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author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2017-02-22 15:43:25 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-22 16:41:28 -0800 |
commit | 4c27fe4c4c84f3afd504ecff2420cc1ad420d38e (patch) | |
tree | 60a79c14f27f4428daccc7c48be7155660102c8e /include/linux/shmem_fs.h | |
parent | ba6907db6de17cf90c4fc67f3eb1d1d37dd0b7ac (diff) | |
download | lwn-4c27fe4c4c84f3afd504ecff2420cc1ad420d38e.tar.gz lwn-4c27fe4c4c84f3afd504ecff2420cc1ad420d38e.zip |
userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support
shmem_mcopy_atomic_pte is the low level routine that implements the
userfaultfd UFFDIO_COPY command. It is based on the existing
mcopy_atomic_pte routine with modifications for shared memory pages.
Link: http://lkml.kernel.org/r/20161216144821.5183-29-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 'include/linux/shmem_fs.h')
-rw-r--r-- | include/linux/shmem_fs.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index ff078e7043b6..fdaac9d4d46d 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -124,4 +124,15 @@ static inline bool shmem_huge_enabled(struct vm_area_struct *vma) } #endif +#ifdef CONFIG_SHMEM +extern int shmem_mcopy_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd, + struct vm_area_struct *dst_vma, + unsigned long dst_addr, + unsigned long src_addr, + struct page **pagep); +#else +#define shmem_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma, dst_addr, \ + src_addr, pagep) ({ BUG(); 0; }) +#endif + #endif |