From patchwork Thu Jan 6 16:37:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Wielaard X-Patchwork-Id: 49632 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 2179D385802E for ; Thu, 6 Jan 2022 16:37:44 +0000 (GMT) X-Original-To: elfutils-devel@sourceware.org Delivered-To: elfutils-devel@sourceware.org Received: from gnu.wildebeest.org (gnu.wildebeest.org [45.83.234.184]) by sourceware.org (Postfix) with ESMTPS id 36B6B3858408 for ; Thu, 6 Jan 2022 16:37:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 36B6B3858408 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=klomp.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=klomp.org Received: from reform (deer0x0f.wildebeest.org [172.31.17.145]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id 1D3A23000340; Thu, 6 Jan 2022 17:37:33 +0100 (CET) Received: by reform (Postfix, from userid 1000) id CAF182E8225E; Thu, 6 Jan 2022 17:37:32 +0100 (CET) From: Mark Wielaard To: elfutils-devel@sourceware.org Subject: [PATCH] libdwfl: Handle unaligned Dyns in dwfl_segment_report_module Date: Thu, 6 Jan 2022 17:37:17 +0100 Message-Id: <20220106163717.116122-1-mark@klomp.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Spam-Status: No, score=-10.0 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: elfutils-devel@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Elfutils-devel mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , Cc: Mark Wielaard Errors-To: elfutils-devel-bounces+patchwork=sourceware.org@sourceware.org Sender: "Elfutils-devel" The xlate functions only handle correctly aligned buffers. But they do handle src == dest. So if the source buffer isn't aligned correctly just copy it first into the destination (which is already correctly aligned). https://sourceware.org/bugzilla/show_bug.cgi?id=28720 Signed-off-by: Mark Wielaard --- libdwfl/ChangeLog | 5 +++++ libdwfl/dwfl_segment_report_module.c | 12 ++++++++++++ 2 files changed, 17 insertions(+) diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index f8319f44..aace969f 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,8 @@ +2022-01-03 Mark Wielaard + + * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy + dyn_data and set xlatefrom.d_buf to dyns when dyns is not aligned. + 2022-01-03 Mark Wielaard * link_map.c (read_addrs): Fix buffer_available nb overflow. diff --git a/libdwfl/dwfl_segment_report_module.c b/libdwfl/dwfl_segment_report_module.c index 5bef249e..1461ae26 100644 --- a/libdwfl/dwfl_segment_report_module.c +++ b/libdwfl/dwfl_segment_report_module.c @@ -844,7 +844,19 @@ dwfl_segment_report_module (Dwfl *dwfl, int ndx, const char *name, xlateto.d_buf = dyns; xlateto.d_size = dyn_filesz; + /* dyn_data may be unaligned, in which case xlatetom would not work. + xlatetom does work when the in and out d_buf are equal (but not + for any other overlap). */ bool is32 = (ei_class == ELFCLASS32); + size_t dyn_align = (is32 + ? __alignof__ (Elf32_Dyn) + : __alignof__ (Elf64_Dyn)); + if (((uintptr_t) dyn_data & (dyn_align - 1)) != 0) + { + memcpy (dyns, dyn_data, dyn_filesz); + xlatefrom.d_buf = dyns; + } + if ((is32 && elf32_xlatetom (&xlateto, &xlatefrom, ei_data) != NULL) || (!is32 && elf64_xlatetom (&xlateto, &xlatefrom, ei_data) != NULL)) {