On 10/21/2016 04:32 PM, Eric Blake wrote: > In fact, applying this patch regresses to the very state that f24582d > tried to prevent. However, I'm unable to see a difference in valgrind > on tests/test-qmp-output-visitor either with or without this patch, > which sadly means our testsuite is not actually testing this scenario. > >>> Should this go into -stable? > > NACK. > > As mentioned in the v1 thread, the leak that Pino was seeing is fixed by > http://lists.nongnu.org/archive/html/qemu-devel/2016-10/msg04023.html > I don't think we don't want this patch.
And below is my hack to test-qmp-output-visitor, which shows (at least under valgrind) that we don't want the patch. I should probably turn that into a formal patch submission; but should I piggyback the existing test or add a new one? With the patch omitted, valgrind is happy; with the patch applied, I see: /visitor/output/struct-errors: ==8458== Invalid read of size 8 ==8458== at 0x175DC2: qobject_decref (qobject.h:81) ==8458== by 0x1767A5: qentry_destroy (qdict.c:413) ==8458== by 0x17690B: qdict_destroy_obj (qdict.c:451) ==8458== by 0x1784AB: qobject_destroy (qobject.c:29) ==8458== by 0x171927: qobject_decref (qobject.h:83) ==8458== by 0x1721B4: qmp_output_free (qmp-output-visitor.c:223) ==8458== by 0x16ED8E: visit_free (qapi-visit-core.c:34) ==8458== by 0x130F39: visitor_output_teardown (test-qmp-output-visitor.c:44) ==8458== by 0x130FE1: visitor_reset (test-qmp-output-visitor.c:59) ==8458== by 0x1326EF: test_visitor_out_struct_errors (test-qmp-output-visitor.c:283) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== Address 0x8259db8 is 8 bytes inside a block of size 4,120 free'd ==8458== at 0x4C2CD5A: free (vg_replace_malloc.c:530) ==8458== by 0x5088F2D: g_free (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x176937: qdict_destroy_obj (qdict.c:456) ==8458== by 0x1784AB: qobject_destroy (qobject.c:29) ==8458== by 0x171927: qobject_decref (qobject.h:83) ==8458== by 0x1721B4: qmp_output_free (qmp-output-visitor.c:223) ==8458== by 0x16ED8E: visit_free (qapi-visit-core.c:34) ==8458== by 0x130F39: visitor_output_teardown (test-qmp-output-visitor.c:44) ==8458== by 0x130FE1: visitor_reset (test-qmp-output-visitor.c:59) ==8458== by 0x1326EF: test_visitor_out_struct_errors (test-qmp-output-visitor.c:283) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== Block was alloc'd at ==8458== at 0x4C2DA60: calloc (vg_replace_malloc.c:711) ==8458== by 0x5088E70: g_malloc0 (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x175EAF: qdict_new (qdict.c:33) ==8458== by 0x171CAB: qmp_output_start_struct (qmp-output-visitor.c:108) ==8458== by 0x16EE4A: visit_start_struct (qapi-visit-core.c:47) ==8458== by 0x1326E3: test_visitor_out_struct_errors (test-qmp-output-visitor.c:282) ==8458== by 0x50A8940: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8B0E: ??? (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8D1D: g_test_run_suite (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x50A8D40: g_test_run (in /usr/lib64/libglib-2.0.so.0.4800.2) ==8458== by 0x134F8D: main (test-qmp-output-visitor.c:899) diff --git i/tests/test-qmp-output-visitor.c w/tests/test-qmp-output-visitor.c index 5e926d3..f1b5591 100644 --- i/tests/test-qmp-output-visitor.c +++ w/tests/test-qmp-output-visitor.c @@ -265,18 +265,22 @@ static void test_visitor_out_struct_errors(TestOutputVisitorData *data, EnumOne bad_values[] = { ENUM_ONE__MAX, -1 }; UserDefOne u = {0}; UserDefOne *pu = &u; - Error *err; + Error *err = NULL; int i; + /* First check: error within struct is detected */ for (i = 0; i < ARRAY_SIZE(bad_values) ; i++) { - err = NULL; u.has_enum1 = true; u.enum1 = bad_values[i]; visit_type_UserDefOne(data->ov, "unused", &pu, &err); - g_assert(err); - error_free(err); + error_free_or_abort(&err); visitor_reset(data); } + + /* Second check: aborting visit early doesn't leak */ + visit_start_struct(data->ov, NULL, NULL, 0, &error_abort); + visit_start_struct(data->ov, "nested", NULL, 0, &error_abort); + visitor_reset(data); } -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
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