Re: [PATCH 07/24] configure, meson: move fuzzing configuration to Meson

[Alexander Bulekov]

On 211007 1508, Paolo Bonzini wrote:
> Cc: Alexander Oleinik <alxndr@bu.edu>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Tested-by: Alexander Bulekov <alxndr@bu.edu>

Thanks!

> ---
>  configure                    | 71 +++---------------------------------
>  meson.build                  | 51 +++++++++++++++++++++++---
>  meson_options.txt            |  4 ++
>  tests/qtest/fuzz/meson.build |  6 ++-
>  4 files changed, 59 insertions(+), 73 deletions(-)
> 
> diff --git a/configure b/configure
> index 5541671b58..f5dfcf1a08 100755
> --- a/configure
> +++ b/configure
> @@ -436,7 +436,7 @@ debug_mutex="no"
>  libpmem="auto"
>  default_devices="true"
>  plugins="$default_feature"
> -fuzzing="no"
> +fuzzing="false"
>  rng_none="no"
>  secret_keyring="$default_feature"
>  libdaxctl="auto"
> @@ -566,15 +566,6 @@ int main(void) { return 0; }
>  EOF
>  }
>  
> -write_c_fuzzer_skeleton() {
> -    cat > $TMPC <<EOF
> -#include <stdint.h>
> -#include <sys/types.h>
> -int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
> -int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { return 0; }
> -EOF
> -}
> -
>  if check_define __linux__ ; then
>    targetos="Linux"
>  elif check_define _WIN32 ; then
> @@ -1538,9 +1529,9 @@ for opt do
>    ;;
>    --disable-containers) use_containers="no"
>    ;;
> -  --enable-fuzzing) fuzzing=yes
> +  --enable-fuzzing) fuzzing=true
>    ;;
> -  --disable-fuzzing) fuzzing=no
> +  --disable-fuzzing) fuzzing=false
>    ;;
>    --gdb=*) gdb_bin="$optarg"
>    ;;
> @@ -4055,26 +4046,6 @@ EOF
>    fi
>  fi
>  
> -##########################################
> -# checks for fuzzer
> -if test "$fuzzing" = "yes" ; then
> -  write_c_fuzzer_skeleton
> -  if test -z "${LIB_FUZZING_ENGINE+xxx}"; then
> -    if compile_prog "$CPU_CFLAGS -Werror -fsanitize=fuzzer" ""; then
> -      have_fuzzer=yes
> -    else
> -      error_exit "Your compiler doesn't support -fsanitize=fuzzer"
> -      exit 1
> -    fi
> -  fi
> -
> -  have_clang_coverage_filter=no
> -  echo > $TMPTXT
> -  if compile_prog "$CPU_CFLAGS -Werror -fsanitize=fuzzer 
> -fsanitize-coverage-allowlist=$TMPTXT" ""; then
> -    have_clang_coverage_filter=yes
> -  fi
> -fi
> -
>  # Thread sanitizer is, for now, much noisier than the other sanitizers;
>  # keep it separate until that is not the case.
>  if test "$tsan" = "yes" && test "$sanitizers" = "yes"; then
> @@ -4700,34 +4671,6 @@ fi
>  if test "$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 "${LIB_FUZZING_ENGINE+xxx}" ; then
> -    # Add CFLAGS to tell clang to add fuzzer-related instrumentation to all 
> the
> -    # compiled code.
> -    QEMU_CFLAGS="$QEMU_CFLAGS -fsanitize=fuzzer-no-link"
> -    # To build non-fuzzer binaries with --enable-fuzzing, link everything 
> with
> -    # fsanitize=fuzzer-no-link. Otherwise, the linker will be unable to bind
> -    # the fuzzer-related callbacks added by instrumentation.
> -    QEMU_LDFLAGS="$QEMU_LDFLAGS -fsanitize=fuzzer-no-link"
> -    # For the actual fuzzer binaries, we need to link against the libfuzzer
> -    # library. Provide the flags for doing this in FUZZ_EXE_LDFLAGS. The 
> meson
> -    # rule for the fuzzer adds these to the link_args. They need to be
> -    # configurable, to support OSS-Fuzz
> -    FUZZ_EXE_LDFLAGS="-fsanitize=fuzzer"
> -  else
> -    FUZZ_EXE_LDFLAGS="$LIB_FUZZING_ENGINE"
> -  fi
> -
> -  # Specify a filter to only instrument code that is directly related to
> -  # virtual-devices.
> -  if test "$have_clang_coverage_filter" = "yes" ; then
> -    cp "$source_path/scripts/oss-fuzz/instrumentation-filter-template" \
> -       instrumentation-filter
> -    QEMU_CFLAGS="$QEMU_CFLAGS 
> -fsanitize-coverage-allowlist=instrumentation-filter"
> -  fi
> -fi
>  
>  if test "$plugins" = "yes" ; then
>      echo "CONFIG_PLUGIN=y" >> $config_host_mak
> @@ -4791,11 +4734,6 @@ if test "$gcov" = "yes" ; then
>    echo "CONFIG_GCOV=y" >> $config_host_mak
>  fi
>  
> -if test "$fuzzing" != "no"; then
> -    echo "CONFIG_FUZZ=y" >> $config_host_mak
> -fi
> -echo "FUZZ_EXE_LDFLAGS=$FUZZ_EXE_LDFLAGS" >> $config_host_mak
> -
>  if test "$rng_none" = "yes"; then
>    echo "CONFIG_RNG_NONE=y" >> $config_host_mak
>  fi
> @@ -5031,7 +4969,8 @@ if test "$skip_meson" = no; then
>          -Dstrip=$(if test "$strip_opt" = yes; then echo true; else echo 
> false; fi) \
>          -Db_pie=$(if test "$pie" = yes; then echo true; else echo false; fi) 
> \
>          -Db_coverage=$(if test "$gcov" = yes; then echo true; else echo 
> false; fi) \
> -        -Db_lto=$lto -Dcfi=$cfi -Dcfi_debug=$cfi_debug \
> +        -Db_lto=$lto -Dcfi=$cfi -Dcfi_debug=$cfi_debug -Dfuzzing=$fuzzing \
> +        $(test -n "${LIB_FUZZING_ENGINE+xxx}" && echo 
> "-Dfuzzing_engine=$LIB_FUZZING_ENGINE") \
>          -Dmalloc=$malloc -Dmalloc_trim=$malloc_trim -Dsparse=$sparse \
>          -Dkvm=$kvm -Dhax=$hax -Dwhpx=$whpx -Dhvf=$hvf -Dnvmm=$nvmm \
>          -Dxen=$xen -Dxen_pci_passthrough=$xen_pci_passthrough -Dtcg=$tcg \
> diff --git a/meson.build b/meson.build
> index f03bfff7a1..745b8c3c46 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -117,10 +117,37 @@ endforeach
>  
>  # Specify linker-script with add_project_link_arguments so that it is not 
> placed
>  # within a linker --start-group/--end-group pair
> -if 'CONFIG_FUZZ' in config_host
> -   add_project_link_arguments(['-Wl,-T,',
> -                               (meson.current_source_dir() / 
> 'tests/qtest/fuzz/fork_fuzz.ld')],
> +if get_option('fuzzing')
> +  add_project_link_arguments(['-Wl,-T,',
> +                              (meson.current_source_dir() / 
> 'tests/qtest/fuzz/fork_fuzz.ld')],
> +                             native: false, language: ['c', 'cpp', 'objc'])
> +
> +  # Specify a filter to only instrument code that is directly related to
> +  # virtual-devices.
> +  configure_file(output: 'instrumentation-filter',
> +                 input: 'scripts/oss-fuzz/instrumentation-filter-template',
> +                 copy: true)
> +  add_global_arguments(
> +      
> cc.get_supported_arguments('-fsanitize-coverage-allowlist=instrumentation-filter'),
> +      native: false, language: ['c', 'cpp', 'objc'])
> +
> +  if get_option('fuzzing_engine') == ''
> +    # Add CFLAGS to tell clang to add fuzzer-related instrumentation to all 
> the
> +    # compiled code.  To build non-fuzzer binaries with --enable-fuzzing, 
> link
> +    # everything with fsanitize=fuzzer-no-link. Otherwise, the linker will be
> +    # unable to bind the fuzzer-related callbacks added by instrumentation.
> +    add_global_arguments('-fsanitize=fuzzer-no-link',
> +                         native: false, language: ['c', 'cpp', 'objc'])
> +    add_global_link_arguments('-fsanitize=fuzzer-no-link',
>                                native: false, language: ['c', 'cpp', 'objc'])
> +    # For the actual fuzzer binaries, we need to link against the libfuzzer
> +    # library. They need to be configurable, to support OSS-Fuzz
> +    fuzz_exe_ldflags = ['-fsanitize=fuzzer']
> +  else
> +    # LIB_FUZZING_ENGINE was set; assume we are running on OSS-Fuzz, and
> +    # the needed CFLAGS have already been provided
> +    fuzz_exe_ldflags = get_option('fuzzing_engine').split()
> +  endif
>  endif
>  
>  add_global_arguments(config_host['QEMU_CFLAGS'].split(),
> @@ -163,6 +190,17 @@ endif
>  # Target-specific checks and dependencies #
>  ###########################################
>  
> +if get_option('fuzzing') and get_option('fuzzing_engine') == '' and \
> +    not cc.links('''
> +          #include <stdint.h>
> +          #include <sys/types.h>
> +          int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size);
> +          int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { 
> return 0; }
> +        ''',
> +        args: ['-Werror', '-fsanitize=fuzzer'])
> +  error('Your compiler does not support -fsanitize=fuzzer')
> +endif
> +
>  if targetos != 'linux' and get_option('mpath').enabled()
>    error('Multipath is supported only on Linux')
>  endif
> @@ -1327,6 +1365,7 @@ config_host_data.set_quoted('CONFIG_SYSCONFDIR', 
> get_option('prefix') / get_opti
>  config_host_data.set('CONFIG_ATTR', libattr.found())
>  config_host_data.set('CONFIG_BRLAPI', brlapi.found())
>  config_host_data.set('CONFIG_COCOA', cocoa.found())
> +config_host_data.set('CONFIG_FUZZ', get_option('fuzzing'))
>  config_host_data.set('CONFIG_LIBUDEV', libudev.found())
>  config_host_data.set('CONFIG_LZO', lzo.found())
>  config_host_data.set('CONFIG_MPATH', mpathpersist.found())
> @@ -1602,7 +1641,7 @@ endif
>  
>  have_ivshmem = config_host_data.get('CONFIG_EVENTFD')
>  host_kconfig = \
> -  ('CONFIG_FUZZ' in config_host ? ['CONFIG_FUZZ=y'] : []) + \
> +  (get_option('fuzzing') ? ['CONFIG_FUZZ=y'] : []) + \
>    ('CONFIG_TPM' in config_host ? ['CONFIG_TPM=y'] : []) + \
>    ('CONFIG_SPICE' in config_host ? ['CONFIG_SPICE=y'] : []) + \
>    (have_ivshmem ? ['CONFIG_IVSHMEM=y'] : []) + \
> @@ -2729,7 +2768,7 @@ foreach target : target_dirs
>          'dependencies': []
>        }]
>      endif
> -    if config_host.has_key('CONFIG_FUZZ')
> +    if get_option('fuzzing')
>        specific_fuzz = specific_fuzz_ss.apply(config_target, strict: false)
>        execs += [{
>          'name': 'qemu-fuzz-' + target_name,
> @@ -2969,7 +3008,7 @@ summary_info += {'module support':    
> config_host.has_key('CONFIG_MODULES')}
>  if config_host.has_key('CONFIG_MODULES')
>    summary_info += {'alternative module path': 
> config_host.has_key('CONFIG_MODULE_UPGRADES')}
>  endif
> -summary_info += {'fuzzing support':   config_host.has_key('CONFIG_FUZZ')}
> +summary_info += {'fuzzing support':   get_option('fuzzing')}
>  if have_system
>    summary_info += {'Audio drivers':     ' '.join(audio_drivers_selected)}
>  endif
> diff --git a/meson_options.txt b/meson_options.txt
> index 052c4f088e..100c30e967 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -11,9 +11,13 @@ option('default_devices', type : 'boolean', value : true,
>  option('audio_drv_list', type: 'array', value: ['default'],
>         choices: ['alsa', 'coreaudio', 'default', 'dsound', 'jack', 'oss', 
> 'pa', 'sdl'],
>         description: 'Set audio driver list')
> +option('fuzzing_engine', type : 'string', value : '',
> +       description: 'fuzzing engine library for OSS-Fuzz')
>  
>  option('docs', type : 'feature', value : 'auto',
>         description: 'Documentations build support')
> +option('fuzzing', type : 'boolean', value: false,
> +       description: 'build fuzzing targets')
>  option('gettext', type : 'feature', value : 'auto',
>         description: 'Localization of the GTK+ user interface')
>  option('install_blobs', type : 'boolean', value : true,
> diff --git a/tests/qtest/fuzz/meson.build b/tests/qtest/fuzz/meson.build
> index 8af6848cd5..189901d4a2 100644
> --- a/tests/qtest/fuzz/meson.build
> +++ b/tests/qtest/fuzz/meson.build
> @@ -1,3 +1,7 @@
> +if not get_option('fuzzing')
> +  subdir_done()
> +endif
> +
>  specific_fuzz_ss.add(files('fuzz.c', 'fork_fuzz.c', 'qos_fuzz.c',
>                             'qtest_wrappers.c'), qos)
>  
> @@ -9,7 +13,7 @@ specific_fuzz_ss.add(when: 'CONFIG_VIRTIO_BLK', if_true: 
> files('virtio_blk_fuzz.
>  specific_fuzz_ss.add(files('generic_fuzz.c'))
>  
>  fork_fuzz = declare_dependency(
> -  link_args: config_host['FUZZ_EXE_LDFLAGS'].split() +
> +  link_args: fuzz_exe_ldflags +
>               ['-Wl,-wrap,qtest_inb',
>                '-Wl,-wrap,qtest_inw',
>                '-Wl,-wrap,qtest_inl',
> -- 
> 2.31.1
> 
>