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From: Roman Khabibov <roman.habibov@tarantool.org>
In-Reply-To: <20200714104027.GF296695@grain>
Date: Mon, 14 Sep 2020 17:43:56 +0300
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References: <20200710120109.91675-1-roman.habibov@tarantool.org>
 <20200710122958.GF1999@grain> <20200714094533.GK5559@tarantool.org>
 <20200714104027.GF296695@grain>
Subject: Re: [Tarantool-patches] [PATCH] serilaizer: check for recursive
	serialization
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To: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: tarantool-patches@dev.tarantool.org

Hi, Cyrill and Igor!

I tried to compare the addresses of the previous and the current =
iteration,
if they are equal, then throw "looks like recursion, bad function!=E2=80=9D=
. But I
got swim tests failing. That is, they use some recursive serializers =
that do
not overflow the stack. Therefore, I settled on the idea of =
=E2=80=8B=E2=80=8Bintroducing a=20
recursion limit.

> On Jul 14, 2020, at 13:40, Cyrill Gorcunov <gorcunov@gmail.com> wrote:
>=20
> On Tue, Jul 14, 2020 at 12:45:33PM +0300, Igor Munkin wrote:
>>>=20
>>> Wait. The @idx stands for index in a table as far as I remember,
>>> this just happen to hit when you're calling youself recursively
>>> but @idx may be > SERIALIZER_CRITICAL_RECURSION_DEPTH for =
nonrecursive
>>> calls as well.
>>=20
>> I guess you've just misread this part: @idx is just a guest stack =
slot
>> where Lua object being serialized is stored. If I get your concerns
>> right, you're talking about the following case:
>=20
> Yes, you're right. Thanks, Igor! I don't have strong preference here
> on how to handle the case. Thus
>=20
> Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>