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https://github.com/netbirdio/gvisor.git
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Dean Deng
8fed97794e
Like task_work in Linux, this allows us to register callbacks to be executed before returning to userspace. This is needed for kcov support, which requires coverage information to be up-to-date whenever we are in user mode. We will provide coverage data through the kcov interface to enable coverage-directed fuzzing in syzkaller. One difference from Linux is that task work cannot queue work before the transition to userspace that it precedes; queued work will be picked up before the next transition. PiperOrigin-RevId: 322889984
39 lines
1.4 KiB
Go
39 lines
1.4 KiB
Go
// Copyright 2020 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 "sync/atomic"
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// TaskWorker is a deferred task.
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//
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// This must be savable.
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type TaskWorker interface {
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// TaskWork will be executed prior to returning to user space. Note that
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// TaskWork may call RegisterWork again, but this will not be executed until
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// the next return to user space, unlike in Linux. This effectively allows
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// registration of indefinite user return hooks, but not by default.
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TaskWork(t *Task)
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}
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// RegisterWork can be used to register additional task work that will be
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// performed prior to returning to user space. See TaskWorker.TaskWork for
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// semantics regarding registration.
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func (t *Task) RegisterWork(work TaskWorker) {
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t.taskWorkMu.Lock()
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defer t.taskWorkMu.Unlock()
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atomic.AddInt32(&t.taskWorkCount, 1)
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t.taskWork = append(t.taskWork, work)
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}
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