commit | 8a25a1756b5600ea65134fe8f7729228ad8c535f | [log] [tgz] |
---|---|---|
author | Peter Collingbourne <pcc@google.com> | Mon Nov 19 12:58:18 2018 -0800 |
committer | Peter Collingbourne <pcc@google.com> | Thu Dec 06 22:14:40 2018 +0000 |
tree | d70b8c894b68a1b26d5bc8f7a2bea4530120da3d | |
parent | e72c597aa7b936a163d0fe027d33339a5603d9be [diff] |
Preserve x18 while calling aptX encoder libraries. Shadow call stack (SCS) is a security mitigation that uses a separate stack (the SCS) for return addresses. In versions of Android newer than P, the compiler normally cooperates with the system to ensure that the SCS address is always stored in register x18. This requires that everything in a process that uses SCS is built with -ffixed-x18. However, two libraries (libaptX_encoder.so and libaptXHD_encoder.so) are supplied in binary format and were not compiled with -ffixed-x18. We are working with the vendor to get these libraries rebuilt with -ffixed-x18, but until then, we need to prevent this library from clobbering x18 so that we can turn on SCS in the Bluetooth process. Bug: 112907825 Bug: 120621517 Change-Id: Id27829ed5696903c42b4aeb75c3b3880c97a3a36
Just build AOSP - Fluoride is there by default.
Instructions for Ubuntu, tested on 14.04 with Clang 3.5.0 and 16.10 with Clang 3.8.0
mkdir ~/fluoride cd ~/fluoride git clone https://android.googlesource.com/platform/system/bt
Install dependencies (require sudo access):
cd ~/fluoride/bt build/install_deps.sh
Then fetch third party dependencies:
cd ~/fluoride/bt mkdir third_party cd third_party git clone https://github.com/google/googletest.git git clone https://android.googlesource.com/platform/external/aac git clone https://android.googlesource.com/platform/external/libchrome git clone https://android.googlesource.com/platform/external/libldac git clone https://android.googlesource.com/platform/external/modp_b64 git clone https://android.googlesource.com/platform/external/tinyxml2
And third party dependencies of third party dependencies:
cd fluoride/bt/third_party/libchrome/base/third_party mkdir valgrind cd valgrind curl https://chromium.googlesource.com/chromium/src/base/+/master/third_party/valgrind/valgrind.h?format=TEXT | base64 -d > valgrind.h curl https://chromium.googlesource.com/chromium/src/base/+/master/third_party/valgrind/memcheck.h?format=TEXT | base64 -d > memcheck.h
NOTE: If system/bt is checked out under AOSP, then create symbolic links instead of downloading sources
cd system/bt mkdir third_party cd third_party ln -s ../../../external/aac aac ln -s ../../../external/libchrome libchrome ln -s ../../../external/libldac libldac ln -s ../../../external/modp_b64 modp_b64 ln -s ../../../external/tinyxml2 tinyxml2 ln -s ../../../external/googletest googletest
cd ~/fluoride/bt gn gen out/Default
cd ~/fluoride/bt ninja -C out/Default all
This will build all targets (the shared library, executables, tests, etc) and put them in out/Default. To build an individual target, replace "all" with the target of your choice, e.g. ninja -C out/Default net_test_osi
.
cd ~/fluoride/bt/out/Default LD_LIBRARY_PATH=./ ./bluetoothtbd -create-ipc-socket=fluoride
Follows the Chromium project Eclipse Setup Instructions until "Optional: Building inside Eclipse" section (don't do that section, we will set it up differently)
Generate Eclipse settings:
cd system/bt gn gen --ide=eclipse out/Default
In Eclipse, do File->Import->C/C++->C/C++ Project Settings, choose the XML location under system/bt/out/Default
Right click on the project. Go to Preferences->C/C++ Build->Builder Settings. Uncheck "Use default build command", but instead using "ninja -C out/Default"
Goto Behaviour tab, change clean command to "-t clean"