<div dir="ltr">I wouldn't be surprised if JITing COFF files on Windows doesn't work so well, since the object file format assumes most symbols are dllimport or within the local 2GB module address range.<div><br></div><div>I'm not familiar with the current JIT state of the art, though.</div></div><br><br><div class="gmail_quote"><div dir="ltr">On Thu, Mar 22, 2018 at 1:45 AM via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><font size="2" face="sans-serif">Hello,</font><font size="3"> <br>
</font><font size="2" face="sans-serif"><br>
I append another clue I found out: The problem is definitely not caused
by "__ImageBase" the problem comes with the "OFFSET".
I generated another object file which crashed. The commonality:</font><font size="3">
</font>
<table width="100%" style="border-collapse:collapse">
<tr valign="top" height="8">
<td width="100%" style="border-style:solid solid solid solid;border-color:#000000;border-width:1px 1px 1px 1px;padding:1px 1px"><font size="2" face="sans-serif">mov
edx, DWORD PTR ?normalPlanschbecken@@3HA ;
normalPlanschbecken</font><font size="3"> </font><font size="2" face="sans-serif"><br>
lea rcx, <b><u>OFFSET FLAT</u></b>:??_C@_0CC@LCMJAIPO@Reading?5?$CCnormalPlanschbecken?$CC?5?$CFi@</font><font size="3">
</font><font size="2" face="sans-serif"><br>
jmp printf</font></td></tr></table>
<br><font size="3"><br>
<br>
<br>
</font><font size="1" color="#5f5f5f" face="sans-serif"><br>
From: </font><font size="1" face="sans-serif">via
llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>></font><font size="3"> </font><font size="1" color="#5f5f5f" face="sans-serif"><br>
To: </font><font size="1" face="sans-serif"><a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a></font><font size="3">
</font><font size="1" color="#5f5f5f" face="sans-serif"><br>
Date: </font><font size="1" face="sans-serif">06.03.2018
10:45</font><font size="3"> </font><font size="1" color="#5f5f5f" face="sans-serif"><br>
Subject: </font><font size="1" face="sans-serif">[llvm-dev]
Broken relocation for generating offsets?</font><font size="3"> </font><font size="1" color="#5f5f5f" face="sans-serif"><br>
Sent by: </font><font size="1" face="sans-serif">"llvm-dev"
<<a href="mailto:llvm-dev-bounces@lists.llvm.org" target="_blank">llvm-dev-bounces@lists.llvm.org</a>></font><font size="3"> <br>
</font>
<hr noshade><font size="3"><br>
<br>
</font><font size="2" face="sans-serif"><br>
Hello LLVM-Mailing-List,</font><font size="3"> </font><font size="2" face="sans-serif"><br>
<br>
I discovered a strange behavior when dealing with object files generated
by the compiler of Visual Studio 2015.</font><font size="3"> </font><font size="2" face="sans-serif"><br>
<br>
When jitting bc files I also add object files to look up functions. These
object files are coming from visual studio. When using a switch case instruction
that compiler often generates code based of __ImageBase. I show you a short
snippet of the assembly output.</font><font size="3"> </font>
<table width="100%" style="border-collapse:collapse">
<tr valign="top" height="8">
<td width="100%" style="border-style:solid solid solid solid;border-color:#000000;border-width:1px 1px 1px 1px;padding:1px 1px"><font size="2" face="sans-serif">mov
eax, DWORD PTR ?myInt@@3HA ; myInt</font><font size="3">
</font><font size="2" face="sans-serif"><br>
lea rdi,<b><u> OFFSET FLAT</u></b>:__ImageBase</font><font size="3">
</font><font size="2" face="sans-serif"><br>
xor ebx, ebx</font></td></tr></table>
<br><font size="3"><br>
</font><font size="2" face="sans-serif"><br>
<br>
Then these offset is used to jump to some labels like "$LL4@execute:".</font><font size="3">
</font><font size="2" face="sans-serif"><br>
<br>
When the object file gets added to the jitting process this offset generation
seems to be broken. Executing the code coming from the object file will
lead to a crash. The crash address will always be exactly the address I
used to overload __ImageBase with. So it seems that the address relocation
is wrong with generating offsets?</font><font size="3"> </font><font size="2" face="sans-serif"><br>
<br>
Kind regards</font><font size="3"> </font><font size="2" face="sans-serif"><br>
Björn</font><font size="3"> </font><font size="2" face="sans-serif"><br>
<br>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr.
DE 114 165 789<br>
Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko
Lampert, Hiroshi Kawamura, Takashi Nagano, Takeshi Fukushima.</font><tt><font size="2"><br>
_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a></font></tt><font size="3" color="blue"><u><br>
</u></font><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank"><tt><font size="2" color="blue"><u>http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</u></font></tt></a><font size="3"><br>
<br>
</font><font size="2" face="sans-serif"><br>
<br>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr.
DE 114 165 789<br>
Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko
Lampert, Hiroshi Kawamura, Takashi Nagano, Takeshi Fukushima.<br>
</font>
<br>
<br><font size="2" face="sans-serif"><br>
Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr.
DE 114 165 789<br>
Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko
Lampert, Hiroshi Kawamura, Takashi Nagano, Takeshi Fukushima.<br>
<br>
</font>_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a><br>
<a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" rel="noreferrer" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><br>
</blockquote></div>