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 E7A631D68D for ; Wed, 4 Oct 2023 18:25:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ioVmor1J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69A5FC433C8; Wed, 4 Oct 2023 18:25:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696443910; bh=V6phDsTMkiZ6GSNfOl4lSbPzN38ZcU7mhvQYEvFI6xY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ioVmor1JNEMfs1TXGjJ3U825VuGyT7fgJHb4IAzLBcHeU4L/mc0XmX4V9NF/5y5eE xNL0pBFQrP89MuaxV5Jlujw7R0ADXDtotSi7Rcr2Njb/vSc93uwwmBWh2hfCbqvtZC IhZ6dZUS0fBIHhmfz2GjdZUKKKuu1eQ4hr5Hu360= 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 6.5 064/321] ionic: fix 16bit math issue when PAGE_SIZE >= 64KB Date: Wed, 4 Oct 2023 19:53:29 +0200 Message-ID: <20231004175232.142436522@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175229.211487444@linuxfoundation.org> References: <20231004175229.211487444@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 6.5-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 0bea208bfba2f..43ce0aac6a94c 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_dev.h +++ b/drivers/net/ethernet/pensando/ionic/ionic_dev.h @@ -187,6 +187,7 @@ 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 26798fc635dbd..44466e8c5d77b 100644 --- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c +++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c @@ -207,7 +207,8 @@ 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, @@ -452,7 +453,8 @@ 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++; @@ -471,7 +473,9 @@ 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