diff options
| -rw-r--r-- | pkg/sentry/fs/attr.go | 5 | ||||
| -rw-r--r-- | pkg/sentry/fs/file.go | 7 | ||||
| -rw-r--r-- | pkg/sentry/fs/splice.go | 5 | ||||
| -rw-r--r-- | pkg/sentry/syscalls/linux/sys_splice.go | 19 | ||||
| -rw-r--r-- | test/syscalls/linux/eventfd.cc | 25 |
5 files changed, 45 insertions, 16 deletions
diff --git a/pkg/sentry/fs/attr.go b/pkg/sentry/fs/attr.go index fa9e7d517..f60bd423d 100644 --- a/pkg/sentry/fs/attr.go +++ b/pkg/sentry/fs/attr.go @@ -206,6 +206,11 @@ func IsPipe(s StableAttr) bool { return s.Type == Pipe } +// IsAnonymous returns true if StableAttr.Type matches any type of anonymous. +func IsAnonymous(s StableAttr) bool { + return s.Type == Anonymous +} + // IsSocket returns true if StableAttr.Type matches any type of socket. func IsSocket(s StableAttr) bool { return s.Type == Socket diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go index ca3466f4f..78100e448 100644 --- a/pkg/sentry/fs/file.go +++ b/pkg/sentry/fs/file.go @@ -555,10 +555,6 @@ type lockedWriter struct { // // This applies only to Write, not WriteAt. Offset int64 - - // Err contains the first error encountered while copying. This is - // useful to determine whether Writer or Reader failed during io.Copy. - Err error } // Write implements io.Writer.Write. @@ -594,8 +590,5 @@ func (w *lockedWriter) WriteAt(buf []byte, offset int64) (int, error) { break } } - if w.Err == nil { - w.Err = err - } return written, err } diff --git a/pkg/sentry/fs/splice.go b/pkg/sentry/fs/splice.go index 791d1526c..33da82868 100644 --- a/pkg/sentry/fs/splice.go +++ b/pkg/sentry/fs/splice.go @@ -167,11 +167,6 @@ func Splice(ctx context.Context, dst *File, src *File, opts SpliceOpts) (int64, if !srcPipe && !opts.SrcOffset { atomic.StoreInt64(&src.offset, src.offset+n) } - - // Don't report any errors if we have some progress without data loss. - if w.Err == nil { - err = nil - } } // Drop locks. diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go index dd3a5807f..f43d6c155 100644 --- a/pkg/sentry/syscalls/linux/sys_splice.go +++ b/pkg/sentry/syscalls/linux/sys_splice.go @@ -211,8 +211,10 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal opts := fs.SpliceOpts{ Length: count, } + inFileAttr := inFile.Dirent.Inode.StableAttr + outFileAttr := outFile.Dirent.Inode.StableAttr switch { - case fs.IsPipe(inFile.Dirent.Inode.StableAttr) && !fs.IsPipe(outFile.Dirent.Inode.StableAttr): + case fs.IsPipe(inFileAttr) && !fs.IsPipe(outFileAttr): if inOffset != 0 { return 0, nil, syserror.ESPIPE } @@ -229,7 +231,7 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal opts.DstOffset = true opts.DstStart = offset } - case !fs.IsPipe(inFile.Dirent.Inode.StableAttr) && fs.IsPipe(outFile.Dirent.Inode.StableAttr): + case !fs.IsPipe(inFileAttr) && fs.IsPipe(outFileAttr): if outOffset != 0 { return 0, nil, syserror.ESPIPE } @@ -246,13 +248,13 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal opts.SrcOffset = true opts.SrcStart = offset } - case fs.IsPipe(inFile.Dirent.Inode.StableAttr) && fs.IsPipe(outFile.Dirent.Inode.StableAttr): + case fs.IsPipe(inFileAttr) && fs.IsPipe(outFileAttr): if inOffset != 0 || outOffset != 0 { return 0, nil, syserror.ESPIPE } // We may not refer to the same pipe; otherwise it's a continuous loop. - if inFile.Dirent.Inode.StableAttr.InodeID == outFile.Dirent.Inode.StableAttr.InodeID { + if inFileAttr.InodeID == outFileAttr.InodeID { return 0, nil, syserror.EINVAL } default: @@ -262,6 +264,15 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal // Splice data. n, err := doSplice(t, outFile, inFile, opts, nonBlock) + // Special files can have additional requirements for granularity. For + // example, read from eventfd returns EINVAL if a size is less 8 bytes. + // Inotify is another example. read will return EINVAL is a buffer is + // too small to return the next event, but a size of an event isn't + // fixed, it is sizeof(struct inotify_event) + {NAME_LEN} + 1. + if n != 0 && err != nil && (fs.IsAnonymous(inFileAttr) || fs.IsAnonymous(outFileAttr)) { + err = nil + } + // See above; inFile is chosen arbitrarily here. return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "splice", inFile) } diff --git a/test/syscalls/linux/eventfd.cc b/test/syscalls/linux/eventfd.cc index 367682c3d..927001eee 100644 --- a/test/syscalls/linux/eventfd.cc +++ b/test/syscalls/linux/eventfd.cc @@ -132,6 +132,31 @@ TEST(EventfdTest, BigWriteBigRead) { EXPECT_EQ(l[0], 1); } +TEST(EventfdTest, SpliceFromPipePartialSucceeds) { + int pipes[2]; + ASSERT_THAT(pipe2(pipes, O_NONBLOCK), SyscallSucceeds()); + const FileDescriptor pipe_rfd(pipes[0]); + const FileDescriptor pipe_wfd(pipes[1]); + constexpr uint64_t kVal{1}; + + FileDescriptor efd = ASSERT_NO_ERRNO_AND_VALUE(NewEventFD(0, EFD_NONBLOCK)); + + uint64_t event_array[2]; + event_array[0] = kVal; + event_array[1] = kVal; + ASSERT_THAT(write(pipe_wfd.get(), event_array, sizeof(event_array)), + SyscallSucceedsWithValue(sizeof(event_array))); + EXPECT_THAT(splice(pipe_rfd.get(), /*__offin=*/nullptr, efd.get(), + /*__offout=*/nullptr, sizeof(event_array[0]) + 1, + SPLICE_F_NONBLOCK), + SyscallSucceedsWithValue(sizeof(event_array[0]))); + + uint64_t val; + ASSERT_THAT(read(efd.get(), &val, sizeof(val)), + SyscallSucceedsWithValue(sizeof(val))); + EXPECT_EQ(val, kVal); +} + // NotifyNonZero is inherently racy, so random save is disabled. TEST(EventfdTest, NotifyNonZero_NoRandomSave) { // Waits will time out at 10 seconds. |