topic Re:Dynamic Memory Allocation in Intel® Software Guard Extensions (Intel® SGX)

Dynamic Memory Allocation

wendychao — Fri, 01 Sep 2023 06:49:47 GMT

Hey,

I'm trying to call the PBC library in SGX Enclave to implement dynamic memory allocation of a 2D array of type element_t in PBC for use by later programs. Unfortunately, encountered some unknown program exits, so I am already struggling with creating the correct code.

I have configured my SGX 2.0 environment after following the instructions sgx_emm and tested the sgx_mm API successfully. the configuration file is as follows

<EnclaveConfiguration> <ProdID>0</ProdID> <ISVSVN>0</ISVSVN> <TCSNum>3</TCSNum> <TCSMinPool>1</TCSMinPool> <TCSPolicy>1</TCSPolicy> <TCSMaxNum>3</TCSMaxNum> <StackMaxSize>0x1000000</StackMaxSize> <StackMinSize>0x10000</StackMinSize> <HeapMaxSize>0xF0000000</HeapMaxSize> <HeapInitSize>0x9000</HeapInitSize> <HeapMinSize>0x08000</HeapMinSize> <UserRegionSize>0x90000000</UserRegionSize> <DisableDebug>0</DisableDebug> <MiscSelect>1</MiscSelect> <MiscMask>0xFFFFFFFF</MiscMask> </EnclaveConfiguration>

Now I need to call the PBC crypto library (already compiled lib_tpbc.a in /opt/intel/sgxsdk/lib64) in SGX Enclave to implement the dynamic memory allocation of a 2D array of type element_t, here is my function implementation.

//动态分配二维数组 void initialize_sets(int numSets, int sizeSet) { void *addr = 0; //const size_t ALLOC_SIZE = 0x10000000; // 256M size_t totalSize = numSets * sizeSet * sizeof(element_t);//1800B const size_t alignedSize = calculate_aligned_size(totalSize); int ret = sgx_mm_alloc(NULL, alignedSize, SGX_EMA_COMMIT_NOW, NULL, NULL, &addr); printf("sgx_mm_alloc = %d\n", ret); //0 e_sets = (element_t **) (&addr); for (int i = 0; i < numSets; i++) { *(e_sets + i) = (element_t *)(addr + i * sizeSet * sizeof(element_t)); for (int j = 0; j < sizeSet; j++) { element_init_Zr(e_sets[i][j], pairing); element_random(e_sets[i][j]); printf("initilize sets[%d][%d]\n", i, j); } } }

Execute ./app and the result is as follows:

My problem is that even though I call sgx_mm_alloc to allocate large enough memory dynamically, it still can't initialize e_sets correctly, e.g., it can allocate 256M of memory successfully, but when numSets =8, sizeSet=15, alignedSize=4KB, the function can only initialize the array up to e_sets[7][6] and exits, and it doesn't report an error, so it's hard for me to locate the error. I don't know what the problem is, please help me to solve this problem.

Thanks for your help very much!

Re:Dynamic Memory Allocation

Iffa_Intel — Mon, 04 Sep 2023 07:29:39 GMT

Hi,

Could you share your hardware setup so that we can check the memory available in your hardware?

Sending us the logs would be beneficial as well.

Cordially,

Iffa

Re: Re:Dynamic Memory Allocation

wendychao — Tue, 05 Sep 2023 00:06:32 GMT

hi Iffa,

Thanks for your response.

Here's some of my hardware setup info.

root@ecsgx:~# lshw -short H/W path Device Class Description =================================================== system Alibaba Cloud ECS /0 bus Motherboard /0/400 processor Intel(R) Xeon(R) Platinum 8369B CPU @ 2.70GHz /0/1000 memory 4GiB System Memory /0/1000/0 memory 4GiB DIMM RAM /0/0 memory 96KiB BIOS /0/100 bridge 440FX - 82441FX PMC [Natoma] /0/100/1 bridge 82371SB PIIX3 ISA [Natoma/Triton II] /0/100/1.3 bridge 82371AB/EB/MB PIIX4 ACPI /0/100/2 display GD 5446 /0/100/3 communication Virtio console /0/100/3/0 generic Virtual I/O device /0/100/4 storage Virtio block device /0/100/4/0 /dev/vda disk 42GB Virtual I/O device /0/100/4/0/1 /dev/vda1 volume 1023KiB BIOS Boot partition /0/100/4/0/2 /dev/vda2 volume 190MiB Windows FAT volume /0/100/4/0/3 /dev/vda3 volume 39GiB EXT4 volume /0/100/5 network Virtio network device /0/100/5/0 eth0 network Ethernet interface /0/100/6 generic Virtio memory balloon /0/100/6/0 generic Virtual I/O device /0/1 system PnP device PNP0b00 /0/2 input PnP device PNP0303 /0/3 input PnP device PNP0f13 /0/4 storage PnP device PNP0700 /0/5 communication PnP device PNP0501

root@ecsgx:~# free -m 总计已用空闲共享缓冲/缓存可用内存： 3746 2439 872 85 434 993 交换： 0 0 0 root@ecsgx:~# cat /proc/meminfo MemTotal: 3836180 kB MemFree: 888676 kB MemAvailable: 1013912 kB Buffers: 12172 kB Cached: 391224 kB SwapCached: 0 kB Active: 184008 kB Inactive: 2477356 kB Active(anon): 4984 kB Inactive(anon): 2349032 kB Active(file): 179024 kB Inactive(file): 128324 kB Unevictable: 21336 kB Mlocked: 18504 kB SwapTotal: 0 kB SwapFree: 0 kB Zswap: 0 kB Zswapped: 0 kB Dirty: 444 kB Writeback: 0 kB AnonPages: 2279308 kB Mapped: 320328 kB Shmem: 87864 kB KReclaimable: 42720 kB Slab: 121240 kB SReclaimable: 42720 kB SUnreclaim: 78520 kB KernelStack: 15364 kB PageTables: 35768 kB SecPageTables: 0 kB NFS_Unstable: 0 kB Bounce: 0 kB WritebackTmp: 0 kB CommitLimit: 1918088 kB Committed_AS: 9041968 kB VmallocTotal: 34359738367 kB VmallocUsed: 66472 kB VmallocChunk: 0 kB Percpu: 1824 kB HardwareCorrupted: 0 kB AnonHugePages: 0 kB ShmemHugePages: 0 kB ShmemPmdMapped: 0 kB FileHugePages: 0 kB FilePmdMapped: 0 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB Hugetlb: 0 kB DirectMap4k: 140568 kB DirectMap2M: 2838528 kB DirectMap1G: 1048576 kB

I am looking forward to your reply, thanks again!

Regards，

wendychao

Re:Dynamic Memory Allocation

Iffa_Intel — Fri, 15 Sep 2023 00:23:41 GMT

Hi,

We require you to create a debug enclave and use gdb to set breakpoints in the enclave and verify everything is as it should be stepping through.

This is the best way to find the source of your issue & debug it.

Cordially,

Iffa

Re:Dynamic Memory Allocation

Iffa_Intel — Mon, 02 Oct 2023 00:30:58 GMT

HI,

Thank you for your question. If you need any additional information from Intel, please submit a new question as Intel is no longer monitoring this thread.

Cordially,

Iffa