@@ -1307,15 +1307,6 @@ static __always_inline int validate_range(struct mm_struct *mm,
return 0;
}
-static inline bool vma_can_userfault(struct vm_area_struct *vma,
- unsigned long vm_flags)
-{
- /* FIXME: add WP support to hugetlbfs and shmem */
- return vma_is_anonymous(vma) ||
- ((is_vm_hugetlb_page(vma) || vma_is_shmem(vma)) &&
- !(vm_flags & VM_UFFD_WP));
-}
-
static int userfaultfd_register(struct userfaultfd_ctx *ctx,
unsigned long arg)
{
@@ -1394,7 +1385,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
/* check not compatible vmas */
ret = -EINVAL;
- if (!vma_can_userfault(cur, vm_flags))
+ if (!vma_can_userfault(cur))
goto out_unlock;
/*
@@ -1453,7 +1444,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
do {
cond_resched();
- BUG_ON(!vma_can_userfault(vma, vm_flags));
+ BUG_ON(!vma_can_userfault(vma));
BUG_ON(vma->vm_userfaultfd_ctx.ctx &&
vma->vm_userfaultfd_ctx.ctx != ctx);
WARN_ON(!(vma->vm_flags & VM_MAYWRITE));
@@ -1602,7 +1593,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
* provides for more strict behavior to notice
* unregistration errors.
*/
- if (!vma_can_userfault(cur, cur->vm_flags))
+ if (!vma_can_userfault(cur))
goto out_unlock;
found = true;
@@ -1616,7 +1607,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
do {
cond_resched();
- BUG_ON(!vma_can_userfault(vma, vma->vm_flags));
+ BUG_ON(!vma_can_userfault(vma));
/*
* Nothing to do: this vma is already registered into this
@@ -16,6 +16,7 @@
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <asm-generic/pgtable_uffd.h>
+#include <linux/hugetlb_inline.h>
/*
* CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
@@ -88,6 +89,12 @@ static inline bool userfaultfd_armed(struct vm_area_struct *vma)
return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
}
+static inline bool vma_can_userfault(struct vm_area_struct *vma)
+{
+ return vma_is_anonymous(vma) || vma_is_shmem(vma) ||
+ is_vm_hugetlb_page(vma);
+}
+
extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
extern void dup_userfaultfd_complete(struct list_head *);
@@ -39,7 +39,8 @@
(__u64)1 << _UFFDIO_WRITEPROTECT)
#define UFFD_API_RANGE_IOCTLS_BASIC \
((__u64)1 << _UFFDIO_WAKE | \
- (__u64)1 << _UFFDIO_COPY)
+ (__u64)1 << _UFFDIO_COPY | \
+ (__u64)1 << _UFFDIO_WRITEPROTECT)
/*
* Valid ioctl command number range with this API is from 0x00 to
@@ -445,7 +445,6 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
err = mfill_zeropage_pte(dst_mm, dst_pmd,
dst_vma, dst_addr);
} else {
- VM_WARN_ON_ONCE(wp_copy);
if (!zeropage)
err = shmem_mcopy_atomic_pte(dst_mm, dst_pmd,
dst_vma, dst_addr,
@@ -671,15 +670,12 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
err = -ENOENT;
dst_vma = find_dst_vma(dst_mm, start, len);
- /*
- * Make sure the vma is not shared, that the dst range is
- * both valid and fully within a single existing vma.
- */
- if (!dst_vma || (dst_vma->vm_flags & VM_SHARED))
+
+ if (!dst_vma)
goto out_unlock;
if (!userfaultfd_wp(dst_vma))
goto out_unlock;
- if (!vma_is_anonymous(dst_vma))
+ if (!vma_can_userfault(dst_vma))
goto out_unlock;
if (is_vm_hugetlb_page(dst_vma)) {
We've had all the necessary changes ready for both shmem and hugetlbfs. Turn on all the shmem/hugetlbfs switches for userfaultfd-wp. Now we can remove the flags parameter for vma_can_userfault() since not used any more. Meanwhile, we can expand UFFD_API_RANGE_IOCTLS_BASIC with _UFFDIO_WRITEPROTECT too because all existing types now support write protection mode. Since vma_can_userfault() will be used elsewhere, move into userfaultfd_k.h. Signed-off-by: Peter Xu <peterx@redhat.com> --- fs/userfaultfd.c | 17 ++++------------- include/linux/userfaultfd_k.h | 7 +++++++ include/uapi/linux/userfaultfd.h | 3 ++- mm/userfaultfd.c | 10 +++------- 4 files changed, 16 insertions(+), 21 deletions(-)