topic Re: Re:Core dump caused by multi-threaded ecall in Intel® Software Guard Extensions (Intel® SGX)

Core dump caused by calling ecall multiple times

LowEntropyBody — Mon, 29 Jun 2020 09:19:30 GMT

I repeatedly call an ecall function. No operation was performed in the function, just return. At the beginning, it went smoothly, but after a while, a core dump occurred. After setting the HeapMaxSize in the configuration to be large, the error time is pushed back. Is there something left in sgx after ecall ends, causing memory overflow? Or is there any way I can solve this problem.

PS：

<EnclaveConfiguration>
<ProdID>0</ProdID>
<ISVSVN>0</ISVSVN>

<StackMaxSize>0x4000000</StackMaxSize>
<HeapMaxSize>0x4000000</HeapMaxSize>
<TCSNum>20</TCSNum>
<TCSPolicy>1</TCSPolicy>

<DisableDebug>0</DisableDebug>
<MiscSelect>0</MiscSelect>
<MiscMask>0xFFFFFFFF</MiscMask>
</EnclaveConfiguration>

Update:

When I set TCSPolicy = 0, this core dump issue will not occur

Re:Core dump caused by multi-threaded ecall

JesusG_Intel — Tue, 30 Jun 2020 01:25:32 GMT

Hello LowEntropyBody,

We are looking into your issue. Please stay tuned.

Re:Core dump caused by multi-threaded ecall

JesusG_Intel — Tue, 30 Jun 2020 23:56:21 GMT

Hello LowEntropyBody,

Since you solved your problem by setting TCSPolicy to 0, do you still need help with this issue?

If you still need help, please send your source code so we can reproduce your issue.

Re: Re:Core dump caused by multi-threaded ecall

LowEntropyBody — Wed, 01 Jul 2020 06:41:32 GMT

I did a test, but I just found the error after calling ecall repeatedly.

I have a question. What are the effects of setting TCSpolicy to 0 and what are the security risks?

ecall like:

void ecall_srd_increase(const char *path)

{

return;

}

trusted {
public void ecall_srd_increase([in, string] const char* path);

}

Re:Core dump caused by multi-threaded ecall

JesusG_Intel — Wed, 01 Jul 2020 18:47:18 GMT

Hello Yang, please read page 49 of the SGX Developer Guide for more info on the Thread Binding Policy: https://software.intel.com/sites/default/files/managed/33/70/intel-sgx-developer-guide.pdf.

Regards,