The patch titled
Subject: coredump: remove vma linked list walk
has been added to the -mm mm-unstable branch. Its filename is
coredump-remove-vma-linked-list-walk.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/coredump-remove-vma-linked-list-walk.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: coredump: remove vma linked list walk
Date: Mon, 22 Aug 2022 15:06:25 +0000
Use the Maple Tree iterator instead. This is too complicated for the VMA
iterator to handle, so let's open-code it for now. If this turns out to
be a common pattern, we can migrate it to common code.
Link: https://lkml.kernel.org/r/20220822150128.1562046-41-Liam.Howlett@xxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: SeongJae Park <sj@xxxxxxxxxx>
Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/coredump.c | 34 ++++++++++++----------------------
1 file changed, 12 insertions(+), 22 deletions(-)
--- a/fs/coredump.c~coredump-remove-vma-linked-list-walk
+++ a/fs/coredump.c
@@ -1072,30 +1072,20 @@ whole:
return vma->vm_end - vma->vm_start;
}
-static struct vm_area_struct *first_vma(struct task_struct *tsk,
- struct vm_area_struct *gate_vma)
-{
- struct vm_area_struct *ret = tsk->mm->mmap;
-
- if (ret)
- return ret;
- return gate_vma;
-}
-
/*
* Helper function for iterating across a vma list. It ensures that the caller
* will visit `gate_vma' prior to terminating the search.
*/
-static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
+static struct vm_area_struct *coredump_next_vma(struct ma_state *mas,
+ struct vm_area_struct *vma,
struct vm_area_struct *gate_vma)
{
- struct vm_area_struct *ret;
-
- ret = this_vma->vm_next;
- if (ret)
- return ret;
- if (this_vma == gate_vma)
+ if (gate_vma && (vma == gate_vma))
return NULL;
+
+ vma = mas_next(mas, ULONG_MAX);
+ if (vma)
+ return vma;
return gate_vma;
}
@@ -1119,9 +1109,10 @@ static void free_vma_snapshot(struct cor
*/
static bool dump_vma_snapshot(struct coredump_params *cprm)
{
- struct vm_area_struct *vma, *gate_vma;
+ struct vm_area_struct *gate_vma, *vma = NULL;
struct mm_struct *mm = current->mm;
- int i;
+ MA_STATE(mas, &mm->mm_mt, 0, 0);
+ int i = 0;
/*
* Once the stack expansion code is fixed to not change VMA bounds
@@ -1141,8 +1132,7 @@ static bool dump_vma_snapshot(struct cor
return false;
}
- for (i = 0, vma = first_vma(current, gate_vma); vma != NULL;
- vma = next_vma(vma, gate_vma), i++) {
+ while ((vma = coredump_next_vma(&mas, vma, gate_vma)) != NULL) {
struct core_vma_metadata *m = cprm->vma_meta + i;
m->start = vma->vm_start;
@@ -1150,10 +1140,10 @@ static bool dump_vma_snapshot(struct cor
m->flags = vma->vm_flags;
m->dump_size = vma_dump_size(vma, cprm->mm_flags);
m->pgoff = vma->vm_pgoff;
-
m->file = vma->vm_file;
if (m->file)
get_file(m->file);
+ i++;
}
mmap_write_unlock(mm);
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
support-highmem-pages-in-vmap_pages_range_noflush.patch
mm-add-vma-iterator.patch
mmap-use-the-vma-iterator-in-count_vma_pages_range.patch
proc-remove-vma-rbtree-use-from-nommu.patch
arm64-remove-mmap-linked-list-from-vdso.patch
parisc-remove-mmap-linked-list-from-cache-handling.patch
powerpc-remove-mmap-linked-list-walks.patch
s390-remove-vma-linked-list-walks.patch
x86-remove-vma-linked-list-walks.patch
xtensa-remove-vma-linked-list-walks.patch
cxl-remove-vma-linked-list-walk.patch
optee-remove-vma-linked-list-walk.patch
um-remove-vma-linked-list-walk.patch
coredump-remove-vma-linked-list-walk.patch
exec-use-vma-iterator-instead-of-linked-list.patch
fs-proc-task_mmu-stop-using-linked-list-and-highest_vm_end.patch
acct-use-vma-iterator-instead-of-linked-list.patch
perf-use-vma-iterator.patch
sched-use-maple-tree-iterator-to-walk-vmas.patch
fork-use-vma-iterator.patch
mm-khugepaged-stop-using-vma-linked-list.patch
mm-ksm-use-vma-iterators-instead-of-vma-linked-list.patch
mm-mlock-use-vma-iterator-and-maple-state-instead-of-vma-linked-list.patch
mm-pagewalk-use-vma_find-instead-of-vma-linked-list.patch
i915-use-the-vma-iterator.patch
nommu-remove-uses-of-vma-linked-list.patch
