Received: by 2002:a05:6a10:22f:0:0:0:0 with SMTP id 15csp352388pxk; Thu, 17 Sep 2020 05:02:36 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyjtpCCPIr5g742fmBHsUo1Pahe33ntx7127HU9wsc1mVxG4iRhMudlHVJFJGHyg90mk7O4 X-Received: by 2002:a17:907:2079:: with SMTP id qp25mr23831722ejb.186.1600344156633; Thu, 17 Sep 2020 05:02:36 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1600344156; cv=none; d=google.com; s=arc-20160816; b=PIocQTaHS+BvrZEWOgjuwcJKP+idDuM8kdJhTnvsqAjZypG6i4DDWPs6suHNj9388+ c0TFarMAlaXYOmIyD9VQd1fES/7/egcwvEX5qGP6eaHUzfDH17otFCjpax813dhF1e1F YywhRF7i4ymMOP/o9O2shICBj3iEeQ6nWVALv+519O5BSeGDwB3LykNVHv3acibxDqKR D0uNzyLcQ6lLHF3n8JR8UgVUPs2sgpmlq75MKDeleNi+uORS8mrfRltn7cH9j+AzLDL+ qMFEwdi9963jMZYYTwNWKBKoUx07pzWOHCiBORCowhhMi0HH4HbhWp4pIZURlLuD6V5B VN7A== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:date:message-id:subject:references:in-reply-to :cc:to:from; bh=wGZPZTxmHTs4JmN3Um3PrReia4V5naYrIWfDo+UNvMU=; b=TMBgBeAGTvtcxHodJqZFRk6sHcUc1hKXBApPk1oahW3flvGMuu9J1DvK62hGdzGscO a/mO8VQkqL9ATx45rbtnOY9u5EDIGMO1eEpxHI11tt9tqk73PJCWYmyBH5BO/KKQkdmx 8NzN1QKHctics6//BsuieEZeX1hs3LTJsr3CAjsuKPCJYHtqDXcTd0kzY8d1mYtZfflX uKc2qXb2hk5tIxMvrbam4DOdY4OSQjflIvj+OD0mT3o7YmAG30pL0cHo3sAkAsXsgcPI 50t+s1C7HWkVKJI/w/ZIHop/bVLRxCRFqrTTpVL4uA9SP7JJZS2F11egEHQ3LExZNCqa bxMA== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id s19si13317343ejv.149.2020.09.17.05.02.13; Thu, 17 Sep 2020 05:02:36 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726917AbgIQMAu (ORCPT + 99 others); Thu, 17 Sep 2020 08:00:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58726 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726643AbgIQL10 (ORCPT ); Thu, 17 Sep 2020 07:27:26 -0400 Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0BB02C06178A for ; Thu, 17 Sep 2020 04:27:21 -0700 (PDT) Received: by ozlabs.org (Postfix, from userid 1034) id 4BsZSP52cjz9sTs; Thu, 17 Sep 2020 21:27:17 +1000 (AEST) From: Michael Ellerman To: Michael Ellerman , Benjamin Herrenschmidt , Paul Mackerras , Christophe Leroy Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org In-Reply-To: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy@csgroup.eu> References: <94ba5a5138f99522e1562dbcdb38d31aa790dc89.1599216721.git.christophe.leroy@csgroup.eu> Subject: Re: [PATCH 1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto() Message-Id: <160034201413.3339803.2260455102175755865.b4-ty@ellerman.id.au> Date: Thu, 17 Sep 2020 21:27:17 +1000 (AEST) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 4 Sep 2020 11:01:30 +0000 (UTC), Christophe Leroy wrote: > __put_user_asm_goto() provides more flexibility to GCC and avoids using > a local variable to tell if the write succeeded or not. > GCC can then avoid implementing a cmp in the fast path. > > See the difference for a small function like the PPC64 version of > save_general_regs() in arch/powerpc/kernel/signal_32.c: > > [...] Applied to powerpc/next. [1/3] powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto() https://git.kernel.org/powerpc/c/ee0a49a6870ea75e25b4d4984c1bb6b3b7c65f2b [2/3] powerpc/uaccess: Switch __patch_instruction() to __put_user_asm_goto() https://git.kernel.org/powerpc/c/e64ac41ab0c510b3f85199a585eb886cad92fb19 [3/3] powerpc/uaccess: Remove __put_user_asm() and __put_user_asm2() https://git.kernel.org/powerpc/c/7fdf966bed155b214f4f1f9b67825a40b2e9b998 cheers