diff options
Diffstat (limited to 'runsc')
| -rw-r--r-- | runsc/boot/BUILD | 9 | ||||
| -rw-r--r-- | runsc/boot/compat.go | 72 | ||||
| -rw-r--r-- | runsc/boot/compat_amd64.go | 54 | ||||
| -rw-r--r-- | runsc/boot/compat_test.go | 66 |
4 files changed, 193 insertions, 8 deletions
diff --git a/runsc/boot/BUILD b/runsc/boot/BUILD index f8f848ebf..04cc0e854 100644 --- a/runsc/boot/BUILD +++ b/runsc/boot/BUILD @@ -6,6 +6,7 @@ go_library( name = "boot", srcs = [ "compat.go", + "compat_amd64.go", "config.go", "controller.go", "debug.go", @@ -59,9 +60,9 @@ go_library( "//pkg/sentry/socket/unix", "//pkg/sentry/state", "//pkg/sentry/strace", - "//pkg/sentry/syscalls:unimplemented_syscall_go_proto", "//pkg/sentry/syscalls/linux", "//pkg/sentry/time", + "//pkg/sentry/unimpl:unimplemented_syscall_go_proto", "//pkg/sentry/usage", "//pkg/sentry/watchdog", "//pkg/syserror", @@ -87,12 +88,16 @@ go_library( go_test( name = "boot_test", size = "small", - srcs = ["loader_test.go"], + srcs = [ + "compat_test.go", + "loader_test.go", + ], embed = [":boot"], deps = [ "//pkg/control/server", "//pkg/log", "//pkg/p9", + "//pkg/sentry/arch:registers_go_proto", "//pkg/sentry/context/contexttest", "//pkg/sentry/fs", "//pkg/unet", diff --git a/runsc/boot/compat.go b/runsc/boot/compat.go index 6766953b3..d18c2f802 100644 --- a/runsc/boot/compat.go +++ b/runsc/boot/compat.go @@ -17,6 +17,8 @@ package boot import ( "fmt" "os" + "sync" + "syscall" "github.com/golang/protobuf/proto" "gvisor.googlesource.com/gvisor/pkg/abi" @@ -25,7 +27,7 @@ import ( "gvisor.googlesource.com/gvisor/pkg/sentry/arch" rpb "gvisor.googlesource.com/gvisor/pkg/sentry/arch/registers_go_proto" "gvisor.googlesource.com/gvisor/pkg/sentry/strace" - spb "gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/unimplemented_syscall_go_proto" + spb "gvisor.googlesource.com/gvisor/pkg/sentry/unimpl/unimplemented_syscall_go_proto" ) func initCompatLogs(fd int) error { @@ -40,15 +42,27 @@ func initCompatLogs(fd int) error { type compatEmitter struct { sink *log.BasicLogger nameMap strace.SyscallMap + + // mu protects the fields below. + mu sync.Mutex + + // trackers map syscall number to the respective tracker instance. + // Protected by 'mu'. + trackers map[uint64]syscallTracker } func newCompatEmitter(logFD int) (*compatEmitter, error) { - // Always logs to default logger. nameMap, ok := strace.Lookup(abi.Linux, arch.AMD64) if !ok { return nil, fmt.Errorf("amd64 Linux syscall table not found") } - c := &compatEmitter{sink: log.Log(), nameMap: nameMap} + + c := &compatEmitter{ + // Always logs to default logger. + sink: log.Log(), + nameMap: nameMap, + trackers: make(map[uint64]syscallTracker), + } if logFD > 0 { f := os.NewFile(uintptr(logFD), "user log file") @@ -61,10 +75,33 @@ func newCompatEmitter(logFD int) (*compatEmitter, error) { // Emit implements eventchannel.Emitter. func (c *compatEmitter) Emit(msg proto.Message) (hangup bool, err error) { // Only interested in UnimplementedSyscall, skip the rest. - if us, ok := msg.(*spb.UnimplementedSyscall); ok { - regs := us.Registers.GetArch().(*rpb.Registers_Amd64).Amd64 - sysnr := regs.OrigRax + us, ok := msg.(*spb.UnimplementedSyscall) + if !ok { + return false, nil + } + regs := us.Registers.GetArch().(*rpb.Registers_Amd64).Amd64 + + c.mu.Lock() + defer c.mu.Unlock() + + sysnr := regs.OrigRax + tr := c.trackers[sysnr] + if tr == nil { + switch sysnr { + case syscall.SYS_PRCTL, syscall.SYS_ARCH_PRCTL: + tr = newCmdTracker(0) + + case syscall.SYS_IOCTL, syscall.SYS_EPOLL_CTL, syscall.SYS_SHMCTL: + tr = newCmdTracker(1) + + default: + tr = &onceTracker{} + } + c.trackers[sysnr] = tr + } + if tr.shouldReport(regs) { c.sink.Infof("Unsupported syscall: %s, regs: %+v", c.nameMap.Name(uintptr(sysnr)), regs) + tr.onReported(regs) } return false, nil } @@ -74,3 +111,26 @@ func (c *compatEmitter) Close() error { c.sink = nil return nil } + +// syscallTracker interface allows filters to apply differently depending on +// the syscall and arguments. +type syscallTracker interface { + // shouldReport returns true is the syscall should be reported. + shouldReport(regs *rpb.AMD64Registers) bool + + // onReported marks the syscall as reported. + onReported(regs *rpb.AMD64Registers) +} + +// onceTracker reports only a single time, used for most syscalls. +type onceTracker struct { + reported bool +} + +func (o *onceTracker) shouldReport(_ *rpb.AMD64Registers) bool { + return !o.reported +} + +func (o *onceTracker) onReported(_ *rpb.AMD64Registers) { + o.reported = true +} diff --git a/runsc/boot/compat_amd64.go b/runsc/boot/compat_amd64.go new file mode 100644 index 000000000..2bb769a49 --- /dev/null +++ b/runsc/boot/compat_amd64.go @@ -0,0 +1,54 @@ +// Copyright 2018 Google LLC +// +// 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 boot + +import ( + "fmt" + + rpb "gvisor.googlesource.com/gvisor/pkg/sentry/arch/registers_go_proto" +) + +// cmdTracker reports only a single time for each different command argument in +// the syscall. It's used for generic syscalls like ioctl to report once per +// 'cmd' +type cmdTracker struct { + // argIdx is the syscall argument index where the command is located. + argIdx int + cmds map[uint32]struct{} +} + +func newCmdTracker(argIdx int) *cmdTracker { + return &cmdTracker{argIdx: argIdx, cmds: make(map[uint32]struct{})} +} + +// cmd returns the command based on the syscall argument index. +func (c *cmdTracker) cmd(regs *rpb.AMD64Registers) uint32 { + switch c.argIdx { + case 0: + return uint32(regs.Rdi) + case 1: + return uint32(regs.Rsi) + } + panic(fmt.Sprintf("unsupported syscall argument index %d", c.argIdx)) +} + +func (c *cmdTracker) shouldReport(regs *rpb.AMD64Registers) bool { + _, ok := c.cmds[c.cmd(regs)] + return !ok +} + +func (c *cmdTracker) onReported(regs *rpb.AMD64Registers) { + c.cmds[c.cmd(regs)] = struct{}{} +} diff --git a/runsc/boot/compat_test.go b/runsc/boot/compat_test.go new file mode 100644 index 000000000..30b94798a --- /dev/null +++ b/runsc/boot/compat_test.go @@ -0,0 +1,66 @@ +// Copyright 2018 Google LLC +// +// 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 boot + +import ( + "testing" + + rpb "gvisor.googlesource.com/gvisor/pkg/sentry/arch/registers_go_proto" +) + +func TestOnceTracker(t *testing.T) { + o := onceTracker{} + if !o.shouldReport(nil) { + t.Error("first call to checkAndMark, got: false, want: true") + } + o.onReported(nil) + for i := 0; i < 2; i++ { + if o.shouldReport(nil) { + t.Error("after first call to checkAndMark, got: true, want: false") + } + } +} + +func TestCmdTracker(t *testing.T) { + for _, tc := range []struct { + name string + idx int + rdi1 uint64 + rdi2 uint64 + rsi1 uint64 + rsi2 uint64 + want bool + }{ + {name: "same rdi", idx: 0, rdi1: 123, rdi2: 123, want: false}, + {name: "same rsi", idx: 1, rsi1: 123, rsi2: 123, want: false}, + {name: "diff rdi", idx: 0, rdi1: 123, rdi2: 321, want: true}, + {name: "diff rsi", idx: 1, rsi1: 123, rsi2: 321, want: true}, + {name: "cmd is uint32", idx: 0, rsi1: 0xdead00000123, rsi2: 0xbeef00000123, want: false}, + } { + t.Run(tc.name, func(t *testing.T) { + c := newCmdTracker(tc.idx) + regs := &rpb.AMD64Registers{Rdi: tc.rdi1, Rsi: tc.rsi1} + if !c.shouldReport(regs) { + t.Error("first call to checkAndMark, got: false, want: true") + } + c.onReported(regs) + + regs.Rdi, regs.Rsi = tc.rdi2, tc.rsi2 + if got := c.shouldReport(regs); tc.want != got { + t.Errorf("after first call to checkAndMark, got: %t, want: %t", got, tc.want) + } + }) + } +} |