Merge branch 'for-6.0/dax' into libnvdimm-fixes

[people/ms/linux.git] / fs / userfaultfd.c

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index e943370107d06afab21d37fc43e2aa3714fb816e..175de70e3adfdd68a88ef6c11e16e68c8f296a17 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -192,17 +192,19 @@ static inline void msg_init(struct uffd_msg *msg)
 }
 
 static inline struct uffd_msg userfault_msg(unsigned long address,
+                                           unsigned long real_address,
                                            unsigned int flags,
                                            unsigned long reason,
                                            unsigned int features)
 {
        struct uffd_msg msg;
+
        msg_init(&msg);
        msg.event = UFFD_EVENT_PAGEFAULT;
 
-       if (!(features & UFFD_FEATURE_EXACT_ADDRESS))
-               address &= PAGE_MASK;
-       msg.arg.pagefault.address = address;
+       msg.arg.pagefault.address = (features & UFFD_FEATURE_EXACT_ADDRESS) ?
+                                   real_address : address;
+
        /*
         * These flags indicate why the userfault occurred:
         * - UFFD_PAGEFAULT_FLAG_WP indicates a write protect fault.
@@ -488,8 +490,8 @@ vm_fault_t handle_userfault(struct vm_fault *vmf, unsigned long reason)
 
        init_waitqueue_func_entry(&uwq.wq, userfaultfd_wake_function);
        uwq.wq.private = current;
-       uwq.msg = userfault_msg(vmf->real_address, vmf->flags, reason,
-                       ctx->features);
+       uwq.msg = userfault_msg(vmf->address, vmf->real_address, vmf->flags,
+                               reason, ctx->features);
        uwq.ctx = ctx;
        uwq.waken = false;
 
@@ -1599,6 +1601,10 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
                        wake_userfault(vma->vm_userfaultfd_ctx.ctx, &range);
                }
 
+               /* Reset ptes for the whole vma range if wr-protected */
+               if (userfaultfd_wp(vma))
+                       uffd_wp_range(mm, vma, start, vma_end - start, false);
+
                new_flags = vma->vm_flags & ~__VM_UFFD_FLAGS;
                prev = vma_merge(mm, prev, start, vma_end, new_flags,
                                 vma->anon_vma, vma->vm_file, vma->vm_pgoff,
@@ -1923,10 +1929,8 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
        ret = -EFAULT;
        if (copy_from_user(&uffdio_api, buf, sizeof(uffdio_api)))
                goto out;
-       features = uffdio_api.features;
-       ret = -EINVAL;
-       if (uffdio_api.api != UFFD_API || (features & ~UFFD_API_FEATURES))
-               goto err_out;
+       /* Ignore unsupported features (userspace built against newer kernel) */
+       features = uffdio_api.features & UFFD_API_FEATURES;
        ret = -EPERM;
        if ((features & UFFD_FEATURE_EVENT_FORK) && !capable(CAP_SYS_PTRACE))
                goto err_out;