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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 - Aarch64 - FreeBSD 12 : Expression evaluation causes segfault"
href="https://bugs.llvm.org/show_bug.cgi?id=42153">42153</a>
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<th>Summary</th>
<td>Aarch64 - FreeBSD 12 : Expression evaluation causes segfault
</td>
</tr>
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<th>Product</th>
<td>lldb
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
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<th>Hardware</th>
<td>Other
</td>
</tr>
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<th>OS</th>
<td>FreeBSD
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>All Bugs
</td>
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<th>Assignee</th>
<td>lldb-dev@lists.llvm.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>itzurabhi@gmail.com
</td>
</tr>
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<th>CC</th>
<td>jdevlieghere@apple.com, llvm-bugs@lists.llvm.org
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<pre>Created <span class=""><a href="attachment.cgi?id=22075" name="attach_22075" title="Backtrace & Thread List">attachment 22075</a> <a href="attachment.cgi?id=22075&action=edit" title="Backtrace & Thread List">[details]</a></span>
Backtrace & Thread List
built the master branch(llvm,lldb,clang) from the git on 4th July 2019 on a
AARCH64 FreeBSD12.0 VM (qemu)
while running sample program with following commands :
// sample
int main(int argc,const char ** argv){
int z = argc + 10;
return z;
}
/////
(LLDB)b main
(LLDB)r
(LLDB)n
(LLDB)p argc
(SEGFAULT)
=============
I faced the same issue on 7.1 release branch also, same segfault/back trace was
generated.So tested latest git in order to see if it was fixed after that.
>From my analysis , this line causes:
(data_sp && ReadGPR() && ReadFPR())
<a href="https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L167">https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L167</a>
m_register_info_up - point to a zero address.only the constructor of the class
calls .reset on this smart pointer.
I have done some debugging and suspect
(RegisterContextPOSIXProcessMonitor_arm64::ReadGPR())
<a href="https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L35">https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L35</a>
or
(RegisterContextPOSIXProcessMonitor_arm64::ReadFPR())
<a href="https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L40">https://github.com/llvm-mirror/lldb/blob/master/source/Plugins/Process/FreeBSD/RegisterContextPOSIXProcessMonitor_arm64.cpp#L40</a>
might be causing the overwrite. please advise on where to look further, I am
ready to work on a fix.</pre>
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