From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 213571D523 for ; Wed, 4 Oct 2023 18:03:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91974C433CD; Wed, 4 Oct 2023 18:03:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696442598; bh=hiA1pVQ1t1euZ/FtB+o6fk8fnfZkNICMzbs/FNsg1Tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EaESA/wkILIPFAMAzXIJmHTOm75L2GODZxP++COcpKhbQZg0QdbqCYgF4aFxORwXa 9wXLf36mMQNl1H+hxZas0cBglUKIwolcXyOD3XW+nmN8tN/XMhf7AljHmsdwI1B4Kc rvVcZh/qvYgx96IMweSw7tj0giCVSi24RrzPHrk4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Christensen , Shannon Nelson , "David S. Miller" , Sasha Levin Subject: [PATCH 5.15 043/183] ionic: fix 16bit math issue when PAGE_SIZE >= 64KB Date: Wed, 4 Oct 2023 19:54:34 +0200 Message-ID: <20231004175205.748015512@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175203.943277832@linuxfoundation.org> References: <20231004175203.943277832@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Christensen [ Upstream commit 8f6b846b0a86c3cbae8a25b772651cfc2270ad0a ] The ionic device supports a maximum buffer length of 16 bits (see ionic_rxq_desc or ionic_rxq_sg_elem). When adding new buffers to the receive rings, the function ionic_rx_fill() uses 16bit math when calculating the number of pages to allocate for an RX descriptor, given the interface's MTU setting. If the system PAGE_SIZE >= 64KB, and the buf_info->page_offset is 0, the remain_len value will never decrement from the original MTU value and the frag_len value will always be 0, causing additional pages to be allocated as scatter- gather elements unnecessarily. A similar math issue exists in ionic_rx_frags(), but no failures have been observed here since a 64KB page should not normally require any scatter-gather elements at any legal Ethernet MTU size. Fixes: 4b0a7539a372 ("ionic: implement Rx page reuse") Signed-off-by: David Christensen Reviewed-by: Shannon Nelson Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/pensando/ionic/ionic_dev.h | 1 + drivers/net/ethernet/pensando/ionic/ionic_txrx.c | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/pensando/ionic/ionic_dev.h b/drivers/net/ethernet/pensando/ionic/ionic_dev.h index 922bb6c9e01d5..676c58dc19817 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h @@ -174,6 +174,7 @@ typedef void (*ionic_desc_cb)(struct ionic_queue *q, struct ionic_desc_info *desc_info, struct ionic_cq_info *cq_info, void *cb_arg); +#define IONIC_MAX_BUF_LEN ((u16)-1) #define IONIC_PAGE_SIZE PAGE_SIZE #define IONIC_PAGE_SPLIT_SZ (PAGE_SIZE / 2) #define IONIC_PAGE_GFP_MASK (GFP_ATOMIC | __GFP_NOWARN |\ diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c index 376f97b4008bb..6604f5862f892 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c @@ -151,7 +151,8 @@ static struct sk_buff *ionic_rx_frags(struct ionic_queue *q, return NULL; } - frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset); + frag_len = min_t(u16, len, min_t(u32, IONIC_MAX_BUF_LEN, + IONIC_PAGE_SIZE - buf_info->page_offset)); len -= frag_len; dma_sync_single_for_cpu(dev, @@ -388,7 +389,8 @@ void ionic_rx_fill(struct ionic_queue *q) /* fill main descriptor - buf[0] */ desc->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset); - frag_len = min_t(u16, len, IONIC_PAGE_SIZE - buf_info->page_offset); + frag_len = min_t(u16, len, min_t(u32, IONIC_MAX_BUF_LEN, + IONIC_PAGE_SIZE - buf_info->page_offset)); desc->len = cpu_to_le16(frag_len); remain_len -= frag_len; buf_info++; @@ -407,7 +409,9 @@ void ionic_rx_fill(struct ionic_queue *q) } sg_elem->addr = cpu_to_le64(buf_info->dma_addr + buf_info->page_offset); - frag_len = min_t(u16, remain_len, IONIC_PAGE_SIZE - buf_info->page_offset); + frag_len = min_t(u16, remain_len, min_t(u32, IONIC_MAX_BUF_LEN, + IONIC_PAGE_SIZE - + buf_info->page_offset)); sg_elem->len = cpu_to_le16(frag_len); remain_len -= frag_len; buf_info++; -- 2.40.1