From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gnu.wildebeest.org (gnu.wildebeest.org [45.83.234.184]) by sourceware.org (Postfix) with ESMTPS id B513A3858404 for ; Tue, 10 Oct 2023 13:43:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org B513A3858404 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 r6.localdomain (82-217-174-174.cable.dynamic.v4.ziggo.nl [82.217.174.174]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id 5F187301FE87; Tue, 10 Oct 2023 15:43:34 +0200 (CEST) Received: by r6.localdomain (Postfix, from userid 1000) id 1B31E3403A4; Tue, 10 Oct 2023 15:43:34 +0200 (CEST) From: Mark Wielaard To: elfutils-devel@sourceware.org Cc: hsm2@rice.edu, Mark Wielaard Subject: [PATCH 04/16] libelf: Fix deadlock in elf_cntl Date: Tue, 10 Oct 2023 15:42:48 +0200 Message-ID: <20231010134300.53830-4-mark@klomp.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231010134300.53830-1-mark@klomp.org> References: <301fac87e83ebbbd677750579ae9a3429b461bdf.camel@klomp.org> <20231010134300.53830-1-mark@klomp.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3033.6 required=5.0 tests=BAYES_00,GIT_PATCH_0,JMQ_SPF_NEUTRAL,KAM_DMARC_STATUS,RCVD_IN_BARRACUDACENTRAL,SPF_HELO_NONE,SPF_PASS,TXREP 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: From: Heather McIntyre * libelf/elf_cntl.c (elf_cntl): Move rwlock_wrlock, rwlock_unlock, inside case switch statements. Signed-off-by: Heather S. McIntyre Signed-off-by: Mark Wielaard --- libelf/elf_cntl.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/libelf/elf_cntl.c b/libelf/elf_cntl.c index 04aa9132..64087c7d 100644 --- a/libelf/elf_cntl.c +++ b/libelf/elf_cntl.c @@ -48,13 +48,16 @@ elf_cntl (Elf *elf, Elf_Cmd cmd) return -1; } - rwlock_wrlock (elf->lock); + switch (cmd) { case ELF_C_FDREAD: + rwlock_rdlock (elf->lock); + int addr_isnull = elf->map_address == NULL; + rwlock_unlock(elf->lock); /* If not all of the file is in the memory read it now. */ - if (elf->map_address == NULL && __libelf_readall (elf) == NULL) + if (addr_isnull && __libelf_readall (elf) == NULL) { /* We were not able to read everything. */ result = -1; @@ -64,7 +67,9 @@ elf_cntl (Elf *elf, Elf_Cmd cmd) case ELF_C_FDDONE: /* Mark the file descriptor as not usable. */ + rwlock_wrlock (elf->lock); elf->fildes = -1; + rwlock_unlock (elf->lock); break; default: @@ -73,7 +78,5 @@ elf_cntl (Elf *elf, Elf_Cmd cmd) break; } - rwlock_unlock (elf->lock); - return result; } -- 2.41.0