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| author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2017-02-22 15:43:34 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-22 16:41:28 -0800 |
| commit | 26071cedc519b822f69cc42dba9be969d2cdeb19 (patch) | |
| tree | ec79aa6a2536f6924e24ccc07ea7a575b1a48c68 /mm/userfaultfd.c | |
| parent | 95cc09d66f523895635eca8aa1f9bc7419e60e32 (diff) | |
| download | lwn-26071cedc519b822f69cc42dba9be969d2cdeb19.tar.gz lwn-26071cedc519b822f69cc42dba9be969d2cdeb19.zip | |
userfaultfd: shmem: use shmem_mcopy_atomic_pte for shared memory
The shmem_mcopy_atomic_pte implements low lever part of UFFDIO_COPY
operation for shared memory VMAs. It's based on mcopy_atomic_pte with
adjustments necessary for shared memory pages.
Link: http://lkml.kernel.org/r/20161216144821.5183-32-aarcange@redhat.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Michael Rapoport <RAPOPORT@il.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/userfaultfd.c')
| -rw-r--r-- | mm/userfaultfd.c | 34 |
1 files changed, 21 insertions, 13 deletions
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index 31207b47ea92..a0817cc470b0 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -16,6 +16,7 @@ #include <linux/mmu_notifier.h> #include <linux/hugetlb.h> #include <linux/pagemap.h> +#include <linux/shmem_fs.h> #include <asm/tlbflush.h> #include "internal.h" @@ -369,7 +370,9 @@ retry: */ err = -EINVAL; dst_vma = find_vma(dst_mm, dst_start); - if (!dst_vma || (dst_vma->vm_flags & VM_SHARED)) + if (!dst_vma) + goto out_unlock; + if (!vma_is_shmem(dst_vma) && dst_vma->vm_flags & VM_SHARED) goto out_unlock; if (dst_start < dst_vma->vm_start || dst_start + len > dst_vma->vm_end) @@ -394,11 +397,7 @@ retry: if (!dst_vma->vm_userfaultfd_ctx.ctx) goto out_unlock; - /* - * FIXME: only allow copying on anonymous vmas, tmpfs should - * be added. - */ - if (!vma_is_anonymous(dst_vma)) + if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) goto out_unlock; /* @@ -407,7 +406,7 @@ retry: * dst_vma. */ err = -ENOMEM; - if (unlikely(anon_vma_prepare(dst_vma))) + if (vma_is_anonymous(dst_vma) && unlikely(anon_vma_prepare(dst_vma))) goto out_unlock; while (src_addr < src_start + len) { @@ -444,12 +443,21 @@ retry: BUG_ON(pmd_none(*dst_pmd)); BUG_ON(pmd_trans_huge(*dst_pmd)); - if (!zeropage) - err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma, - dst_addr, src_addr, &page); - else - err = mfill_zeropage_pte(dst_mm, dst_pmd, dst_vma, - dst_addr); + if (vma_is_anonymous(dst_vma)) { + if (!zeropage) + err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma, + dst_addr, src_addr, + &page); + else + err = mfill_zeropage_pte(dst_mm, dst_pmd, + dst_vma, dst_addr); + } else { + err = -EINVAL; /* if zeropage is true return -EINVAL */ + if (likely(!zeropage)) + err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd, + dst_vma, dst_addr, + src_addr, &page); + } cond_resched(); |