From patchwork Wed Dec 18 23:41:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pablo Neira Ayuso X-Patchwork-Id: 13914301 X-Patchwork-Delegate: kuba@kernel.org Received: from mail.netfilter.org (mail.netfilter.org [217.70.188.207]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C4D211FAC55; Wed, 18 Dec 2024 23:41:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.188.207 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734565313; cv=none; b=U2fcP8mknqeEcU5ecb8dNpVpNtawmcD2Tr4QDA7qsRQcYEOq9LE2QTCfLkDKjKURVYQsHx77pyKRCH8XsQW9caopGrtTAZpqYf+LqZhhdRo5bAozhLYsZnxefW+tar/Pob/m1JZo+/4w9aLtkWAODvbuz2rtU78sClC0MwwVN4A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734565313; c=relaxed/simple; bh=hlTUwRtcm8X5JqChNop5tLa5z5lb/W4oTXOG4zmP21s=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=hAMGojv4rRNyNeGj7CApysukSeoyiFTZv/InOfAdLz3zuoETzT/prtXxiBevZlTfCe8SJjVGYRNJuTD63TvKIKk938d5ovtQ8j20xUXjA3wonWqsy4Blggth44WCIdhie4Vyhpxxawci5dHg/1gQiH34UrKziAYFx4uLaGm2kFQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; arc=none smtp.client-ip=217.70.188.207 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, fw@strlen.de Subject: [PATCH net 1/2] ipvs: Fix clamp() of ip_vs_conn_tab on small memory systems Date: Thu, 19 Dec 2024 00:41:36 +0100 Message-Id: <20241218234137.1687288-2-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20241218234137.1687288-1-pablo@netfilter.org> References: <20241218234137.1687288-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: David Laight The 'max_avail' value is calculated from the system memory size using order_base_2(). order_base_2(x) is defined as '(x) ? fn(x) : 0'. The compiler generates two copies of the code that follows and then expands clamp(max, min, PAGE_SHIFT - 12) (11 on 32bit). This triggers a compile-time assert since min is 5. In reality a system would have to have less than 512MB memory for the bounds passed to clamp to be reversed. Swap the order of the arguments to clamp() to avoid the warning. Replace the clamp_val() on the line below with clamp(). clamp_val() is just 'an accident waiting to happen' and not needed here. Detected by compile time checks added to clamp(), specifically: minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() Reported-by: Linux Kernel Functional Testing Closes: https://lore.kernel.org/all/CA+G9fYsT34UkGFKxus63H6UVpYi5GRZkezT9MRLfAbM3f6ke0g@mail.gmail.com/ Fixes: 4f325e26277b ("ipvs: dynamically limit the connection hash table") Tested-by: Bartosz Golaszewski Reviewed-by: Bartosz Golaszewski Signed-off-by: David Laight Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_conn.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c index 98d7dbe3d787..c0289f83f96d 100644 --- a/net/netfilter/ipvs/ip_vs_conn.c +++ b/net/netfilter/ipvs/ip_vs_conn.c @@ -1495,8 +1495,8 @@ int __init ip_vs_conn_init(void) max_avail -= 2; /* ~4 in hash row */ max_avail -= 1; /* IPVS up to 1/2 of mem */ max_avail -= order_base_2(sizeof(struct ip_vs_conn)); - max = clamp(max, min, max_avail); - ip_vs_conn_tab_bits = clamp_val(ip_vs_conn_tab_bits, min, max); + max = clamp(max_avail, min, max); + ip_vs_conn_tab_bits = clamp(ip_vs_conn_tab_bits, min, max); ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits; ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;