The patch titled
Subject: mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix
has been added to the -mm tree. Its filename is
mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix.patch
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------------------------------------------------------
From: Peter Xu <peterx@xxxxxxxxxx>
Subject: mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix
The required change attached; this is quite special that we only referenced the
mm once in each of the function, so that temp variable can actually be avoided.
Ideally there should be some way to only define the variable on archs that need
this mm pointer (e.g., when set_pte_at() or some similar function is called
multiple times in some function, it should still be helpful to introduce a
local variable to keep dst_vma->vm_mm). However I don't know a good way to do
this...
Link: https://lkml.kernel.org/r/20201006200138.GA6026@xz-x1
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
--- a/mm/memory.c~mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix
+++ a/mm/memory.c
@@ -798,7 +798,6 @@ copy_present_page(struct vm_area_struct
pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss,
struct page **prealloc, pte_t pte, struct page *page)
{
- struct mm_struct *dst_mm = dst_vma->vm_mm;
struct mm_struct *src_mm = src_vma->vm_mm;
struct page *new_page;
@@ -874,7 +873,7 @@ copy_present_page(struct vm_area_struct
/* All done, just insert the new page copy in the child */
pte = mk_pte(new_page, dst_vma->vm_page_prot);
pte = maybe_mkwrite(pte_mkdirty(pte), dst_vma);
- set_pte_at(dst_mm, addr, dst_pte, pte);
+ set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
return 0;
}
@@ -887,7 +886,6 @@ copy_present_pte(struct vm_area_struct *
pte_t *dst_pte, pte_t *src_pte, unsigned long addr, int *rss,
struct page **prealloc)
{
- struct mm_struct *dst_mm = dst_vma->vm_mm;
struct mm_struct *src_mm = src_vma->vm_mm;
unsigned long vm_flags = src_vma->vm_flags;
pte_t pte = *src_pte;
@@ -932,7 +930,7 @@ copy_present_pte(struct vm_area_struct *
if (!(vm_flags & VM_UFFD_WP))
pte = pte_clear_uffd_wp(pte);
- set_pte_at(dst_mm, addr, dst_pte, pte);
+ set_pte_at(dst_vma->vm_mm, addr, dst_pte, pte);
return 0;
}
_
Patches currently in -mm which might be from peterx@xxxxxxxxxx are
mm-remove-src-dst-mm-parameter-in-copy_page_range.patch
mm-remove-src-dst-mm-parameter-in-copy_page_range-v2.patch
mm-remove-src-dst-mm-parameter-in-copy_page_range-v2-fix.patch
