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>,
"Zong Li" <zong.li@sifive.com>
Subject: [PATCH v14 13/22] mm: pagewalk: Add test_p?d callbacks
Date: Mon, 28 Oct 2019 13:59:01 +0000 [thread overview]
Message-ID: <20191028135910.33253-14-steven.price@arm.com> (raw)
In-Reply-To: <20191028135910.33253-1-steven.price@arm.com>
It is useful to be able to skip parts of the page table tree even when
walking without VMAs. Add test_p?d callbacks similar to test_walk but
which are called just before a table at that level is walked. If the
callback returns non-zero then the entire table is skipped.
Tested-by: Zong Li <zong.li@sifive.com>
Signed-off-by: Steven Price <steven.price@arm.com>
---
include/linux/pagewalk.h | 11 +++++++++++
mm/pagewalk.c | 24 ++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/pagewalk.h b/include/linux/pagewalk.h
index 12004b097eae..df424197a25a 100644
--- a/include/linux/pagewalk.h
+++ b/include/linux/pagewalk.h
@@ -24,6 +24,11 @@ struct mm_walk;
* "do page table walk over the current vma", returning
* a negative value means "abort current page table walk
* right now" and returning 1 means "skip the current vma"
+ * @test_pmd: similar to test_walk(), but called for every pmd.
+ * @test_pud: similar to test_walk(), but called for every pud.
+ * @test_p4d: similar to test_walk(), but called for every p4d.
+ * Returning 0 means walk this part of the page tables,
+ * returning 1 means to skip this range.
*
* p?d_entry callbacks are called even if those levels are folded on a
* particular architecture/configuration.
@@ -46,6 +51,12 @@ struct mm_walk_ops {
struct mm_walk *walk);
int (*test_walk)(unsigned long addr, unsigned long next,
struct mm_walk *walk);
+ int (*test_pmd)(unsigned long addr, unsigned long next,
+ pmd_t *pmd_start, struct mm_walk *walk);
+ int (*test_pud)(unsigned long addr, unsigned long next,
+ pud_t *pud_start, struct mm_walk *walk);
+ int (*test_p4d)(unsigned long addr, unsigned long next,
+ p4d_t *p4d_start, struct mm_walk *walk);
};
/**
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 4139e9163aee..43acffefd43f 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -34,6 +34,14 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ if (ops->test_pmd) {
+ err = ops->test_pmd(addr, end, pmd_offset(pud, 0UL), walk);
+ if (err < 0)
+ return err;
+ if (err > 0)
+ return 0;
+ }
+
pmd = pmd_offset(pud, addr);
do {
again:
@@ -85,6 +93,14 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ if (ops->test_pud) {
+ err = ops->test_pud(addr, end, pud_offset(p4d, 0UL), walk);
+ if (err < 0)
+ return err;
+ if (err > 0)
+ return 0;
+ }
+
pud = pud_offset(p4d, addr);
do {
again:
@@ -128,6 +144,14 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
const struct mm_walk_ops *ops = walk->ops;
int err = 0;
+ if (ops->test_p4d) {
+ err = ops->test_p4d(addr, end, p4d_offset(pgd, 0UL), walk);
+ if (err < 0)
+ return err;
+ if (err > 0)
+ return 0;
+ }
+
p4d = p4d_offset(pgd, addr);
do {
next = p4d_addr_end(addr, end);
--
2.20.1
next prev parent reply other threads:[~2019-10-28 14:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-28 13:58 [PATCH v14 00/22] Generic page walk and ptdump Steven Price
2019-10-28 13:58 ` [PATCH v14 01/22] mm: Add generic p?d_leaf() macros Steven Price
2019-10-28 13:58 ` [PATCH v14 02/22] arc: mm: Add p?d_leaf() definitions Steven Price
2019-10-28 13:58 ` [PATCH v14 03/22] arm: " Steven Price
2019-10-28 13:58 ` [PATCH v14 04/22] arm64: " Steven Price
2019-10-30 15:31 ` Catalin Marinas
2019-10-28 13:58 ` [PATCH v14 05/22] mips: " Steven Price
2019-10-28 13:58 ` [PATCH v14 06/22] powerpc: " Steven Price
2019-10-28 13:58 ` [PATCH v14 07/22] riscv: " Steven Price
2019-10-28 13:58 ` [PATCH v14 08/22] s390: " Steven Price
2019-10-28 13:58 ` [PATCH v14 09/22] sparc: " Steven Price
2019-10-28 13:58 ` [PATCH v14 10/22] x86: " Steven Price
2019-10-28 13:58 ` [PATCH v14 11/22] mm: pagewalk: Add p4d_entry() and pgd_entry() Steven Price
2019-10-28 13:59 ` [PATCH v14 12/22] mm: pagewalk: Allow walking without vma Steven Price
2019-10-31 15:15 ` [mm] 9343f6818b: BUG:kernel_NULL_pointer_dereference,address kernel test robot
2019-10-31 17:22 ` Steven Price
2019-10-28 13:59 ` Steven Price [this message]
2019-10-28 13:59 ` [PATCH v14 14/22] mm: pagewalk: Add 'depth' parameter to pte_hole Steven Price
2019-10-28 13:59 ` [PATCH v14 15/22] x86: mm: Point to struct seq_file from struct pg_state Steven Price
2019-10-28 13:59 ` [PATCH v14 16/22] x86: mm+efi: Convert ptdump_walk_pgd_level() to take a mm_struct Steven Price
2019-10-28 13:59 ` [PATCH v14 17/22] x86: mm: Convert ptdump_walk_pgd_level_debugfs() to take an mm_struct Steven Price
2019-10-28 13:59 ` [PATCH v14 18/22] x86: mm: Convert ptdump_walk_pgd_level_core() " Steven Price
2019-10-28 13:59 ` [PATCH v14 19/22] mm: Add generic ptdump Steven Price
2019-10-30 16:48 ` Catalin Marinas
2019-10-28 13:59 ` [PATCH v14 20/22] x86: mm: Convert dump_pagetables to use walk_page_range Steven Price
2019-10-28 13:59 ` [PATCH v14 21/22] arm64: mm: Convert mm/dump.c to use walk_page_range() Steven Price
2019-10-30 16:45 ` Catalin Marinas
2019-10-31 13:32 ` Steven Price
2019-10-31 13:33 ` [PATCH] mm: ptdump: Reduce level numbers by 1 in note_page() Steven Price
2019-10-31 14:36 ` Catalin Marinas
2019-10-31 14:00 ` [PATCH v14 21/22] arm64: mm: Convert mm/dump.c to use walk_page_range() Catalin Marinas
2019-10-31 14:37 ` Catalin Marinas
2019-10-28 13:59 ` [PATCH v14 22/22] arm64: mm: Display non-present entries in ptdump Steven Price
2019-10-30 16:50 ` Catalin Marinas
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