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 DE45EC2BB3F for ; Mon, 20 Nov 2023 23:08:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229719AbjKTXIZ (ORCPT ); Mon, 20 Nov 2023 18:08:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229448AbjKTXIY (ORCPT ); Mon, 20 Nov 2023 18:08:24 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 04B51A2 for ; Mon, 20 Nov 2023 15:08:21 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 00B7BC433C8; Mon, 20 Nov 2023 23:08:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1700521699; bh=CFqoX8V2WNEiSzZISkGpjZgqDIO60dgqCnVyQdufY0k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Pm0ocCOuOM935pl00FZ7y8WqMAQHOpgOGaD6c9Umz3wSPv+b+ywRvOFVrGqJDsjpe MOsKExWGV46pb4wNHQhYNdmWdwFDRVCR/NvTlAfJC8ZM0zlAVG239yHgDJBfDTh0wJ 5LibP1FfBpF5Cnazh/45hzIPRACn0/CDLcwOYP6Iqmd1SaJ5Oc2HzW07QFFy7Nslwn Tn0X8yTzXAP70Gn8/WJ9CKIXnxzSTXPbukl5EMSXBQ6uXbqxGX11uklzQfh/I/Hux8 f4kJEYXAQR/Hsg36Qvqtp9TMUhuYYzAyQubKIN/oQJclZXgxyXYXTm0EuwEnbzWrhY YXmhg5H72w8Jw== Date: Mon, 20 Nov 2023 16:08:17 -0700 From: Nathan Chancellor To: WANG Rui Cc: Huacai Chen , WANG Xuerui , Jinyang He , Xi Ruoyao , linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, loongson-kernel@lists.loongnix.cn Subject: Re: [PATCH] LoongArch: Record pc instead of offset in la-abs relocation Message-ID: <20231120230817.GA2116806@dev-arch.thelio-3990X> References: <20231116130331.241395-1-wangrui@loongson.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231116130331.241395-1-wangrui@loongson.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rui, On Thu, Nov 16, 2023 at 09:03:31PM +0800, WANG Rui wrote: > To clarify, the previous version functioned flawlessly. However, it's > worth noting that the LLVM's LoongArch backend currently lacks support > for cross-section label calculations. With this patch, we enable the use > of clang to compile relocatable kernels. > > Signed-off-by: WANG Rui Thanks a lot for the patch! This fixes the CONFIG_RELOCATABLE build for me as well. Tested-by: Nathan Chancellor Something I noticed while testing is that a kernel linked with ld.lld does not boot while one linked with ld.bfd did. I think this might be the same issue that Xuerui filed on our issue tracker but I figured I would mention it in case not: https://github.com/ClangBuiltLinux/linux/issues/1883 Cheers, Nathan > --- > arch/loongarch/include/asm/asmmacro.h | 3 +-- > arch/loongarch/include/asm/setup.h | 2 +- > arch/loongarch/kernel/relocate.c | 2 +- > 3 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/arch/loongarch/include/asm/asmmacro.h b/arch/loongarch/include/asm/asmmacro.h > index c9544f358c33..655db7d7a427 100644 > --- a/arch/loongarch/include/asm/asmmacro.h > +++ b/arch/loongarch/include/asm/asmmacro.h > @@ -609,8 +609,7 @@ > lu32i.d \reg, 0 > lu52i.d \reg, \reg, 0 > .pushsection ".la_abs", "aw", %progbits > - 768: > - .dword 768b-766b > + .dword 766b > .dword \sym > .popsection > #endif > diff --git a/arch/loongarch/include/asm/setup.h b/arch/loongarch/include/asm/setup.h > index a0bc159ce8bd..ee52fb1e9963 100644 > --- a/arch/loongarch/include/asm/setup.h > +++ b/arch/loongarch/include/asm/setup.h > @@ -25,7 +25,7 @@ extern void set_merr_handler(unsigned long offset, void *addr, unsigned long len > #ifdef CONFIG_RELOCATABLE > > struct rela_la_abs { > - long offset; > + long pc; > long symvalue; > }; > > diff --git a/arch/loongarch/kernel/relocate.c b/arch/loongarch/kernel/relocate.c > index 6c3eff9af9fb..288b739ca88d 100644 > --- a/arch/loongarch/kernel/relocate.c > +++ b/arch/loongarch/kernel/relocate.c > @@ -52,7 +52,7 @@ static inline void __init relocate_absolute(long random_offset) > for (p = begin; (void *)p < end; p++) { > long v = p->symvalue; > uint32_t lu12iw, ori, lu32id, lu52id; > - union loongarch_instruction *insn = (void *)p - p->offset; > + union loongarch_instruction *insn = (void *)p->pc; > > lu12iw = (v >> 12) & 0xfffff; > ori = v & 0xfff; > -- > 2.42.1 > >