<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/82307>82307</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [libFuzzer] Incorrect coverage number in fork mode
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          yescallop
      </td>
    </tr>
</table>

<pre>
    When running the fuzzer in fork mode, the coverage number starts out always the same as the feature number, for example:
```
#109599: cov: 10365 ft: 10365 corp: 6188 exec/s 54799 oom/timeout/crash: 0/0/0 time: 2s job: 1 dft_time: 0
```
This does not happen when running the fuzzer in normal mode:
```
#10090  INITED cov: 2273 ft: 10366 corp: 6173/210Kb exec/s: 0 rss: 179Mb
```
I believe that this is caused by the following line:
https://github.com/llvm/llvm-project/blob/d9f9775ac6289271d57671c55166fa0cad61075b/compiler-rt/lib/fuzzer/FuzzerFork.cpp#L352

I'll open a pull request after I figure out how to test my change.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyUU02P5CYQ_TX4UtoWLhvTPvgwScdSKx-nlXKMMJRtdrFxAE9v76-PcG9nRsomUiRbFFRRvPfgqRjttBJ1TPzAxKVQe5p96O4UtXLOb8Xgzb37faYVwr6udp0gzQTj_vUrBbArjD58hsUbYvjjkdL-lYKaCNZ9GShATCqkCH5PoNxN3eNRFdVCoB7xSCrt4bkh9xl9APqils0Rq14YvzD-whr-7XtMsSp5K9qWVS_5zDyUvGoEjOkt1j5sedaU5zPQF9IM-wiilm0L3i8M-2QX8nti2Oug4pyLOcP--CEn8wpG-OSHoy2YMf3xXOffhfZxthGMpwirTzCrbaMVbv8u4erDotxDxP9iy1sOcP3t-vGny5MxoqzeEW7eEZYVwx5L_vPwN_EDMoR4BKVsfx2-e9gVBnKWXgnSrBKkTMdG0GqPZGC4P-B75_wtk3F2fcM9p7Tl9gx7hv1k07wPJ30o7dzrc_iwBf-JdFZ9cH5g2Jt2bKUUSjd4blGWRshGllqIsmlGxbUyTcmlyKXaL5t1FD6EvN_ZvPYQk2HfH0Hvw-eT3jaG1S-VwG8sH-QYSufA5ztRsO3OQaA_d4oJ1JgowBVGO-XnmF_s7G-QPKScXu6gZ7VOdCpMV5m2alVBXSn5ueZNVYti7uqmNorrpq1UZUqpjcZyFNJoHBTJ0hS2Q441R-RclC0XJ01jdW7a-myaUQ6kWc1pUdadskwnH6bCxrhTd8aKy8KpgVw8vIq40g2OJEPM1g3dIe2wT5HV3NmY4luXZJM7TO7s8NCIiQtcV-1DIJ3-4dr3zi724Lr_fbEHtMiwP6D_FQAA___w9lyD">