From 5e47215080018b7eea2054ec70f5d686715d66ee Mon Sep 17 00:00:00 2001
From: Josh Steadmon <steadmon@google.com>
Date: Fri, 12 Oct 2018 17:58:40 -0700
Subject: fuzz: add basic fuzz testing target.

fuzz-pack-headers.c provides a fuzzing entry point compatible with
libFuzzer (and possibly other fuzzing engines).

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'Makefile')

diff --git a/Makefile b/Makefile
index 13e1c52478..7f5a19b8ab 100644
--- a/Makefile
+++ b/Makefile
@@ -590,6 +590,8 @@ XDIFF_OBJS =
 VCSSVN_OBJS =
 GENERATED_H =
 EXTRA_CPPFLAGS =
+FUZZ_OBJS =
+FUZZ_PROGRAMS =
 LIB_OBJS =
 PROGRAM_OBJS =
 PROGRAMS =
@@ -682,6 +684,13 @@ SCRIPTS = $(SCRIPT_SH_INS) \
 
 ETAGS_TARGET = TAGS
 
+FUZZ_OBJS += fuzz-pack-headers.o
+
+# Always build fuzz objects even if not testing, to prevent bit-rot.
+all:: $(FUZZ_OBJS)
+
+FUZZ_PROGRAMS += $(patsubst %.o,%,$(FUZZ_OBJS))
+
 # Empty...
 EXTRA_PROGRAMS =
 
@@ -2250,6 +2259,7 @@ TEST_OBJS := $(patsubst %$X,%.o,$(TEST_PROGRAMS)) $(patsubst %,t/helper/%,$(TEST
 OBJECTS := $(LIB_OBJS) $(BUILTIN_OBJS) $(PROGRAM_OBJS) $(TEST_OBJS) \
 	$(XDIFF_OBJS) \
 	$(VCSSVN_OBJS) \
+	$(FUZZ_OBJS) \
 	common-main.o \
 	git.o
 ifndef NO_CURL
@@ -2937,6 +2947,7 @@ clean: profile-clean coverage-clean cocciclean
 	$(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB)
 	$(RM) $(ALL_PROGRAMS) $(SCRIPT_LIB) $(BUILT_INS) git$X
 	$(RM) $(TEST_PROGRAMS) $(NO_INSTALL)
+	$(RM) $(FUZZ_PROGRAMS)
 	$(RM) -r bin-wrappers $(dep_dirs)
 	$(RM) -r po/build/
 	$(RM) *.pyc *.pyo */*.pyc */*.pyo command-list.h $(ETAGS_TARGET) tags cscope*
@@ -3061,3 +3072,24 @@ cover_db: coverage-report
 cover_db_html: cover_db
 	cover -report html -outputdir cover_db_html cover_db
 
+
+### Fuzz testing
+#
+# Building fuzz targets generally requires a special set of compiler flags that
+# are not necessarily appropriate for general builds, and that vary greatly
+# depending on the compiler version used.
+#
+# An example command to build against libFuzzer from LLVM 4.0.0:
+#
+# make CC=clang CXX=clang++ \
+#      CFLAGS="-fsanitize-coverage=trace-pc-guard -fsanitize=address" \
+#      LIB_FUZZING_ENGINE=/usr/lib/llvm-4.0/lib/libFuzzer.a \
+#      fuzz-all
+#
+.PHONY: fuzz-all
+
+$(FUZZ_PROGRAMS): all
+	$(QUIET_LINK)$(CXX) $(CFLAGS) $(LIB_OBJS) $(BUILTIN_OBJS) \
+		$(XDIFF_OBJS) $(EXTLIBS) git.o $@.o $(LIB_FUZZING_ENGINE) -o $@
+
+fuzz-all: $(FUZZ_PROGRAMS)
-- 
cgit v1.2.3


From 1127a98ccea2a911d2043dcc9ce301e080a3cc39 Mon Sep 17 00:00:00 2001
From: Josh Steadmon <steadmon@google.com>
Date: Fri, 12 Oct 2018 17:58:41 -0700
Subject: fuzz: add fuzz testing for packfile indices.

Breaks the majority of check_packed_git_idx() into a separate function,
load_idx(). The latter function operates on arbitrary buffers, which
makes it suitable as a fuzzing test target.

Signed-off-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 Makefile | 1 +
 1 file changed, 1 insertion(+)

(limited to 'Makefile')

diff --git a/Makefile b/Makefile
index 7f5a19b8ab..1b3d893090 100644
--- a/Makefile
+++ b/Makefile
@@ -685,6 +685,7 @@ SCRIPTS = $(SCRIPT_SH_INS) \
 ETAGS_TARGET = TAGS
 
 FUZZ_OBJS += fuzz-pack-headers.o
+FUZZ_OBJS += fuzz-pack-idx.o
 
 # Always build fuzz objects even if not testing, to prevent bit-rot.
 all:: $(FUZZ_OBJS)
-- 
cgit v1.2.3