The patch titled
Subject: mm: remove the vma check in migrate_vma_setup()
has been added to the -mm mm-unstable branch. Its filename is
mm-remove-the-vma-check-in-migrate_vma_setup.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-the-vma-check-in-migrate_vma_setup.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: Alistair Popple <apopple@xxxxxxxxxx>
Subject: mm: remove the vma check in migrate_vma_setup()
Date: Tue, 28 Jun 2022 22:54:17 -0500
migrate_vma_setup() checks that a valid vma is passed so that the page
tables can be walked to find the pfns associated with a given address
range. However in some cases the pfns are already known, such as when
migrating device coherent pages during pin_user_pages() meaning a valid
vma isn't required.
Link: https://lkml.kernel.org/r/20220629035426.20013-6-alex.sierra@xxxxxxx
Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Jason Gunthorpe <jgg@xxxxxxxxxx>
Cc: Jerome Glisse <jglisse@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Ralph Campbell <rcampbell@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate_device.c | 32 ++++++++++++++++----------------
1 file changed, 16 insertions(+), 16 deletions(-)
--- a/mm/migrate_device.c~mm-remove-the-vma-check-in-migrate_vma_setup
+++ a/mm/migrate_device.c
@@ -486,24 +486,24 @@ int migrate_vma_setup(struct migrate_vma
args->start &= PAGE_MASK;
args->end &= PAGE_MASK;
- if (!args->vma || is_vm_hugetlb_page(args->vma) ||
- (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma))
- return -EINVAL;
- if (nr_pages <= 0)
- return -EINVAL;
- if (args->start < args->vma->vm_start ||
- args->start >= args->vma->vm_end)
- return -EINVAL;
- if (args->end <= args->vma->vm_start || args->end > args->vma->vm_end)
- return -EINVAL;
if (!args->src || !args->dst)
return -EINVAL;
+ if (args->vma) {
+ if (is_vm_hugetlb_page(args->vma) ||
+ (args->vma->vm_flags & VM_SPECIAL) || vma_is_dax(args->vma))
+ return -EINVAL;
+ if (args->start < args->vma->vm_start ||
+ args->start >= args->vma->vm_end)
+ return -EINVAL;
+ if (args->end <= args->vma->vm_start ||
+ args->end > args->vma->vm_end)
+ return -EINVAL;
+ memset(args->src, 0, sizeof(*args->src) * nr_pages);
+ args->cpages = 0;
+ args->npages = 0;
- memset(args->src, 0, sizeof(*args->src) * nr_pages);
- args->cpages = 0;
- args->npages = 0;
-
- migrate_vma_collect(args);
+ migrate_vma_collect(args);
+ }
if (args->cpages)
migrate_vma_unmap(args);
@@ -685,7 +685,7 @@ void migrate_vma_pages(struct migrate_vm
continue;
}
- if (!page) {
+ if (!page && migrate->vma) {
if (!(migrate->src[i] & MIGRATE_PFN_MIGRATE))
continue;
if (!notified) {
_
Patches currently in -mm which might be from apopple@xxxxxxxxxx are
mm-remove-the-vma-check-in-migrate_vma_setup.patch
mm-gup-migrate-device-coherent-pages-when-pinning-instead-of-failing.patch
