[Qemu-devel] [PATCH v10 05/30] qapi: Plug leaks in test-qmp-*

[Eric Blake]

Make valgrind happy with the current state of the tests, so that
it is easier to see if future patches introduce new memory problems
without being drowned in noise.  Many of the leaks were due to
calling a second init without tearing down the data from an earlier
visit.  But since teardown is already idempotent, and we already
register teardown as part of input_visitor_test_add(), it is nicer
to just make init() safe to call multiple times than it is to have
to make all tests call teardown.

Another common leak was forgetting to clean up an error object,
after testing that an error was raised.

Another leak was in test_visitor_in_struct_nested(), failing to
clean the base member of UserDefTwo.  Cleaning that up left
check_and_free_str() as dead code (since using the qapi_free_*
takes care of recursion, and we don't want double frees).

A final leak was in test_visitor_out_any(), which was reassigning
the qobj local variable to a subset of the overall structure
needing freeing; it did not result in a use-after-free, but
was not cleaning up all the qdict.

test-qmp-event and test-qmp-commands were already clean.

Signed-off-by: Eric Blake <address@hidden>

---
v10: improve commit message, split out refactor of test init so
that both init and init_raw benefit from change
v9: move earlier in series (was 13/17)
v8: no change
v7: no change
v6: make init repeatable rather than adding teardown everywhere,
fix additional leak with UserDefTwo base, plug additional files
---
 tests/test-qmp-input-strict.c   |  9 +++++++++
 tests/test-qmp-input-visitor.c  | 41 +++++++----------------------------------
 tests/test-qmp-output-visitor.c |  3 ++-
 3 files changed, 18 insertions(+), 35 deletions(-)

diff --git a/tests/test-qmp-input-strict.c b/tests/test-qmp-input-strict.c
index 77151de..95cd8e1 100644
--- a/tests/test-qmp-input-strict.c
+++ b/tests/test-qmp-input-strict.c
@@ -49,6 +49,8 @@ static Visitor 
*validate_test_init_internal(TestInputVisitorData *data,
 {
     Visitor *v;

+    validate_teardown(data, NULL);
+
     data->obj = qobject_from_jsonv(json_string, ap);
     g_assert(data->obj);

@@ -191,6 +193,7 @@ static void test_validate_fail_struct(TestInputVisitorData 
*data,

     visit_type_TestStruct(v, &p, NULL, &err);
     g_assert(err);
+    error_free(err);
     if (p) {
         g_free(p->string);
     }
@@ -208,6 +211,7 @@ static void 
test_validate_fail_struct_nested(TestInputVisitorData *data,

     visit_type_UserDefTwo(v, &udp, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefTwo(udp);
 }

@@ -222,6 +226,7 @@ static void test_validate_fail_list(TestInputVisitorData 
*data,

     visit_type_UserDefOneList(v, &head, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefOneList(head);
 }

@@ -237,6 +242,7 @@ static void 
test_validate_fail_union_native_list(TestInputVisitorData *data,

     visit_type_UserDefNativeListUnion(v, &tmp, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefNativeListUnion(tmp);
 }

@@ -251,6 +257,7 @@ static void 
test_validate_fail_union_flat(TestInputVisitorData *data,

     visit_type_UserDefFlatUnion(v, &tmp, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefFlatUnion(tmp);
 }

@@ -266,6 +273,7 @@ static void 
test_validate_fail_union_flat_no_discrim(TestInputVisitorData *data,

     visit_type_UserDefFlatUnion2(v, &tmp, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefFlatUnion2(tmp);
 }

@@ -280,6 +288,7 @@ static void 
test_validate_fail_alternate(TestInputVisitorData *data,

     visit_type_UserDefAlternate(v, &tmp, NULL, &err);
     g_assert(err);
+    error_free(err);
     qapi_free_UserDefAlternate(tmp);
 }

diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c
index 933243d..8ecbc21 100644
--- a/tests/test-qmp-input-visitor.c
+++ b/tests/test-qmp-input-visitor.c
@@ -45,6 +45,8 @@ static Visitor 
*visitor_input_test_init_internal(TestInputVisitorData *data,
 {
     Visitor *v;

+    visitor_input_teardown(data, NULL);
+
     data->obj = qobject_from_jsonv(json_string, ap);
     g_assert(data->obj);

@@ -174,12 +176,7 @@ static void test_visitor_in_enum(TestInputVisitorData 
*data,
         visit_type_EnumOne(v, &res, NULL, &err);
         g_assert(!err);
         g_assert_cmpint(i, ==, res);
-
-        visitor_input_teardown(data, NULL);
     }
-
-    data->obj = NULL;
-    data->qiv = NULL;
 }


@@ -202,12 +199,6 @@ static void test_visitor_in_struct(TestInputVisitorData 
*data,
     g_free(p);
 }

-static void check_and_free_str(char *str, const char *cmp)
-{
-    g_assert_cmpstr(str, ==, cmp);
-    g_free(str);
-}
-
 static void test_visitor_in_struct_nested(TestInputVisitorData *data,
                                           const void *unused)
 {
@@ -223,17 +214,14 @@ static void 
test_visitor_in_struct_nested(TestInputVisitorData *data,
     visit_type_UserDefTwo(v, &udp, NULL, &err);
     g_assert(!err);

-    check_and_free_str(udp->string0, "string0");
-    check_and_free_str(udp->dict1->string1, "string1");
+    g_assert_cmpstr(udp->string0, ==, "string0");
+    g_assert_cmpstr(udp->dict1->string1, ==, "string1");
     g_assert_cmpint(udp->dict1->dict2->userdef->integer, ==, 42);
-    check_and_free_str(udp->dict1->dict2->userdef->string, "string");
-    check_and_free_str(udp->dict1->dict2->string, "string2");
+    g_assert_cmpstr(udp->dict1->dict2->userdef->string, ==, "string");
+    g_assert_cmpstr(udp->dict1->dict2->string, ==, "string2");
     g_assert(udp->dict1->has_dict3 == false);

-    g_free(udp->dict1->dict2->userdef);
-    g_free(udp->dict1->dict2);
-    g_free(udp->dict1);
-    g_free(udp);
+    qapi_free_UserDefTwo(udp);
 }

 static void test_visitor_in_list(TestInputVisitorData *data,
@@ -343,14 +331,12 @@ static void 
test_visitor_in_alternate(TestInputVisitorData *data,
     g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_I);
     g_assert_cmpint(tmp->u.i, ==, 42);
     qapi_free_UserDefAlternate(tmp);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "'string'");
     visit_type_UserDefAlternate(v, &tmp, NULL, &error_abort);
     g_assert_cmpint(tmp->type, ==, USER_DEF_ALTERNATE_KIND_S);
     g_assert_cmpstr(tmp->u.s, ==, "string");
     qapi_free_UserDefAlternate(tmp);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "false");
     visit_type_UserDefAlternate(v, &tmp, NULL, &err);
@@ -358,7 +344,6 @@ static void test_visitor_in_alternate(TestInputVisitorData 
*data,
     error_free(err);
     err = NULL;
     qapi_free_UserDefAlternate(tmp);
-    visitor_input_teardown(data, NULL);
 }

 static void test_visitor_in_alternate_number(TestInputVisitorData *data,
@@ -381,7 +366,6 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     error_free(err);
     err = NULL;
     qapi_free_AltStrBool(asb);
-    visitor_input_teardown(data, NULL);

     /* FIXME: Order of alternate should not affect semantics; asn should
      * parse the same as ans */
@@ -393,35 +377,30 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     error_free(err);
     err = NULL;
     qapi_free_AltStrNum(asn);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltNumStr(v, &ans, NULL, &error_abort);
     g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
     g_assert_cmpfloat(ans->u.n, ==, 42);
     qapi_free_AltNumStr(ans);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltStrInt(v, &asi, NULL, &error_abort);
     g_assert_cmpint(asi->type, ==, ALT_STR_INT_KIND_I);
     g_assert_cmpint(asi->u.i, ==, 42);
     qapi_free_AltStrInt(asi);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
     g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_I);
     g_assert_cmpint(ain->u.i, ==, 42);
     qapi_free_AltIntNum(ain);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
     g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_I);
     g_assert_cmpint(ani->u.i, ==, 42);
     qapi_free_AltNumInt(ani);
-    visitor_input_teardown(data, NULL);

     /* Parsing a double */

@@ -431,21 +410,18 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     error_free(err);
     err = NULL;
     qapi_free_AltStrBool(asb);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltStrNum(v, &asn, NULL, &error_abort);
     g_assert_cmpint(asn->type, ==, ALT_STR_NUM_KIND_N);
     g_assert_cmpfloat(asn->u.n, ==, 42.5);
     qapi_free_AltStrNum(asn);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumStr(v, &ans, NULL, &error_abort);
     g_assert_cmpint(ans->type, ==, ALT_NUM_STR_KIND_N);
     g_assert_cmpfloat(ans->u.n, ==, 42.5);
     qapi_free_AltNumStr(ans);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltStrInt(v, &asi, NULL, &err);
@@ -453,21 +429,18 @@ static void 
test_visitor_in_alternate_number(TestInputVisitorData *data,
     error_free(err);
     err = NULL;
     qapi_free_AltStrInt(asi);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltIntNum(v, &ain, NULL, &error_abort);
     g_assert_cmpint(ain->type, ==, ALT_INT_NUM_KIND_N);
     g_assert_cmpfloat(ain->u.n, ==, 42.5);
     qapi_free_AltIntNum(ain);
-    visitor_input_teardown(data, NULL);

     v = visitor_input_test_init(data, "42.5");
     visit_type_AltNumInt(v, &ani, NULL, &error_abort);
     g_assert_cmpint(ani->type, ==, ALT_NUM_INT_KIND_N);
     g_assert_cmpfloat(ani->u.n, ==, 42.5);
     qapi_free_AltNumInt(ani);
-    visitor_input_teardown(data, NULL);
 }

 static void test_native_list_integer_helper(TestInputVisitorData *data,
diff --git a/tests/test-qmp-output-visitor.c b/tests/test-qmp-output-visitor.c
index 9364843..8606111 100644
--- a/tests/test-qmp-output-visitor.c
+++ b/tests/test-qmp-output-visitor.c
@@ -391,6 +391,7 @@ static void test_visitor_out_any(TestOutputVisitorData 
*data,
     qobj = QOBJECT(qdict);
     visit_type_any(data->ov, &qobj, NULL, &err);
     g_assert(!err);
+    qobject_decref(qobj);
     obj = qmp_output_get_qobject(data->qov);
     g_assert(obj != NULL);
     qdict = qobject_to_qdict(obj);
@@ -411,7 +412,6 @@ static void test_visitor_out_any(TestOutputVisitorData 
*data,
     g_assert(qstring);
     g_assert_cmpstr(qstring_get_str(qstring), ==, "foo");
     qobject_decref(obj);
-    qobject_decref(qobj);
 }

 static void test_visitor_out_union_flat(TestOutputVisitorData *data,
@@ -463,6 +463,7 @@ static void 
test_visitor_out_alternate(TestOutputVisitorData *data,
     g_assert_cmpint(qint_get_int(qobject_to_qint(arg)), ==, 42);

     qapi_free_UserDefAlternate(tmp);
+    qobject_decref(arg);
 }

 static void test_visitor_out_empty(TestOutputVisitorData *data,
-- 
2.4.3