From patchwork Mon Aug 17 15:13:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 266205 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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 ED9C1C433DF for ; Mon, 17 Aug 2020 18:27:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D305120738 for ; Mon, 17 Aug 2020 18:27:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597688829; bh=ijLv8baprODevFJjA62UKt0f4cZ3pmjZbBlZNqDOh+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tRtp0ZMPsicb0pkuS9dl87awQS/eARVoqFOyysUIBKAvAAqSR7sXR0ZQ8H4uAJAmI BCowZiJ2bmydv4Z0StE7AX3gBa+flalGreopJkPoz4WltJbMKafe2Zo+XZHNMu3DV0 9RcJfkozRh1EsY+uYGTYz+1RGhVg2U4oOny/ZSMk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390489AbgHQS1G (ORCPT ); Mon, 17 Aug 2020 14:27:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:49618 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388178AbgHQQCK (ORCPT ); Mon, 17 Aug 2020 12:02:10 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 6EB6B20825; Mon, 17 Aug 2020 16:02:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597680128; bh=ijLv8baprODevFJjA62UKt0f4cZ3pmjZbBlZNqDOh+k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=f8RJZCD+Dhr8ygza7jp2mpCWkboXq1hPdBYAD24MbUUs4LT40BITxTyrjWwdqE6TC zLPWJHPNrJRyyFxBJdITe8KV4AcrclCetgn+A0yEAAykgea2+ADyfEQkzgnL4ORNPX NmPRjRLWwHZyR96QT/c5emprmaqnEYoPwbu41g2k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Gregory Herrero , "Steven Rostedt (VMware)" , Catalin Marinas , Sasha Levin Subject: [PATCH 5.4 033/270] recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64. Date: Mon, 17 Aug 2020 17:13:54 +0200 Message-Id: <20200817143757.447789143@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143755.807583758@linuxfoundation.org> References: <20200817143755.807583758@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Gregory Herrero [ Upstream commit ea0eada45632f4807b2f49de951072283e2d781c ] Currently, if a section has a relocation to '_mcount' symbol, a new __mcount_loc entry will be added whatever the relocation type is. This is problematic when a relocation to '_mcount' is in the middle of a section and is not a call for ftrace use. Such relocation could be generated with below code for example: bool is_mcount(unsigned long addr) { return (target == (unsigned long) &_mcount); } With this snippet of code, ftrace will try to patch the mcount location generated by this code on module load and fail with: Call trace: ftrace_bug+0xa0/0x28c ftrace_process_locs+0x2f4/0x430 ftrace_module_init+0x30/0x38 load_module+0x14f0/0x1e78 __do_sys_finit_module+0x100/0x11c __arm64_sys_finit_module+0x28/0x34 el0_svc_common+0x88/0x194 el0_svc_handler+0x38/0x8c el0_svc+0x8/0xc ---[ end trace d828d06b36ad9d59 ]--- ftrace failed to modify [] 0xffffa2dbf3a3a41c actual: 66:a9:3c:90 Initializing ftrace call sites ftrace record flags: 2000000 (0) expected tramp: ffffa2dc6cf66724 So Limit the relocation type to R_AARCH64_CALL26 as in perl version of recordmcount. Fixes: af64d2aa872a ("ftrace: Add arm64 support to recordmcount") Signed-off-by: Gregory Herrero Acked-by: Steven Rostedt (VMware) Link: https://lore.kernel.org/r/20200717143338.19302-1-gregory.herrero@oracle.com Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin --- scripts/recordmcount.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/scripts/recordmcount.c b/scripts/recordmcount.c index 7225107a9aafe..e59022b3f1254 100644 --- a/scripts/recordmcount.c +++ b/scripts/recordmcount.c @@ -434,6 +434,11 @@ static int arm_is_fake_mcount(Elf32_Rel const *rp) return 1; } +static int arm64_is_fake_mcount(Elf64_Rel const *rp) +{ + return ELF64_R_TYPE(w(rp->r_info)) != R_AARCH64_CALL26; +} + /* 64-bit EM_MIPS has weird ELF64_Rela.r_info. * http://techpubs.sgi.com/library/manuals/4000/007-4658-001/pdf/007-4658-001.pdf * We interpret Table 29 Relocation Operation (Elf64_Rel, Elf64_Rela) [p.40] @@ -547,6 +552,7 @@ static int do_file(char const *const fname) make_nop = make_nop_arm64; rel_type_nop = R_AARCH64_NONE; ideal_nop = ideal_nop4_arm64; + is_fake_mcount64 = arm64_is_fake_mcount; break; case EM_IA_64: reltype = R_IA64_IMM64; break; case EM_MIPS: /* reltype: e_class */ break;