<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Crash on exit when compiling with ThinLTO"
href="https://bugs.llvm.org/show_bug.cgi?id=43927">43927</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Crash on exit when compiling with ThinLTO
</td>
</tr>
<tr>
<th>Product</th>
<td>OpenMP
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Runtime Library
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>aaronpuchert@alice-dsl.net
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>When building with
-DLLVM_ENABLE_PROJECTS="clang;openmp" \
-DLLVM_ENABLE_LTO=Thin \
-DLLVM_USE_LINKER=gold
programs using libomp.so crash on exit in a call from _dl_fini in glibc. That
is because
$ readelf -d libomp.so
Dynamic section at offset 0xeec80 contains 32 entries:
Tag Type Name/Value
[...]
0x000000000000000c (INIT) 0x1af00
0x000000000000000d (FINI) 0x0
[...]
So it calls into offset 0x0 of the binary, which has to go wrong. Now why does
that happen? In openmp/runtime/cmake/LibompHandleFlags.cmake,
-Wl,-fini=__kmp_internal_end_fini
is added to LDFLAGS. Now
readelf -s llvm/lib/libomp.so | grep __kmp_internal_end_fini
indicates that this function isn't there. That is probably because LTO sees
that the function is unused and not exported, so it can be removed.
I don't know if this is a bug in LTO (i.e. the argument to -fini should be
kept) or if we need to export this function.</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>