Check in gVisor.

PiperOrigin-RevId: 194583126
Change-Id: Ica1d8821a90f74e7e745962d71801c598c652463

1 files changed, 58 insertions, 0 deletions

diff --git a/runsc/fsgofer/fsgofer_unsafe.go b/runsc/fsgofer/fsgofer_unsafe.go
new file mode 100644
index 000000000..e676809ac
--- /dev/null
+++ b/runsc/fsgofer/fsgofer_unsafe.go
@@ -0,0 +1,58 @@
+// Copyright 2018 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fsgofer
+
+import (
+	"syscall"
+	"unsafe"
+
+	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
+)
+
+func statAt(dirFd int, name string) (syscall.Stat_t, error) {
+	nameBytes, err := syscall.BytePtrFromString(name)
+	if err != nil {
+		return syscall.Stat_t{}, extractErrno(err)
+	}
+	namePtr := uintptr(unsafe.Pointer(nameBytes))
+
+	var stat syscall.Stat_t
+	statPtr := uintptr(unsafe.Pointer(&stat))
+
+	if _, _, err := syscall.Syscall6(syscall.SYS_NEWFSTATAT, uintptr(dirFd), namePtr, statPtr, linux.AT_SYMLINK_NOFOLLOW, 0, 0); err != 0 {
+		return syscall.Stat_t{}, err
+	}
+	return stat, nil
+}
+
+func utimensat(dirFd int, name string, times [2]syscall.Timespec, flags int) error {
+	// utimensat(2) doesn't accept empty name, instead name must be nil to make it
+	// operate directly on 'dirFd' unlike other *at syscalls.
+	var namePtr uintptr
+	if name != "" {
+		nameBytes, err := syscall.BytePtrFromString(name)
+		if err != nil {
+			return extractErrno(err)
+		}
+		namePtr = uintptr(unsafe.Pointer(nameBytes))
+	}
+
+	timesPtr := uintptr(unsafe.Pointer(&times[0]))
+
+	if _, _, err := syscall.Syscall6(syscall.SYS_UTIMENSAT, uintptr(dirFd), namePtr, timesPtr, uintptr(flags), 0, 0); err != 0 {
+		return err
+	}
+	return nil
+}