diff options
author | gVisor bot <gvisor-bot@google.com> | 2020-10-02 19:27:31 +0000 |
---|---|---|
committer | gVisor bot <gvisor-bot@google.com> | 2020-10-02 19:27:31 +0000 |
commit | a0b63cf9de4a2ccac12b5697e7e0f749656da396 (patch) | |
tree | ec187a7c2bbb4b2ea1bb2de67e0ed6d26ed62722 | |
parent | a0712b6e67d589768f80acbef2776b06962ade27 (diff) | |
parent | 4f462b0ed9912fa19b3a3eab6d2f08a98d364574 (diff) |
Merge release-20200921.0-102-g4f462b0ed (automated)
-rw-r--r-- | pkg/abi/linux/linux_abi_autogen_unsafe.go | 248 | ||||
-rw-r--r-- | pkg/abi/linux/seccomp.go | 19 | ||||
-rw-r--r-- | pkg/abi/linux/signalfd.go | 4 | ||||
-rw-r--r-- | pkg/sentry/fsimpl/signalfd/signalfd.go | 14 | ||||
-rw-r--r-- | pkg/sentry/kernel/kernel_abi_autogen_unsafe.go | 118 | ||||
-rw-r--r-- | pkg/sentry/kernel/kernel_state_autogen.go | 3 | ||||
-rw-r--r-- | pkg/sentry/kernel/seccomp.go | 46 | ||||
-rw-r--r-- | pkg/sentry/kernel/signalfd/signalfd.go | 14 | ||||
-rw-r--r-- | pkg/sentry/kernel/vdso.go | 19 |
9 files changed, 442 insertions, 43 deletions
diff --git a/pkg/abi/linux/linux_abi_autogen_unsafe.go b/pkg/abi/linux/linux_abi_autogen_unsafe.go index b6f87d678..b6b61a128 100644 --- a/pkg/abi/linux/linux_abi_autogen_unsafe.go +++ b/pkg/abi/linux/linux_abi_autogen_unsafe.go @@ -66,6 +66,7 @@ var _ marshal.Marshallable = (*PollFD)(nil) var _ marshal.Marshallable = (*RSeqCriticalSection)(nil) var _ marshal.Marshallable = (*RobustListHead)(nil) var _ marshal.Marshallable = (*Rusage)(nil) +var _ marshal.Marshallable = (*SeccompData)(nil) var _ marshal.Marshallable = (*Sembuf)(nil) var _ marshal.Marshallable = (*SemidDS)(nil) var _ marshal.Marshallable = (*ShmInfo)(nil) @@ -73,6 +74,7 @@ var _ marshal.Marshallable = (*ShmParams)(nil) var _ marshal.Marshallable = (*ShmidDS)(nil) var _ marshal.Marshallable = (*Sigevent)(nil) var _ marshal.Marshallable = (*SignalSet)(nil) +var _ marshal.Marshallable = (*SignalfdSiginfo)(nil) var _ marshal.Marshallable = (*SockAddrInet)(nil) var _ marshal.Marshallable = (*SockAddrInet6)(nil) var _ marshal.Marshallable = (*SockAddrLink)(nil) @@ -6592,6 +6594,112 @@ func (r *Rusage) WriteTo(writer io.Writer) (int64, error) { } // SizeBytes implements marshal.Marshallable.SizeBytes. +func (s *SeccompData) SizeBytes() int { + return 16 + + 8*6 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (s *SeccompData) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Nr)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Arch)) + dst = dst[4:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.InstructionPointer)) + dst = dst[8:] + for idx := 0; idx < 6; idx++ { + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Args[idx])) + dst = dst[8:] + } +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (s *SeccompData) UnmarshalBytes(src []byte) { + s.Nr = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Arch = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.InstructionPointer = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + for idx := 0; idx < 6; idx++ { + s.Args[idx] = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + } +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (s *SeccompData) Packed() bool { + return true +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (s *SeccompData) MarshalUnsafe(dst []byte) { + safecopy.CopyIn(dst, unsafe.Pointer(s)) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (s *SeccompData) UnmarshalUnsafe(src []byte) { + safecopy.CopyOut(unsafe.Pointer(s), src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (s *SeccompData) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) // escapes: replaced by intrinsic. + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (s *SeccompData) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + return s.CopyOutN(cc, addr, s.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (s *SeccompData) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := cc.CopyInBytes(addr, buf) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) // escapes: replaced by intrinsic. + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (s *SeccompData) WriteTo(writer io.Writer) (int64, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(s))) + hdr.Len = s.SizeBytes() + hdr.Cap = s.SizeBytes() + + length, err := writer.Write(buf) + // Since we bypassed the compiler's escape analysis, indicate that s + // must live until the use above. + runtime.KeepAlive(s) // escapes: replaced by intrinsic. + return int64(length), err +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. func (s *SemidDS) SizeBytes() int { return 24 + (*IPCPerm)(nil).SizeBytes() + @@ -7504,6 +7612,146 @@ func (s *Sigevent) WriteTo(writer io.Writer) (int64, error) { } // SizeBytes implements marshal.Marshallable.SizeBytes. +func (s *SignalfdSiginfo) SizeBytes() int { + return 82 + + 1*48 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (s *SignalfdSiginfo) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Signo)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Errno)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Code)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.PID)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.UID)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.FD)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.TID)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Band)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Overrun)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.TrapNo)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Status)) + dst = dst[4:] + usermem.ByteOrder.PutUint32(dst[:4], uint32(s.Int)) + dst = dst[4:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Ptr)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.UTime)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.STime)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(s.Addr)) + dst = dst[8:] + usermem.ByteOrder.PutUint16(dst[:2], uint16(s.AddrLSB)) + dst = dst[2:] + // Padding: dst[:sizeof(uint8)*48] ~= [48]uint8{0} + dst = dst[1*(48):] +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (s *SignalfdSiginfo) UnmarshalBytes(src []byte) { + s.Signo = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Errno = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Code = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.PID = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.UID = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.FD = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.TID = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Band = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Overrun = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.TrapNo = uint32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Status = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Int = int32(usermem.ByteOrder.Uint32(src[:4])) + src = src[4:] + s.Ptr = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + s.UTime = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + s.STime = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + s.Addr = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + s.AddrLSB = uint16(usermem.ByteOrder.Uint16(src[:2])) + src = src[2:] + // Padding: ~ copy([48]uint8(s._), src[:sizeof(uint8)*48]) + src = src[1*(48):] +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (s *SignalfdSiginfo) Packed() bool { + return false +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (s *SignalfdSiginfo) MarshalUnsafe(dst []byte) { + // Type SignalfdSiginfo doesn't have a packed layout in memory, fallback to MarshalBytes. + s.MarshalBytes(dst) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (s *SignalfdSiginfo) UnmarshalUnsafe(src []byte) { + // Type SignalfdSiginfo doesn't have a packed layout in memory, fallback to UnmarshalBytes. + s.UnmarshalBytes(src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (s *SignalfdSiginfo) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) { + // Type SignalfdSiginfo doesn't have a packed layout in memory, fall back to MarshalBytes. + buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. + s.MarshalBytes(buf) // escapes: fallback. + return cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay. +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (s *SignalfdSiginfo) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + return s.CopyOutN(cc, addr, s.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (s *SignalfdSiginfo) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + // Type SignalfdSiginfo doesn't have a packed layout in memory, fall back to UnmarshalBytes. + buf := cc.CopyScratchBuffer(s.SizeBytes()) // escapes: okay. + length, err := cc.CopyInBytes(addr, buf) // escapes: okay. + // Unmarshal unconditionally. If we had a short copy-in, this results in a + // partially unmarshalled struct. + s.UnmarshalBytes(buf) // escapes: fallback. + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (s *SignalfdSiginfo) WriteTo(writer io.Writer) (int64, error) { + // Type SignalfdSiginfo doesn't have a packed layout in memory, fall back to MarshalBytes. + buf := make([]byte, s.SizeBytes()) + s.MarshalBytes(buf) + length, err := writer.Write(buf) + return int64(length), err +} + +// SizeBytes implements marshal.Marshallable.SizeBytes. //go:nosplit func (i *InetAddr) SizeBytes() int { return 1 * 4 diff --git a/pkg/abi/linux/seccomp.go b/pkg/abi/linux/seccomp.go index b07cafe12..5be3f10f9 100644 --- a/pkg/abi/linux/seccomp.go +++ b/pkg/abi/linux/seccomp.go @@ -83,3 +83,22 @@ type SockFprog struct { pad [6]byte Filter *BPFInstruction } + +// SeccompData is equivalent to struct seccomp_data, which contains the data +// passed to seccomp-bpf filters. +// +// +marshal +type SeccompData struct { + // Nr is the system call number. + Nr int32 + + // Arch is an AUDIT_ARCH_* value indicating the system call convention. + Arch uint32 + + // InstructionPointer is the value of the instruction pointer at the time + // of the system call. + InstructionPointer uint64 + + // Args contains the first 6 system call arguments. + Args [6]uint64 +} diff --git a/pkg/abi/linux/signalfd.go b/pkg/abi/linux/signalfd.go index 85fad9956..468c6a387 100644 --- a/pkg/abi/linux/signalfd.go +++ b/pkg/abi/linux/signalfd.go @@ -23,6 +23,8 @@ const ( ) // SignalfdSiginfo is the siginfo encoding for signalfds. +// +// +marshal type SignalfdSiginfo struct { Signo uint32 Errno int32 @@ -41,5 +43,5 @@ type SignalfdSiginfo struct { STime uint64 Addr uint64 AddrLSB uint16 - _ [48]uint8 + _ [48]uint8 `marshal:"unaligned"` } diff --git a/pkg/sentry/fsimpl/signalfd/signalfd.go b/pkg/sentry/fsimpl/signalfd/signalfd.go index bf11b425a..10f1452ef 100644 --- a/pkg/sentry/fsimpl/signalfd/signalfd.go +++ b/pkg/sentry/fsimpl/signalfd/signalfd.go @@ -16,7 +16,6 @@ package signalfd import ( "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/kernel" "gvisor.dev/gvisor/pkg/sentry/vfs" @@ -95,8 +94,7 @@ func (sfd *SignalFileDescription) Read(ctx context.Context, dst usermem.IOSequen } // Copy out the signal info using the specified format. - var buf [128]byte - binary.Marshal(buf[:0], usermem.ByteOrder, &linux.SignalfdSiginfo{ + infoNative := linux.SignalfdSiginfo{ Signo: uint32(info.Signo), Errno: info.Errno, Code: info.Code, @@ -105,9 +103,13 @@ func (sfd *SignalFileDescription) Read(ctx context.Context, dst usermem.IOSequen Status: info.Status(), Overrun: uint32(info.Overrun()), Addr: info.Addr(), - }) - n, err := dst.CopyOut(ctx, buf[:]) - return int64(n), err + } + n, err := infoNative.WriteTo(dst.Writer(ctx)) + if err == usermem.ErrEndOfIOSequence { + // Partial copy-out ok. + err = nil + } + return n, err } // Readiness implements waiter.Waitable.Readiness. diff --git a/pkg/sentry/kernel/kernel_abi_autogen_unsafe.go b/pkg/sentry/kernel/kernel_abi_autogen_unsafe.go index eaa2ebdb3..9ac2a552a 100644 --- a/pkg/sentry/kernel/kernel_abi_autogen_unsafe.go +++ b/pkg/sentry/kernel/kernel_abi_autogen_unsafe.go @@ -15,6 +15,7 @@ import ( // Marshallable types used by this file. var _ marshal.Marshallable = (*ThreadID)(nil) +var _ marshal.Marshallable = (*vdsoParams)(nil) // SizeBytes implements marshal.Marshallable.SizeBytes. //go:nosplit @@ -105,3 +106,120 @@ func (t *ThreadID) WriteTo(w io.Writer) (int64, error) { return int64(length), err } +// SizeBytes implements marshal.Marshallable.SizeBytes. +func (v *vdsoParams) SizeBytes() int { + return 64 +} + +// MarshalBytes implements marshal.Marshallable.MarshalBytes. +func (v *vdsoParams) MarshalBytes(dst []byte) { + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.monotonicReady)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.monotonicBaseCycles)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.monotonicBaseRef)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.monotonicFrequency)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.realtimeReady)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.realtimeBaseCycles)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.realtimeBaseRef)) + dst = dst[8:] + usermem.ByteOrder.PutUint64(dst[:8], uint64(v.realtimeFrequency)) + dst = dst[8:] +} + +// UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes. +func (v *vdsoParams) UnmarshalBytes(src []byte) { + v.monotonicReady = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.monotonicBaseCycles = int64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.monotonicBaseRef = int64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.monotonicFrequency = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.realtimeReady = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.realtimeBaseCycles = int64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.realtimeBaseRef = int64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] + v.realtimeFrequency = uint64(usermem.ByteOrder.Uint64(src[:8])) + src = src[8:] +} + +// Packed implements marshal.Marshallable.Packed. +//go:nosplit +func (v *vdsoParams) Packed() bool { + return true +} + +// MarshalUnsafe implements marshal.Marshallable.MarshalUnsafe. +func (v *vdsoParams) MarshalUnsafe(dst []byte) { + safecopy.CopyIn(dst, unsafe.Pointer(v)) +} + +// UnmarshalUnsafe implements marshal.Marshallable.UnmarshalUnsafe. +func (v *vdsoParams) UnmarshalUnsafe(src []byte) { + safecopy.CopyOut(unsafe.Pointer(v), src) +} + +// CopyOutN implements marshal.Marshallable.CopyOutN. +//go:nosplit +func (v *vdsoParams) CopyOutN(cc marshal.CopyContext, addr usermem.Addr, limit int) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(v))) + hdr.Len = v.SizeBytes() + hdr.Cap = v.SizeBytes() + + length, err := cc.CopyOutBytes(addr, buf[:limit]) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that v + // must live until the use above. + runtime.KeepAlive(v) // escapes: replaced by intrinsic. + return length, err +} + +// CopyOut implements marshal.Marshallable.CopyOut. +//go:nosplit +func (v *vdsoParams) CopyOut(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + return v.CopyOutN(cc, addr, v.SizeBytes()) +} + +// CopyIn implements marshal.Marshallable.CopyIn. +//go:nosplit +func (v *vdsoParams) CopyIn(cc marshal.CopyContext, addr usermem.Addr) (int, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(v))) + hdr.Len = v.SizeBytes() + hdr.Cap = v.SizeBytes() + + length, err := cc.CopyInBytes(addr, buf) // escapes: okay. + // Since we bypassed the compiler's escape analysis, indicate that v + // must live until the use above. + runtime.KeepAlive(v) // escapes: replaced by intrinsic. + return length, err +} + +// WriteTo implements io.WriterTo.WriteTo. +func (v *vdsoParams) WriteTo(writer io.Writer) (int64, error) { + // Construct a slice backed by dst's underlying memory. + var buf []byte + hdr := (*reflect.SliceHeader)(unsafe.Pointer(&buf)) + hdr.Data = uintptr(gohacks.Noescape(unsafe.Pointer(v))) + hdr.Len = v.SizeBytes() + hdr.Cap = v.SizeBytes() + + length, err := writer.Write(buf) + // Since we bypassed the compiler's escape analysis, indicate that v + // must live until the use above. + runtime.KeepAlive(v) // escapes: replaced by intrinsic. + return int64(length), err +} + diff --git a/pkg/sentry/kernel/kernel_state_autogen.go b/pkg/sentry/kernel/kernel_state_autogen.go index f20800960..7ff5e1eb9 100644 --- a/pkg/sentry/kernel/kernel_state_autogen.go +++ b/pkg/sentry/kernel/kernel_state_autogen.go @@ -2259,6 +2259,7 @@ func (x *VDSOParamPage) StateFields() []string { "mfp", "fr", "seq", + "copyScratchBuffer", } } @@ -2269,6 +2270,7 @@ func (x *VDSOParamPage) StateSave(m state.Sink) { m.Save(0, &x.mfp) m.Save(1, &x.fr) m.Save(2, &x.seq) + m.Save(3, &x.copyScratchBuffer) } func (x *VDSOParamPage) afterLoad() {} @@ -2277,6 +2279,7 @@ func (x *VDSOParamPage) StateLoad(m state.Source) { m.Load(0, &x.mfp) m.Load(1, &x.fr) m.Load(2, &x.seq) + m.Load(3, &x.copyScratchBuffer) } func init() { diff --git a/pkg/sentry/kernel/seccomp.go b/pkg/sentry/kernel/seccomp.go index c38c5a40c..387edfa91 100644 --- a/pkg/sentry/kernel/seccomp.go +++ b/pkg/sentry/kernel/seccomp.go @@ -18,7 +18,6 @@ import ( "syscall" "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/bpf" "gvisor.dev/gvisor/pkg/sentry/arch" "gvisor.dev/gvisor/pkg/syserror" @@ -27,25 +26,18 @@ import ( const maxSyscallFilterInstructions = 1 << 15 -// seccompData is equivalent to struct seccomp_data, which contains the data -// passed to seccomp-bpf filters. -type seccompData struct { - // nr is the system call number. - nr int32 - - // arch is an AUDIT_ARCH_* value indicating the system call convention. - arch uint32 - - // instructionPointer is the value of the instruction pointer at the time - // of the system call. - instructionPointer uint64 - - // args contains the first 6 system call arguments. - args [6]uint64 -} - -func (d *seccompData) asBPFInput() bpf.Input { - return bpf.InputBytes{binary.Marshal(nil, usermem.ByteOrder, d), usermem.ByteOrder} +// dataAsBPFInput returns a serialized BPF program, only valid on the current task +// goroutine. +// +// Note: this is called for every syscall, which is a very hot path. +func dataAsBPFInput(t *Task, d *linux.SeccompData) bpf.Input { + buf := t.CopyScratchBuffer(d.SizeBytes()) + d.MarshalUnsafe(buf) + return bpf.InputBytes{ + Data: buf, + // Go-marshal always uses the native byte order. + Order: usermem.ByteOrder, + } } func seccompSiginfo(t *Task, errno, sysno int32, ip usermem.Addr) *arch.SignalInfo { @@ -112,20 +104,20 @@ func (t *Task) checkSeccompSyscall(sysno int32, args arch.SyscallArguments, ip u } func (t *Task) evaluateSyscallFilters(sysno int32, args arch.SyscallArguments, ip usermem.Addr) uint32 { - data := seccompData{ - nr: sysno, - arch: t.tc.st.AuditNumber, - instructionPointer: uint64(ip), + data := linux.SeccompData{ + Nr: sysno, + Arch: t.tc.st.AuditNumber, + InstructionPointer: uint64(ip), } // data.args is []uint64 and args is []arch.SyscallArgument (uintptr), so // we can't do any slicing tricks or even use copy/append here. for i, arg := range args { - if i >= len(data.args) { + if i >= len(data.Args) { break } - data.args[i] = arg.Uint64() + data.Args[i] = arg.Uint64() } - input := data.asBPFInput() + input := dataAsBPFInput(t, &data) ret := uint32(linux.SECCOMP_RET_ALLOW) f := t.syscallFilters.Load() diff --git a/pkg/sentry/kernel/signalfd/signalfd.go b/pkg/sentry/kernel/signalfd/signalfd.go index b07e1c1bd..78f718cfe 100644 --- a/pkg/sentry/kernel/signalfd/signalfd.go +++ b/pkg/sentry/kernel/signalfd/signalfd.go @@ -17,7 +17,6 @@ package signalfd import ( "gvisor.dev/gvisor/pkg/abi/linux" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/context" "gvisor.dev/gvisor/pkg/sentry/fs" "gvisor.dev/gvisor/pkg/sentry/fs/anon" @@ -103,8 +102,7 @@ func (s *SignalOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS } // Copy out the signal info using the specified format. - var buf [128]byte - binary.Marshal(buf[:0], usermem.ByteOrder, &linux.SignalfdSiginfo{ + infoNative := linux.SignalfdSiginfo{ Signo: uint32(info.Signo), Errno: info.Errno, Code: info.Code, @@ -113,9 +111,13 @@ func (s *SignalOperations) Read(ctx context.Context, _ *fs.File, dst usermem.IOS Status: info.Status(), Overrun: uint32(info.Overrun()), Addr: info.Addr(), - }) - n, err := dst.CopyOut(ctx, buf[:]) - return int64(n), err + } + n, err := infoNative.WriteTo(dst.Writer(ctx)) + if err == usermem.ErrEndOfIOSequence { + // Partial copy-out ok. + err = nil + } + return n, err } // Readiness implements waiter.Waitable.Readiness. diff --git a/pkg/sentry/kernel/vdso.go b/pkg/sentry/kernel/vdso.go index e44a139b3..9bc452e67 100644 --- a/pkg/sentry/kernel/vdso.go +++ b/pkg/sentry/kernel/vdso.go @@ -17,7 +17,6 @@ package kernel import ( "fmt" - "gvisor.dev/gvisor/pkg/binary" "gvisor.dev/gvisor/pkg/safemem" "gvisor.dev/gvisor/pkg/sentry/memmap" "gvisor.dev/gvisor/pkg/sentry/pgalloc" @@ -28,6 +27,8 @@ import ( // // They are exposed to the VDSO via a parameter page managed by VDSOParamPage, // which also includes a sequence counter. +// +// +marshal type vdsoParams struct { monotonicReady uint64 monotonicBaseCycles int64 @@ -68,6 +69,13 @@ type VDSOParamPage struct { // checked in state_test_util tests, causing this field to change across // save / restore. seq uint64 + + // copyScratchBuffer is a temporary buffer used to marshal the params before + // copying it to the real parameter page. The parameter page is typically + // updated at a moderate frequency of ~O(seconds) throughout the lifetime of + // the sentry, so reusing this buffer is a good tradeoff between memory + // usage and the cost of allocation. + copyScratchBuffer []byte } // NewVDSOParamPage returns a VDSOParamPage. @@ -79,7 +87,11 @@ type VDSOParamPage struct { // * VDSOParamPage must be the only writer to fr. // * mfp.MemoryFile().MapInternal(fr) must return a single safemem.Block. func NewVDSOParamPage(mfp pgalloc.MemoryFileProvider, fr memmap.FileRange) *VDSOParamPage { - return &VDSOParamPage{mfp: mfp, fr: fr} + return &VDSOParamPage{ + mfp: mfp, + fr: fr, + copyScratchBuffer: make([]byte, (*vdsoParams)(nil).SizeBytes()), + } } // access returns a mapping of the param page. @@ -133,7 +145,8 @@ func (v *VDSOParamPage) Write(f func() vdsoParams) error { // Get the new params. p := f() - buf := binary.Marshal(nil, usermem.ByteOrder, p) + buf := v.copyScratchBuffer[:p.SizeBytes()] + p.MarshalUnsafe(buf) // Skip the sequence counter. if _, err := safemem.Copy(paramPage.DropFirst(8), safemem.BlockFromSafeSlice(buf)); err != nil { |