Bad libusgx_switchless.a in SGX 2.11 prebuilt SDK package

[dingelish]

/usr/bin/ld: /opt/sgxsdk/lib64/libsgx_uswitchless.a(sl_uswitchless_untrusted.o): unable to initialize decompress status for section .debug_info
/usr/bin/ld: /opt/sgxsdk/lib64/libsgx_uswitchless.a(sl_uswitchless_untrusted.o): unable to initialize decompress status for section .debug_info
/opt/sgxsdk/lib64/libsgx_uswitchless.a: member /opt/sgxsdk/lib64/libsgx_uswitchless.a(sl_uswitchless_untrusted.o) in archive is not an object
collect2: error: ld returned 1 exit status

to reproduce, please docker build the following Dockerfiles. they all result in the above error message

Ubuntu 18.04:

FROM ubuntu:18.04
RUN apt update && apt install -y build-essential curl
RUN cd /root && \
    curl -o sdk.bin https://download.01.org/intel-sgx/sgx-linux/2.11/distro/ubuntu18.04-server/sgx_linux_x64_sdk_2.11.100.2.bin && \
    chmod +x sdk.bin && \
    echo -e 'no\n/opt' | ./sdk.bin

RUN bash -c "source /opt/sgxsdk/environment && cd /opt/sgxsdk/SampleCode/Switchless && make"

Centos 8

FROM centos:8

RUN dnf group install -y 'Development Tools'

RUN cd /root && \
    curl -o sdk.bin https://download.01.org/intel-sgx/sgx-linux/2.11/distro/centos8.1-server/sgx_linux_x64_sdk_2.11.100.2.bin && \
    chmod +x sdk.bin && \
    echo -e 'no\n/opt' | ./sdk.bin

RUN bash -c "source /opt/sgxsdk/environment && cd /opt/sgxsdk/SampleCode/Switchless && make"

[lzha101]

Generally, this error should be related to different binutils used. The SDK installer on download.01.org are built with the mitigation LVI binutils. Could you try to configure the LVI binutils in the Docker as well?

[dingelish]

interesting. i can confirm use the prebuilt bintuils can fix this issue. one more question: does this means that switchless feature requires the latest binutils?

[lzha101]

I don't think so. It should depend on what binutils version is used to build the SDK. If you build your own SGX SDK installer with the system default binutils, suppose you can build the sample successfully with the system binutils as well.
To avoid the binutils incompatible errors, it is better to keep the same binutils to build the SDK and the final binaries.

[dingelish]

understand. could you please confirm that the prebuilt static libraries in Intel SDK are compiled using the toolchain provided in as.ld.objdump.gold.r2.tar.gz ? thanks!

[lzha101]

Yes. All the SDK installers for 2.11 release provided in download.01.org are built with the prebuilt toolchain as.ld.objdump.gold.r2.tar.gz. And the prebuilt static libraries on that release are also built with that toolchain.

[dingelish]

awesome! and could we have the exact source code (git hash is good)and configurations (like the argument of ./configure) for that copy of toolchain? thanks!

[lzha101]

The toolchain is based on https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=a09f656b267b9a684f038fba7cadfe98e2f18892, built with default configurations.

[dingelish]

@lzha101 thanks so much for your help!