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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AC57C3A5A3 for ; Wed, 28 Aug 2019 03:07:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFA4E214DA for ; Wed, 28 Aug 2019 03:07:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726315AbfH1DHq (ORCPT ); Tue, 27 Aug 2019 23:07:46 -0400 Received: from 59-120-53-16.HINET-IP.hinet.net ([59.120.53.16]:16571 "EHLO ATCSQR.andestech.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726178AbfH1DHq (ORCPT ); Tue, 27 Aug 2019 23:07:46 -0400 Received: from mail.andestech.com (atcpcs16.andestech.com [10.0.1.222]) by ATCSQR.andestech.com with ESMTP id x7S2s7NW017694; Wed, 28 Aug 2019 10:54:07 +0800 (GMT-8) (envelope-from nickhu@andestech.com) Received: from andestech.com (10.0.15.65) by ATCPCS16.andestech.com (10.0.1.222) with Microsoft SMTP Server id 14.3.123.3; Wed, 28 Aug 2019 11:06:44 +0800 Date: Wed, 28 Aug 2019 11:06:44 +0800 From: Nick Hu To: Andrey Ryabinin , Paul Walmsley CC: Alan Quey-Liang =?utf-8?B?S2FvKOmrmOmtgeiJryk=?= , "paul.walmsley@sifive.com" , "palmer@sifive.com" , "aou@eecs.berkeley.edu" , "green.hu@gmail.com" , "deanbo422@gmail.com" , "tglx@linutronix.de" , "linux-riscv@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "glider@google.com" , "dvyukov@google.com" , "Anup.Patel@wdc.com" , "gregkh@linuxfoundation.org" , "alexios.zavras@intel.com" , "atish.patra@wdc.com" , =?utf-8?B?6Zui6IG3Wm9uZyBab25nLVhpYW4gTGko5p2O5a6X5oayKQ==?= , "kasan-dev@googlegroups.com" Subject: Re: [PATCH 1/2] riscv: Add memmove string operation. Message-ID: <20190828030644.GA20064@andestech.com> References: <09d5108e-f0ba-13d3-be9e-119f49f6bd85@virtuozzo.com> <20190827090738.GA22972@andestech.com> <92dd5f5f-c8a2-53c3-4d61-44acc4366844@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <92dd5f5f-c8a2-53c3-4d61-44acc4366844@virtuozzo.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Originating-IP: [10.0.15.65] X-DNSRBL: X-MAIL: ATCSQR.andestech.com x7S2s7NW017694 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, On Tue, Aug 27, 2019 at 05:33:11PM +0800, Andrey Ryabinin wrote: > > > On 8/27/19 12:07 PM, Nick Hu wrote: > > Hi Andrey > > > > On Thu, Aug 22, 2019 at 11:59:02PM +0800, Andrey Ryabinin wrote: > >> On 8/7/19 10:19 AM, Nick Hu wrote: > >>> There are some features which need this string operation for compilation, > >>> like KASAN. So the purpose of this porting is for the features like KASAN > >>> which cannot be compiled without it. > >>> > >> > >> Compilation error can be fixed by diff bellow (I didn't test it). > >> If you don't need memmove very early (before kasan_early_init()) than arch-specific not-instrumented memmove() > >> isn't necessary to have. > >> > >> --- > >> mm/kasan/common.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/mm/kasan/common.c b/mm/kasan/common.c > >> index 6814d6d6a023..897f9520bab3 100644 > >> --- a/mm/kasan/common.c > >> +++ b/mm/kasan/common.c > >> @@ -107,6 +107,7 @@ void *memset(void *addr, int c, size_t len) > >> return __memset(addr, c, len); > >> } > >> > >> +#ifdef __HAVE_ARCH_MEMMOVE > >> #undef memmove > >> void *memmove(void *dest, const void *src, size_t len) > >> { > >> @@ -115,6 +116,7 @@ void *memmove(void *dest, const void *src, size_t len) > >> > >> return __memmove(dest, src, len); > >> } > >> +#endif > >> > >> #undef memcpy > >> void *memcpy(void *dest, const void *src, size_t len) > >> -- > >> 2.21.0 > >> > >> > >> > > I have confirmed that the string operations are not used before kasan_early_init(). > > But I can't make sure whether other ARCHs would need it before kasan_early_init(). > > Do you have any idea to check that? Should I cc all other ARCH maintainers? > > > This doesn't affect other ARCHes in any way. If other arches have their own not-instrumented > memmove implementation (and they do), they will continue to be able to use it early. I prefer Andrey's method since porting the generic string operations with newlib ones should be a separated patch from KASAN. Nick