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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58369C433F5 for ; Wed, 3 Nov 2021 07:27:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2DF15603E9 for ; Wed, 3 Nov 2021 07:27:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232077AbhKCH3e (ORCPT ); Wed, 3 Nov 2021 03:29:34 -0400 Received: from szxga08-in.huawei.com ([45.249.212.255]:27109 "EHLO szxga08-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231994AbhKCH3c (ORCPT ); Wed, 3 Nov 2021 03:29:32 -0400 Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4HkdZS0sGcz1DJ8Z; Wed, 3 Nov 2021 15:24:48 +0800 (CST) Received: from kwepemm600017.china.huawei.com (7.193.23.234) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 15:26:51 +0800 Received: from [10.174.179.234] (10.174.179.234) by kwepemm600017.china.huawei.com (7.193.23.234) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.15; Wed, 3 Nov 2021 15:26:49 +0800 Subject: Re: [PATCH bpf-next] riscv, bpf: fix some compiler error To: =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= References: <20211102145642.724820-1-tongtiangen@huawei.com> <448599f5-e773-6ab5-bdaf-289f583edf01@huawei.com> CC: Paul Walmsley , Palmer Dabbelt , Palmer Dabbelt , Albert Ou , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , linux-riscv , LKML , Netdev , bpf From: tongtiangen Message-ID: Date: Wed, 3 Nov 2021 15:26:48 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.179.234] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemm600017.china.huawei.com (7.193.23.234) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/11/3 14:10, Björn Töpel wrote: > On Wed, 3 Nov 2021 at 04:06, tongtiangen wrote: >> > [...] >>> >> Hi Björn: >> From the perspective of development, introduce asm/extable.h is also prepare for the >> subsequent modification of exception_table_entry, such as: >> 1. https://lkml.org/lkml/2021/10/20/591 >> 2. https://lore.kernel.org/linux-arm-kernel/20211019160219.5202-11-mark.rutland@arm.com/ >> >> Therefore, the prototype declarations and definitions related to kernel config are placed in head file, >> which can avoid compiler error and simplify the rendering of functions. >> > > Sure, but *this* patch is about getting the broken RV32 build to work, > aimed for the bpf tree. Moving the extable.h is unrelated, and should > not be done here. IMO it would be better to have this patch small/easy > to read. I can't really see how this patch helps, when merging with > Jisheng's work. > > ...and I still think that: > --8<-- > diff --git a/arch/riscv/mm/extable.c b/arch/riscv/mm/extable.c > index 18bf338303b6..ddb7d3b99e89 100644 > --- a/arch/riscv/mm/extable.c > +++ b/arch/riscv/mm/extable.c > @@ -11,7 +11,7 @@ > #include > #include > > -#ifdef CONFIG_BPF_JIT > +#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I) > int rv_bpf_fixup_exception(const struct exception_table_entry *ex, > struct pt_regs *regs); > #endif > > @@ -23,7 +23,7 @@ int fixup_exception(struct pt_regs *regs) > if (!fixup) > return 0; > > -#ifdef CONFIG_BPF_JIT > +#if defined(CONFIG_BPF_JIT) && defined(CONFIG_ARCH_RV64I) > if (regs->epc >= BPF_JIT_REGION_START && regs->epc < BPF_JIT_REGION_END) > return rv_bpf_fixup_exception(fixup, regs); > #endif > diff --git a/arch/riscv/net/bpf_jit_comp64.c b/arch/riscv/net/bpf_jit_comp64.c > index 2ca345c7b0bf..6372a235522d 100644 > --- a/arch/riscv/net/bpf_jit_comp64.c > +++ b/arch/riscv/net/bpf_jit_comp64.c > @@ -459,6 +459,8 @@ static int emit_call(bool fixed, u64 addr, struct > rv_jit_context *ctx) > #define BPF_FIXUP_OFFSET_MASK GENMASK(26, 0) > #define BPF_FIXUP_REG_MASK GENMASK(31, 27) > > +int rv_bpf_fixup_exception(const struct exception_table_entry *ex, > + struct pt_regs *regs); > int rv_bpf_fixup_exception(const struct exception_table_entry *ex, > struct pt_regs *regs) > { > -->8-- > > is much simpler. Adding a function declaration in bpf_jit_comp64.c file cannot fix this compiler error: .... when CONFIG_BPF_JIT and CONFIG_ARCH_64I is open, There is the following compiler error (W=1): error: no previous prototype for 'rv_bpf_fixup_exception' .... To fix this compiler error, you need to make a declaration in a header file, which is also the reason for introducing extable.h. Before making this patch, I thought about this change, but on the whole, I think the modification scheme of adding header files moved me.;-) > > > > Thoughts? > Björn > > > > >> Thanks. >> Tong. >> >>> >>> Björn >>> . >>> > . >