From b21b1db7003aea8615ab9e6a4f07b74c97a32c24 Mon Sep 17 00:00:00 2001 From: Fabricio Voznika Date: Mon, 24 Jun 2019 15:01:58 -0700 Subject: Allow to change logging options using 'runsc debug' New options are: runsc debug --strace=off|all|function1,function2 runsc debug --log-level=warning|info|debug runsc debug --log-packets=true|false Updates #407 PiperOrigin-RevId: 254843128 --- pkg/log/log.go | 13 ++++ pkg/sentry/control/BUILD | 3 + pkg/sentry/control/logging.go | 136 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 152 insertions(+) create mode 100644 pkg/sentry/control/logging.go (limited to 'pkg') diff --git a/pkg/log/log.go b/pkg/log/log.go index 0765a1963..ab9ad01ef 100644 --- a/pkg/log/log.go +++ b/pkg/log/log.go @@ -50,6 +50,19 @@ const ( Debug ) +func (l Level) String() string { + switch l { + case Warning: + return "Warning" + case Info: + return "Info" + case Debug: + return "Debug" + default: + return fmt.Sprintf("Invalid level: %d", l) + } +} + // Emitter is the final destination for logs. type Emitter interface { // Emit emits the given log statement. This allows for control over the diff --git a/pkg/sentry/control/BUILD b/pkg/sentry/control/BUILD index 15a1fe8a9..5dccb8e3c 100644 --- a/pkg/sentry/control/BUILD +++ b/pkg/sentry/control/BUILD @@ -6,6 +6,7 @@ go_library( name = "control", srcs = [ "control.go", + "logging.go", "pprof.go", "proc.go", "state.go", @@ -26,8 +27,10 @@ go_library( "//pkg/sentry/kernel/time", "//pkg/sentry/limits", "//pkg/sentry/state", + "//pkg/sentry/strace", "//pkg/sentry/usage", "//pkg/sentry/watchdog", + "//pkg/tcpip/link/sniffer", "//pkg/urpc", ], ) diff --git a/pkg/sentry/control/logging.go b/pkg/sentry/control/logging.go new file mode 100644 index 000000000..811f24324 --- /dev/null +++ b/pkg/sentry/control/logging.go @@ -0,0 +1,136 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package control + +import ( + "fmt" + "sync/atomic" + + "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/sentry/strace" + "gvisor.dev/gvisor/pkg/tcpip/link/sniffer" +) + +// LoggingArgs are the arguments to use for changing the logging +// level and strace list. +type LoggingArgs struct { + // SetLevel is a flag used to indicate that we should update + // the logging level. We should be able to change the strace + // list without affecting the logging level and vice versa. + SetLevel bool + + // Level is the log level that will be set if SetLevel is true. + Level log.Level + + // SetLogPackets indicates that we should update the log packets flag. + SetLogPackets bool + + // LogPackets is the actual value to set for LogPackets. + // SetLogPackets must be enabled to indicate that we're changing + // the value. + LogPackets bool + + // SetStrace is a flag used to indicate that strace related + // arguments were passed in. + SetStrace bool + + // EnableStrace is a flag from the CLI that specifies whether to + // enable strace at all. If this flag is false then a completely + // pristine copy of the syscall table will be swapped in. This + // approach is used to remain consistent with an empty strace + // whitelist meaning trace all system calls. + EnableStrace bool + + // Strace is the whitelist of syscalls to trace to log. If this + // and StraceEventWhitelist are empty trace all system calls. + StraceWhitelist []string + + // SetEventStrace is a flag used to indicate that event strace + // related arguments were passed in. + SetEventStrace bool + + // StraceEventWhitelist is the whitelist of syscalls to trace + // to event log. + StraceEventWhitelist []string +} + +// Logging provides functions related to logging. +type Logging struct{} + +// Change will change the log level and strace arguments. Although +// this functions signature requires an error it never acctually +// return san error. It's required by the URPC interface. +// Additionally, it may look odd that this is the only method +// attached to an empty struct but this is also part of how +// URPC dispatches. +func (l *Logging) Change(args *LoggingArgs, code *int) error { + if args.SetLevel { + // Logging uses an atomic for the level so this is thread safe. + log.SetLevel(args.Level) + } + + if args.SetLogPackets { + if args.LogPackets { + atomic.StoreUint32(&sniffer.LogPackets, 1) + } else { + atomic.StoreUint32(&sniffer.LogPackets, 0) + } + log.Infof("LogPackets set to: %v", atomic.LoadUint32(&sniffer.LogPackets)) + } + + if args.SetStrace { + if err := l.configureStrace(args); err != nil { + return fmt.Errorf("error configuring strace: %v", err) + } + } + + if args.SetEventStrace { + if err := l.configureEventStrace(args); err != nil { + return fmt.Errorf("error configuring event strace: %v", err) + } + } + + return nil +} + +func (l *Logging) configureStrace(args *LoggingArgs) error { + if args.EnableStrace { + // Install the whitelist specified. + if len(args.StraceWhitelist) > 0 { + if err := strace.Enable(args.StraceWhitelist, strace.SinkTypeLog); err != nil { + return err + } + } else { + // For convenience, if strace is enabled but whitelist + // is empty, enable everything to log. + strace.EnableAll(strace.SinkTypeLog) + } + } else { + // Uninstall all strace functions. + strace.Disable(strace.SinkTypeLog) + } + return nil +} + +func (l *Logging) configureEventStrace(args *LoggingArgs) error { + if len(args.StraceEventWhitelist) > 0 { + if err := strace.Enable(args.StraceEventWhitelist, strace.SinkTypeEvent); err != nil { + return err + } + } else { + strace.Disable(strace.SinkTypeEvent) + } + return nil +} -- cgit v1.2.3