46 lines
1.2 KiB
Go
46 lines
1.2 KiB
Go
// Copyright 2018 The gVisor Authors.
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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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package pagetables
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// Address constraints.
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//
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// The lowerTop and upperBottom currently apply to four-level pagetables;
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// additional refactoring would be necessary to support five-level pagetables.
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const (
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lowerTop = 0x00007fffffffffff
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upperBottom = 0xffff800000000000
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pteShift = 12
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pmdShift = 21
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pudShift = 30
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pgdShift = 39
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pteMask = 0x1ff << pteShift
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pmdMask = 0x1ff << pmdShift
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pudMask = 0x1ff << pudShift
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pgdMask = 0x1ff << pgdShift
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pteSize = 1 << pteShift
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pmdSize = 1 << pmdShift
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pudSize = 1 << pudShift
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pgdSize = 1 << pgdShift
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executeDisable = 1 << 63
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entriesPerPage = 512
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)
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// PTEs is a collection of entries.
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type PTEs [entriesPerPage]PTE
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