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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - libomp crash in __tls_get_addr when clang is bootstrapped with LTO"
href="https://bugs.llvm.org/show_bug.cgi?id=33088">33088</a>
</td>
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<tr>
<th>Summary</th>
<td>libomp crash in __tls_get_addr when clang is bootstrapped with LTO
</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>enhancement
</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>ismail@i10z.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
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<pre>I bootstrapped clang with (fat-)lto and the following simple openmp code now
crashes at exit:
havana ~ > cat omp_hello.c
#include <omp.h>
#include <stdio.h>
#include <stdlib.h>
int main (int argc, char *argv[])
{
int nthreads, tid;
/* Fork a team of threads giving them their own copies of variables */
#pragma omp parallel private(nthreads, tid)
{
/* Obtain thread number */
tid = omp_get_thread_num();
printf("Hello World from thread = %d\n", tid);
/* Only master thread does this */
if (tid == 0)
{
nthreads = omp_get_num_threads();
printf("Number of threads = %d\n", nthreads);
}
} /* All threads join master thread and disband */
}
havana ~ > clang-5 -v
openSUSE Linux clang version 5.0.0 (trunk 303241) (based on LLVM 5.0.0svn)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /suse/idoenmez/bin
Found candidate GCC installation: /usr/lib64/gcc/x86_64-suse-linux/6
Selected GCC installation: /usr/lib64/gcc/x86_64-suse-linux/6
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
havana ~ > clang-5 -g3 -fsanitize=address -fopenmp omp_hello.c -flto
-Wl,-rpath,/opt/clang/lib64
havana ~ > ./a.out
Hello World from thread = 0
Hello World from thread = 3
Hello World from thread = 7
Hello World from thread = 4
Hello World from thread = 6
Hello World from thread = 5
Hello World from thread = 1
Hello World from thread = 2
Number of threads = 8
ASAN:DEADLYSIGNAL
=================================================================
==2830==ERROR: AddressSanitizer: SEGV on unknown address 0x7fb09cd5a000 (pc
0x7fb09cd5a047 bp 0x7ffdb7a451a0 sp 0x7ffdb7a450d8 T0)
==2830==The signal is caused by a WRITE memory access.
#0 0x7fb09cd5a046 in __tls_get_addr (/opt/clang/lib64/libomp.so+0x46)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/opt/clang/lib64/libomp.so+0x46) in
__tls_get_addr
==2830==ABORTING</pre>
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