It is neater to keep this in the QEMU repo, since any change that requires an update to the oss-fuzz build configuration, can make the necessary changes in the same series.
Suggested-by: Philippe Mathieu-Daudé <f4...@amsat.org> Signed-off-by: Alexander Bulekov <alx...@bu.edu> --- In v3 I tried to make this build outside the oss-fuzz docker environment. I wasn't able to find a way to use the Makefile to install the pc-bios and qemu-fuzz binaries per Philippe's suggestion. Additionally, right now I create a separate build directory within the the tree for build. I am not sure whether this is a good approach, but we must rely on some default that will work with both oss-fuzz and on a developer's machine. MAINTAINERS | 1 + scripts/oss-fuzz/build.sh | 99 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+) create mode 100755 scripts/oss-fuzz/build.sh diff --git a/MAINTAINERS b/MAINTAINERS index 3abe3faa4e..094a37ebb3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2336,6 +2336,7 @@ R: Bandan Das <b...@redhat.com> R: Stefan Hajnoczi <stefa...@redhat.com> S: Maintained F: tests/qtest/fuzz/ +F: scripts/oss-fuzz/ Register API M: Alistair Francis <alist...@alistair23.me> diff --git a/scripts/oss-fuzz/build.sh b/scripts/oss-fuzz/build.sh new file mode 100755 index 0000000000..4be6b21caf --- /dev/null +++ b/scripts/oss-fuzz/build.sh @@ -0,0 +1,99 @@ +#!/bin/sh +# +# OSS-Fuzz build script. See: +# https://google.github.io/oss-fuzz/getting-started/new-project-guide/#buildsh +# +# The file is consumed by: +# https://github.com/google/oss-fuzz/blob/master/projects/qemu/Dockerfiles +# +# This code is licensed under the GPL version 2 or later. See +# the COPYING file in the top-level directory. +# + +# build project +# e.g. +# ./autogen.sh +# ./configure +# make -j$(nproc) all + +# build fuzzers +# e.g. +# $CXX $CXXFLAGS -std=c++11 -Iinclude \ +# /path/to/name_of_fuzzer.cc -o $OUT/name_of_fuzzer \ +# $LIB_FUZZING_ENGINE /path/to/library.a + +# There seems to be a bug in clang-11 (used for builds on oss-fuzz) : +# accel/tcg/cputlb.o: In function `load_memop': +# accel/tcg/cputlb.c:1505: undefined reference to `qemu_build_not_reached' +# +# When building with optimization, the compiler is expected to prove that the +# statement cannot be reached, and remove it. For some reason clang-11 doesn't +# remove it, resulting in an unresolved reference to qemu_build_not_reached +# Undefine the __OPTIMIZE__ macro which compiler.h relies on to choose whether +# to " #define qemu_build_not_reached() g_assert_not_reached() " +EXTRA_CFLAGS="$CFLAGS -U __OPTIMIZE__" + +if ! { [ -e "./COPYING" ] && + [ -e "./MAINTAINERS" ] && + [ -e "./Makefile" ] && + [ -e "./docs" ] && + [ -e "./VERSION" ] && + [ -e "./linux-user" ] && + [ -e "./softmmu" ];} ; then + echo "Please run the script from the top of the QEMU tree" + exit +fi + +mkdir -p "./build-oss-fuzz/" +cd "./build-oss-fuzz/" || exit + + +if [ -z ${LIB_FUZZING_ENGINE+x} ]; then + LIB_FUZZING_ENGINE="-fsanitize=fuzzer" +fi + +if [ -z ${OUT+x} ]; then + DEST_DIR=$(realpath "./DEST_DIR") +else + DEST_DIR=$OUT +fi + +mkdir -p "$DEST_DIR/lib/" # Copy the shared libraries here + +# Build once to get the list of dynamic lib paths, and copy them over +../configure --disable-werror --cc="$CC" --cxx="$CXX" \ + --extra-cflags="$EXTRA_CFLAGS" + +if ! make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" \ + i386-softmmu/fuzz; then + echo "Build failed. Please specify a compiler with fuzzing support"\ + "using the \$CC and \$CXX environemnt variables, or specify a"\ + "\$LIB_FUZZING_ENGINE compatible with your compiler" + echo "For example: CC=clang CXX=clang++ $0" + exit 0 +fi + +for i in $(ldd ./i386-softmmu/qemu-fuzz-i386 | cut -f3 -d' '); do + cp "$i" "$DEST_DIR/lib/" +done +rm ./i386-softmmu/qemu-fuzz-i386 + +# Build a second time to build the final binary with correct rpath +../configure --bindir="$DEST_DIR" --datadir="$DEST_DIR/data/" --disable-werror \ + --cc="$CC" --cxx="$CXX" --extra-cflags="$EXTRA_CFLAGS" \ + --extra-ldflags="-Wl,-rpath,'\$\$ORIGIN/lib'" +make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" i386-softmmu/fuzz + +# Copy over the datadir +cp -r ../pc-bios/ "$DEST_DIR/pc-bios" + +# Run the fuzzer with no arguments, to print the help-string and get the list +# of available fuzz-targets. Copy over the qemu-fuzz-i386, naming it according +# to each available fuzz target (See 05509c8e6d fuzz: select fuzz target using +# executable name) +for target in $(./i386-softmmu/qemu-fuzz-i386 | awk '$1 ~ /\*/ {print $2}'); +do + cp ./i386-softmmu/qemu-fuzz-i386 "$DEST_DIR/qemu-fuzz-i386-target-$target" +done + +echo "Done. The fuzzers are located in $DEST_DIR" -- 2.26.2
