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| 1 | +// Copyright 2016 syzkaller project authors. All rights reserved. |
| 2 | +// Use of this source code is governed by Apache 2 LICENSE that can be found in the LICENSE file. |
| 3 | + |
| 4 | +// TODO: strip " (discriminator N)", "constprop", "isra" from function names. |
| 5 | + |
| 6 | +package symbolizer |
| 7 | + |
| 8 | +import ( |
| 9 | + "bufio" |
| 10 | + "fmt" |
| 11 | + "io" |
| 12 | + "os/exec" |
| 13 | + "strconv" |
| 14 | + "strings" |
| 15 | + |
| 16 | + "github.com/google/syzkaller/pkg/osutil" |
| 17 | + "github.com/google/syzkaller/sys/targets" |
| 18 | +) |
| 19 | + |
| 20 | +type addr2Liner struct { |
| 21 | + target *targets.Target |
| 22 | + subprocs map[string]*subprocess |
| 23 | + interner Interner |
| 24 | +} |
| 25 | + |
| 26 | +type subprocess struct { |
| 27 | + cmd *exec.Cmd |
| 28 | + stdin io.Closer |
| 29 | + stdout io.Closer |
| 30 | + input *bufio.Writer |
| 31 | + scanner *bufio.Scanner |
| 32 | +} |
| 33 | + |
| 34 | +func (s *addr2Liner) Symbolize(bin string, pcs ...uint64) ([]Frame, error) { |
| 35 | + sub, err := s.getSubprocess(bin) |
| 36 | + if err != nil { |
| 37 | + return nil, err |
| 38 | + } |
| 39 | + return symbolize(&s.interner, sub.input, sub.scanner, pcs) |
| 40 | +} |
| 41 | + |
| 42 | +func (s *addr2Liner) Close() { |
| 43 | + for _, sub := range s.subprocs { |
| 44 | + sub.stdin.Close() |
| 45 | + sub.stdout.Close() |
| 46 | + sub.cmd.Process.Kill() |
| 47 | + sub.cmd.Wait() |
| 48 | + } |
| 49 | +} |
| 50 | + |
| 51 | +func (s *addr2Liner) getSubprocess(bin string) (*subprocess, error) { |
| 52 | + if sub := s.subprocs[bin]; sub != nil { |
| 53 | + return sub, nil |
| 54 | + } |
| 55 | + addr2line, err := s.target.Addr2Line() |
| 56 | + if err != nil { |
| 57 | + return nil, err |
| 58 | + } |
| 59 | + cmd := osutil.Command(addr2line, "-afi", "-e", bin) |
| 60 | + stdin, err := cmd.StdinPipe() |
| 61 | + if err != nil { |
| 62 | + return nil, err |
| 63 | + } |
| 64 | + stdout, err := cmd.StdoutPipe() |
| 65 | + if err != nil { |
| 66 | + stdin.Close() |
| 67 | + return nil, err |
| 68 | + } |
| 69 | + if err := cmd.Start(); err != nil { |
| 70 | + stdin.Close() |
| 71 | + stdout.Close() |
| 72 | + return nil, err |
| 73 | + } |
| 74 | + sub := &subprocess{ |
| 75 | + cmd: cmd, |
| 76 | + stdin: stdin, |
| 77 | + stdout: stdout, |
| 78 | + input: bufio.NewWriter(stdin), |
| 79 | + scanner: bufio.NewScanner(stdout), |
| 80 | + } |
| 81 | + if s.subprocs == nil { |
| 82 | + s.subprocs = make(map[string]*subprocess) |
| 83 | + } |
| 84 | + s.subprocs[bin] = sub |
| 85 | + return sub, nil |
| 86 | +} |
| 87 | + |
| 88 | +func symbolize(interner *Interner, input *bufio.Writer, scanner *bufio.Scanner, pcs []uint64) ([]Frame, error) { |
| 89 | + var frames []Frame |
| 90 | + done := make(chan error, 1) |
| 91 | + go func() { |
| 92 | + var err error |
| 93 | + defer func() { |
| 94 | + done <- err |
| 95 | + }() |
| 96 | + if !scanner.Scan() { |
| 97 | + if err = scanner.Err(); err == nil { |
| 98 | + err = io.EOF |
| 99 | + } |
| 100 | + return |
| 101 | + } |
| 102 | + for range pcs { |
| 103 | + var frames1 []Frame |
| 104 | + frames1, err = parse(interner, scanner) |
| 105 | + if err != nil { |
| 106 | + return |
| 107 | + } |
| 108 | + frames = append(frames, frames1...) |
| 109 | + } |
| 110 | + for i := 0; i < 2; i++ { |
| 111 | + scanner.Scan() |
| 112 | + } |
| 113 | + }() |
| 114 | + |
| 115 | + for _, pc := range pcs { |
| 116 | + if _, err := fmt.Fprintf(input, "0x%x\n", pc); err != nil { |
| 117 | + return nil, err |
| 118 | + } |
| 119 | + } |
| 120 | + // Write an invalid PC so that parse doesn't block reading input. |
| 121 | + // We read out result for this PC at the end of the function. |
| 122 | + if _, err := fmt.Fprintf(input, "0xffffffffffffffff\n"); err != nil { |
| 123 | + return nil, err |
| 124 | + } |
| 125 | + input.Flush() |
| 126 | + |
| 127 | + if err := <-done; err != nil { |
| 128 | + return nil, err |
| 129 | + } |
| 130 | + return frames, nil |
| 131 | +} |
| 132 | + |
| 133 | +func parse(interner *Interner, s *bufio.Scanner) ([]Frame, error) { |
| 134 | + pc, err := strconv.ParseUint(s.Text(), 0, 64) |
| 135 | + if err != nil { |
| 136 | + return nil, fmt.Errorf("failed to parse pc '%v' in addr2line output: %w", s.Text(), err) |
| 137 | + } |
| 138 | + var frames []Frame |
| 139 | + for { |
| 140 | + if !s.Scan() { |
| 141 | + break |
| 142 | + } |
| 143 | + ln := s.Text() |
| 144 | + if len(ln) > 3 && ln[0] == '0' && ln[1] == 'x' { |
| 145 | + break |
| 146 | + } |
| 147 | + fn := ln |
| 148 | + if !s.Scan() { |
| 149 | + err := s.Err() |
| 150 | + if err == nil { |
| 151 | + err = io.EOF |
| 152 | + } |
| 153 | + return nil, fmt.Errorf("failed to read file:line from addr2line: %w", err) |
| 154 | + } |
| 155 | + ln = s.Text() |
| 156 | + colon := strings.LastIndexByte(ln, ':') |
| 157 | + if colon == -1 { |
| 158 | + return nil, fmt.Errorf("failed to parse file:line in addr2line output: %v", ln) |
| 159 | + } |
| 160 | + lineEnd := colon + 1 |
| 161 | + for lineEnd < len(ln) && ln[lineEnd] >= '0' && ln[lineEnd] <= '9' { |
| 162 | + lineEnd++ |
| 163 | + } |
| 164 | + file := ln[:colon] |
| 165 | + line, err := strconv.Atoi(ln[colon+1 : lineEnd]) |
| 166 | + if err != nil || fn == "" || fn == "??" || file == "" || file == "??" || line <= 0 { |
| 167 | + continue |
| 168 | + } |
| 169 | + frames = append(frames, Frame{ |
| 170 | + PC: pc, |
| 171 | + Func: interner.Do(fn), |
| 172 | + File: interner.Do(file), |
| 173 | + Line: line, |
| 174 | + Inline: true, |
| 175 | + }) |
| 176 | + } |
| 177 | + if err := s.Err(); err != nil { |
| 178 | + return nil, err |
| 179 | + } |
| 180 | + if len(frames) != 0 { |
| 181 | + frames[len(frames)-1].Inline = false |
| 182 | + } |
| 183 | + return frames, nil |
| 184 | +} |
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