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<p class=MsoNormal>(llvm 2.6)<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>We have an application where we are using LLVM to generate
ELF object files for X86_64. At runtime we load these objects files
into memory using our own ELF loader.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Everything is working except for the jump tables.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>The ELF emitter is generating JMPQ instructions using
X86::reloc_absolute_word_sext relocations which we are unable to patch to the
jump table in the .rodata segment unless we force that segment to load in the
low 2GB of the address range. Currently we just request pages of memory from
the OS and that memory is much deeper in the address space.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Is there proper way to patch the address or instruction
(ewww) or have the ELF emitter generate a RIP based instruction. If a
real linker doesn’t patch the instruction, does the ELF loader always try
to load .rodata segments in the low 2GB of memory regardless of if it is from
the main image or from a shared library? <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks for any help.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>---<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Tim
Smith<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Principal Programmer
- Austin MMO<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif"'>BioWare,
Edmonton Studio</span><o:p></o:p></p>
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