diff options
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 5d37c37854b0..ea9008254df4 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -633,6 +633,34 @@ void mremap_userfaultfd_complete(struct vm_userfaultfd_ctx *vm_ctx, userfaultfd_event_wait_completion(ctx, &ewq); } +void madvise_userfault_dontneed(struct vm_area_struct *vma, + struct vm_area_struct **prev, + unsigned long start, unsigned long end) +{ + struct mm_struct *mm = vma->vm_mm; + struct userfaultfd_ctx *ctx; + struct userfaultfd_wait_queue ewq; + + ctx = vma->vm_userfaultfd_ctx.ctx; + if (!ctx || !(ctx->features & UFFD_FEATURE_EVENT_MADVDONTNEED)) + return; + + userfaultfd_ctx_get(ctx); + up_read(&mm->mmap_sem); + + *prev = NULL; /* We wait for ACK w/o the mmap semaphore */ + + msg_init(&ewq.msg); + + ewq.msg.event = UFFD_EVENT_MADVDONTNEED; + ewq.msg.arg.madv_dn.start = start; + ewq.msg.arg.madv_dn.end = end; + + userfaultfd_event_wait_completion(ctx, &ewq); + + down_read(&mm->mmap_sem); +} + static int userfaultfd_release(struct inode *inode, struct file *file) { struct userfaultfd_ctx *ctx = file->private_data; |