From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 649E1C43334 for ; Mon, 11 Jul 2022 14:37:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229974AbiGKOhr (ORCPT ); Mon, 11 Jul 2022 10:37:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57846 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229579AbiGKOhq (ORCPT ); Mon, 11 Jul 2022 10:37:46 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79C3665D7D for ; Mon, 11 Jul 2022 07:37:45 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id d16so7266640wrv.10 for ; Mon, 11 Jul 2022 07:37:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=iJtfzfcC1AnsDV/pvGZu2fxxfQmMd6+WOUgRm2id0vA=; b=I0e3YydFgfpoaHWWDRkccW6qtvLN35SFDD/+T6Zf3YSIMWNNV3Mff+f6Xw61zVX2cs 1uWFO47xJ8qdEm8xYURWHIZELaONyqchlS9wilP7b4oGmx9pxRIAyswMWZZvBk+smMZs yt12KfMRmGjE7ITc9L9FP7FjpGG+tPFOdmowu1VcdHgpplgc5wTqflQTOes3qwN03qrq eQVm0ExSbWAc4Rs5CMLNMlspn2+A8dO/qLPCZt/mPy0Zq5OQ1y8RZVetuvUzkDzMhtXK UlvFSooupOa8nvx5j/W5rUWkIdPIT7Phoh0fet6WUybKhUPjpAePCaRIYdnqI4FifzE2 vNBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=iJtfzfcC1AnsDV/pvGZu2fxxfQmMd6+WOUgRm2id0vA=; b=fTj1Tpp1RZecVfwekgfAImNeTcMkqkcjb51gAUFMnpkTjpbKuK2RTGq4XY7JxtbSQi GSXGrNaPCOlHT+icNFR7NVLyAqnlQiH4Og0+oLQjzj11gdm46p7GT4/h7hsQ7oUQy0/K xEIgktDcF823eaCzS49x7DVSAtW9ulJ9g3Zqn3UtHpaaYYjAj+7kUNkj+pFwVvKR5GcA 5SOkOe6WdpeRgrrOg1xfC2sCVXoPiTd+tbh8EEqeANqgjHgFYQRJDqrxR8foai4h98/A BXK1ImHq6tIHe9stIdOExAYlPEgTuHN3OoPAERe/3meq3OZapwStK32fnB70JwcP1ZC2 q9UQ== X-Gm-Message-State: AJIora/7n9AtJtJA4ji2X30VP1ynIrst0/Jdkl8uWaigkhc307O39b7I R5cVgmVcGsPC/Ob8JwFtnnkmaQ== X-Google-Smtp-Source: AGRyM1t1yyqWZwS7XrcViX/JC5qBkc6Z05thqF1oYvTfe7VDmx7hhI7m+JnQqN9Z2J8tfLCknsoQtw== X-Received: by 2002:adf:f38f:0:b0:21d:66b5:21c with SMTP id m15-20020adff38f000000b0021d66b5021cmr16896532wro.144.1657550264039; Mon, 11 Jul 2022 07:37:44 -0700 (PDT) Received: from myrica (cpc92880-cmbg19-2-0-cust679.5-4.cable.virginm.net. [82.27.106.168]) by smtp.gmail.com with ESMTPSA id k5-20020a05600c1c8500b003974cb37a94sm10468691wms.22.2022.07.11.07.37.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Jul 2022 07:37:43 -0700 (PDT) Date: Mon, 11 Jul 2022 15:37:17 +0100 From: Jean-Philippe Brucker To: Xu Kuohai Cc: bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Will Deacon , KP Singh , Mark Rutland , Catalin Marinas , Daniel Borkmann , Alexei Starovoitov , Andrii Nakryiko , Zi Shen Lim , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , "David S . Miller" , Hideaki YOSHIFUJI , David Ahern , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H . Peter Anvin" , Jakub Kicinski , Jesper Dangaard Brouer , Russell King , James Morse , Hou Tao , Jason Wang Subject: Re: [PATCH bpf-next v7 4/4] bpf, arm64: bpf trampoline for arm64 Message-ID: References: <20220708093032.1832755-1-xukuohai@huawei.com> <20220708093032.1832755-5-xukuohai@huawei.com> <4852eba8-9fd0-6894-934c-ab89c0c7cea9@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4852eba8-9fd0-6894-934c-ab89c0c7cea9@huawei.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Jul 11, 2022 at 10:16:00PM +0800, Xu Kuohai wrote: > >> + if (save_ret) > >> + emit(A64_STR64I(p->jited ? r0 : A64_R(0), A64_SP, retval_off), > >> + ctx); > > > > This should be only A64_R(0), not r0. r0 happens to equal A64_R(0) when > > jitted due to the way build_epilogue() builds the function at the moment, > > but we shouldn't rely on that. > > > > looks like I misunderstood something, will change it to: > > /* store return value, which is held in x0 for interpreter and in > * bpf register r0 for JIT, It's simpler than that: in both cases the return value is in x0 because the function follows the procedure call standard. You could drop the comment to avoid confusion and only do the change to A64_R(0) Thanks, Jean > > > but r0 happens to equal x0 due to the > * way build_epilogue() builds the JIT image. > */ > if (save_ret) > emit(A64_STR64I(A64_R(0), A64_SP, retval_off), ctx); > > > Apart from that, for the series > > > > Reviewed-by: Jean-Philippe Brucker > > > > .