<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/74487>74487</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [libc] hermetic build fails at `_start`
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            libc
      </td>
    </tr>

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

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

<pre>
    On my machine, `hermetic` tests are still failing from time to time. In debug build, such tests are failing right at `_start`.

`llvm-project/build/projects/libc/test/src/__support/libc.test.src.__support.endian_test.__hermetic__.__build__`.

Compiler:
```
clang version 16.0.6 (https://gitlab.archlinux.org/archlinux/packaging/packages/clang.git ff762c61c53dca880df8ed701c1bf9c73117e675)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
```

It seems that the _start function is attempting to read data based at `fs`, and that instruction triggers a SEGV.


</pre>
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