MAINTAINERS | 1 + scripts/oss-fuzz/build.sh | 99 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+) create mode 100755 scripts/oss-fuzz/build.sh
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 <f4bug@amsat.org>
Signed-off-by: Alexander Bulekov <alxndr@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 <bsd@redhat.com>
R: Stefan Hajnoczi <stefanha@redhat.com>
S: Maintained
F: tests/qtest/fuzz/
+F: scripts/oss-fuzz/
Register API
M: Alistair Francis <alistair@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
Hi Alex, On Thursday, 2020-06-11 at 02:13:55 -04, Alexander Bulekov wrote: > 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 <f4bug@amsat.org> > Signed-off-by: Alexander Bulekov <alxndr@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. I'm happy that it can be used outside of OSS-Fuzz to permit creating and testing without having to set up the whole OSS-Fuzz test environment, especially for small changes. Personally, I think not using the Makefile is fine for this specific use-case - it's a very specific environment/configuration. So, in general, Reviewed-by: Darren Kenny <darren.kenny@oracle.com> but there are a couple of comments below, mostly suggestions... > > 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 <bsd@redhat.com> > R: Stefan Hajnoczi <stefanha@redhat.com> > S: Maintained > F: tests/qtest/fuzz/ > +F: scripts/oss-fuzz/ > > Register API > M: Alistair Francis <alistair@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 It may be worth adding a '-e' option here, to have the script always fail on uncaught errors. > +# > +# 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 It's just a suggestion, but I've always favoured creating a specific function to handle exits, e.g.: fatal() { echo "Error: %{*}, exiting." exit 1 } and then using that anywhere there is an unexpected exit, like here. > +fi > + > +mkdir -p "./build-oss-fuzz/" > +cd "./build-oss-fuzz/" || exit fatal() also becomes useful here, to allow a meaningful exit message - very useful later if you're looking back at logs and wondering why it exited early. Might also be worth adding the || fatal '..' to the mkdir line too, which is more likely to fail first if the cd is going to fail. > + > + > +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 This is more of an error condition, so probably would benefit from a non-zero exit code, otherwise something testing this build script for success would end up continuing when in reality it probably shouldn't. > +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" Add an 'exit 0' here. > -- > 2.26.2 Thanks, Darren.
Patchew URL: https://patchew.org/QEMU/20200611061355.31967-1-alxndr@bu.edu/ Hi, This series seems to have some coding style problems. See output below for more information: Message-id: 20200611061355.31967-1-alxndr@bu.edu Subject: [PATCH v3] fuzz: add oss-fuzz build-script Type: series === TEST SCRIPT BEGIN === #!/bin/bash git rev-parse base > /dev/null || exit 0 git config --local diff.renamelimit 0 git config --local diff.renames True git config --local diff.algorithm histogram ./scripts/checkpatch.pl --mailback base.. === TEST SCRIPT END === Updating 3c8cf5a9c21ff8782164d1def7f44bd888713384 From https://github.com/patchew-project/qemu - [tag update] patchew/20200611055807.15921-1-huth@tuxfamily.org -> patchew/20200611055807.15921-1-huth@tuxfamily.org Switched to a new branch 'test' 94a2568 fuzz: add oss-fuzz build-script === OUTPUT BEGIN === WARNING: added, moved or deleted file(s), does MAINTAINERS need updating? #28: new file mode 100755 ERROR: trailing whitespace #108: FILE: scripts/oss-fuzz/build.sh:76: +for i in $(ldd ./i386-softmmu/qemu-fuzz-i386 | cut -f3 -d' '); do $ total: 1 errors, 1 warnings, 106 lines checked Commit 94a2568dab4e (fuzz: add oss-fuzz build-script) has style problems, please review. If any of these errors are false positives report them to the maintainer, see CHECKPATCH in MAINTAINERS. === OUTPUT END === Test command exited with code: 1 The full log is available at http://patchew.org/logs/20200611061355.31967-1-alxndr@bu.edu/testing.checkpatch/?type=message. --- Email generated automatically by Patchew [https://patchew.org/]. Please send your feedback to patchew-devel@redhat.com
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