From patchwork Thu Jan 6 17:02:22 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Wielaard X-Patchwork-Id: 49634 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 EDE05385802B for ; Thu, 6 Jan 2022 17:02:33 +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 D92983858410 for ; Thu, 6 Jan 2022 17:02:27 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D92983858410 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 B9DBD3000340; Thu, 6 Jan 2022 18:02:25 +0100 (CET) Received: by reform (Postfix, from userid 1000) id 48B7B2E83336; Thu, 6 Jan 2022 18:02:25 +0100 (CET) From: Mark Wielaard To: elfutils-devel@sourceware.org Subject: [PATCH] libdwfl: Declare possible zero sized arrays only when non-zero Date: Thu, 6 Jan 2022 18:02:22 +0100 Message-Id: <20220106170222.130901-1-mark@klomp.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Spam-Status: No, score=-9.8 required=5.0 tests=BAYES_00, GIT_PATCH_0, JMQ_SPF_NEUTRAL, 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 gcc undefined sanitizer complains when seeing a zero sized array declaration. Move the declaration to the point in the code where we know they aren't zero sized. https://sourceware.org/bugzilla/show_bug.cgi?id=28720 Signed-off-by: Mark Wielaard --- libdwfl/ChangeLog | 5 +++++ libdwfl/link_map.c | 4 ++-- 2 files changed, 7 insertions(+), 2 deletions(-) diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index aace969f..b2588b12 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,8 @@ +2022-01-03 Mark Wielaard + + * link_map.c (dwfl_link_map_report): Only declare d32 and d64 before + actual use. + 2022-01-03 Mark Wielaard * dwfl_segment_report_module.c (dwfl_segment_report_module): Copy diff --git a/libdwfl/link_map.c b/libdwfl/link_map.c index 99222bb9..c0207cd3 100644 --- a/libdwfl/link_map.c +++ b/libdwfl/link_map.c @@ -1037,8 +1037,6 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size, return false; } void *buf = malloc (dyn_filesz); - Elf32_Dyn (*d32)[dyn_filesz / sizeof (Elf32_Dyn)] = buf; - Elf64_Dyn (*d64)[dyn_filesz / sizeof (Elf64_Dyn)] = buf; if (unlikely (buf == NULL)) { __libdwfl_seterrno (DWFL_E_NOMEM); @@ -1068,6 +1066,7 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size, /* We are looking for DT_DEBUG. */ if (elfclass == ELFCLASS32) { + Elf32_Dyn (*d32)[dyn_filesz / sizeof (Elf32_Dyn)] = buf; size_t n = dyn_filesz / sizeof (Elf32_Dyn); for (size_t i = 0; i < n; ++i) if ((*d32)[i].d_tag == DT_DEBUG) @@ -1078,6 +1077,7 @@ dwfl_link_map_report (Dwfl *dwfl, const void *auxv, size_t auxv_size, } else { + Elf64_Dyn (*d64)[dyn_filesz / sizeof (Elf64_Dyn)] = buf; size_t n = dyn_filesz / sizeof (Elf64_Dyn); for (size_t i = 0; i < n; ++i) if ((*d64)[i].d_tag == DT_DEBUG)