From patchwork Tue Apr 16 12:22:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Wieczorkiewicz, Pawel" X-Patchwork-Id: 10902911 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BDBC617EF for ; Tue, 16 Apr 2019 12:28:42 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 98D7121F61 for ; Tue, 16 Apr 2019 12:28:42 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8984422B1F; Tue, 16 Apr 2019 12:28:42 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,DKIM_ADSP_ALL, DKIM_INVALID,DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 1082A1FEBD for ; Tue, 16 Apr 2019 12:28:41 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hGNAn-0002Gk-Pq; Tue, 16 Apr 2019 12:26:49 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hGNAm-0002GZ-Pi for xen-devel@lists.xen.org; Tue, 16 Apr 2019 12:26:48 +0000 X-Inumbo-ID: e776ceb0-6042-11e9-92d7-bc764e045a96 Received: from smtp-fw-6002.amazon.com (unknown [52.95.49.90]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTPS id e776ceb0-6042-11e9-92d7-bc764e045a96; Tue, 16 Apr 2019 12:26:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.de; i=@amazon.de; q=dns/txt; s=amazon201209; t=1555417607; x=1586953607; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version; bh=A4jBU1aY1vYkz+8w5Ecnf0TXkWqb6f5o6G47fRcwIpM=; b=F9JmUBpMR+n+5CxbGXN5uhOLaIccOzhTY7c5xULz7/fYPh6bJMOwKeec 7PZoCVy+19bpADMI9b/iBIQeReu/ZfSDsV/sZsGsKOsfeLN5m5OI67xjP nPEELTUQfwQms6CNTFZa0VpepXY8/1LtMnmZ43dZFQtIPh5afMSfzpW8p M=; X-IronPort-AV: E=Sophos;i="5.60,357,1549929600"; d="scan'208";a="397054190" Received: from iad6-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2c-1968f9fa.us-west-2.amazon.com) ([10.124.125.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 16 Apr 2019 12:22:55 +0000 Received: from EX13MTAUEA001.ant.amazon.com (pdx1-ws-svc-p6-lb9-vlan2.pdx.amazon.com [10.236.137.194]) by email-inbound-relay-2c-1968f9fa.us-west-2.amazon.com (8.14.7/8.14.7) with ESMTP id x3GCMo4H095938 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Tue, 16 Apr 2019 12:22:54 GMT Received: from EX13D03EUC003.ant.amazon.com (10.43.164.192) by EX13MTAUEA001.ant.amazon.com (10.43.61.243) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Tue, 16 Apr 2019 12:22:54 +0000 Received: from EX13MTAUEB001.ant.amazon.com (10.43.60.96) by EX13D03EUC003.ant.amazon.com (10.43.164.192) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Tue, 16 Apr 2019 12:22:52 +0000 Received: from dev-dsk-wipawel-1a-0c4e6d58.eu-west-1.amazon.com (10.4.134.33) by mail-relay.amazon.com (10.43.60.129) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Tue, 16 Apr 2019 12:22:51 +0000 From: Pawel Wieczorkiewicz To: Date: Tue, 16 Apr 2019 12:22:40 +0000 Message-ID: <20190416122241.28342-2-wipawel@amazon.de> X-Mailer: git-send-email 2.16.5 In-Reply-To: <20190416122241.28342-1-wipawel@amazon.de> References: <20190416122241.28342-1-wipawel@amazon.de> MIME-Version: 1.0 Precedence: Bulk Subject: [Xen-devel] [livepatch-build-tools part3 2/3] create-diff-object: Extend patchability verification: STN_UNDEF X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: mpohlack@amazon.de, ross.lagerwall@citrix.com, Pawel Wieczorkiewicz , konrad.wilk@oracle.com Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP During verification check if all sections do not contain any entries with undefined symbols (STN_UNDEF). This situation can happen when a section is copied over from its original object to a patched object, but various symbols related to the section are not copied along. This scenario happens typically during stacked hotpatches creation (between 2 different hotpatch modules). Signed-off-by: Pawel Wieczorkiewicz Reviewed-by: Martin Pohlack Reviewed-by: Bjoern Doebel Reviewed-by: Norbert Manthey Reviewed-by: Andra-Irina Paraschiv CR: https://code.amazon.com/reviews/CR-7368645 --- create-diff-object.c | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) diff --git a/create-diff-object.c b/create-diff-object.c index af2245c..96b6716 100644 --- a/create-diff-object.c +++ b/create-diff-object.c @@ -1448,6 +1448,31 @@ static void kpatch_print_changes(struct kpatch_elf *kelf) } } +static inline int get_section_entry_size(const struct section *sec, struct kpatch_elf *kelf) +{ + int entry_size; + + /* + * Base sections typically do not define fixed size elements. + * Detect section's element size in case it's a special section. + * Otherwise, skip it due to an unknown sh_entsize. + */ + entry_size = sec->sh.sh_entsize; + if (entry_size == 0) { + struct special_section *special; + + /* Find special section group_size. */ + for (special = special_sections; special->name; special++) { + /* Match sections starting with special->name prefix */ + if (!strncmp(sec->name, special->name, strlen(special->name))) { + return special->group_size(kelf, 0); + } + } + } + + return entry_size; +} + static void kpatch_verify_patchability(struct kpatch_elf *kelf) { struct section *sec; @@ -1471,6 +1496,41 @@ static void kpatch_verify_patchability(struct kpatch_elf *kelf) errs++; } + if (sec->include) { + if (!is_standard_section(sec) && !is_rela_section(sec) && + !is_debug_section(sec) && !is_special_section(sec)) { + if (!is_referenced_section(sec, kelf)) { + log_normal("section %s included, but not referenced\n", sec->name); + errs++; + } + } + + /* Check if a RELA section does not contain any entries with + * undefined symbols (STN_UNDEF). This situation can happen + * when a section is copied over from its original object to + * a patched object, but various symbols related to the section + * are not copied along. + */ + if (is_rela_section(sec)) { + int offset, entry_size = get_section_entry_size(sec, kelf); + struct rela *rela; + + for ( offset = 0; offset < sec->base->data->d_size && entry_size; offset += entry_size ) { + list_for_each_entry(rela, &sec->relas, list) { + if (rela->offset < offset || rela->offset >= offset + entry_size) + continue; + + if ((GELF_R_SYM(rela->rela.r_info) == STN_UNDEF) || + (!rela->sym->include && (rela->sym->status == SAME))) { + log_normal("section %s has an entry with a STN_UNDEF symbol: %s\n", + sec->name, rela->sym->name ? rela->sym->name : "none"); + errs++; + } + } + } + } + } + /* * ensure we aren't including .data.* or .bss.* * (.data.unlikely is ok b/c it only has __warned vars)