From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by sourceware.org (Postfix) with ESMTPS id 952373861836 for ; Mon, 1 Feb 2021 14:43:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 952373861836 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=tdevries@suse.de X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A018AABD5 for ; Mon, 1 Feb 2021 14:43:24 +0000 (UTC) Date: Mon, 1 Feb 2021 15:43:22 +0100 From: Tom de Vries To: gdb-patches@sourceware.org Subject: [PATCH][gdb/symtab] Fix assert in write_one_signatured_type Message-ID: <20210201144321.GA1874@delia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) X-Spam-Status: No, score=-12.3 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Feb 2021 14:43:27 -0000 Hi, When running test-case gdb.dwarf2/fission-reread.exp with target board cc-with-gdb-index, we run into an abort during the generation of the gdb-index by cc-with-tweaks.sh: ... build/gdb/testsuite/cache/gdb.sh: line 1: 27275 Aborted (core dumped) ... This can be reproduced on the command line like this: ... $ gdb -batch ./outputs/gdb.dwarf2/fission-reread/fission-reread \ -ex 'save gdb-index ./outputs/gdb.dwarf2/fission-reread' warning: Could not find DWO TU fission-reread.dwo(0x9022f1ceac7e8b19) \ referenced by TU at offset 0x0 [in module fission-reread] warning: Could not find DWO CU fission-reread.dwo(0x807060504030201) \ referenced by CU at offset 0x561 [in module fission-reread] Aborted (core dumped) ... The abort is a segfault due to a using a nullptr psymtab in write_one_signatured_type. The problem is that we're trying to write index entries for the type unit with signature: ... (gdb) p /x entry->signature $2 = 0x9022f1ceac7e8b19 ... which is a skeleton type unit: ... Contents of the .debug_types section: Compilation Unit @ offset 0x0: Length: 0x4a (32-bit) Version: 4 Abbrev Offset: 0x165 Pointer Size: 4 Signature: 0x9022f1ceac7e8b19 Type Offset: 0x0 <0><17>: Abbrev Number: 2 (DW_TAG_type_unit) <18> DW_AT_comp_dir : /tmp/src/gdb/testsuite <2f> DW_AT_GNU_dwo_name: fission-reread.dwo <42> DW_AT_GNU_pubnames: 0x0 <46> DW_AT_GNU_pubtypes: 0x0 <4a> DW_AT_GNU_addr_base: 0x0 ... referring to a .dwo file, but as the warnings show, the .dwo file is not found. Fix this by skipping the type unit in write_one_signatured_type if psymtab == nullptr. Tested on x86_64-linux. Any comments? Thanks, - Tom [gdb/symtab] Fix assert in write_one_signatured_type gdb/ChangeLog: 2021-02-01 Tom de Vries PR symtab/24620 * dwarf2/index-write.c (write_one_signatured_type): Skip if psymtab == nullptr. --- gdb/dwarf2/index-write.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/gdb/dwarf2/index-write.c b/gdb/dwarf2/index-write.c index 66781feaf46..a7b9ae66cae 100644 --- a/gdb/dwarf2/index-write.c +++ b/gdb/dwarf2/index-write.c @@ -616,6 +616,14 @@ write_one_signatured_type (void **slot, void *d) struct signatured_type *entry = (struct signatured_type *) *slot; partial_symtab *psymtab = entry->per_cu.v.psymtab; + if (psymtab == nullptr) + { + /* We can end up here when processing a skeleton CU referring to a + .dwo file that hasn't been found. There's not much we can do in + such a case, so skip this CU. */ + return 1; + } + write_psymbols (info->symtab, info->psyms_seen, psymtab->global_psymbols, info->cu_index, 0);