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=-10.9 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 BC517C433E1 for ; Tue, 25 Aug 2020 12:06:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EFE02071E for ; Tue, 25 Aug 2020 12:06:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730108AbgHYMGg (ORCPT ); Tue, 25 Aug 2020 08:06:36 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:62715 "EHLO pegase1.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728093AbgHYMGe (ORCPT ); Tue, 25 Aug 2020 08:06:34 -0400 Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4BbSQF70Pmz9txtG; Tue, 25 Aug 2020 14:06:29 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id 8AaT7tXaia4q; Tue, 25 Aug 2020 14:06:29 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4BbSQF5K6zz9txtB; Tue, 25 Aug 2020 14:06:29 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 0E4628B814; Tue, 25 Aug 2020 14:06:31 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id 0TBW-9nZB4Hz; Tue, 25 Aug 2020 14:06:30 +0200 (CEST) Received: from [192.168.4.90] (unknown [192.168.4.90]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 491A78B812; Tue, 25 Aug 2020 14:06:30 +0200 (CEST) Subject: Re: [PATCH v5 5/8] powerpc/watchpoint: Fix exception handling for CONFIG_HAVE_HW_BREAKPOINT=N To: Ravi Bangoria , christophe.leroy@c-s.fr Cc: mpe@ellerman.id.au, mikey@neuling.org, paulus@samba.org, naveen.n.rao@linux.vnet.ibm.com, pedromfc@linux.ibm.com, rogealve@linux.ibm.com, jniethe5@gmail.com, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20200825043617.1073634-1-ravi.bangoria@linux.ibm.com> <20200825043617.1073634-6-ravi.bangoria@linux.ibm.com> <91d34b89-603a-fddc-ea0f-53a79b287eed@csgroup.eu> <1e706137-3de9-a713-5a86-48fbc5e6f740@linux.ibm.com> From: Christophe Leroy Message-ID: Date: Tue, 25 Aug 2020 14:06:21 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <1e706137-3de9-a713-5a86-48fbc5e6f740@linux.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 25/08/2020 à 13:07, Ravi Bangoria a écrit : > Hi Christophe, > >>> diff --git a/arch/powerpc/kernel/ptrace/ptrace-noadv.c >>> b/arch/powerpc/kernel/ptrace/ptrace-noadv.c >>> index 57a0ab822334..866597b407bc 100644 >>> --- a/arch/powerpc/kernel/ptrace/ptrace-noadv.c >>> +++ b/arch/powerpc/kernel/ptrace/ptrace-noadv.c >>> @@ -286,11 +286,16 @@ long ppc_del_hwdebug(struct task_struct *child, >>> long data) >>>       } >>>       return ret; >>>   #else /* CONFIG_HAVE_HW_BREAKPOINT */ >>> +    if (child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED) >> >> I think child->thread.hw_brk[data - 1].flags & HW_BRK_FLAG_DISABLED >> should go around additionnal () > > Not sure I follow. Neither do I .... I thought that GCC would emit a warning for that, but in fact it only emit warnings for things like: if (flags & HW_BRK_FLAG_DISABLED == HW_BRK_FLAG_DISABLED) > >> >>> +        goto del; >>> + >>>       if (child->thread.hw_brk[data - 1].address == 0) >>>           return -ENOENT; >> >> What about replacing the above if by: >>      if (!(child->thread.hw_brk[data - 1].flags) & >> HW_BRK_FLAG_DISABLED) && >>          child->thread.hw_brk[data - 1].address == 0) >>          return -ENOENT; > okay.. that's more compact. > > But more importantly, what I wanted to know is whether > CONFIG_HAVE_HW_BREAKPOINT > is set or not in production/distro builds for 8xx. Because I see it's > not set in > 8xx defconfigs. Yes in our production configs with have CONFIG_PERF_EVENTS, that implies CONFIG_HAVE_HW_BREAKPOINT Christophe