From 0c586946ea26610b87c4ff7bda783a5a9ca11ec0 Mon Sep 17 00:00:00 2001 From: Andrei Vagin Date: Wed, 22 Apr 2020 17:48:59 -0700 Subject: Specify a memory file in platform.New(). PiperOrigin-RevId: 307941984 --- pkg/abi/linux/BUILD | 1 + pkg/abi/linux/arch_amd64.go | 23 +++++++++++++++++++++++ pkg/abi/linux/seccomp.go | 7 +++++++ pkg/flipcall/packet_window_allocator.go | 4 ++-- pkg/seccomp/seccomp_unsafe.go | 9 +-------- pkg/sentry/kernel/task_run.go | 1 + pkg/sentry/platform/kvm/context.go | 3 +++ pkg/sentry/platform/kvm/kvm.go | 5 +++++ pkg/sentry/platform/platform.go | 21 +++++++++++++++++++++ pkg/sentry/platform/ptrace/ptrace.go | 13 +++++++++++++ pkg/sentry/platform/ptrace/subprocess.go | 2 +- runsc/cmd/BUILD | 2 +- runsc/cmd/boot.go | 9 +++++++-- runsc/sandbox/sandbox.go | 10 +++++++--- tools/nogo/config.go | 3 +++ 15 files changed, 96 insertions(+), 17 deletions(-) create mode 100644 pkg/abi/linux/arch_amd64.go diff --git a/pkg/abi/linux/BUILD b/pkg/abi/linux/BUILD index 322d1ccc4..59b0e138a 100644 --- a/pkg/abi/linux/BUILD +++ b/pkg/abi/linux/BUILD @@ -10,6 +10,7 @@ go_library( name = "linux", srcs = [ "aio.go", + "arch_amd64.go", "audit.go", "bpf.go", "capability.go", diff --git a/pkg/abi/linux/arch_amd64.go b/pkg/abi/linux/arch_amd64.go new file mode 100644 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/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 . +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 100644 --- 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 . -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/BUILD b/runsc/cmd/BUILD index d0bb4613a..4900fbe16 100644 --- a/runsc/cmd/BUILD +++ b/runsc/cmd/BUILD @@ -44,13 +44,13 @@ go_library( "//pkg/sentry/control", "//pkg/sentry/kernel", "//pkg/sentry/kernel/auth", + "//pkg/sentry/platform", "//pkg/state", "//pkg/state/statefile", "//pkg/sync", "//pkg/unet", "//pkg/urpc", "//runsc/boot", - "//runsc/boot/platforms", "//runsc/console", "//runsc/container", "//runsc/flag", 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") diff --git a/tools/nogo/config.go b/tools/nogo/config.go index 0c4b7dd40..6958fca69 100644 --- a/tools/nogo/config.go +++ b/tools/nogo/config.go @@ -103,6 +103,9 @@ var analyzerConfig = map[*analysis.Analyzer]matcher{ "pkg/sentry/platform/ring0/pagetables/allocator_unsafe.go", // Special case. "pkg/sentry/platform/safecopy/safecopy_unsafe.go", // Special case. "pkg/sentry/vfs/mount_unsafe.go", // Special case. + "pkg/sentry/platform/systrap/stub_unsafe.go", // Special case. + "pkg/sentry/platform/systrap/switchto_google_unsafe.go", // Special case. + "pkg/sentry/platform/systrap/sysmsg_thread_unsafe.go", // Special case. ), ), unusedresult.Analyzer: alwaysMatches(), -- cgit v1.2.3