The patch titled
Subject: userfaultfd: shmem: allow registration of shared memory ranges
has been added to the -mm tree. Its filename is
userfaultfd-shmem-allow-registration-of-shared-memory-ranges.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-shmem-allow-registration-of-shared-memory-ranges.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-shmem-allow-registration-of-shared-memory-ranges.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Subject: userfaultfd: shmem: allow registration of shared memory ranges
Expand the userfaultfd_register/unregister routines to allow shared memory
VMAs. Currently, there is no UFFDIO_ZEROPAGE and write-protection support
for shared memory VMAs, which is reflected in ioctl methods supported by
uffdio_register.
Link: http://lkml.kernel.org/r/20161216144821.5183-34-aarcange@xxxxxxxxxx
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: Michael Rapoport <RAPOPORT@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 21 +++++++--------------
include/uapi/linux/userfaultfd.h | 2 +-
tools/testing/selftests/vm/userfaultfd.c | 2 +-
3 files changed, 9 insertions(+), 16 deletions(-)
diff -puN fs/userfaultfd.c~userfaultfd-shmem-allow-registration-of-shared-memory-ranges fs/userfaultfd.c
--- a/fs/userfaultfd.c~userfaultfd-shmem-allow-registration-of-shared-memory-ranges
+++ a/fs/userfaultfd.c
@@ -1065,7 +1065,8 @@ static __always_inline int validate_rang
static inline bool vma_can_userfault(struct vm_area_struct *vma)
{
- return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma);
+ return vma_is_anonymous(vma) || is_vm_hugetlb_page(vma) ||
+ vma_is_shmem(vma);
}
static int userfaultfd_register(struct userfaultfd_ctx *ctx,
@@ -1078,7 +1079,7 @@ static int userfaultfd_register(struct u
struct uffdio_register __user *user_uffdio_register;
unsigned long vm_flags, new_flags;
bool found;
- bool huge_pages;
+ bool non_anon_pages;
unsigned long start, end, vma_end;
user_uffdio_register = (struct uffdio_register __user *) arg;
@@ -1142,13 +1143,9 @@ static int userfaultfd_register(struct u
/*
* Search for not compatible vmas.
- *
- * FIXME: this shall be relaxed later so that it doesn't fail
- * on tmpfs backed vmas (in addition to the current allowance
- * on anonymous vmas).
*/
found = false;
- huge_pages = false;
+ non_anon_pages = false;
for (cur = vma; cur && cur->vm_start < end; cur = cur->vm_next) {
cond_resched();
@@ -1187,8 +1184,8 @@ static int userfaultfd_register(struct u
/*
* Note vmas containing huge pages
*/
- if (is_vm_hugetlb_page(cur))
- huge_pages = true;
+ if (is_vm_hugetlb_page(cur) || vma_is_shmem(cur))
+ non_anon_pages = true;
found = true;
}
@@ -1259,7 +1256,7 @@ out_unlock:
* userland which ioctls methods are guaranteed to
* succeed on this range.
*/
- if (put_user(huge_pages ? UFFD_API_RANGE_IOCTLS_HPAGE :
+ if (put_user(non_anon_pages ? UFFD_API_RANGE_IOCTLS_BASIC :
UFFD_API_RANGE_IOCTLS,
&user_uffdio_register->ioctls))
ret = -EFAULT;
@@ -1319,10 +1316,6 @@ static int userfaultfd_unregister(struct
/*
* Search for not compatible vmas.
- *
- * FIXME: this shall be relaxed later so that it doesn't fail
- * on tmpfs backed vmas (in addition to the current allowance
- * on anonymous vmas).
*/
found = false;
ret = -EINVAL;
diff -puN include/uapi/linux/userfaultfd.h~userfaultfd-shmem-allow-registration-of-shared-memory-ranges include/uapi/linux/userfaultfd.h
--- a/include/uapi/linux/userfaultfd.h~userfaultfd-shmem-allow-registration-of-shared-memory-ranges
+++ a/include/uapi/linux/userfaultfd.h
@@ -30,7 +30,7 @@
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY | \
(__u64)1 << _UFFDIO_ZEROPAGE)
-#define UFFD_API_RANGE_IOCTLS_HPAGE \
+#define UFFD_API_RANGE_IOCTLS_BASIC \
((__u64)1 << _UFFDIO_WAKE | \
(__u64)1 << _UFFDIO_COPY)
diff -puN tools/testing/selftests/vm/userfaultfd.c~userfaultfd-shmem-allow-registration-of-shared-memory-ranges tools/testing/selftests/vm/userfaultfd.c
--- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-shmem-allow-registration-of-shared-memory-ranges
+++ a/tools/testing/selftests/vm/userfaultfd.c
@@ -129,7 +129,7 @@ static void allocate_area(void **alloc_a
#else /* HUGETLB_TEST */
-#define EXPECTED_IOCTLS UFFD_API_RANGE_IOCTLS_HPAGE
+#define EXPECTED_IOCTLS UFFD_API_RANGE_IOCTLS_BASIC
static int release_pages(char *rel_area)
{
_
Patches currently in -mm which might be from rppt@xxxxxxxxxxxxxxxxxx are
userfaultfd-non-cooperative-dup_userfaultfd-use-mm_count-instead-of-mm_users.patch
userfaultfd-introduce-vma_can_userfault.patch
userfaultfd-shmem-add-shmem_mcopy_atomic_pte-for-userfaultfd-support.patch
userfaultfd-shmem-introduce-vma_is_shmem.patch
userfaultfd-shmem-use-shmem_mcopy_atomic_pte-for-shared-memory.patch
userfaultfd-shmem-add-userfaultfd-hook-for-shared-memory-faults.patch
userfaultfd-shmem-allow-registration-of-shared-memory-ranges.patch
userfaultfd-shmem-add-userfaultfd_shmem-test.patch
userfaultfd-non-cooperative-selftest-introduce-userfaultfd_open.patch
userfaultfd-non-cooperative-selftest-add-ufd-parameter-to-copy_page.patch
userfaultfd-non-cooperative-selftest-add-test-for-fork-madvdontneed-and-remap-events.patch
--
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