diff options
| -rw-r--r-- | pkg/atomicbitops/aligned_32bit_unsafe.go | 86 | ||||
| -rw-r--r-- | pkg/atomicbitops/aligned_64bit.go | 67 | ||||
| -rw-r--r-- | pkg/tcpip/socketops.go | 9 | ||||
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 5 | ||||
| -rw-r--r-- | pkg/tcpip/tcpip.go | 8 |
5 files changed, 165 insertions, 10 deletions
diff --git a/pkg/atomicbitops/aligned_32bit_unsafe.go b/pkg/atomicbitops/aligned_32bit_unsafe.go new file mode 100644 index 000000000..a5c762f67 --- /dev/null +++ b/pkg/atomicbitops/aligned_32bit_unsafe.go @@ -0,0 +1,86 @@ +// Copyright 2021 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 arm 386 + +package atomicbitops + +import ( + "sync/atomic" + "unsafe" +) + +// AlignedAtomicInt64 is an atomic int64 that is guaranteed to be 64-bit +// aligned, even on 32-bit systems. +// +// Per https://golang.org/pkg/sync/atomic/#pkg-note-BUG: +// +// "On ARM, 386, and 32-bit MIPS, it is the caller's responsibility to arrange +// for 64-bit alignment of 64-bit words accessed atomically. The first word in +// a variable or in an allocated struct, array, or slice can be relied upon to +// be 64-bit aligned." +type AlignedAtomicInt64 struct { + value [15]byte +} + +func (aa *AlignedAtomicInt64) ptr() *int64 { + return (*int64)(unsafe.Pointer((uintptr(unsafe.Pointer(&aa.value)) + 7) &^ 7)) +} + +// Load is analagous to atomic.LoadInt64. +func (aa *AlignedAtomicInt64) Load() int64 { + return atomic.LoadInt64(aa.ptr()) +} + +// Store is analagous to atomic.StoreInt64. +func (aa *AlignedAtomicInt64) Store(v int64) { + atomic.StoreInt64(aa.ptr(), v) +} + +// Add is analagous to atomic.AddInt64. +func (aa *AlignedAtomicInt64) Add(v int64) int64 { + return atomic.AddInt64(aa.ptr(), v) +} + +// AlignedAtomicUint64 is an atomic uint64 that is guaranteed to be 64-bit +// aligned, even on 32-bit systems. +// +// Per https://golang.org/pkg/sync/atomic/#pkg-note-BUG: +// +// "On ARM, 386, and 32-bit MIPS, it is the caller's responsibility to arrange +// for 64-bit alignment of 64-bit words accessed atomically. The first word in +// a variable or in an allocated struct, array, or slice can be relied upon to +// be 64-bit aligned." +type AlignedAtomicUint64 struct { + value [15]byte +} + +func (aa *AlignedAtomicUint64) ptr() *uint64 { + return (*uint64)(unsafe.Pointer((uintptr(unsafe.Pointer(&aa.value)) + 7) &^ 7)) +} + +// Load is analagous to atomic.LoadUint64. +func (aa *AlignedAtomicUint64) Load() uint64 { + return atomic.LoadUint64(aa.ptr()) +} + +// Store is analagous to atomic.StoreUint64. +func (aa *AlignedAtomicUint64) Store(v uint64) { + atomic.StoreUint64(aa.ptr(), v) +} + +// Add is analagous to atomic.AddUint64. +func (aa *AlignedAtomicUint64) Add(v uint64) uint64 { + return atomic.AddUint64(aa.ptr(), v) +} diff --git a/pkg/atomicbitops/aligned_64bit.go b/pkg/atomicbitops/aligned_64bit.go new file mode 100644 index 000000000..5898653d8 --- /dev/null +++ b/pkg/atomicbitops/aligned_64bit.go @@ -0,0 +1,67 @@ +// Copyright 2021 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 !arm,!386 + +package atomicbitops + +import "sync/atomic" + +// AlignedAtomicInt64 is an atomic int64 that is guaranteed to be 64-bit +// aligned, even on 32-bit systems. On 64-bit machines, it's just a regular +// int64. +// +// See aligned_unsafe.go in this directory for justification. +type AlignedAtomicInt64 struct { + value int64 +} + +// Load is analagous to atomic.LoadInt64. +func (aa *AlignedAtomicInt64) Load() int64 { + return atomic.LoadInt64(&aa.value) +} + +// Store is analagous to atomic.StoreInt64. +func (aa *AlignedAtomicInt64) Store(v int64) { + atomic.StoreInt64(&aa.value, v) +} + +// Add is analagous to atomic.AddInt64. +func (aa *AlignedAtomicInt64) Add(v int64) int64 { + return atomic.AddInt64(&aa.value, v) +} + +// AlignedAtomicUint64 is an atomic uint64 that is guaranteed to be 64-bit +// aligned, even on 32-bit systems. On 64-bit machines, it's just a regular +// uint64. +// +// See aligned_unsafe.go in this directory for justification. +type AlignedAtomicUint64 struct { + value uint64 +} + +// Load is analagous to atomic.LoadUint64. +func (aa *AlignedAtomicUint64) Load() uint64 { + return atomic.LoadUint64(&aa.value) +} + +// Store is analagous to atomic.StoreUint64. +func (aa *AlignedAtomicUint64) Store(v uint64) { + atomic.StoreUint64(&aa.value, v) +} + +// Add is analagous to atomic.AddUint64. +func (aa *AlignedAtomicUint64) Add(v uint64) uint64 { + return atomic.AddUint64(&aa.value, v) +} diff --git a/pkg/tcpip/socketops.go b/pkg/tcpip/socketops.go index dc37e61a4..5f8f2abe1 100644 --- a/pkg/tcpip/socketops.go +++ b/pkg/tcpip/socketops.go @@ -18,6 +18,7 @@ import ( "math" "sync/atomic" + "gvisor.dev/gvisor/pkg/atomicbitops" "gvisor.dev/gvisor/pkg/sync" ) @@ -205,7 +206,7 @@ type SocketOptions struct { getSendBufferLimits GetSendBufferLimits `state:"manual"` // sendBufferSize determines the send buffer size for this socket. - sendBufferSize int64 + sendBufferSize atomicbitops.AlignedAtomicInt64 // mu protects the access to the below fields. mu sync.Mutex `state:"nosave"` @@ -595,7 +596,7 @@ func (so *SocketOptions) SetBindToDevice(bindToDevice int32) Error { // GetSendBufferSize gets value for SO_SNDBUF option. func (so *SocketOptions) GetSendBufferSize() int64 { - return atomic.LoadInt64(&so.sendBufferSize) + return so.sendBufferSize.Load() } // SetSendBufferSize sets value for SO_SNDBUF option. notify indicates if the @@ -604,7 +605,7 @@ func (so *SocketOptions) SetSendBufferSize(sendBufferSize int64, notify bool) { v := sendBufferSize if !notify { - atomic.StoreInt64(&so.sendBufferSize, v) + so.sendBufferSize.Store(v) return } @@ -630,5 +631,5 @@ func (so *SocketOptions) SetSendBufferSize(sendBufferSize int64, notify bool) { // Notify endpoint about change in buffer size. newSz := so.handler.OnSetSendBufferSize(v) - atomic.StoreInt64(&so.sendBufferSize, newSz) + so.sendBufferSize.Store(newSz) } diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 931a97ddc..fd806f46e 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -29,6 +29,7 @@ import ( "time" "golang.org/x/time/rate" + "gvisor.dev/gvisor/pkg/atomicbitops" "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/tcpip" @@ -366,10 +367,10 @@ type ResumableEndpoint interface { } // uniqueIDGenerator is a default unique ID generator. -type uniqueIDGenerator uint64 +type uniqueIDGenerator atomicbitops.AlignedAtomicUint64 func (u *uniqueIDGenerator) UniqueID() uint64 { - return atomic.AddUint64((*uint64)(u), 1) + return ((*atomicbitops.AlignedAtomicUint64)(u)).Add(1) } // Stack is a networking stack, with all supported protocols, NICs, and route diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 87ea09a5e..9f15eb0d9 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -37,9 +37,9 @@ import ( "reflect" "strconv" "strings" - "sync/atomic" "time" + "gvisor.dev/gvisor/pkg/atomicbitops" "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/waiter" ) @@ -1204,7 +1204,7 @@ type NetworkProtocolNumber uint32 // A StatCounter keeps track of a statistic. type StatCounter struct { - count uint64 + count atomicbitops.AlignedAtomicUint64 } // Increment adds one to the counter. @@ -1219,12 +1219,12 @@ func (s *StatCounter) Decrement() { // Value returns the current value of the counter. func (s *StatCounter) Value() uint64 { - return atomic.LoadUint64(&s.count) + return s.count.Load() } // IncrementBy increments the counter by v. func (s *StatCounter) IncrementBy(v uint64) { - atomic.AddUint64(&s.count, v) + s.count.Add(v) } func (s *StatCounter) String() string { |