fuzz: Add support for custom fuzzing library

On oss-fuzz, we must use the LIB_FUZZING_ENGINE and CFLAGS environment
variables, rather than -fsanitize=fuzzer. With this change, when
LIB_FUZZING_ENGINE is set, the --enable-fuzzing configure option will
use that environment variable during the linking stage, rather than
-fsanitize=fuzzer

Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20200902173652.307222-3-alxndr@bu.edu>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Alexander Bulekov 2020-09-02 13:36:51 -04:00 committed by Paolo Bonzini
parent c46f76d158
commit 54c9e41d47
2 changed files with 12 additions and 4 deletions

10
configure vendored
View File

@ -6048,7 +6048,7 @@ fi
##########################################
# checks for fuzzer
if test "$fuzzing" = "yes" ; then
if test "$fuzzing" = "yes" && test -z "${LIB_FUZZING_ENGINE+xxx}"; then
write_c_fuzzer_skeleton
if compile_prog "$CPU_CFLAGS -Werror -fsanitize=fuzzer" ""; then
have_fuzzer=yes
@ -7354,7 +7354,14 @@ if test "$have_mlockall" = "yes" ; then
echo "HAVE_MLOCKALL=y" >> $config_host_mak
fi
if test "$fuzzing" = "yes" ; then
# If LIB_FUZZING_ENGINE is set, assume we are running on OSS-Fuzz, and the
# needed CFLAGS have already been provided
if test -z "${LIB_FUZZING_ENGINE+xxx}" ; then
QEMU_CFLAGS="$QEMU_CFLAGS -fsanitize=fuzzer-no-link"
FUZZ_EXE_LDFLAGS="-fsanitize=fuzzer"
else
FUZZ_EXE_LDFLAGS="$LIB_FUZZING_ENGINE"
fi
fi
if test "$plugins" = "yes" ; then
@ -7455,6 +7462,7 @@ fi
if test "$fuzzing" != "no"; then
echo "CONFIG_FUZZ=y" >> $config_host_mak
fi
echo "FUZZ_EXE_LDFLAGS=$FUZZ_EXE_LDFLAGS" >> $config_host_mak
if test "$edk2_blobs" = "yes" ; then
echo "DECOMPRESS_EDK2_BLOBS=y" >> $config_host_mak

View File

@ -7,8 +7,8 @@ specific_fuzz_ss.add(when: 'CONFIG_VIRTIO_NET', if_true: files('virtio_net_fuzz.
specific_fuzz_ss.add(when: 'CONFIG_VIRTIO_SCSI', if_true: files('virtio_scsi_fuzz.c'))
fork_fuzz = declare_dependency(
link_args: ['-fsanitize=fuzzer',
'-Wl,-wrap,qtest_inb',
link_args: config_host['FUZZ_EXE_LDFLAGS'].split() +
['-Wl,-wrap,qtest_inb',
'-Wl,-wrap,qtest_inw',
'-Wl,-wrap,qtest_inl',
'-Wl,-wrap,qtest_outb',