diff options
Diffstat (limited to 'pkg/sentry/platform/ptrace')
| -rw-r--r-- | pkg/sentry/platform/ptrace/BUILD | 3 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/filters.go | 33 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/ptrace.go | 25 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/ptrace_unsafe.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/stub_unsafe.go | 4 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess.go | 50 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_amd64.go | 39 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_linux.go | 15 | ||||
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_linux_amd64_unsafe.go | 2 |
9 files changed, 141 insertions, 34 deletions
diff --git a/pkg/sentry/platform/ptrace/BUILD b/pkg/sentry/platform/ptrace/BUILD index 434d003a3..1b6c54e96 100644 --- a/pkg/sentry/platform/ptrace/BUILD +++ b/pkg/sentry/platform/ptrace/BUILD @@ -5,6 +5,7 @@ package(licenses = ["notice"]) go_library( name = "ptrace", srcs = [ + "filters.go", "ptrace.go", "ptrace_unsafe.go", "stub_amd64.s", @@ -15,7 +16,7 @@ go_library( "subprocess_linux_amd64_unsafe.go", "subprocess_unsafe.go", ], - importpath = "gvisor.googlesource.com/gvisor/pkg/sentry/platform/ptrace", + importpath = "gvisor.dev/gvisor/pkg/sentry/platform/ptrace", visibility = ["//:sandbox"], deps = [ "//pkg/abi/linux", diff --git a/pkg/sentry/platform/ptrace/filters.go b/pkg/sentry/platform/ptrace/filters.go new file mode 100644 index 000000000..1e07cfd0d --- /dev/null +++ b/pkg/sentry/platform/ptrace/filters.go @@ -0,0 +1,33 @@ +// Copyright 2019 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. + +package ptrace + +import ( + "syscall" + + "golang.org/x/sys/unix" + "gvisor.dev/gvisor/pkg/seccomp" +) + +// SyscallFilters returns syscalls made exclusively by the ptrace platform. +func (*PTrace) SyscallFilters() seccomp.SyscallRules { + return seccomp.SyscallRules{ + unix.SYS_GETCPU: {}, + unix.SYS_SCHED_SETAFFINITY: {}, + syscall.SYS_PTRACE: {}, + syscall.SYS_TGKILL: {}, + syscall.SYS_WAIT4: {}, + } +} diff --git a/pkg/sentry/platform/ptrace/ptrace.go b/pkg/sentry/platform/ptrace/ptrace.go index 6a890dd81..6fd30ed25 100644 --- a/pkg/sentry/platform/ptrace/ptrace.go +++ b/pkg/sentry/platform/ptrace/ptrace.go @@ -45,13 +45,14 @@ package ptrace import ( + "os" "sync" - "gvisor.googlesource.com/gvisor/pkg/abi/linux" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform/interrupt" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/platform" + "gvisor.dev/gvisor/pkg/sentry/platform/interrupt" + "gvisor.dev/gvisor/pkg/sentry/usermem" ) var ( @@ -236,3 +237,17 @@ func (p *PTrace) NewAddressSpace(_ interface{}) (platform.AddressSpace, <-chan s func (*PTrace) NewContext() platform.Context { return &context{} } + +type constructor struct{} + +func (*constructor) New(*os.File) (platform.Platform, error) { + return New() +} + +func (*constructor) OpenDevice() (*os.File, error) { + return nil, nil +} + +func init() { + platform.Register("ptrace", &constructor{}) +} diff --git a/pkg/sentry/platform/ptrace/ptrace_unsafe.go b/pkg/sentry/platform/ptrace/ptrace_unsafe.go index 585f6c1fb..2706039a5 100644 --- a/pkg/sentry/platform/ptrace/ptrace_unsafe.go +++ b/pkg/sentry/platform/ptrace/ptrace_unsafe.go @@ -18,8 +18,8 @@ import ( "syscall" "unsafe" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/usermem" ) // GETREGSET/SETREGSET register set types. diff --git a/pkg/sentry/platform/ptrace/stub_unsafe.go b/pkg/sentry/platform/ptrace/stub_unsafe.go index 54d5021a9..aa1b87237 100644 --- a/pkg/sentry/platform/ptrace/stub_unsafe.go +++ b/pkg/sentry/platform/ptrace/stub_unsafe.go @@ -19,8 +19,8 @@ import ( "syscall" "unsafe" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform/safecopy" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/sentry/platform/safecopy" + "gvisor.dev/gvisor/pkg/sentry/usermem" ) // stub is defined in arch-specific assembly. diff --git a/pkg/sentry/platform/ptrace/subprocess.go b/pkg/sentry/platform/ptrace/subprocess.go index d3b196924..15e84735e 100644 --- a/pkg/sentry/platform/ptrace/subprocess.go +++ b/pkg/sentry/platform/ptrace/subprocess.go @@ -21,10 +21,11 @@ import ( "sync" "syscall" - "gvisor.googlesource.com/gvisor/pkg/procid" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" - "gvisor.googlesource.com/gvisor/pkg/sentry/platform" - "gvisor.googlesource.com/gvisor/pkg/sentry/usermem" + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/procid" + "gvisor.dev/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/platform" + "gvisor.dev/gvisor/pkg/sentry/usermem" ) // globalPool exists to solve two distinct problems: @@ -122,7 +123,7 @@ type subprocess struct { contexts map[*context]struct{} } -// newSubprocess returns a useable subprocess. +// newSubprocess returns a usable subprocess. // // This will either be a newly created subprocess, or one from the global pool. // The create function will be called in the latter case, which is guaranteed @@ -154,6 +155,7 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) { errChan <- err return } + firstThread.grabInitRegs() // Ready to handle requests. errChan <- nil @@ -178,6 +180,7 @@ func newSubprocess(create func() (*thread, error)) (*subprocess, error) { // Detach the thread. t.detach() + t.initRegs = firstThread.initRegs // Return the thread. r <- t @@ -252,7 +255,7 @@ func (s *subprocess) newThread() *thread { return t } -// attach attachs to the thread. +// attach attaches to the thread. func (t *thread) attach() { if _, _, errno := syscall.RawSyscall(syscall.SYS_PTRACE, syscall.PTRACE_ATTACH, uintptr(t.tid), 0); errno != 0 { panic(fmt.Sprintf("unable to attach: %v", errno)) @@ -268,7 +271,9 @@ func (t *thread) attach() { // Initialize options. t.init() +} +func (t *thread) grabInitRegs() { // Grab registers. // // Note that we adjust the current register RIP value to be just before @@ -280,9 +285,9 @@ func (t *thread) attach() { t.initRegs.Rip -= initRegsRipAdjustment } -// detach detachs from the thread. +// detach detaches from the thread. // -// Because the SIGSTOP is not supressed, the thread will enter group-stop. +// Because the SIGSTOP is not suppressed, the thread will enter group-stop. func (t *thread) detach() { if _, _, errno := syscall.RawSyscall6(syscall.SYS_PTRACE, syscall.PTRACE_DETACH, uintptr(t.tid), 0, uintptr(syscall.SIGSTOP), 0, 0); errno != 0 { panic(fmt.Sprintf("can't detach new clone: %v", errno)) @@ -300,6 +305,18 @@ const ( killed ) +func (t *thread) dumpAndPanic(message string) { + var regs syscall.PtraceRegs + message += "\n" + if err := t.getRegs(®s); err == nil { + message += dumpRegs(®s) + } else { + log.Warningf("unable to get registers: %v", err) + } + message += fmt.Sprintf("stubStart\t = %016x\n", stubStart) + panic(message) +} + // wait waits for a stop event. // // Precondition: outcome is a valid waitOutcome. @@ -320,7 +337,7 @@ func (t *thread) wait(outcome waitOutcome) syscall.Signal { switch outcome { case stopped: if !status.Stopped() { - panic(fmt.Sprintf("ptrace status unexpected: got %v, wanted stopped", status)) + t.dumpAndPanic(fmt.Sprintf("ptrace status unexpected: got %v, wanted stopped", status)) } stopSig := status.StopSignal() if stopSig == 0 { @@ -334,12 +351,12 @@ func (t *thread) wait(outcome waitOutcome) syscall.Signal { return stopSig case killed: if !status.Exited() && !status.Signaled() { - panic(fmt.Sprintf("ptrace status unexpected: got %v, wanted exited", status)) + t.dumpAndPanic(fmt.Sprintf("ptrace status unexpected: got %v, wanted exited", status)) } return syscall.Signal(status.ExitStatus()) default: // Should not happen. - panic(fmt.Sprintf("unknown outcome: %v", outcome)) + t.dumpAndPanic(fmt.Sprintf("unknown outcome: %v", outcome)) } } } @@ -357,13 +374,16 @@ func (t *thread) destroy() { // init initializes trace options. func (t *thread) init() { - // Set our TRACESYSGOOD option to differeniate real SIGTRAP. + // Set the TRACESYSGOOD option to differentiate real SIGTRAP. + // set PTRACE_O_EXITKILL to ensure that the unexpected exit of the + // sentry will immediately kill the associated stubs. + const PTRACE_O_EXITKILL = 0x100000 _, _, errno := syscall.RawSyscall6( syscall.SYS_PTRACE, syscall.PTRACE_SETOPTIONS, uintptr(t.tid), 0, - syscall.PTRACE_O_TRACESYSGOOD, + syscall.PTRACE_O_TRACESYSGOOD|syscall.PTRACE_O_TRACEEXIT|PTRACE_O_EXITKILL, 0, 0) if errno != 0 { panic(fmt.Sprintf("ptrace set options failed: %v", errno)) @@ -406,7 +426,7 @@ func (t *thread) syscall(regs *syscall.PtraceRegs) (uintptr, error) { // between syscall-enter-stop and syscall-exit-stop; it happens *after* // syscall-exit-stop.)" - ptrace(2), "Syscall-stops" if sig := t.wait(stopped); sig != (syscallEvent | syscall.SIGTRAP) { - panic(fmt.Sprintf("wait failed: expected SIGTRAP, got %v [%d]", sig, sig)) + t.dumpAndPanic(fmt.Sprintf("wait failed: expected SIGTRAP, got %v [%d]", sig, sig)) } // Grab registers. @@ -538,7 +558,7 @@ func (s *subprocess) switchToApp(c *context, ac arch.Context) bool { if c.signalInfo.Code > 0 { // The signal was generated by the kernel. We inspect // the signal information, and may patch it in order to - // faciliate vsyscall emulation. See patchSignalInfo. + // facilitate vsyscall emulation. See patchSignalInfo. patchSignalInfo(regs, &c.signalInfo) return false } else if c.signalInfo.Code <= 0 && c.signalInfo.Pid() == int32(os.Getpid()) { diff --git a/pkg/sentry/platform/ptrace/subprocess_amd64.go b/pkg/sentry/platform/ptrace/subprocess_amd64.go index 77a0e908f..a70512913 100644 --- a/pkg/sentry/platform/ptrace/subprocess_amd64.go +++ b/pkg/sentry/platform/ptrace/subprocess_amd64.go @@ -17,9 +17,11 @@ package ptrace import ( + "fmt" + "strings" "syscall" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/sentry/arch" ) const ( @@ -102,3 +104,38 @@ func syscallReturnValue(regs *syscall.PtraceRegs) (uintptr, error) { } return uintptr(rval), nil } + +func dumpRegs(regs *syscall.PtraceRegs) string { + var m strings.Builder + + fmt.Fprintf(&m, "Registers:\n") + fmt.Fprintf(&m, "\tR15\t = %016x\n", regs.R15) + fmt.Fprintf(&m, "\tR14\t = %016x\n", regs.R14) + fmt.Fprintf(&m, "\tR13\t = %016x\n", regs.R13) + fmt.Fprintf(&m, "\tR12\t = %016x\n", regs.R12) + fmt.Fprintf(&m, "\tRbp\t = %016x\n", regs.Rbp) + fmt.Fprintf(&m, "\tRbx\t = %016x\n", regs.Rbx) + fmt.Fprintf(&m, "\tR11\t = %016x\n", regs.R11) + fmt.Fprintf(&m, "\tR10\t = %016x\n", regs.R10) + fmt.Fprintf(&m, "\tR9\t = %016x\n", regs.R9) + fmt.Fprintf(&m, "\tR8\t = %016x\n", regs.R8) + fmt.Fprintf(&m, "\tRax\t = %016x\n", regs.Rax) + fmt.Fprintf(&m, "\tRcx\t = %016x\n", regs.Rcx) + fmt.Fprintf(&m, "\tRdx\t = %016x\n", regs.Rdx) + fmt.Fprintf(&m, "\tRsi\t = %016x\n", regs.Rsi) + fmt.Fprintf(&m, "\tRdi\t = %016x\n", regs.Rdi) + fmt.Fprintf(&m, "\tOrig_rax = %016x\n", regs.Orig_rax) + fmt.Fprintf(&m, "\tRip\t = %016x\n", regs.Rip) + fmt.Fprintf(&m, "\tCs\t = %016x\n", regs.Cs) + fmt.Fprintf(&m, "\tEflags\t = %016x\n", regs.Eflags) + fmt.Fprintf(&m, "\tRsp\t = %016x\n", regs.Rsp) + fmt.Fprintf(&m, "\tSs\t = %016x\n", regs.Ss) + fmt.Fprintf(&m, "\tFs_base\t = %016x\n", regs.Fs_base) + fmt.Fprintf(&m, "\tGs_base\t = %016x\n", regs.Gs_base) + fmt.Fprintf(&m, "\tDs\t = %016x\n", regs.Ds) + fmt.Fprintf(&m, "\tEs\t = %016x\n", regs.Es) + fmt.Fprintf(&m, "\tFs\t = %016x\n", regs.Fs) + fmt.Fprintf(&m, "\tGs\t = %016x\n", regs.Gs) + + return m.String() +} diff --git a/pkg/sentry/platform/ptrace/subprocess_linux.go b/pkg/sentry/platform/ptrace/subprocess_linux.go index 914be7486..87ded0bbd 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux.go @@ -20,11 +20,11 @@ import ( "fmt" "syscall" - "gvisor.googlesource.com/gvisor/pkg/abi/linux" - "gvisor.googlesource.com/gvisor/pkg/log" - "gvisor.googlesource.com/gvisor/pkg/procid" - "gvisor.googlesource.com/gvisor/pkg/seccomp" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" + "gvisor.dev/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/procid" + "gvisor.dev/gvisor/pkg/seccomp" + "gvisor.dev/gvisor/pkg/sentry/arch" ) const syscallEvent syscall.Signal = 0x80 @@ -235,6 +235,7 @@ func attachedThread(flags uintptr, defaultAction linux.BPFAction) (*thread, erro return nil, fmt.Errorf("wait failed: expected SIGSTOP, got %v", sig) } t.attach() + t.grabInitRegs() return t, nil } @@ -305,7 +306,7 @@ func (s *subprocess) createStub() (*thread, error) { arch.SyscallArgument{Value: 0}, arch.SyscallArgument{Value: 0}) if err != nil { - return nil, err + return nil, fmt.Errorf("creating stub process: %v", err) } // Wait for child to enter group-stop, so we don't stop its @@ -324,7 +325,7 @@ func (s *subprocess) createStub() (*thread, error) { arch.SyscallArgument{Value: 0}, arch.SyscallArgument{Value: 0}) if err != nil { - return nil, err + return nil, fmt.Errorf("waiting on stub process: %v", err) } childT := &thread{ diff --git a/pkg/sentry/platform/ptrace/subprocess_linux_amd64_unsafe.go b/pkg/sentry/platform/ptrace/subprocess_linux_amd64_unsafe.go index 1bf7eab28..e977992f9 100644 --- a/pkg/sentry/platform/ptrace/subprocess_linux_amd64_unsafe.go +++ b/pkg/sentry/platform/ptrace/subprocess_linux_amd64_unsafe.go @@ -23,7 +23,7 @@ import ( "unsafe" "golang.org/x/sys/unix" - "gvisor.googlesource.com/gvisor/pkg/abi/linux" + "gvisor.dev/gvisor/pkg/abi/linux" ) // maskPool contains reusable CPU masks for setting affinity. Unfortunately, |