Re: [PATCH for-5.1] qapi: Fix visit_type_STRUCT() not to fail for null object

[Li Qiang]

Markus Armbruster <armbru@redhat.com> 于2020年7月16日周四 下午11:07写道：
>
> To make deallocating partially constructed objects work, the
> visit_type_STRUCT() need to succeed without doing anything when passed
> a null object.
>
> Commit cdd2b228b9 "qapi: Smooth visitor error checking in generated
> code" broke that.  To reproduce, run tests/test-qobject-input-visitor
> with AddressSanitizer:
>
>     ==4353==ERROR: LeakSanitizer: detected memory leaks
>
>     Direct leak of 16 byte(s) in 1 object(s) allocated from:
>         #0 0x7f192d0c5d28 in __interceptor_calloc 
> (/usr/lib/x86_64-linux-gnu/libasan.so.4+0xded28)
>         #1 0x7f192cd21b10 in g_malloc0 
> (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x51b10)
>         #2 0x556725f6bbee in visit_next_list qapi/qapi-visit-core.c:86
>         #3 0x556725f49e15 in visit_type_UserDefOneList 
> tests/test-qapi-visit.c:474
>         #4 0x556725f4489b in test_visitor_in_fail_struct_in_list 
> tests/test-qobject-input-visitor.c:1086
>         #5 0x7f192cd42f29  
> (/usr/lib/x86_64-linux-gnu/libglib-2.0.so.0+0x72f29)
>
>     SUMMARY: AddressSanitizer: 16 byte(s) leaked in 1 allocation(s).
>
> Test case /visitor/input/fail/struct-in-list feeds a list with a bad
> element to the QObject input visitor.  Visiting that element duly
> fails, and aborts the visit with the list only partially constructed:
> the faulty object is null.  Cleaning up the partially constructed list
> visits that null object, fails, and aborts the visit before the list
> node gets freed.
>
> Fix the the generated visit_type_STRUCT() to succeed for null objects.
>
> Fixes: cdd2b228b973d2a29edf7696ef6e8b08ec329019
> Reported-by: Li Qiang <liq3ea@163.com>
> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Oh, I also sent this too.
Not matter, just ignore my patch.

Tested-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>


> ---
>  scripts/qapi/visit.py | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/scripts/qapi/visit.py b/scripts/qapi/visit.py
> index 3fb2f30510..cdabc5fa28 100644
> --- a/scripts/qapi/visit.py
> +++ b/scripts/qapi/visit.py
> @@ -249,6 +249,7 @@ bool visit_type_%(c_name)s(Visitor *v, const char *name, 
> %(c_name)s **obj, Error
>      if (!*obj) {
>          /* incomplete */
>          assert(visit_is_dealloc(v));
> +        ok = true;
>          goto out_obj;
>      }
>      if (!visit_type_%(c_name)s_members(v, *obj, errp)) {
> --
> 2.26.2
>
>