diff options
| -rw-r--r-- | fs/userfaultfd.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index febbd2b165df..5f11678907d5 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -983,6 +983,96 @@ out: return ret; } +static int userfaultfd_copy(struct userfaultfd_ctx *ctx, + unsigned long arg) +{ + __s64 ret; + struct uffdio_copy uffdio_copy; + struct uffdio_copy __user *user_uffdio_copy; + struct userfaultfd_wake_range range; + + user_uffdio_copy = (struct uffdio_copy __user *) arg; + + ret = -EFAULT; + if (copy_from_user(&uffdio_copy, user_uffdio_copy, + /* don't copy "copy" last field */ + sizeof(uffdio_copy)-sizeof(__s64))) + goto out; + + ret = validate_range(ctx->mm, uffdio_copy.dst, uffdio_copy.len); + if (ret) + goto out; + /* + * double check for wraparound just in case. copy_from_user() + * will later check uffdio_copy.src + uffdio_copy.len to fit + * in the userland range. + */ + ret = -EINVAL; + if (uffdio_copy.src + uffdio_copy.len <= uffdio_copy.src) + goto out; + if (uffdio_copy.mode & ~UFFDIO_COPY_MODE_DONTWAKE) + goto out; + + ret = mcopy_atomic(ctx->mm, uffdio_copy.dst, uffdio_copy.src, + uffdio_copy.len); + if (unlikely(put_user(ret, &user_uffdio_copy->copy))) + return -EFAULT; + if (ret < 0) + goto out; + BUG_ON(!ret); + /* len == 0 would wake all */ + range.len = ret; + if (!(uffdio_copy.mode & UFFDIO_COPY_MODE_DONTWAKE)) { + range.start = uffdio_copy.dst; + wake_userfault(ctx, &range); + } + ret = range.len == uffdio_copy.len ? 0 : -EAGAIN; +out: + return ret; +} + +static int userfaultfd_zeropage(struct userfaultfd_ctx *ctx, + unsigned long arg) +{ + __s64 ret; + struct uffdio_zeropage uffdio_zeropage; + struct uffdio_zeropage __user *user_uffdio_zeropage; + struct userfaultfd_wake_range range; + + user_uffdio_zeropage = (struct uffdio_zeropage __user *) arg; + + ret = -EFAULT; + if (copy_from_user(&uffdio_zeropage, user_uffdio_zeropage, + /* don't copy "zeropage" last field */ + sizeof(uffdio_zeropage)-sizeof(__s64))) + goto out; + + ret = validate_range(ctx->mm, uffdio_zeropage.range.start, + uffdio_zeropage.range.len); + if (ret) + goto out; + ret = -EINVAL; + if (uffdio_zeropage.mode & ~UFFDIO_ZEROPAGE_MODE_DONTWAKE) + goto out; + + ret = mfill_zeropage(ctx->mm, uffdio_zeropage.range.start, + uffdio_zeropage.range.len); + if (unlikely(put_user(ret, &user_uffdio_zeropage->zeropage))) + return -EFAULT; + if (ret < 0) + goto out; + /* len == 0 would wake all */ + BUG_ON(!ret); + range.len = ret; + if (!(uffdio_zeropage.mode & UFFDIO_ZEROPAGE_MODE_DONTWAKE)) { + range.start = uffdio_zeropage.range.start; + wake_userfault(ctx, &range); + } + ret = range.len == uffdio_zeropage.range.len ? 0 : -EAGAIN; +out: + return ret; +} + /* * userland asks for a certain API version and we return which bits * and ioctl commands are implemented in this kernel for such API @@ -1038,6 +1128,12 @@ static long userfaultfd_ioctl(struct file *file, unsigned cmd, case UFFDIO_WAKE: ret = userfaultfd_wake(ctx, arg); break; + case UFFDIO_COPY: + ret = userfaultfd_copy(ctx, arg); + break; + case UFFDIO_ZEROPAGE: + ret = userfaultfd_zeropage(ctx, arg); + break; } return ret; } |