WIP: update tizen_qemu_defconfig

[platform/kernel/linux-starfive.git] / fs / userfaultfd.c

diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 98ac37e..154c103 100644 (file)
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -108,6 +108,21 @@ static bool userfaultfd_is_initialized(struct userfaultfd_ctx *ctx)
        return ctx->features & UFFD_FEATURE_INITIALIZED;
 }
 
+static void userfaultfd_set_vm_flags(struct vm_area_struct *vma,
+                                    vm_flags_t flags)
+{
+       const bool uffd_wp_changed = (vma->vm_flags ^ flags) & VM_UFFD_WP;
+
+       vma->vm_flags = flags;
+       /*
+        * For shared mappings, we want to enable writenotify while
+        * userfaultfd-wp is enabled (see vma_wants_writenotify()). We'll simply
+        * recalculate vma->vm_page_prot whenever userfaultfd-wp changes.
+        */
+       if ((vma->vm_flags & VM_SHARED) && uffd_wp_changed)
+               vma_set_page_prot(vma);
+}
+
 static int userfaultfd_wake_function(wait_queue_entry_t *wq, unsigned mode,
                                     int wake_flags, void *key)
 {
@@ -618,7 +633,8 @@ static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
                for_each_vma(vmi, vma) {
                        if (vma->vm_userfaultfd_ctx.ctx == release_new_ctx) {
                                vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
-                               vma->vm_flags &= ~__VM_UFFD_FLAGS;
+                               userfaultfd_set_vm_flags(vma,
+                                                        vma->vm_flags & ~__VM_UFFD_FLAGS);
                        }
                }
                mmap_write_unlock(mm);
@@ -652,7 +668,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs)
        octx = vma->vm_userfaultfd_ctx.ctx;
        if (!octx || !(octx->features & UFFD_FEATURE_EVENT_FORK)) {
                vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
-               vma->vm_flags &= ~__VM_UFFD_FLAGS;
+               userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS);
                return 0;
        }
 
@@ -733,7 +749,7 @@ void mremap_userfaultfd_prep(struct vm_area_struct *vma,
        } else {
                /* Drop uffd context if remap feature not enabled */
                vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
-               vma->vm_flags &= ~__VM_UFFD_FLAGS;
+               userfaultfd_set_vm_flags(vma, vma->vm_flags & ~__VM_UFFD_FLAGS);
        }
 }
 
@@ -895,7 +911,7 @@ static int userfaultfd_release(struct inode *inode, struct file *file)
                        prev = vma;
                }
 
-               vma->vm_flags = new_flags;
+               userfaultfd_set_vm_flags(vma, new_flags);
                vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
        }
        mmap_write_unlock(mm);
@@ -1463,7 +1479,7 @@ static int userfaultfd_register(struct userfaultfd_ctx *ctx,
                 * the next vma was merged into the current one and
                 * the current one has not been updated yet.
                 */
-               vma->vm_flags = new_flags;
+               userfaultfd_set_vm_flags(vma, new_flags);
                vma->vm_userfaultfd_ctx.ctx = ctx;
 
                if (is_vm_hugetlb_page(vma) && uffd_disable_huge_pmd_share(vma))
@@ -1651,7 +1667,7 @@ static int userfaultfd_unregister(struct userfaultfd_ctx *ctx,
                 * the next vma was merged into the current one and
                 * the current one has not been updated yet.
                 */
-               vma->vm_flags = new_flags;
+               userfaultfd_set_vm_flags(vma, new_flags);
                vma->vm_userfaultfd_ctx = NULL_VM_UFFD_CTX;
 
        skip:
@@ -1950,8 +1966,10 @@ static int userfaultfd_api(struct userfaultfd_ctx *ctx,
        ret = -EFAULT;
        if (copy_from_user(&uffdio_api, buf, sizeof(uffdio_api)))
                goto out;
-       /* Ignore unsupported features (userspace built against newer kernel) */
-       features = uffdio_api.features & UFFD_API_FEATURES;
+       features = uffdio_api.features;
+       ret = -EINVAL;
+       if (uffdio_api.api != UFFD_API || (features & ~UFFD_API_FEATURES))
+               goto err_out;
        ret = -EPERM;
        if ((features & UFFD_FEATURE_EVENT_FORK) && !capable(CAP_SYS_PTRACE))
                goto err_out;