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=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 3D888C4332B for ; Thu, 4 Mar 2021 14:22:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0B0B164F04 for ; Thu, 4 Mar 2021 14:22:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241865AbhCDOVn (ORCPT ); Thu, 4 Mar 2021 09:21:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:44826 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240128AbhCDOVM (ORCPT ); Thu, 4 Mar 2021 09:21:12 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15BD564F23; Thu, 4 Mar 2021 14:20:32 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94) (envelope-from ) id 1lHoq6-001nvD-UP; Thu, 04 Mar 2021 09:20:30 -0500 Message-ID: <20210304142030.817013350@goodmis.org> User-Agent: quilt/0.66 Date: Thu, 04 Mar 2021 09:19:53 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Will Deacon , Chen Jun Subject: [for-linus][PATCH 1/5] ftrace: Have recordmcount use w8 to read relp->r_info in arm64_is_fake_mcount References: <20210304141952.446924335@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chen Jun On little endian system, Use aarch64_be(gcc v7.3) downloaded from linaro.org to build image with CONFIG_CPU_BIG_ENDIAN = y, CONFIG_FTRACE = y, CONFIG_DYNAMIC_FTRACE = y. gcc will create symbols of _mcount but recordmcount can not create mcount_loc for *.o. aarch64_be-linux-gnu-objdump -r fs/namei.o | grep mcount 00000000000000d0 R_AARCH64_CALL26 _mcount ... 0000000000007190 R_AARCH64_CALL26 _mcount The reason is than funciton arm64_is_fake_mcount can not work correctly. A symbol of _mcount in *.o compiled with big endian compiler likes: 00 00 00 2d 00 00 01 1b w(rp->r_info) will return 0x2d instead of 0x011b. Because w() takes uint32_t as parameter, which truncates rp->r_info. Use w8() instead w() to read relp->r_info Link: https://lkml.kernel.org/r/20210222135840.56250-1-chenjun102@huawei.com Fixes: ea0eada45632 ("recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64.") Acked-by: Will Deacon Signed-off-by: Chen Jun Signed-off-by: Steven Rostedt (VMware) --- scripts/recordmcount.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index b9c2ee7ab43f..cce12e1971d8 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -438,7 +438,7 @@ static int arm_is_fake_mcount(Elf32_Rel const *rp) static int arm64_is_fake_mcount(Elf64_Rel const *rp) { - return ELF64_R_TYPE(w(rp->r_info)) != R_AARCH64_CALL26; + return ELF64_R_TYPE(w8(rp->r_info)) != R_AARCH64_CALL26; } /* 64-bit EM_MIPS has weird ELF64_Rela.r_info. -- 2.30.0