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| 1 | +// SPDX-License-Identifier: Apache-2.0 |
| 2 | +/* Copyright 2024 Authors of Cilium */ |
| 3 | + |
| 4 | +package pwru |
| 5 | + |
| 6 | +import ( |
| 7 | + "context" |
| 8 | + "errors" |
| 9 | + "fmt" |
| 10 | + "log" |
| 11 | + "os" |
| 12 | + "sync" |
| 13 | + "syscall" |
| 14 | + |
| 15 | + "github.com/cheggaaa/pb/v3" |
| 16 | + "github.com/cilium/ebpf" |
| 17 | + "github.com/cilium/ebpf/link" |
| 18 | + "golang.org/x/sync/errgroup" |
| 19 | +) |
| 20 | + |
| 21 | +type Kprobe struct { |
| 22 | + hookFunc string // internal use |
| 23 | + HookFuncs []string |
| 24 | + Prog *ebpf.Program |
| 25 | +} |
| 26 | + |
| 27 | +func attachKprobes(ctx context.Context, bar *pb.ProgressBar, kprobes []Kprobe) (links []link.Link, ignored int, err error) { |
| 28 | + links = make([]link.Link, 0, len(kprobes)) |
| 29 | + for _, kprobe := range kprobes { |
| 30 | + select { |
| 31 | + case <-ctx.Done(): |
| 32 | + return |
| 33 | + |
| 34 | + default: |
| 35 | + } |
| 36 | + |
| 37 | + var kp link.Link |
| 38 | + kp, err = link.Kprobe(kprobe.hookFunc, kprobe.Prog, nil) |
| 39 | + if err != nil { |
| 40 | + if !errors.Is(err, os.ErrNotExist) && !errors.Is(err, syscall.EADDRNOTAVAIL) { |
| 41 | + err = fmt.Errorf("opening kprobe %s: %w", kprobe.hookFunc, err) |
| 42 | + return |
| 43 | + } else { |
| 44 | + err = nil |
| 45 | + ignored++ |
| 46 | + } |
| 47 | + } else { |
| 48 | + links = append(links, kp) |
| 49 | + } |
| 50 | + |
| 51 | + bar.Increment() |
| 52 | + } |
| 53 | + |
| 54 | + return |
| 55 | +} |
| 56 | + |
| 57 | +// AttachKprobes attaches kprobes concurrently. |
| 58 | +func AttachKprobes(ctx context.Context, bar *pb.ProgressBar, kps []Kprobe, batch uint) (links []link.Link, ignored int) { |
| 59 | + if batch == 0 { |
| 60 | + log.Fatal("--filter-kprobe-batch must be greater than 0") |
| 61 | + } |
| 62 | + |
| 63 | + var kprobes []Kprobe |
| 64 | + for _, kp := range kps { |
| 65 | + for _, fn := range kp.HookFuncs { |
| 66 | + kprobes = append(kprobes, Kprobe{ |
| 67 | + hookFunc: fn, |
| 68 | + Prog: kp.Prog, |
| 69 | + }) |
| 70 | + } |
| 71 | + } |
| 72 | + |
| 73 | + if len(kprobes) == 0 { |
| 74 | + return |
| 75 | + } |
| 76 | + |
| 77 | + errg, ctx := errgroup.WithContext(ctx) |
| 78 | + |
| 79 | + var mu sync.Mutex |
| 80 | + links = make([]link.Link, 0, len(kprobes)) |
| 81 | + |
| 82 | + attaching := func(kprobes []Kprobe) error { |
| 83 | + l, i, e := attachKprobes(ctx, bar, kprobes) |
| 84 | + if e != nil { |
| 85 | + return e |
| 86 | + } |
| 87 | + |
| 88 | + mu.Lock() |
| 89 | + links = append(links, l...) |
| 90 | + ignored += i |
| 91 | + mu.Unlock() |
| 92 | + |
| 93 | + return nil |
| 94 | + } |
| 95 | + |
| 96 | + var i uint |
| 97 | + for i = 0; i+batch < uint(len(kprobes)); i += batch { |
| 98 | + kps := kprobes[i : i+batch] |
| 99 | + errg.Go(func() error { |
| 100 | + return attaching(kps) |
| 101 | + }) |
| 102 | + } |
| 103 | + if i < uint(len(kprobes)) { |
| 104 | + kps := kprobes[i:] |
| 105 | + errg.Go(func() error { |
| 106 | + return attaching(kps) |
| 107 | + }) |
| 108 | + } |
| 109 | + |
| 110 | + if err := errg.Wait(); err != nil { |
| 111 | + log.Fatalf("Attaching kprobes: %v\n", err) |
| 112 | + } |
| 113 | + |
| 114 | + return |
| 115 | +} |
| 116 | + |
| 117 | +// DetachKprobes detaches kprobes concurrently. |
| 118 | +func DetachKprobes(links []link.Link, showProgressBar bool, batch uint) { |
| 119 | + log.Println("Detaching kprobes...") |
| 120 | + |
| 121 | + if batch < 2 { |
| 122 | + for _, l := range links { |
| 123 | + _ = l.Close() |
| 124 | + } |
| 125 | + |
| 126 | + return |
| 127 | + } |
| 128 | + |
| 129 | + var errg errgroup.Group |
| 130 | + var bar *pb.ProgressBar |
| 131 | + |
| 132 | + if showProgressBar { |
| 133 | + bar = pb.StartNew(len(links)) |
| 134 | + defer bar.Finish() |
| 135 | + } |
| 136 | + increment := func() { |
| 137 | + if showProgressBar { |
| 138 | + bar.Increment() |
| 139 | + } |
| 140 | + } |
| 141 | + |
| 142 | + var i uint |
| 143 | + for i = 0; i+batch < uint(len(links)); i += batch { |
| 144 | + l := links[i : i+batch] |
| 145 | + errg.Go(func() error { |
| 146 | + for _, l := range l { |
| 147 | + _ = l.Close() |
| 148 | + increment() |
| 149 | + } |
| 150 | + return nil |
| 151 | + }) |
| 152 | + } |
| 153 | + for ; i < uint(len(links)); i++ { |
| 154 | + _ = links[i].Close() |
| 155 | + increment() |
| 156 | + } |
| 157 | + |
| 158 | + _ = errg.Wait() |
| 159 | +} |
| 160 | + |
| 161 | +// AttachKprobeMulti attaches kprobe-multi serially. |
| 162 | +func AttachKprobeMulti(ctx context.Context, bar *pb.ProgressBar, kprobes []Kprobe, a2n Addr2Name) (links []link.Link, ignored int) { |
| 163 | + links = make([]link.Link, 0, len(kprobes)) |
| 164 | + |
| 165 | + for _, kp := range kprobes { |
| 166 | + select { |
| 167 | + case <-ctx.Done(): |
| 168 | + return |
| 169 | + default: |
| 170 | + } |
| 171 | + |
| 172 | + addrs := make([]uintptr, 0, len(kp.HookFuncs)) |
| 173 | + for _, fn := range kp.HookFuncs { |
| 174 | + if addr, ok := a2n.Name2AddrMap[fn]; ok { |
| 175 | + addrs = append(addrs, addr...) |
| 176 | + } else { |
| 177 | + ignored += 1 |
| 178 | + bar.Increment() |
| 179 | + continue |
| 180 | + } |
| 181 | + } |
| 182 | + |
| 183 | + if len(addrs) == 0 { |
| 184 | + continue |
| 185 | + } |
| 186 | + |
| 187 | + opts := link.KprobeMultiOptions{Addresses: addrs} |
| 188 | + l, err := link.KprobeMulti(kp.Prog, opts) |
| 189 | + bar.Add(len(kp.HookFuncs)) |
| 190 | + if err != nil { |
| 191 | + log.Fatalf("Opening kprobe-multi: %s\n", err) |
| 192 | + } |
| 193 | + |
| 194 | + links = append(links, l) |
| 195 | + } |
| 196 | + |
| 197 | + return |
| 198 | +} |
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