59 lines
1.8 KiB
Go
59 lines
1.8 KiB
Go
// Copyright 2018 Google Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// +build i386 amd64
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package arch
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import (
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"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
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)
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const (
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// SignalStackFlagOnStack is possible set on return from getaltstack,
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// in order to indicate that the thread is currently on the alt stack.
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SignalStackFlagOnStack = 1
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// SignalStackFlagDisable is a flag to indicate the stack is disabled.
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SignalStackFlagDisable = 2
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)
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// IsEnabled returns true iff this signal stack is marked as enabled.
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func (s SignalStack) IsEnabled() bool {
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return s.Flags&SignalStackFlagDisable == 0
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}
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// Top returns the stack's top address.
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func (s SignalStack) Top() usermem.Addr {
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return usermem.Addr(s.Addr + s.Size)
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}
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// SetOnStack marks this signal stack as in use. (This is only called on copies
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// sent to user applications, so there's no corresponding ClearOnStack.)
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func (s *SignalStack) SetOnStack() {
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s.Flags |= SignalStackFlagOnStack
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}
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// NativeSignalStack is a type that is equivalent to stack_t in the guest
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// architecture.
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type NativeSignalStack interface {
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// SerializeFrom copies the data in the host SignalStack s into this
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// object.
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SerializeFrom(s *SignalStack)
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// DeserializeTo copies the data in this object into the host SignalStack
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// s.
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DeserializeTo(s *SignalStack)
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}
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