19 ` [PATCH v5 16/19] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-03-21 14:19 ` [PATCH v5 17/19] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-03-21 14:19 ` [PATCH v5 18/19] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-03-21 14:19 ` [PATCH v5 19/19] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price
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