mirror of
https://github.com/netbirdio/gvisor.git
synced 2026-05-22 17:12:49 -07:00
Jamie Liu
a1cb52447f
Checks in Task.block() and Task.Value() are conditional on race detection being enabled, since these functions are relatively hot. Checks in Task.SleepStart() and Task.UninterruptibleSleepStart() are enabled unconditionally, since these functions are not thought to lie on any critical paths, and misuse of these functions is required for b/168241471 to manifest. PiperOrigin-RevId: 342342175
99 lines
2.9 KiB
Go
99 lines
2.9 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 kernel
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import (
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"gvisor.dev/gvisor/pkg/context"
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)
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// contextID is the kernel package's type for context.Context.Value keys.
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type contextID int
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const (
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// CtxCanTrace is a Context.Value key for a function with the same
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// signature and semantics as kernel.Task.CanTrace.
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CtxCanTrace contextID = iota
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// CtxKernel is a Context.Value key for a Kernel.
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CtxKernel
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// CtxPIDNamespace is a Context.Value key for a PIDNamespace.
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CtxPIDNamespace
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// CtxTask is a Context.Value key for a Task.
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CtxTask
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// CtxUTSNamespace is a Context.Value key for a UTSNamespace.
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CtxUTSNamespace
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// CtxIPCNamespace is a Context.Value key for a IPCNamespace.
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CtxIPCNamespace
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)
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// ContextCanTrace returns true if ctx is permitted to trace t, in the same sense
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// as kernel.Task.CanTrace.
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func ContextCanTrace(ctx context.Context, t *Task, attach bool) bool {
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if v := ctx.Value(CtxCanTrace); v != nil {
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return v.(func(*Task, bool) bool)(t, attach)
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}
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return false
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}
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// KernelFromContext returns the Kernel in which ctx is executing, or nil if
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// there is no such Kernel.
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func KernelFromContext(ctx context.Context) *Kernel {
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if v := ctx.Value(CtxKernel); v != nil {
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return v.(*Kernel)
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}
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return nil
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}
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// PIDNamespaceFromContext returns the PID namespace in which ctx is executing,
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// or nil if there is no such PID namespace.
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func PIDNamespaceFromContext(ctx context.Context) *PIDNamespace {
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if v := ctx.Value(CtxPIDNamespace); v != nil {
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return v.(*PIDNamespace)
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}
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return nil
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}
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// UTSNamespaceFromContext returns the UTS namespace in which ctx is executing,
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// or nil if there is no such UTS namespace.
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func UTSNamespaceFromContext(ctx context.Context) *UTSNamespace {
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if v := ctx.Value(CtxUTSNamespace); v != nil {
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return v.(*UTSNamespace)
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}
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return nil
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}
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// IPCNamespaceFromContext returns the IPC namespace in which ctx is executing,
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// or nil if there is no such IPC namespace. It takes a reference on the
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// namespace.
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func IPCNamespaceFromContext(ctx context.Context) *IPCNamespace {
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if v := ctx.Value(CtxIPCNamespace); v != nil {
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return v.(*IPCNamespace)
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}
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return nil
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}
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// TaskFromContext returns the Task associated with ctx, or nil if there is no
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// such Task.
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func TaskFromContext(ctx context.Context) *Task {
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if v := ctx.Value(CtxTask); v != nil {
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return v.(*Task)
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}
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return nil
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}
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