Dmitrii Kuvaiskii
c0dc5fce2f
Previously, we introduced `sgx.zero_heap_on_demand` in Linux-SGX as a knob to trade off runtime degradation on memory allocations for faster enclave start-up times. This was an incorrect fix because Linux-SGX's `_DkVirtualMemoryAlloc()` always zeroess the requested memory region, so there was a double-zero of the heap at runtime. Note that LibOS layer silently assumes that `_DkVirtualMemoryAlloc()` zeroes out the memory, and many applications rely on this (Apache, Blender in my experiments). Thus, this commit keeps the zero-out in `_DkVirtualMemoryAlloc()` and removes zero-outs on enclave init and in `get_enclave_pages()`. This renders `sgx.zero_heap_on_demand` useless, so this manifest option is also removed. Also note that this commit doesn't introduce any performance degradation (in fact, now Graphene behaves as if `sgx.zero_heap_on_demand = 1` always).
Python example
This directory contains an example for running Python 3 in Graphene, including the Makefile and a template for generating the manifest. The application is tested on Ubuntu 16.04 and Ubuntu 18.04, with both normal Linux and SGX platforms. The tested versions of Python are 3.5 and 3.6.
Generating the manifest
Installing prerequisites
For generating the manifest and running the test scripts, please run the following command to install the required utility packages (Ubuntu-specific):
sudo apt-get install libnss-mdns
Building for Linux
Run make (non-debug) or make DEBUG=1 (debug) in the directory.
Building for SGX
Run make SGX=1 (non-debug) or make SGX=1 DEBUG=1 (debug) in the directory.
Building with a local Python installation
By default, the make command creates the manifest for the Python binary from
the system installation. If you have a local installation, you may create the
manifest with the PYTHONPATH variable set accordingly. You can also specify
a particular version of Python. For example:
make PYTHONPATH=<python install path> PYTHONVERSION=python3.6 SGX=1
By default, PYTHONPATH=/usr and PYTHONVERSION=python3.5.
Run Python with Graphene
Here's an example of running Python scripts under Graphene:
Without SGX:
./pal_loader python.manifest scripts/helloworld.py
./pal_loader python.manifest scripts/fibonacci.py
With SGX:
SGX=1 ./pal_loader python.manifest scripts/helloworld.py
SGX=1 ./pal_loader python.manifest scripts/fibonacci.py
You can also manually run included tests:
SGX=1 ./run-tests.sh