diff --git a/CMakeLists.txt b/CMakeLists.txt
index 50f092ec78a..459fbaa5644 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5541,7 +5541,7 @@ target_link_libraries(channel_create_test
 endif (gRPC_BUILD_TESTS)
 
 add_executable(check_epollexclusive
-  test/build/check_epollexclusive.cc
+  test/build/check_epollexclusive.c
 )
 
 
@@ -14765,7 +14765,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(api_fuzzer_one_entry
   test/core/end2end/fuzzers/api_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14796,7 +14796,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(client_fuzzer_one_entry
   test/core/end2end/fuzzers/client_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14827,7 +14827,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(hpack_parser_fuzzer_test_one_entry
   test/core/transport/chttp2/hpack_parser_fuzzer_test.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14858,7 +14858,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(http_request_fuzzer_test_one_entry
   test/core/http/request_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14889,7 +14889,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(http_response_fuzzer_test_one_entry
   test/core/http/response_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14920,7 +14920,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(json_fuzzer_test_one_entry
   test/core/json/fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14951,7 +14951,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(nanopb_fuzzer_response_test_one_entry
   test/core/nanopb/fuzzer_response.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -14982,7 +14982,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(nanopb_fuzzer_serverlist_test_one_entry
   test/core/nanopb/fuzzer_serverlist.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -15013,7 +15013,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(percent_decode_fuzzer_one_entry
   test/core/slice/percent_decode_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -15044,7 +15044,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(percent_encode_fuzzer_one_entry
   test/core/slice/percent_encode_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -15075,7 +15075,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(server_fuzzer_one_entry
   test/core/end2end/fuzzers/server_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -15106,7 +15106,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(ssl_server_fuzzer_one_entry
   test/core/security/ssl_server_fuzzer.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
@@ -15137,7 +15137,7 @@ if (gRPC_BUILD_TESTS)
 
 add_executable(uri_fuzzer_test_one_entry
   test/core/client_channel/uri_fuzzer_test.cc
-  test/core/util/one_corpus_entry_fuzzer.c
+  test/core/util/one_corpus_entry_fuzzer.cc
 )
 
 
diff --git a/Makefile b/Makefile
index 04a6084510f..53836be33d7 100644
--- a/Makefile
+++ b/Makefile
@@ -9233,7 +9233,7 @@ endif
 
 
 CHECK_EPOLLEXCLUSIVE_SRC = \
-    test/build/check_epollexclusive.cc \
+    test/build/check_epollexclusive.c \
 
 CHECK_EPOLLEXCLUSIVE_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(CHECK_EPOLLEXCLUSIVE_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -19848,7 +19848,7 @@ endif
 
 API_FUZZER_ONE_ENTRY_SRC = \
     test/core/end2end/fuzzers/api_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 API_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(API_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -19883,7 +19883,7 @@ endif
 
 CLIENT_FUZZER_ONE_ENTRY_SRC = \
     test/core/end2end/fuzzers/client_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 CLIENT_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(CLIENT_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -19918,7 +19918,7 @@ endif
 
 HPACK_PARSER_FUZZER_TEST_ONE_ENTRY_SRC = \
     test/core/transport/chttp2/hpack_parser_fuzzer_test.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 HPACK_PARSER_FUZZER_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(HPACK_PARSER_FUZZER_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -19953,7 +19953,7 @@ endif
 
 HTTP_REQUEST_FUZZER_TEST_ONE_ENTRY_SRC = \
     test/core/http/request_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 HTTP_REQUEST_FUZZER_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(HTTP_REQUEST_FUZZER_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -19988,7 +19988,7 @@ endif
 
 HTTP_RESPONSE_FUZZER_TEST_ONE_ENTRY_SRC = \
     test/core/http/response_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 HTTP_RESPONSE_FUZZER_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(HTTP_RESPONSE_FUZZER_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20023,7 +20023,7 @@ endif
 
 JSON_FUZZER_TEST_ONE_ENTRY_SRC = \
     test/core/json/fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 JSON_FUZZER_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(JSON_FUZZER_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20058,7 +20058,7 @@ endif
 
 NANOPB_FUZZER_RESPONSE_TEST_ONE_ENTRY_SRC = \
     test/core/nanopb/fuzzer_response.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 NANOPB_FUZZER_RESPONSE_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(NANOPB_FUZZER_RESPONSE_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20093,7 +20093,7 @@ endif
 
 NANOPB_FUZZER_SERVERLIST_TEST_ONE_ENTRY_SRC = \
     test/core/nanopb/fuzzer_serverlist.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 NANOPB_FUZZER_SERVERLIST_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(NANOPB_FUZZER_SERVERLIST_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20128,7 +20128,7 @@ endif
 
 PERCENT_DECODE_FUZZER_ONE_ENTRY_SRC = \
     test/core/slice/percent_decode_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 PERCENT_DECODE_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(PERCENT_DECODE_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20163,7 +20163,7 @@ endif
 
 PERCENT_ENCODE_FUZZER_ONE_ENTRY_SRC = \
     test/core/slice/percent_encode_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 PERCENT_ENCODE_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(PERCENT_ENCODE_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20198,7 +20198,7 @@ endif
 
 SERVER_FUZZER_ONE_ENTRY_SRC = \
     test/core/end2end/fuzzers/server_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 SERVER_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(SERVER_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20233,7 +20233,7 @@ endif
 
 SSL_SERVER_FUZZER_ONE_ENTRY_SRC = \
     test/core/security/ssl_server_fuzzer.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 SSL_SERVER_FUZZER_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(SSL_SERVER_FUZZER_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
@@ -20268,7 +20268,7 @@ endif
 
 URI_FUZZER_TEST_ONE_ENTRY_SRC = \
     test/core/client_channel/uri_fuzzer_test.cc \
-    test/core/util/one_corpus_entry_fuzzer.c \
+    test/core/util/one_corpus_entry_fuzzer.cc \
 
 URI_FUZZER_TEST_ONE_ENTRY_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(URI_FUZZER_TEST_ONE_ENTRY_SRC))))
 ifeq ($(NO_SECURE),true)
diff --git a/build.yaml b/build.yaml
index 5d53bea378f..e93c9294e7e 100644
--- a/build.yaml
+++ b/build.yaml
@@ -1892,7 +1892,7 @@ targets:
   build: tool
   language: c
   src:
-  - test/build/check_epollexclusive.cc
+  - test/build/check_epollexclusive.c
   deps:
   - grpc
   - gpr
diff --git a/test/core/slice/slice_test.cc b/test/core/slice/slice_test.cc
index cda37fb8d95..ad62344e4d8 100644
--- a/test/core/slice/slice_test.cc
+++ b/test/core/slice/slice_test.cc
@@ -43,8 +43,8 @@ static void test_slice_malloc_returns_something_sensible(void) {
     slice = grpc_slice_malloc(length);
     /* If there is a length, slice.data must be non-NULL. If length is zero
        we don't care. */
-    if (length) {
-      GPR_ASSERT(GRPC_SLICE_START_PTR(slice));
+    if (length > GRPC_SLICE_INLINED_SIZE) {
+      GPR_ASSERT(slice.data.refcounted.bytes);
     }
     /* Returned slice length must be what was requested. */
     GPR_ASSERT(GRPC_SLICE_LENGTH(slice) == length);
diff --git a/tools/buildgen/plugins/make_fuzzer_tests.py b/tools/buildgen/plugins/make_fuzzer_tests.py
index 6d318fe8310..56dad2d5610 100644
--- a/tools/buildgen/plugins/make_fuzzer_tests.py
+++ b/tools/buildgen/plugins/make_fuzzer_tests.py
@@ -26,8 +26,8 @@ def mako_plugin(dictionary):
       new_target['build'] = 'test'
       new_target['name'] += '_one_entry'
       new_target['run'] = False
-      new_target['src'].append('test/core/util/one_corpus_entry_fuzzer.c')
-      new_target['own_src'].append('test/core/util/one_corpus_entry_fuzzer.c')
+      new_target['src'].append('test/core/util/one_corpus_entry_fuzzer.cc')
+      new_target['own_src'].append('test/core/util/one_corpus_entry_fuzzer.cc')
       targets.append(new_target)
       for corpus in new_target['corpus_dirs']:
         for fn in sorted(glob.glob('%s/*' % corpus)):
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index 231cbe550e7..de2bb4fb9b8 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -276,7 +276,7 @@
     "language": "c", 
     "name": "check_epollexclusive", 
     "src": [
-      "test/build/check_epollexclusive.cc"
+      "test/build/check_epollexclusive.c"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5770,7 +5770,7 @@
     "name": "api_fuzzer_one_entry", 
     "src": [
       "test/core/end2end/fuzzers/api_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5788,7 +5788,7 @@
     "name": "client_fuzzer_one_entry", 
     "src": [
       "test/core/end2end/fuzzers/client_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5806,7 +5806,7 @@
     "name": "hpack_parser_fuzzer_test_one_entry", 
     "src": [
       "test/core/transport/chttp2/hpack_parser_fuzzer_test.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5824,7 +5824,7 @@
     "name": "http_request_fuzzer_test_one_entry", 
     "src": [
       "test/core/http/request_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5842,7 +5842,7 @@
     "name": "http_response_fuzzer_test_one_entry", 
     "src": [
       "test/core/http/response_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5860,7 +5860,7 @@
     "name": "json_fuzzer_test_one_entry", 
     "src": [
       "test/core/json/fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5878,7 +5878,7 @@
     "name": "nanopb_fuzzer_response_test_one_entry", 
     "src": [
       "test/core/nanopb/fuzzer_response.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5896,7 +5896,7 @@
     "name": "nanopb_fuzzer_serverlist_test_one_entry", 
     "src": [
       "test/core/nanopb/fuzzer_serverlist.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5914,7 +5914,7 @@
     "name": "percent_decode_fuzzer_one_entry", 
     "src": [
       "test/core/slice/percent_decode_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5932,7 +5932,7 @@
     "name": "percent_encode_fuzzer_one_entry", 
     "src": [
       "test/core/slice/percent_encode_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5950,7 +5950,7 @@
     "name": "server_fuzzer_one_entry", 
     "src": [
       "test/core/end2end/fuzzers/server_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5968,7 +5968,7 @@
     "name": "ssl_server_fuzzer_one_entry", 
     "src": [
       "test/core/security/ssl_server_fuzzer.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"
@@ -5986,7 +5986,7 @@
     "name": "uri_fuzzer_test_one_entry", 
     "src": [
       "test/core/client_channel/uri_fuzzer_test.cc", 
-      "test/core/util/one_corpus_entry_fuzzer.c"
+      "test/core/util/one_corpus_entry_fuzzer.cc"
     ], 
     "third_party": false, 
     "type": "target"