The patch titled
Subject: mm: pagewalk: add test_p?d callbacks
has been added to the -mm tree. Its filename is
mm-pagewalk-add-test_pd-callbacks.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-pagewalk-add-test_pd-callbacks.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-pagewalk-add-test_pd-callbacks.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Steven Price <steven.price@xxxxxxx>
Subject: mm: pagewalk: add test_p?d callbacks
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.
Link: http://lkml.kernel.org/r/20190731154603.41797-14-steven.price@xxxxxxx
Signed-off-by: Steven Price <steven.price@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/mm.h | 11 +++++++++++
mm/pagewalk.c | 24 ++++++++++++++++++++++++
2 files changed, 35 insertions(+)
--- a/include/linux/mm.h~mm-pagewalk-add-test_pd-callbacks
+++ a/include/linux/mm.h
@@ -1466,6 +1466,11 @@ void unmap_vmas(struct mmu_gather *tlb,
* value means "do page table walk over the current vma,"
* and a negative one means "abort current page table walk
* right now." 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.
* @mm: mm_struct representing the target process of page table walk
* @vma: vma currently walked (NULL if walking outside vmas)
* @private: private data for callbacks' usage
@@ -1493,6 +1498,12 @@ struct mm_walk {
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);
struct mm_struct *mm;
struct vm_area_struct *vma;
void *private;
--- a/mm/pagewalk.c~mm-pagewalk-add-test_pd-callbacks
+++ a/mm/pagewalk.c
@@ -32,6 +32,14 @@ static int walk_pmd_range(pud_t *pud, un
unsigned long next;
int err = 0;
+ if (walk->test_pmd) {
+ err = walk->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:
@@ -82,6 +90,14 @@ static int walk_pud_range(p4d_t *p4d, un
unsigned long next;
int err = 0;
+ if (walk->test_pud) {
+ err = walk->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:
@@ -124,6 +140,14 @@ static int walk_p4d_range(pgd_t *pgd, un
unsigned long next;
int err = 0;
+ if (walk->test_p4d) {
+ err = walk->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);
_
Patches currently in -mm which might be from steven.price@xxxxxxx are
mm-add-generic-pd_leaf-macros.patch
arc-mm-add-pd_leaf-definitions.patch
arm-mm-add-pd_leaf-definitions.patch
arm64-mm-add-pd_leaf-definitions.patch
mips-mm-add-pd_leaf-definitions.patch
powerpc-mm-add-pd_leaf-definitions.patch
riscv-mm-add-pd_leaf-definitions.patch
s390-mm-add-pd_leaf-definitions.patch
sparc-mm-add-pd_leaf-definitions.patch
x86-mm-add-pd_leaf-definitions.patch
mm-pagewalk-add-p4d_entry-and-pgd_entry.patch
mm-pagewalk-allow-walking-without-vma.patch
mm-pagewalk-add-test_pd-callbacks.patch
mm-pagewalk-add-depth-parameter-to-pte_hole.patch
x86-mm-point-to-struct-seq_file-from-struct-pg_state.patch
x86-mmefi-convert-ptdump_walk_pgd_level-to-take-a-mm_struct.patch
x86-mm-convert-ptdump_walk_pgd_level_debugfs-to-take-an-mm_struct.patch
x86-mm-convert-ptdump_walk_pgd_level_core-to-take-an-mm_struct.patch
mm-add-generic-ptdump.patch
x86-mm-convert-dump_pagetables-to-use-walk_page_range.patch
arm64-mm-convert-mm-dumpc-to-use-walk_page_range.patch
arm64-mm-display-non-present-entries-in-ptdump.patch
