init: verify that function is initcall_t at compile-time

[linux-2.6-microblaze.git] / include / linux / userfaultfd_k.h

diff --git a/include/linux/userfaultfd_k.h b/include/linux/userfaultfd_k.h
index a8e5f3e..794d153 100644 (file)
--- a/include/linux/userfaultfd_k.h
+++ b/include/linux/userfaultfd_k.h
@@ -17,6 +17,9 @@
 #include <linux/mm.h>
 #include <asm-generic/pgtable_uffd.h>
 
+/* The set of all possible UFFD-related VM flags. */
+#define __VM_UFFD_FLAGS (VM_UFFD_MISSING | VM_UFFD_WP | VM_UFFD_MINOR)
+
 /*
  * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining
  * new flags, since they might collide with O_* ones. We want
@@ -34,6 +37,22 @@ extern int sysctl_unprivileged_userfaultfd;
 
 extern vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason);
 
+/*
+ * The mode of operation for __mcopy_atomic and its helpers.
+ *
+ * This is almost an implementation detail (mcopy_atomic below doesn't take this
+ * as a parameter), but it's exposed here because memory-kind-specific
+ * implementations (e.g. hugetlbfs) need to know the mode of operation.
+ */
+enum mcopy_atomic_mode {
+       /* A normal copy_from_user into the destination range. */
+       MCOPY_ATOMIC_NORMAL,
+       /* Don't copy; map the destination range to the zero page. */
+       MCOPY_ATOMIC_ZEROPAGE,
+       /* Just install pte(s) with the existing page(s) in the page cache. */
+       MCOPY_ATOMIC_CONTINUE,
+};
+
 extern ssize_t mcopy_atomic(struct mm_struct *dst_mm, unsigned long dst_start,
                            unsigned long src_start, unsigned long len,
                            bool *mmap_changing, __u64 mode);
@@ -41,6 +60,8 @@ extern ssize_t mfill_zeropage(struct mm_struct *dst_mm,
                              unsigned long dst_start,
                              unsigned long len,
                              bool *mmap_changing);
+extern ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long dst_start,
+                             unsigned long len, bool *mmap_changing);
 extern int mwriteprotect_range(struct mm_struct *dst_mm,
                               unsigned long start, unsigned long len,
                               bool enable_wp, bool *mmap_changing);
@@ -52,6 +73,22 @@ static inline bool is_mergeable_vm_userfaultfd_ctx(struct vm_area_struct *vma,
        return vma->vm_userfaultfd_ctx.ctx == vm_ctx.ctx;
 }
 
+/*
+ * Never enable huge pmd sharing on some uffd registered vmas:
+ *
+ * - VM_UFFD_WP VMAs, because write protect information is per pgtable entry.
+ *
+ * - VM_UFFD_MINOR VMAs, because otherwise we would never get minor faults for
+ *   VMAs which share huge pmds. (If you have two mappings to the same
+ *   underlying pages, and fault in the non-UFFD-registered one with a write,
+ *   with huge pmd sharing this would *also* setup the second UFFD-registered
+ *   mapping, and we'd not get minor faults.)
+ */
+static inline bool uffd_disable_huge_pmd_share(struct vm_area_struct *vma)
+{
+       return vma->vm_flags & (VM_UFFD_WP | VM_UFFD_MINOR);
+}
+
 static inline bool userfaultfd_missing(struct vm_area_struct *vma)
 {
        return vma->vm_flags & VM_UFFD_MISSING;
@@ -62,6 +99,11 @@ static inline bool userfaultfd_wp(struct vm_area_struct *vma)
        return vma->vm_flags & VM_UFFD_WP;
 }
 
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+       return vma->vm_flags & VM_UFFD_MINOR;
+}
+
 static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
                                      pte_t pte)
 {
@@ -76,7 +118,7 @@ static inline bool userfaultfd_huge_pmd_wp(struct vm_area_struct *vma,
 
 static inline bool userfaultfd_armed(struct vm_area_struct *vma)
 {
-       return vma->vm_flags & (VM_UFFD_MISSING | VM_UFFD_WP);
+       return vma->vm_flags & __VM_UFFD_FLAGS;
 }
 
 extern int dup_userfaultfd(struct vm_area_struct *, struct list_head *);
@@ -123,6 +165,11 @@ static inline bool userfaultfd_wp(struct vm_area_struct *vma)
        return false;
 }
 
+static inline bool userfaultfd_minor(struct vm_area_struct *vma)
+{
+       return false;
+}
+
 static inline bool userfaultfd_pte_wp(struct vm_area_struct *vma,
                                      pte_t pte)
 {