From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp33.i.mail.ru (smtp33.i.mail.ru [94.100.177.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 9423E45C305 for ; Fri, 4 Dec 2020 19:46:37 +0300 (MSK) Date: Fri, 4 Dec 2020 19:46:35 +0300 From: "Alexander V. Tikhonov" Message-ID: References: <20201204162441.GC5396@tarantool.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201204162441.GC5396@tarantool.org> Subject: Re: [Tarantool-patches] [PATCH luajit] x64: Fix __call metamethod return dispatch. List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Munkin Cc: tarantool-patches@dev.tarantool.org Hi Igor, thanks for the patch, as I see no new degradations found [1], patch LGTM. [1] - https://gitlab.com/tarantool/tarantool/-/pipelines/225349795 On Fri, Dec 04, 2020 at 07:24:41PM +0300, Igor Munkin wrote: > Sasha, > > Could you please confirm whether CI is OK? > > On 04.12.20, Igor Munkin wrote: > > From: Mike Pall > > > > After linking new cframe to the chain KBASEa still stores the address of > > the previous one. If the execution proceeds to KBASE > > value (i.e. low 32 bits of the stored address) might be equal to the > > current BASE address value so the execution takes the invalid path. Such > > address clashing occurs only on x86_64 platform with disabled LJ_GC64, > > so 64-bit registers have to be compared in x64 build. > > > > NB: Though there is only 32-bit load to restore BASE value prior to the > > comparison, the high 32 bits of RDX are reset to zeros, according to x86 > > long mode semantics. > > > > Igor Munkin: > > * backported the original patch to tarantool/luajit repo > > * extended the original commit message with the rationale > > > > For more info and explanation see LuaJIT/LuaJIT#636. > > > > Relates to tarantool/tarantool#4518 > > Relates to tarantool/tarantool#4649 > > > > Signed-off-by: Igor Munkin > > --- > > > > Issues: > > * https://github.com/tarantool/tarantool/issues/4518 > > * https://github.com/tarantool/tarantool/issues/4649 > > Branch: > > * https://github.com/tarantool/luajit/tree/imun/gh-4518-cmp-64-bit-regs-in-vmeta-call > > > > CI is kinda green, considering C6 EOL and the corresponding failures: > > * https://gitlab.com/tarantool/tarantool/-/pipelines/225349795 > > > > @ChangeLog: > > * Fixed address clashing occurring while __call metamethod dispatching > > (gh-4518, gh-4649). > > > > Unfortunately, there is neither test nor reproducer for this failure, so > > we'll know that the patch works only on production installations. > > > > > > > > > -- > Best regards, > IM