retdec-llvmir2hll crashes in the SimpleCopyPropagationOptimizer phase

[decidedlygray]

Hello,

I'm trying to decompile a rather larger (3.5MB) ELF x86 binary and I am seeing a crash during the optimizations phase of decompilation. I'm hoping you might have some pointers on how to prevent this crash, or a way to work around it (maybe ignore/skip optimizations somehow).

Issue Description

What command am I running?

A pretty vanilla command:

./retdec-decompiler.sh -o /home/user/mybinary.ext /home/user/mybinary

The binary is stripped but not packed.

What am I seeing?

The process makes it through this decompile step:

##### Decompiling /home/user/mybinary into /home/user/mybinary.ext.backend.bc....

Then fails during:

##### Decompiling /home/user/mybinary.ext.backend.bc into /home/user/mybinary.ext

What error message am I seeing?

After making it through several phases of the second Decompiling step, it fails with the following information:

 -> converting function_82f85c0() ( 138.19s )
 -> converting _fini() ( 138.19s )
 -> converting function_82f8600() ( 138.19s )
Running phase: removing functions prefixed with [__decompiler_undefined_function_] ( 138.35s )
Running phase: removing functions from standard libraries ( 149.06s )
 -> removing tolower() ( 149.06s )
Running phase: removing code that is not reachable in a CFG ( 149.06s )
Warning: [NonRecursiveCFGBuilder] there is no node for an edge to `v3_82e3b47 = *(IntToPtrCastExpr<ptr>((v0_82e3b47 + 4)))` -> skipping this edge
Warning: [NonRecursiveCFGBuilder] there is no node for an edge to `v3_82e4507 = *(IntToPtrCastExpr<ptr>((v0_82e4507 + 4)))` -> skipping this edge
Running phase: signed/unsigned types fixing ( 153.00s )
Running phase: converting LLVM intrinsic functions to standard functions ( 166.99s )
Running phase: obtaining debug information ( 169.24s )
Running phase: alias analysis [simple] ( 169.41s )
Running phase: optimizations [normal] ( 171.17s )
 -> running RemoveUselessCastsOptimizer ( 171.17s )
 -> running UnusedGlobalVarOptimizer ( 172.46s )
 -> running DeadLocalAssignOptimizer ( 174.33s )
 -> running SimpleCopyPropagationOptimizer ( 224.00s )
Warning: [NonRecursiveCFGBuilder] there is no node for an edge to `v3_82e3b47 = *(IntToPtrCastExpr<ptr>((v0_82e3b47 + 4)))` -> skipping this edge
Warning: [NonRecursiveCFGBuilder] there is no node for an edge to `v3_82e4507 = *(IntToPtrCastExpr<ptr>((v0_82e4507 + 4)))` -> skipping this edge
./retdec-decompiler.sh: line 940: 25960 Killed                  "$LLVMIR2HLL" "${LLVMIR2HLL_PARAMS[@]}"
Error: Decompilation of file '/home/user/mybinary.ext.backend.bc' failed

So something is going wrong around here... https://github.com/avast-tl/retdec/blob/master/scripts/retdec-decompiler.sh#L945

What is interesting is the "Killed" message. Is something getting forcefully killed because it is taking too long maybe?

My System Information

retdec Version

I successfully cloned and built the project yesterday 1/31/2018

OS Info

x86_64 Ubuntu 16.04.3 (xenial)

[silverbacknet]

This strongly points to #16 & #13, did you track memory usage while it was running?

[decidedlygray]

Aha! Yes it does. This is likely a duplicate. I thought I had searched deep enough through the issues, but I didn’t see those.

My crash is occurring at he same point #13 mentions. I will try the flags mentioned in the comments of that issue to disable optimizations while tracking memory usage and see what happens.

[s3rvac]

Thank you for the report. Would you be able to share with us the input binary file? Otherwise, I am afraid there is not much we can do about it, other than pointing you towards #13.

[decidedlygray]

Absolutely. It's a publicly available binary so there are no issues there - https://mega.nz/#!p3BCFCCL!J9R9nL-jzKY-HJvSO477WrWBfnl6BXQ_hC2D-WIw88A

Thanks for following up