diff options
Diffstat (limited to 'fs/userfaultfd.c')
-rw-r--r-- | fs/userfaultfd.c | 78 |
1 files changed, 75 insertions, 3 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index e8af40b05549..959551ff9a95 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -45,7 +45,6 @@ static struct ctl_table vm_userfaultfd_table[] = { .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_ONE, }, - { } }; #endif @@ -1033,7 +1032,7 @@ static int resolve_userfault_fork(struct userfaultfd_ctx *new, { int fd; - fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, new, + fd = anon_inode_create_getfd("[userfaultfd]", &userfaultfd_fops, new, O_RDONLY | (new->flags & UFFD_SHARED_FCNTL_FLAGS), inode); if (fd < 0) return fd; @@ -2005,6 +2004,75 @@ static inline unsigned int uffd_ctx_features(__u64 user_features) return (unsigned int)user_features | UFFD_FEATURE_INITIALIZED; } +static int userfaultfd_move(struct userfaultfd_ctx *ctx, + unsigned long arg) +{ + __s64 ret; + struct uffdio_move uffdio_move; + struct uffdio_move __user *user_uffdio_move; + struct userfaultfd_wake_range range; + struct mm_struct *mm = ctx->mm; + + user_uffdio_move = (struct uffdio_move __user *) arg; + + if (atomic_read(&ctx->mmap_changing)) + return -EAGAIN; + + if (copy_from_user(&uffdio_move, user_uffdio_move, + /* don't copy "move" last field */ + sizeof(uffdio_move)-sizeof(__s64))) + return -EFAULT; + + /* Do not allow cross-mm moves. */ + if (mm != current->mm) + return -EINVAL; + + ret = validate_range(mm, uffdio_move.dst, uffdio_move.len); + if (ret) + return ret; + + ret = validate_range(mm, uffdio_move.src, uffdio_move.len); + if (ret) + return ret; + + if (uffdio_move.mode & ~(UFFDIO_MOVE_MODE_ALLOW_SRC_HOLES| + UFFDIO_MOVE_MODE_DONTWAKE)) + return -EINVAL; + + if (mmget_not_zero(mm)) { + mmap_read_lock(mm); + + /* Re-check after taking mmap_lock */ + if (likely(!atomic_read(&ctx->mmap_changing))) + ret = move_pages(ctx, mm, uffdio_move.dst, uffdio_move.src, + uffdio_move.len, uffdio_move.mode); + else + ret = -EINVAL; + + mmap_read_unlock(mm); + mmput(mm); + } else { + return -ESRCH; + } + + if (unlikely(put_user(ret, &user_uffdio_move->move))) + return -EFAULT; + if (ret < 0) + goto out; + + /* len == 0 would wake all */ + VM_WARN_ON(!ret); + range.len = ret; + if (!(uffdio_move.mode & UFFDIO_MOVE_MODE_DONTWAKE)) { + range.start = uffdio_move.dst; + wake_userfault(ctx, &range); + } + ret = range.len == uffdio_move.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 @@ -2097,6 +2165,9 @@ static long userfaultfd_ioctl(struct file *file, unsigned cmd, case UFFDIO_ZEROPAGE: ret = userfaultfd_zeropage(ctx, arg); break; + case UFFDIO_MOVE: + ret = userfaultfd_move(ctx, arg); + break; case UFFDIO_WRITEPROTECT: ret = userfaultfd_writeprotect(ctx, arg); break; @@ -2189,7 +2260,8 @@ static int new_userfaultfd(int flags) /* prevent the mm struct to be freed */ mmgrab(ctx->mm); - fd = anon_inode_getfd_secure("[userfaultfd]", &userfaultfd_fops, ctx, + /* Create a new inode so that the LSM can block the creation. */ + fd = anon_inode_create_getfd("[userfaultfd]", &userfaultfd_fops, ctx, O_RDONLY | (flags & UFFD_SHARED_FCNTL_FLAGS), NULL); if (fd < 0) { mmdrop(ctx->mm); |