xref: /openbmc/qemu/scripts/oss-fuzz/build.sh (revision 4f7b1ecb)
1#!/bin/bash -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#     -fsanitize=fuzzer /path/to/library.a
24
25fatal () {
26    echo "Error : ${*}, exiting."
27    exit 1
28}
29
30OSS_FUZZ_BUILD_DIR="./build-oss-fuzz/"
31
32# There seems to be a bug in clang-11 (used for builds on oss-fuzz) :
33#   accel/tcg/cputlb.o: In function `load_memop':
34#   accel/tcg/cputlb.c:1505: undefined reference to `qemu_build_not_reached'
35#
36# When building with optimization, the compiler is expected to prove that the
37# statement cannot be reached, and remove it. For some reason clang-11 doesn't
38# remove it, resulting in an unresolved reference to qemu_build_not_reached
39# Undefine the __OPTIMIZE__ macro which compiler.h relies on to choose whether
40# to " #define qemu_build_not_reached()  g_assert_not_reached() "
41EXTRA_CFLAGS="$CFLAGS -U __OPTIMIZE__"
42
43if ! { [ -e "./COPYING" ] &&
44   [ -e "./MAINTAINERS" ] &&
45   [ -e "./Makefile" ] &&
46   [ -d "./docs" ] &&
47   [ -e "./VERSION" ] &&
48   [ -d "./linux-user" ] &&
49   [ -d "./system" ];} ; then
50    fatal "Please run the script from the top of the QEMU tree"
51fi
52
53mkdir -p $OSS_FUZZ_BUILD_DIR || fatal "mkdir $OSS_FUZZ_BUILD_DIR failed"
54cd $OSS_FUZZ_BUILD_DIR || fatal "cd $OSS_FUZZ_BUILD_DIR failed"
55
56
57if [ -z ${OUT+x} ]; then
58    DEST_DIR=$(realpath "./DEST_DIR")
59else
60    DEST_DIR=$OUT
61fi
62
63mkdir -p "$DEST_DIR/lib/"  # Copy the shared libraries here
64
65# Build once to get the list of dynamic lib paths, and copy them over
66../configure --disable-werror --cc="$CC" --cxx="$CXX" --enable-fuzzing \
67    --prefix="/opt/qemu-oss-fuzz" \
68    --extra-cflags="$EXTRA_CFLAGS" --target-list="i386-softmmu"
69
70if ! make "-j$(nproc)" qemu-fuzz-i386; then
71    fatal "Build failed. Please specify a compiler with fuzzing support"\
72          "using the \$CC and \$CXX environment variables"\
73          "\nFor example: CC=clang CXX=clang++ $0"
74fi
75
76if [ "$GITLAB_CI" != "true" ]; then
77    for i in $(ldd ./qemu-fuzz-i386 | cut -f3 -d' '); do
78        cp "$i" "$DEST_DIR/lib/"
79    done
80    rm qemu-fuzz-i386
81
82    # Build a second time to build the final binary with correct rpath
83    ../configure --disable-werror --cc="$CC" --cxx="$CXX" --enable-fuzzing \
84        --prefix="/opt/qemu-oss-fuzz" \
85        --extra-cflags="$EXTRA_CFLAGS" --extra-ldflags="-Wl,-rpath,\$ORIGIN/lib" \
86        --target-list="i386-softmmu"
87    make "-j$(nproc)" qemu-fuzz-i386 V=1
88fi
89
90# Place data files in the preinstall tree
91make install DESTDIR=$DEST_DIR/qemu-bundle
92rm -rf $DEST_DIR/qemu-bundle/opt/qemu-oss-fuzz/bin
93rm -rf $DEST_DIR/qemu-bundle/opt/qemu-oss-fuzz/libexec
94
95export ASAN_OPTIONS=detect_leaks=0
96targets=$(./qemu-fuzz-i386 | grep generic-fuzz | awk '$1 ~ /\*/  {print $2}')
97base_copy="$DEST_DIR/qemu-fuzz-i386-target-$(echo "$targets" | head -n 1)"
98
99cp "./qemu-fuzz-i386" "$base_copy"
100
101# Run the fuzzer with no arguments, to print the help-string and get the list
102# of available fuzz-targets. Copy over the qemu-fuzz-i386, naming it according
103# to each available fuzz target (See 05509c8e6d fuzz: select fuzz target using
104# executable name)
105for target in $(echo "$targets" | tail -n +2);
106do
107    # Ignore the generic-fuzz target, as it requires some environment variables
108    # to be configured. We have some generic-fuzz-{pc-q35, floppy, ...} targets
109    # that are thin wrappers around this target that set the required
110    # environment variables according to predefined configs.
111    if [[ $target == "generic-fuzz-"* ]]; then
112        ln  $base_copy \
113            "$DEST_DIR/qemu-fuzz-i386-target-$target"
114    fi
115done
116
117echo "Done. The fuzzers are located in $DEST_DIR"
118exit 0
119