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@kernel.org>,
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>,
"Andrew Morton" <akpm@linux-foundation.org>
Subject: [PATCH v13 12/22] mm: pagewalk: Allow walking without vma
Date: Thu, 24 Oct 2019 10:37:06 +0100 [thread overview]
Message-ID: <20191024093716.49420-13-steven.price@arm.com> (raw)
In-Reply-To: <20191024093716.49420-1-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 fc4d98a3a5a0..4139e9163aee 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -38,7 +38,7 @@ 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 (ops->pte_hole)
err = ops->pte_hole(addr, next, walk);
if (err)
@@ -61,9 +61,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
if (!ops->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_leaf(*pmd)) {
+ continue;
+ }
+
err = walk_pte_range(pmd, addr, next, walk);
if (err)
break;
@@ -84,7 +89,7 @@ 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 (ops->pte_hole)
err = ops->pte_hole(addr, next, walk);
if (err)
@@ -98,9 +103,13 @@ 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_leaf(*pud)) {
+ continue;
+ }
if (ops->pmd_entry || ops->pte_entry)
err = walk_pmd_range(pud, addr, next, walk);
--
2.20.1
next prev parent reply other threads:[~2019-10-24 9:38 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-24 9:36 [PATCH v13 00/22] Generic page walk and ptdump Steven Price
2019-10-24 9:36 ` [PATCH v13 01/22] mm: Add generic p?d_leaf() macros Steven Price
2019-10-24 9:36 ` [PATCH v13 02/22] arc: mm: Add p?d_leaf() definitions Steven Price
2019-10-24 9:36 ` [PATCH v13 03/22] arm: " Steven Price
2019-10-24 9:36 ` [PATCH v13 04/22] arm64: " Steven Price
2019-10-24 9:36 ` [PATCH v13 05/22] mips: " Steven Price
2019-10-24 9:37 ` [PATCH v13 06/22] powerpc: " Steven Price
2019-10-24 9:37 ` [PATCH v13 07/22] riscv: " Steven Price
2019-10-24 13:09 ` Zong Li
2019-10-24 9:37 ` [PATCH v13 08/22] s390: " Steven Price
2019-10-24 9:37 ` [PATCH v13 09/22] sparc: " Steven Price
2019-10-24 16:46 ` David Miller
2019-10-24 9:37 ` [PATCH v13 10/22] x86: " Steven Price
2019-10-24 9:37 ` [PATCH v13 11/22] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-10-24 9:37 ` Steven Price [this message]
2019-10-27 7:59 ` [PATCH v13 12/22] mm: pagewalk: Allow walking without vma kbuild test robot
2019-10-28 10:46 ` Steven Price
2019-10-24 9:37 ` [PATCH v13 13/22] mm: pagewalk: Add test_p?d callbacks Steven Price
2019-10-24 9:37 ` [PATCH v13 14/22] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price
2019-10-24 9:37 ` [PATCH v13 15/22] x86: mm: Point to struct seq_file from struct pg_state Steven Price
2019-10-24 9:37 ` [PATCH v13 16/22] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-10-24 9:37 ` [PATCH v13 17/22] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-10-24 9:37 ` [PATCH v13 18/22] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-10-24 9:37 ` [PATCH v13 19/22] mm: Add generic ptdump Steven Price
2019-10-24 9:37 ` [PATCH v13 20/22] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price
2019-10-24 9:37 ` [PATCH v13 21/22] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-10-24 9:37 ` [PATCH v13 22/22] arm64: mm: Display non-present entries in ptdump Steven Price
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