<html>
<head>
<base href="https://llvm.org/bugs/" />
</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 --- - -fstack-protector fails to link on powerpc64le linux"
href="https://llvm.org/bugs/show_bug.cgi?id=26226">26226</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>-fstack-protector fails to link on powerpc64le linux
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</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>Backend: PowerPC
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>timshen91@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Example:
// clang++ -target powerpc64le-unknown-linux-gnu -fstack-protector a.cc
int main() {
char arr[2048];
arr[2048+15] = 0;
return 0;
}
Linker complains undefined reference to `__stack_chk_guard'.
In fact, glibc stores stack_guard not as a global/TLS variable, but a data
member in TCB:
<a href="https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/powerpc/nptl/tls.h;h=0e889bc122c9bf91bae1adf43977e9e04c1e5595;hb=HEAD#l99">https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/powerpc/nptl/tls.h;h=0e889bc122c9bf91bae1adf43977e9e04c1e5595;hb=HEAD#l99</a>
x86 suffered from the same issue, and then was fixed by:
<a href="http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20100705/103635.html">http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20100705/103635.html</a>
The fix specifies an address space (which finally turns into fs/gs access) and
hard code the offset to indicate the location of the stack guard.
How do we fix this? Do we use the same address space trick?
Thanks!</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>