From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-out1.suse.de (smtp-out1.suse.de [IPv6:2001:67c:2178:6::1c]) by sourceware.org (Postfix) with ESMTPS id AFB1E3858D20 for ; Wed, 9 Aug 2023 15:09:17 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org AFB1E3858D20 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.de Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 5D3E82183F; Wed, 9 Aug 2023 15:09:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1691593756; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=aobQo5wNfW2wMxpKaY5+yg/Q9etJVB/mBVudLm/0C/w=; b=e99uUtOxBv863JI1M5ol6LNT5Bxn7YqAwe0hzpTYeoBq4EEYQN70Vcn4pOzDmHx/91dD04 PxpKnvdQdq33pkjfI1boMj9elycoEnm1EN836OHK5OWFJVbVSWxM+yiRFHOKM0tAc+C5TQ yiFnfC22FfzBotgxMmydQ7LvNhYIBXg= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1691593756; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=aobQo5wNfW2wMxpKaY5+yg/Q9etJVB/mBVudLm/0C/w=; b=Di4KwWr6PLP8rRkE0ynGBRHE7cPE3TNZfzrER+4JU7LoAeTXpf+idZLB/aMPnYsgCUcM8m 2uwOs1VAV2818UAQ== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 480C513251; Wed, 9 Aug 2023 15:09:16 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id T/x/EBys02SYQAAAMHmgww (envelope-from ); Wed, 09 Aug 2023 15:09:16 +0000 From: Tom de Vries To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [PATCH] [gdb/symtab] Fix off-by-one error in cooked_indexer::recurse Date: Wed, 9 Aug 2023 17:08:57 +0200 Message-Id: <20230809150857.22557-1-tdevries@suse.de> X-Mailer: git-send-email 2.35.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.9 required=5.0 tests=BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,GIT_PATCH_0,SPF_HELO_NONE,SPF_PASS,TXREP,T_FILL_THIS_FORM_SHORT autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: Test-case gdb.dwarf2/pr13961.exp contains: ... <1><25>: Abbrev Number: 8 (DW_TAG_class_type) <26> DW_AT_specification: <0x2a> <1><2a>: Abbrev Number: 2 (DW_TAG_class_type) <2b> DW_AT_name : foo <2f> DW_AT_byte_size : 4 <30> DW_AT_decl_file : 1 <31> DW_AT_decl_line : 1 <32> DW_AT_sibling : <0x44> ... The DIE at 0x25 contains an intra-CU forward reference, and is deferred during DIE indexing in the cooked_index, by adding it to m_deferred_entries. The resulting cooked index entries are: ... [12] ((cooked_index_entry *) 0x3dbbd00) name: foo canonical: foo DWARF tag: DW_TAG_class_type flags: 0x0 [] DIE offset: 0x25 parent: ((cooked_index_entry *) 0x3dbbca0) [foo] [13] ((cooked_index_entry *) 0x3dbbca0) name: foo canonical: foo DWARF tag: DW_TAG_class_type flags: 0x0 [] DIE offset: 0x2a parent: ((cooked_index_entry *) 0) ... Notice that 0x2a is the parent of 0x25. The parent field is documented as: ... /* The parent entry. This is NULL for top-level entries. Otherwise, it points to the parent entry, such as a namespace or class. */ const cooked_index_entry *parent_entry; ... so I'd expect no parent for 0x25. The parent is set here in cooked_indexer::make_index: ... for (const auto &entry : m_deferred_entries) { void *obj = m_die_range_map.find (entry.spec_offset); cooked_index_entry *parent = static_cast (obj); m_index_storage->add (entry.die_offset, entry.tag, entry.flags, entry.name, parent, m_per_cu); } ... and AFAICT, we store in m_die_range_map the parent of the respective spec_offset DIE (though that's not clear from the comment describing it). So, the root cause of this is that when we lookup the parent for DIE 0x25, we get m_die_range_map.find (0x2a) == 0x2a. This is an off-by-one error, fixed in cooked_indexer::recurse by: ... - CORE_ADDR start = form_addr (parent_entry->die_offset, + CORE_ADDR start = form_addr (parent_entry->die_offset + 1, ... which gives us: ... [12] ((cooked_index_entry *) 0x41e21f0) name: foo canonical: foo DWARF tag: DW_TAG_class_type flags: 0x0 [] DIE offset: 0x25 parent: ((cooked_index_entry *) 0) [13] ((cooked_index_entry *) 0x41e2190) name: foo canonical: foo DWARF tag: DW_TAG_class_type flags: 0x0 [] DIE offset: 0x2a parent: ((cooked_index_entry *) 0) ... Tested on x86_64-linux. PR symtab/30739 Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30739 --- gdb/dwarf2/read.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index dd4fac52ca8..a64f82bd24a 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -16477,7 +16477,9 @@ cooked_indexer::recurse (cutu_reader *reader, if (parent_entry != nullptr) { - CORE_ADDR start = form_addr (parent_entry->die_offset, + /* Both start and end are inclusive, so use both "+ 1" and "- 1" to + limit the range to the children of parent_entry. */ + CORE_ADDR start = form_addr (parent_entry->die_offset + 1, reader->cu->per_cu->is_dwz); CORE_ADDR end = form_addr (sect_offset (info_ptr - 1 - reader->buffer), reader->cu->per_cu->is_dwz); base-commit: 3cdc2d7e66ab6a48014dcd425c88cfd42a964321 -- 2.35.3