From patchwork Mon Jul 10 06:59:38 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13306344 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B57EBEB64D9 for ; Mon, 10 Jul 2023 07:10:21 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.560995.877271 (Exim 4.92) (envelope-from ) id 1qIl1s-0002yI-Uw; Mon, 10 Jul 2023 07:09:52 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 560995.877271; Mon, 10 Jul 2023 07:09:52 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qIl1s-0002y5-S4; Mon, 10 Jul 2023 07:09:52 +0000 Received: by outflank-mailman (input) for mailman id 560995; Mon, 10 Jul 2023 07:09:52 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1qIkt1-0002bQ-0o for xen-devel@lists.xenproject.org; Mon, 10 Jul 2023 07:00:43 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.220.29]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 7b82f9d1-1eef-11ee-8611-37d641c3527e; Mon, 10 Jul 2023 09:00:41 +0200 (CEST) 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-out2.suse.de (Postfix) with ESMTPS id 419821F747; Mon, 10 Jul 2023 07:00:41 +0000 (UTC) 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 14BA41361C; Mon, 10 Jul 2023 07:00:41 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id 0DKOA5msq2QGYwAAMHmgww (envelope-from ); Mon, 10 Jul 2023 07:00:41 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 7b82f9d1-1eef-11ee-8611-37d641c3527e DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1688972441; 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: in-reply-to:in-reply-to:references:references; bh=HISzN7bRVjI3VR79BWGkvbZ0+p8FLjRndAnfEz4SFQg=; b=OM+Tbvc9TedBnMetKo/FIcOn6GO0WQ85CUvpTwDI12eRgoiK9cjz54V1lSh3gQnWTZv0+p GmeokX41MdR/LxXWG4tAcXakn3a8PklZNoMDWjedjfxNpBpNgXFFY4kke01CpVt1UINvt2 dx8fSc6C/1PWR2uVj2hfMTQfc6sselA= From: Juergen Gross To: xen-devel@lists.xenproject.org Cc: Juergen Gross , Wei Liu , Julien Grall , Anthony PERARD Subject: [PATCH v2 09/18] tools/xenstore: let hashtable_add() fail in case of existing entry Date: Mon, 10 Jul 2023 08:59:38 +0200 Message-Id: <20230710065947.4201-10-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230710065947.4201-1-jgross@suse.com> References: <20230710065947.4201-1-jgross@suse.com> MIME-Version: 1.0 Silently adding another entry with the same key to a hashtable is a perfect receipt for later failure with hard to diagnose symptoms. Let hashtable_add() fail in case another entry with the same key is already existing. Signed-off-by: Juergen Gross Reviewed-by: Julien Grall --- V2: - split off from next patch (Julien Grall) - fix coding style (Julien Grall) - use for () loop (Julien Grall) --- tools/xenstore/hashtable.c | 39 ++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) diff --git a/tools/xenstore/hashtable.c b/tools/xenstore/hashtable.c index 9daddd9782..29c247f918 100644 --- a/tools/xenstore/hashtable.c +++ b/tools/xenstore/hashtable.c @@ -141,11 +141,33 @@ static int hashtable_expand(struct hashtable *h) return 0; } +static struct entry *hashtable_search_entry(const struct hashtable *h, + const void *k) +{ + struct entry *e; + unsigned int hashvalue, index; + + hashvalue = hash(h, k); + index = indexFor(h->tablelength, hashvalue); + e = h->table[index]; + + for (e = h->table[index]; e; e = e->next) + { + /* Check hash value to short circuit heavier comparison */ + if ((hashvalue == e->h) && (h->eqfn(k, e->k))) + return e; + } + + return NULL; +} int hashtable_add(struct hashtable *h, const void *k, void *v) { - /* This method allows duplicate keys - but they shouldn't be used */ unsigned int index; struct entry *e; + + if (hashtable_search_entry(h, k)) + return EEXIST; + if (++(h->entrycount) > h->loadlimit) { /* Ignore the return value. If expand fails, we should @@ -176,17 +198,10 @@ int hashtable_add(struct hashtable *h, const void *k, void *v) void *hashtable_search(const struct hashtable *h, const void *k) { struct entry *e; - unsigned int hashvalue, index; - hashvalue = hash(h,k); - index = indexFor(h->tablelength,hashvalue); - e = h->table[index]; - while (NULL != e) - { - /* Check hash value to short circuit heavier comparison */ - if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v; - e = e->next; - } - return NULL; + + e = hashtable_search_entry(h, k); + + return e ? e->v : NULL; } void