badd60d3f6
These are currently only used inside this package, so we might as well un-export them until we need them elsewhere. Also updated SetOOMScore() to first check for privileged; check for privileged looks to be the "faster" path, and checking it first could (in case of non- privileged) save having to read and parse /proc/self/uid_map. Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
69 lines
1.8 KiB
Go
69 lines
1.8 KiB
Go
/*
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Copyright The containerd Authors.
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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*/
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package sys
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import (
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"fmt"
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"io/ioutil"
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"os"
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"strconv"
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"strings"
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"github.com/containerd/containerd/pkg/userns"
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"golang.org/x/sys/unix"
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)
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const (
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// OOMScoreMaxKillable is the maximum score keeping the process killable by the oom killer
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OOMScoreMaxKillable = -999
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// OOMScoreAdjMax is from OOM_SCORE_ADJ_MAX https://github.com/torvalds/linux/blob/master/include/uapi/linux/oom.h
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OOMScoreAdjMax = 1000
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)
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// SetOOMScore sets the oom score for the provided pid
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func SetOOMScore(pid, score int) error {
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path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
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f, err := os.OpenFile(path, os.O_WRONLY, 0)
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if err != nil {
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return err
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}
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defer f.Close()
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if _, err = f.WriteString(strconv.Itoa(score)); err != nil {
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if os.IsPermission(err) && (!runningPrivileged() || userns.RunningInUserNS()) {
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return nil
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}
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return err
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}
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return nil
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}
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// GetOOMScoreAdj gets the oom score for a process
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func GetOOMScoreAdj(pid int) (int, error) {
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path := fmt.Sprintf("/proc/%d/oom_score_adj", pid)
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data, err := ioutil.ReadFile(path)
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if err != nil {
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return 0, err
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}
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return strconv.Atoi(strings.TrimSpace(string(data)))
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}
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// runningPrivileged returns true if the effective user ID of the
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// calling process is 0
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func runningPrivileged() bool {
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return unix.Geteuid() == 0
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}
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