Awesome
clang-kernel-build
Steps to build the Linux kernel using Clang
-
Start with an empty dir
git clone https://github.com/ramosian-glider/clang-kernel-build.git cd clang-kernel-build export WORLD=`pwd`
-
Install Clang from Chromium:
cd $WORLD # Instruction taken from http://llvm.org/docs/LibFuzzer.html mkdir TMP_CLANG cd TMP_CLANG git clone https://chromium.googlesource.com/chromium/src/tools/clang cd .. TMP_CLANG/clang/scripts/update.py
(To update Clang later on, do (cd TMP_CLANG/clang ; git pull)
and run update.py
again.)
-
Clone the Linux source tree
cd $WORLD git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git cd linux-stable git reset --hard v5.2-rc4
-
Configure and build the kernel
cd $WORLD export CLANG_PATH=`pwd`/third_party/llvm-build/Release+Asserts/bin/ cd linux-stable make CC=$CLANG_PATH/clang defconfig make CC=$CLANG_PATH/clang -j64 2>&1 | tee build.log
-
Set up the VM:
cd $WORLD wget https://raw.githubusercontent.com/google/sanitizers/master/address-sanitizer/kernel_buildbot/create_os_image.sh # create_os_image.sh requires sudo sh create_os_image.sh
-
Run the VM
cd $WORLD ./run_qemu.sh # in a separate console: ssh -i ssh/id_rsa -p 10023 root@localhost
Debugging
```
# Start the VM before running GDB
cd $WORLD
gdb -x gdb.script
(gdb) br dump_stack
```
Hacking
```
# Perform these steps instead of Step 4 above.
cd $WORLD/linux-stable
make CC=$CLANG_PATH/clang defconfig
make CC=`pwd`/../clang_wrapper.py 2>&1 | tee build.log
```
The handy clang_wrapper.py
lets you add arguments to Clang invocation, measure compilation times or fall back to GCC for certain files.
Also, get yourself a log symbolizer: https://raw.githubusercontent.com/google/sanitizers/master/address-sanitizer/tools/kasan_symbolize.py