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 88014143736; Thu, 13 Feb 2025 15:26:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739460378; cv=none; b=IBvTAkwOm5lDZSBnHZTuKbjUpGKmK6JKPB56JYcL1vPM40jx19TDV8cCgbMg/r7ag7ztDSC/t3FrD/aTYiPXpUJmHBQ0j17lNako21IYYErF6PrvxONaJnyxh4lZnHu31Ay1/Vpta2aoxySdEDY8Ki948UYo21ByMBoxclKpAWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739460378; c=relaxed/simple; bh=EGKLViv7PAWKlOlfef+wIS4g0OE5WMycD5thbNFnwwo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=sN+2/KUc7++rmjgekJrMgAU0QN2chm+ySP2Jqv3S7dFJhhea1all5zM1qMRmLB31c3jDNBhxbF3iMy98L3LjLBoYCZIoh6KNxM76sFbCNdGsYGJPuMwDpzMFPWOilzWl3t6r5i7PJTSQA/7j9EvLItKQulxyN4jys3yzqKP8OjM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=g64ZMYzb; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="g64ZMYzb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6D39C4CED1; Thu, 13 Feb 2025 15:26:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1739460378; bh=EGKLViv7PAWKlOlfef+wIS4g0OE5WMycD5thbNFnwwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g64ZMYzbbL4aRJgikv+m3zaRCMMAIOz3z/dNJrgzrRL3QzzbaLy33MIab6xRvL8nS Ewrs1kjxsQ0TcXp96ThwhzXh/X1icmd5F02RbsD65hfu5otcjCJaGbhMIrKb3MoH5S u/LV9qijhXVyuccpBFL+leX50IciMIJPoGCDCC6k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sankararaman Jayaraman , Ronak Doshi , Simon Horman , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 067/273] vmxnet3: Fix tx queue race condition with XDP Date: Thu, 13 Feb 2025 15:27:19 +0100 Message-ID: <20250213142410.003070152@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250213142407.354217048@linuxfoundation.org> References: <20250213142407.354217048@linuxfoundation.org> User-Agent: quilt/0.68 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sankararaman Jayaraman [ Upstream commit 3f1baa91a1fdf3de9dbad4bd615b35fab347874b ] If XDP traffic runs on a CPU which is greater than or equal to the number of the Tx queues of the NIC, then vmxnet3_xdp_get_tq() always picks up queue 0 for transmission as it uses reciprocal scale instead of simple modulo operation. vmxnet3_xdp_xmit() and vmxnet3_xdp_xmit_frame() use the above returned queue without any locking which can lead to race conditions when multiple XDP xmits run in parallel on different CPU's. This patch uses a simple module scheme when the current CPU equals or exceeds the number of Tx queues on the NIC. It also adds locking in vmxnet3_xdp_xmit() and vmxnet3_xdp_xmit_frame() functions. Fixes: 54f00cce1178 ("vmxnet3: Add XDP support.") Signed-off-by: Sankararaman Jayaraman Signed-off-by: Ronak Doshi Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250131042340.156547-1-sankararaman.jayaraman@broadcom.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/vmxnet3/vmxnet3_xdp.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/net/vmxnet3/vmxnet3_xdp.c b/drivers/net/vmxnet3/vmxnet3_xdp.c index 1341374a4588a..616ecc38d1726 100644 --- a/drivers/net/vmxnet3/vmxnet3_xdp.c +++ b/drivers/net/vmxnet3/vmxnet3_xdp.c @@ -28,7 +28,7 @@ vmxnet3_xdp_get_tq(struct vmxnet3_adapter *adapter) if (likely(cpu < tq_number)) tq = &adapter->tx_queue[cpu]; else - tq = &adapter->tx_queue[reciprocal_scale(cpu, tq_number)]; + tq = &adapter->tx_queue[cpu % tq_number]; return tq; } @@ -124,6 +124,7 @@ vmxnet3_xdp_xmit_frame(struct vmxnet3_adapter *adapter, u32 buf_size; u32 dw2; + spin_lock_irq(&tq->tx_lock); dw2 = (tq->tx_ring.gen ^ 0x1) << VMXNET3_TXD_GEN_SHIFT; dw2 |= xdpf->len; ctx.sop_txd = tq->tx_ring.base + tq->tx_ring.next2fill; @@ -134,6 +135,7 @@ vmxnet3_xdp_xmit_frame(struct vmxnet3_adapter *adapter, if (vmxnet3_cmd_ring_desc_avail(&tq->tx_ring) == 0) { tq->stats.tx_ring_full++; + spin_unlock_irq(&tq->tx_lock); return -ENOSPC; } @@ -142,8 +144,10 @@ vmxnet3_xdp_xmit_frame(struct vmxnet3_adapter *adapter, tbi->dma_addr = dma_map_single(&adapter->pdev->dev, xdpf->data, buf_size, DMA_TO_DEVICE); - if (dma_mapping_error(&adapter->pdev->dev, tbi->dma_addr)) + if (dma_mapping_error(&adapter->pdev->dev, tbi->dma_addr)) { + spin_unlock_irq(&tq->tx_lock); return -EFAULT; + } tbi->map_type |= VMXNET3_MAP_SINGLE; } else { /* XDP buffer from page pool */ page = virt_to_page(xdpf->data); @@ -182,6 +186,7 @@ vmxnet3_xdp_xmit_frame(struct vmxnet3_adapter *adapter, dma_wmb(); gdesc->dword[2] = cpu_to_le32(le32_to_cpu(gdesc->dword[2]) ^ VMXNET3_TXD_GEN); + spin_unlock_irq(&tq->tx_lock); /* No need to handle the case when tx_num_deferred doesn't reach * threshold. Backend driver at hypervisor side will poll and reset @@ -225,6 +230,7 @@ vmxnet3_xdp_xmit(struct net_device *dev, { struct vmxnet3_adapter *adapter = netdev_priv(dev); struct vmxnet3_tx_queue *tq; + struct netdev_queue *nq; int i; if (unlikely(test_bit(VMXNET3_STATE_BIT_QUIESCED, &adapter->state))) @@ -236,6 +242,9 @@ vmxnet3_xdp_xmit(struct net_device *dev, if (tq->stopped) return -ENETDOWN; + nq = netdev_get_tx_queue(adapter->netdev, tq->qid); + + __netif_tx_lock(nq, smp_processor_id()); for (i = 0; i < n; i++) { if (vmxnet3_xdp_xmit_frame(adapter, frames[i], tq, true)) { tq->stats.xdp_xmit_err++; @@ -243,6 +252,7 @@ vmxnet3_xdp_xmit(struct net_device *dev, } } tq->stats.xdp_xmit += i; + __netif_tx_unlock(nq); return i; } -- 2.39.5