scripts/oss-fuzz/build.sh

   1 #!/bin/sh -e
   2 #
   3 # OSS-Fuzz build script. See:
   4 # https://google.github.io/oss-fuzz/getting-started/new-project-guide/#buildsh
   5 #
   6 # The file is consumed by:
   7 # https://github.com/google/oss-fuzz/blob/master/projects/qemu/Dockerfiles
   8 #
   9 # This code is licensed under the GPL version 2 or later.  See
  10 # the COPYING file in the top-level directory.
  11 #
  12
  13 # build project
  14 # e.g.
  15 # ./autogen.sh
  16 # ./configure
  17 # make -j$(nproc) all
  18
  19 # build fuzzers
  20 # e.g.
  21 # $CXX $CXXFLAGS -std=c++11 -Iinclude \
  22 #     /path/to/name_of_fuzzer.cc -o $OUT/name_of_fuzzer \
  23 #     $LIB_FUZZING_ENGINE /path/to/library.a
  24
  25 fatal () {
  26     echo "Error : ${*}, exiting."
  27     exit 1
  28 }
  29
  30 OSS_FUZZ_BUILD_DIR="./build-oss-fuzz/"
  31
  32 # There seems to be a bug in clang-11 (used for builds on oss-fuzz) :
  33 #   accel/tcg/cputlb.o: In function `load_memop':
  34 #   accel/tcg/cputlb.c:1505: undefined reference to `qemu_build_not_reached'
  35 #
  36 # When building with optimization, the compiler is expected to prove that the
  37 # statement cannot be reached, and remove it. For some reason clang-11 doesn't
  38 # remove it, resulting in an unresolved reference to qemu_build_not_reached
  39 # Undefine the __OPTIMIZE__ macro which compiler.h relies on to choose whether
  40 # to " #define qemu_build_not_reached()  g_assert_not_reached() "
  41 EXTRA_CFLAGS="$CFLAGS -U __OPTIMIZE__"
  42
  43 if ! { [ -e "./COPYING" ] &&
  44    [ -e "./MAINTAINERS" ] &&
  45    [ -e "./Makefile" ] &&
  46    [ -e "./docs" ] &&
  47    [ -e "./VERSION" ] &&
  48    [ -e "./linux-user" ] &&
  49    [ -e "./softmmu" ];} ; then
  50     fatal "Please run the script from the top of the QEMU tree"
  51 fi
  52
  53 mkdir -p $OSS_FUZZ_BUILD_DIR || fatal "mkdir $OSS_FUZZ_BUILD_DIR failed"
  54 cd $OSS_FUZZ_BUILD_DIR || fatal "cd $OSS_FUZZ_BUILD_DIR failed"
  55
  56
  57 if [ -z ${LIB_FUZZING_ENGINE+x} ]; then
  58     LIB_FUZZING_ENGINE="-fsanitize=fuzzer"
  59 fi
  60
  61 if [ -z ${OUT+x} ]; then
  62     DEST_DIR=$(realpath "./DEST_DIR")
  63 else
  64     DEST_DIR=$OUT
  65 fi
  66
  67 mkdir -p "$DEST_DIR/lib/"  # Copy the shared libraries here
  68
  69 # Build once to get the list of dynamic lib paths, and copy them over
  70 ../configure --disable-werror --cc="$CC" --cxx="$CXX" \
  71     --extra-cflags="$EXTRA_CFLAGS" --target-list="i386-softmmu"
  72
  73 if ! make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" \
  74     i386-softmmu/fuzz; then
  75     fatal "Build failed. Please specify a compiler with fuzzing support"\
  76           "using the \$CC and \$CXX environemnt variables, or specify a"\
  77           "\$LIB_FUZZING_ENGINE compatible with your compiler"\
  78           "\nFor example: CC=clang CXX=clang++ $0"
  79 fi
  80
  81 for i in $(ldd ./i386-softmmu/qemu-fuzz-i386 | cut -f3 -d' '); do
  82     cp "$i" "$DEST_DIR/lib/"
  83 done
  84 rm ./i386-softmmu/qemu-fuzz-i386
  85
  86 # Build a second time to build the final binary with correct rpath
  87 ../configure --bindir="$DEST_DIR" --datadir="$DEST_DIR/data/" --disable-werror \
  88     --cc="$CC" --cxx="$CXX" --extra-cflags="$EXTRA_CFLAGS" \
  89     --extra-ldflags="-Wl,-rpath,'\$\$ORIGIN/lib'"
  90 make CONFIG_FUZZ=y CFLAGS="$LIB_FUZZING_ENGINE" "-j$(nproc)" i386-softmmu/fuzz
  91
  92 # Copy over the datadir
  93 cp  -r ../pc-bios/ "$DEST_DIR/pc-bios"
  94
  95 # Run the fuzzer with no arguments, to print the help-string and get the list
  96 # of available fuzz-targets. Copy over the qemu-fuzz-i386, naming it according
  97 # to each available fuzz target (See 05509c8e6d fuzz: select fuzz target using
  98 # executable name)
  99 for target in $(./i386-softmmu/qemu-fuzz-i386 | awk '$1 ~ /\*/  {print $2}');
 100 do
 101     cp ./i386-softmmu/qemu-fuzz-i386 "$DEST_DIR/qemu-fuzz-i386-target-$target"
 102 done
 103
 104 echo "Done. The fuzzers are located in $DEST_DIR"
 105 exit 0