Merge release-20200323.0-215-g0c58694 (automated)

15 files changed, 98 insertions, 21 deletions

diff --git a/pkg/abi/linux/arch_amd64.go b/pkg/abi/linux/arch_amd64.go
new file mode 100755
index 000000000..0be31e755
--- /dev/null
+++ b/pkg/abi/linux/arch_amd64.go
@@ -0,0 +1,23 @@
+// Copyright 2020 The gVisor Authors.
+
+// 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.
+
+// +build amd64
+
+package linux
+
+// Start and end addresses of the vsyscall page.
+const (
+	VSyscallStartAddr uint64 = 0xffffffffff600000
+	VSyscallEndAddr   uint64 = 0xffffffffff601000
+)
diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go
index 7fed2c978..ac6932361 100755
--- a/pkg/abi/linux/linux_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go
@@ -128,7 +128,7 @@ func (s *Statx) Packed() bool {
 
 // MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe.
 func (s *Statx) MarshalUnsafe(dst []byte) {
-    if s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
+    if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
         safecopy.CopyIn(dst, unsafe.Pointer(s))
     } else {
         s.MarshalBytes(dst)
@@ -137,7 +137,7 @@ func (s *Statx) MarshalUnsafe(dst []byte) {
 
 // UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe.
 func (s *Statx) UnmarshalUnsafe(src []byte) {
-    if s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() && s.Ctime.Packed() {
+    if s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
         safecopy.CopyOut(unsafe.Pointer(s), src)
     } else {
         s.UnmarshalBytes(src)
@@ -147,7 +147,7 @@ func (s *Statx) UnmarshalUnsafe(src []byte) {
 // CopyOutN implements marshal.Marshallable.CopyOutN.
 //go:nosplit
 func (s *Statx) CopyOutN(task marshal.Task, addr usermem.Addr, limit int) (int, error) {
-    if !s.Btime.Packed() && s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() {
+    if !s.Ctime.Packed() && s.Mtime.Packed() && s.Atime.Packed() && s.Btime.Packed() {
         // Type Statx doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         s.MarshalBytes(buf) // escapes: fallback.
diff --git a/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go b/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
index 3d5a64872..75397fd08 100755
--- a/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
+++ b/pkg/abi/linux/linux_amd64_abi_autogen_unsafe.go
@@ -1,6 +1,7 @@
 // Automatically generated marshal implementation. See tools/go_marshal.
 
 // +build amd64
+// +build amd64
 
 package linux
 
@@ -252,7 +253,7 @@ func (s *Stat) CopyOut(task marshal.Task, addr usermem.Addr) (int, error) {
 // CopyIn implements marshal.Marshallable.CopyIn.
 //go:nosplit
 func (s *Stat) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
-    if !s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
+    if !s.CTime.Packed() && s.ATime.Packed() && s.MTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to UnmarshalBytes.
         buf := task.CopyScratchBuffer(s.SizeBytes()) // escapes: okay.
         length, err := task.CopyInBytes(addr, buf) // escapes: okay.
@@ -278,7 +279,7 @@ func (s *Stat) CopyIn(task marshal.Task, addr usermem.Addr) (int, error) {
 
 // WriteTo implements io.WriterTo.WriteTo.
 func (s *Stat) WriteTo(w io.Writer) (int64, error) {
-    if !s.MTime.Packed() && s.CTime.Packed() && s.ATime.Packed() {
+    if !s.ATime.Packed() && s.MTime.Packed() && s.CTime.Packed() {
         // Type Stat doesn't have a packed layout in memory, fall back to MarshalBytes.
         buf := make([]byte, s.SizeBytes())
         s.MarshalBytes(buf)
diff --git a/pkg/abi/linux/linux_amd64_state_autogen.go b/pkg/abi/linux/linux_amd64_state_autogen.go
index a5f55a80b..a98193a5b 100755
--- a/pkg/abi/linux/linux_amd64_state_autogen.go
+++ b/pkg/abi/linux/linux_amd64_state_autogen.go
@@ -1,5 +1,6 @@
 // automatically generated by stateify.
 
 // +build amd64
+// +build amd64
 
 package linux
diff --git a/pkg/abi/linux/seccomp.go b/pkg/abi/linux/seccomp.go
index 4eeb5cd7a..d0607e256 100644
--- a/pkg/abi/linux/seccomp.go
+++ b/pkg/abi/linux/seccomp.go
@@ -63,3 +63,10 @@ func (a BPFAction) String() string {
 func (a BPFAction) Data() uint16 {
 	return uint16(a & SECCOMP_RET_DATA)
 }
+
+// SockFprog is sock_fprog taken from <linux/filter.h>.
+type SockFprog struct {
+	Len    uint16
+	pad    [6]byte
+	Filter *BPFInstruction
+}
diff --git a/pkg/flipcall/packet_window_allocator.go b/pkg/flipcall/packet_window_allocator.go
index ccb918fab..af9cc3d21 100755
--- a/pkg/flipcall/packet_window_allocator.go
+++ b/pkg/flipcall/packet_window_allocator.go
@@ -134,7 +134,7 @@ func (pwa *PacketWindowAllocator) Allocate(size int) (PacketWindowDescriptor, er
 	start := pwa.nextAlloc
 	pwa.nextAlloc = end
 	return PacketWindowDescriptor{
-		FD:     pwa.fd,
+		FD:     pwa.FD(),
 		Offset: start,
 		Length: size,
 	}, nil
@@ -158,7 +158,7 @@ func (pwa *PacketWindowAllocator) ensureFileSize(min int64) error {
 		}
 		newSize = newNewSize
 	}
-	if err := syscall.Ftruncate(pwa.fd, newSize); err != nil {
+	if err := syscall.Ftruncate(pwa.FD(), newSize); err != nil {
 		return fmt.Errorf("ftruncate failed: %v", err)
 	}
 	pwa.fileSize = newSize
diff --git a/pkg/seccomp/seccomp_unsafe.go b/pkg/seccomp/seccomp_unsafe.go
index be328db12..f7e986589 100644
--- a/pkg/seccomp/seccomp_unsafe.go
+++ b/pkg/seccomp/seccomp_unsafe.go
@@ -21,13 +21,6 @@ import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 )
 
-// sockFprog is sock_fprog taken from <linux/filter.h>.
-type sockFprog struct {
-	Len    uint16
-	pad    [6]byte
-	Filter *linux.BPFInstruction
-}
-
 // SetFilter installs the given BPF program.
 //
 // This is safe to call from an afterFork context.
@@ -39,7 +32,7 @@ func SetFilter(instrs []linux.BPFInstruction) syscall.Errno {
 		return errno
 	}
 
-	sockProg := sockFprog{
+	sockProg := linux.SockFprog{
 		Len:    uint16(len(instrs)),
 		Filter: (*linux.BPFInstruction)(unsafe.Pointer(&instrs[0])),
 	}
diff --git a/pkg/sentry/kernel/task_run.go b/pkg/sentry/kernel/task_run.go
index 2ba8d7e63..d654dd997 100644
--- a/pkg/sentry/kernel/task_run.go
+++ b/pkg/sentry/kernel/task_run.go
@@ -96,6 +96,7 @@ func (t *Task) run(threadID uintptr) {
 			t.tg.liveGoroutines.Done()
 			t.tg.pidns.owner.liveGoroutines.Done()
 			t.tg.pidns.owner.runningGoroutines.Done()
+			t.p.Release()
 
 			// Keep argument alive because stack trace for dead variables may not be correct.
 			runtime.KeepAlive(threadID)
diff --git a/pkg/sentry/platform/kvm/context.go b/pkg/sentry/platform/kvm/context.go
index c769ac7b4..6507121ea 100644
--- a/pkg/sentry/platform/kvm/context.go
+++ b/pkg/sentry/platform/kvm/context.go
@@ -85,3 +85,6 @@ func (c *context) Switch(as platform.AddressSpace, ac arch.Context, _ int32) (*a
 func (c *context) Interrupt() {
 	c.interrupt.NotifyInterrupt()
 }
+
+// Release implements platform.Context.Release().
+func (c *context) Release() {}
diff --git a/pkg/sentry/platform/kvm/kvm.go b/pkg/sentry/platform/kvm/kvm.go
index a9b4af43e..ae813e24e 100644
--- a/pkg/sentry/platform/kvm/kvm.go
+++ b/pkg/sentry/platform/kvm/kvm.go
@@ -191,6 +191,11 @@ func (*constructor) OpenDevice() (*os.File, error) {
 	return OpenDevice()
 }
 
+// Flags implements platform.Constructor.Flags().
+func (*constructor) Requirements() platform.Requirements {
+	return platform.Requirements{}
+}
+
 func init() {
 	platform.Register("kvm", &constructor{})
 }
diff --git a/pkg/sentry/platform/platform.go b/pkg/sentry/platform/platform.go
index 2ca696382..171513f3f 100644
--- a/pkg/sentry/platform/platform.go
+++ b/pkg/sentry/platform/platform.go
@@ -148,6 +148,9 @@ type Context interface {
 	// Interrupt interrupts a concurrent call to Switch(), causing it to return
 	// ErrContextInterrupt.
 	Interrupt()
+
+	// Release() releases any resources associated with this context.
+	Release()
 }
 
 var (
@@ -353,10 +356,28 @@ func (fr FileRange) String() string {
 	return fmt.Sprintf("[%#x, %#x)", fr.Start, fr.End)
 }
 
+// Requirements is used to specify platform specific requirements.
+type Requirements struct {
+	// RequiresCurrentPIDNS indicates that the sandbox has to be started in the
+	// current pid namespace.
+	RequiresCurrentPIDNS bool
+	// RequiresCapSysPtrace indicates that the sandbox has to be started with
+	// the CAP_SYS_PTRACE capability.
+	RequiresCapSysPtrace bool
+}
+
 // Constructor represents a platform type.
 type Constructor interface {
+	// New returns a new platform instance.
+	//
+	// Arguments:
+	//
+	// * deviceFile - the device file (e.g. /dev/kvm for the KVM platform).
 	New(deviceFile *os.File) (Platform, error)
 	OpenDevice() (*os.File, error)
+
+	// Requirements returns platform specific requirements.
+	Requirements() Requirements
 }
 
 // platforms contains all available platform types.
diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go
index 03adb624b..08d055e05 100644
--- a/pkg/sentry/platform/ptrace/ptrace.go
+++ b/pkg/sentry/platform/ptrace/ptrace.go
@@ -177,6 +177,9 @@ func (c *context) Interrupt() {
 	c.interrupt.NotifyInterrupt()
 }
 
+// Release implements platform.Context.Release().
+func (c *context) Release() {}
+
 // PTrace represents a collection of ptrace subprocesses.
 type PTrace struct {
 	platform.MMapMinAddr
@@ -248,6 +251,16 @@ func (*constructor) OpenDevice() (*os.File, error) {
 	return nil, nil
 }
 
+// Flags implements platform.Constructor.Flags().
+func (*constructor) Requirements() platform.Requirements {
+	// TODO(b/75837838): Also set a new PID namespace so that we limit
+	// access to other host processes.
+	return platform.Requirements{
+		RequiresCapSysPtrace: true,
+		RequiresCurrentPIDNS: true,
+	}
+}
+
 func init() {
 	platform.Register("ptrace", &constructor{})
 }
diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go
index a644609ef..773ddb1ed 100644
--- a/pkg/sentry/platform/ptrace/subprocess.go
+++ b/pkg/sentry/platform/ptrace/subprocess.go
@@ -332,7 +332,7 @@ func (t *thread) unexpectedStubExit() {
 	msg, err := t.getEventMessage()
 	status := syscall.WaitStatus(msg)
 	if status.Signaled() && status.Signal() == syscall.SIGKILL {
-		// SIGKILL can be only sent by an user or OOM-killer. In both
+		// SIGKILL can be only sent by a user or OOM-killer. In both
 		// these cases, we don't need to panic. There is no reasons to
 		// think that something wrong in gVisor.
 		log.Warningf("The ptrace stub process %v has been killed by SIGKILL.", t.tgid)
diff --git a/runsc/cmd/boot.go b/runsc/cmd/boot.go
index 0938944a6..4c2ac6ff0 100644
--- a/runsc/cmd/boot.go
+++ b/runsc/cmd/boot.go
@@ -25,8 +25,8 @@ import (
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/sentry/platform"
 	"gvisor.dev/gvisor/runsc/boot"
-	"gvisor.dev/gvisor/runsc/boot/platforms"
 	"gvisor.dev/gvisor/runsc/flag"
 	"gvisor.dev/gvisor/runsc/specutils"
 )
@@ -183,7 +183,12 @@ func (b *Boot) Execute(_ context.Context, f *flag.FlagSet, args ...interface{})
 		if caps == nil {
 			caps = &specs.LinuxCapabilities{}
 		}
-		if conf.Platform == platforms.Ptrace {
+
+		gPlatform, err := platform.Lookup(conf.Platform)
+		if err != nil {
+			Fatalf("loading platform: %v", err)
+		}
+		if gPlatform.Requirements().RequiresCapSysPtrace {
 			// Ptrace platform requires extra capabilities.
 			const c = "CAP_SYS_PTRACE"
 			caps.Bounding = append(caps.Bounding, c)
diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go
index e82bcef6f..e4ec16e2f 100644
--- a/runsc/sandbox/sandbox.go
+++ b/runsc/sandbox/sandbox.go
@@ -446,9 +446,13 @@ func (s *Sandbox) createSandboxProcess(conf *boot.Config, args *Args, startSyncF
 		nextFD++
 	}
 
-	// If the platform needs a device FD we must pass it in.
-	if deviceFile, err := deviceFileForPlatform(conf.Platform); err != nil {
+	gPlatform, err := platform.Lookup(conf.Platform)
+	if err != nil {
 		return err
+	}
+
+	if deviceFile, err := gPlatform.OpenDevice(); err != nil {
+		return fmt.Errorf("opening device file for platform %q: %v", gPlatform, err)
 	} else if deviceFile != nil {
 		defer deviceFile.Close()
 		cmd.ExtraFiles = append(cmd.ExtraFiles, deviceFile)
@@ -539,7 +543,7 @@ func (s *Sandbox) createSandboxProcess(conf *boot.Config, args *Args, startSyncF
 		{Type: specs.UTSNamespace},
 	}
 
-	if conf.Platform == platforms.Ptrace {
+	if gPlatform.Requirements().RequiresCurrentPIDNS {
 		// TODO(b/75837838): Also set a new PID namespace so that we limit
 		// access to other host processes.
 		log.Infof("Sandbox will be started in the current PID namespace")