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mm/fork: Pass new vma pointer into copy_page_range()

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This prepares for the future work to trigger early cow on pinned pages
during fork().

No functional change intended.

Signed-off-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Peter Xu 2020-09-25 18:25:58 -04:00 committed by Linus Torvalds
parent 008cfe4418
commit 7a4830c380
3 changed files with 11 additions and 7 deletions
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2
include/linux/mm.h
View File

@ -1646,7 +1646,7 @@ struct mmu_notifier_range;
void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
unsigned long end, unsigned long floor, unsigned long ceiling);
int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
struct vm_area_struct *vma);
struct vm_area_struct *vma, struct vm_area_struct *new);
int follow_pte_pmd(struct mm_struct *mm, unsigned long address,
struct mmu_notifier_range *range,
pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp);

2
kernel/fork.c
View File

@ -589,7 +589,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
mm->map_count++;
if (!(tmp->vm_flags & VM_WIPEONFORK))
retval = copy_page_range(mm, oldmm, mpnt);
retval = copy_page_range(mm, oldmm, mpnt, tmp);
if (tmp->vm_ops && tmp->vm_ops->open)
tmp->vm_ops->open(tmp);

14
mm/memory.c
View File

@ -819,6 +819,7 @@ copy_present_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
static int copy_pte_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
pmd_t *dst_pmd, pmd_t *src_pmd, struct vm_area_struct *vma,
struct vm_area_struct *new,
unsigned long addr, unsigned long end)
{
pte_t *orig_src_pte, *orig_dst_pte;
@ -889,6 +890,7 @@ again:
static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
pud_t *dst_pud, pud_t *src_pud, struct vm_area_struct *vma,
struct vm_area_struct *new,
unsigned long addr, unsigned long end)
{
pmd_t *src_pmd, *dst_pmd;
@ -915,7 +917,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src
if (pmd_none_or_clear_bad(src_pmd))
continue;
if (copy_pte_range(dst_mm, src_mm, dst_pmd, src_pmd,
vma, addr, next))
vma, new, addr, next))
return -ENOMEM;
} while (dst_pmd++, src_pmd++, addr = next, addr != end);
return 0;
@ -923,6 +925,7 @@ static inline int copy_pmd_range(struct mm_struct *dst_mm, struct mm_struct *src
static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
p4d_t *dst_p4d, p4d_t *src_p4d, struct vm_area_struct *vma,
struct vm_area_struct *new,
unsigned long addr, unsigned long end)
{
pud_t *src_pud, *dst_pud;
@ -949,7 +952,7 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src
if (pud_none_or_clear_bad(src_pud))
continue;
if (copy_pmd_range(dst_mm, src_mm, dst_pud, src_pud,
vma, addr, next))
vma, new, addr, next))
return -ENOMEM;
} while (dst_pud++, src_pud++, addr = next, addr != end);
return 0;
@ -957,6 +960,7 @@ static inline int copy_pud_range(struct mm_struct *dst_mm, struct mm_struct *src
static inline int copy_p4d_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
pgd_t *dst_pgd, pgd_t *src_pgd, struct vm_area_struct *vma,
struct vm_area_struct *new,
unsigned long addr, unsigned long end)
{
p4d_t *src_p4d, *dst_p4d;
@ -971,14 +975,14 @@ static inline int copy_p4d_range(struct mm_struct *dst_mm, struct mm_struct *src
if (p4d_none_or_clear_bad(src_p4d))
continue;
if (copy_pud_range(dst_mm, src_mm, dst_p4d, src_p4d,
vma, addr, next))
vma, new, addr, next))
return -ENOMEM;
} while (dst_p4d++, src_p4d++, addr = next, addr != end);
return 0;
}
int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
struct vm_area_struct *vma)
struct vm_area_struct *vma, struct vm_area_struct *new)
{
pgd_t *src_pgd, *dst_pgd;
unsigned long next;
@ -1033,7 +1037,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
if (pgd_none_or_clear_bad(src_pgd))
continue;
if (unlikely(copy_p4d_range(dst_mm, src_mm, dst_pgd, src_pgd,
vma, addr, next))) {
vma, new, addr, next))) {
ret = -ENOMEM;
break;
}