Hook up oss-fuzz test cases as tests

This is a bit painful because a separate build of systemd is necessary. The
tests are guarded by tests!=false and slow-tests==true. Running them is not
slow, but compilation certainly is. If this proves unwieldy, we can add a
separate option controlling those builds later.

The build for each sanitizer has its own directory, and we build all fuzzer
tests there, and then pull them out one-by-one by linking into the target
position as necessary. It would be nicer to just build the desired fuzzer, but
we need to build the whole nested build as one unit.

[I also tried making systemd and nested meson subproject. This would work
nicely, but meson does not allow that because the nested target names are the
same as the outer project names. If that is ever fixed, that would be the way
to go.]

v2:
- make sure things still work if memory sanitizer is not available
v3:
- switch to syntax which works with meson 0.42.1 found in Ubuntu

4 files changed, 104 insertions, 1 deletions

diff --git a/meson.build b/meson.build
index 2e3898b3b1..4af9c7bf97 100644
--- a/meson.build
+++ b/meson.build
@@ -259,6 +259,7 @@ substs.set('RC_LOCAL_SCRIPT_PATH_STOP',                       get_option('halt-l
 cc = meson.get_compiler('c')
 pkgconfig = import('pkgconfig')
 check_compilation_sh = find_program('tools/meson-check-compilation.sh')
+meson_build_sh = find_program('tools/meson-build.sh')
 
 if get_option('tests') != 'false'
         cxx = find_program('c++', required : false)
@@ -385,6 +386,20 @@ foreach arg : ['-Wl,-z,relro',
         endif
 endforeach
 
+# Check if various sanitizers are supported
+sanitizers = []
+foreach arg : ['address']
+
+        have = run_command(check_compilation_sh,
+                           cc.cmd_array(), '-x', 'c',
+                           '-fsanitize=@0@'.format(arg),
+                           '-include', link_test_c).returncode() == 0
+        message('@0@ sanitizer supported: @1@'.format(arg, have ? 'yes' : 'no'))
+        if have
+                sanitizers += arg
+        endif
+endforeach
+
 if get_option('buildtype') != 'debug'
         foreach arg : ['-ffunction-sections',
                        '-fdata-sections']
@@ -517,6 +532,7 @@ awk = find_program('awk')
 m4 = find_program('m4')
 stat = find_program('stat')
 git = find_program('git', required : false)
+env = find_program('env')
 
 meson_make_symlink = meson.source_root() + '/tools/meson-make-symlink.sh'
 mkdir_p = 'mkdir -p $DESTDIR/@0@'
@@ -1201,10 +1217,11 @@ endforeach
 
 want_tests = get_option('tests')
 install_tests = get_option('install-tests')
+slow_tests = get_option('slow-tests')
 tests = []
 fuzzers = []
 
-conf.set10('SYSTEMD_SLOW_TESTS_DEFAULT', get_option('slow-tests'))
+conf.set10('SYSTEMD_SLOW_TESTS_DEFAULT', slow_tests)
 
 #####################################################################
 
@@ -2572,6 +2589,50 @@ endforeach
 
 ############################################################
 
+prev = ''
+foreach p : fuzz_regression_tests
+        a = p.split('/')[-3]
+        b = p.split('/')[-2]
+        c = p.split('/')[-1]
+
+        if a == 'address'
+                build = sanitize_address
+        else
+                error('unknown sanitizer @0@'.format(a))
+        endif
+
+        name = '@1@:@0@'.format(a, b)
+
+        if name != prev
+                if want_tests == 'false'
+                        message('Not compiling @0@ because tests is set to false'.format(name))
+                elif not sanitizers.contains(a)
+                        message('Not compiling @0@ because @1@ sanitizer is not available'.format(name, a))
+                elif slow_tests
+                        exe = custom_target(
+                                name,
+                                output : name,
+                                depends : build,
+                                command : [env, 'ln', '-fs',
+                                           join_paths(build.full_path(), b),
+                                           '@OUTPUT@'],
+                                build_by_default : true)
+                else
+                        message('Not compiling @0@ because slow-tests is set to false'.format(name))
+                endif
+        endif
+        prev = name
+
+        if want_tests != 'false' and slow_tests
+                test(c, env, args : [exe.full_path(),
+                                     join_paths(meson.source_root(),
+                                                'test/fuzz-regressions',
+                                                p)])
+        endif
+endforeach
+
+############################################################
+
 if git.found()
         all_files = run_command(
                 git,
diff --git a/test/fuzz-regressions/meson.build b/test/fuzz-regressions/meson.build
new file mode 100644
index 0000000000..de69c941ea
--- /dev/null
+++ b/test/fuzz-regressions/meson.build
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: LGPL-2.1+
+#
+# Copyright 2018 Zbigniew Jędrzejewski-Szmek
+#
+# systemd is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation; either version 2.1 of the License, or
+# (at your option) any later version.
+#
+# systemd is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with systemd; If not, see <http://www.gnu.org/licenses/>.
+
+sanitize_address = custom_target(
+        'sanitize-address-fuzzers',
+        output : 'sanitize-address-fuzzers',
+        command : [meson_build_sh,
+                   meson.source_root(),
+                   '@OUTPUT@',
+                   'fuzzers',
+                   '-Db_lundef=false -Db_sanitize=address'])
+
+fuzz_regression_tests = '''
+        address/fuzz-dns-packet/oss-fuzz-5465
+        address/fuzz-dns-packet/issue-7888
+'''.split()
diff --git a/test/meson.build b/test/meson.build
index 5c533f4833..4667628b24 100644
--- a/test/meson.build
+++ b/test/meson.build
@@ -228,3 +228,5 @@ if conf.get('ENABLE_HWDB') == 1
              hwdb_test_sh,
              timeout : 90)
 endif
+
+subdir('fuzz-regressions')
diff --git a/tools/meson-build.sh b/tools/meson-build.sh
new file mode 100755
index 0000000000..302749d8ed
--- /dev/null
+++ b/tools/meson-build.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+set -eux
+
+src="$1"
+dst="$2"
+target="$3"
+options="$4"
+
+[ -d "$dst" ] || meson "$src" "$dst" $options
+ninja -C "$dst" "$target"