From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.70 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794117496; b=MfA4/z2Wex/hRe+UQJ/Em1jfrguHBTqozHWtN1q2hRfykZM4b7oKuM5Nyc8dhBUkXueQ QqTlJfFFE4U05Rl1IriqNRgTYFhJpSy7KY4kY7jNq92kb2d6KEBCT5JBhyZMDYCCkSTzc +iS8uRKi/rJ2RVF/7nPNB/davMuxMRoZ7xcHUq3wtyF41JeFzoiFHJ/0wBAiUn6HZrjTn 3OFAzqBpGDuGDHpcmZRZi2SYl6J77jKX/+KSINstTeqQQtjCKNVVM2dO987cXlHHAvuJW VZ9edRxe6e3OccZHXwNJV4qEtUun8WOyeHSQfvVyCtqg1pZkX+yv6KY1raRkLu6rqLg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794117496; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Gm-Message-State:X-Received:Date:In-Reply-To:Mime-Version: References:X-Mailer:Message-ID:Subject:From:To:Cc:Content-Type; bh=7n5mV7LlVJBcizMSVH3942EO35b0cUF5y9HFomTyAB0=; b=Txmn4kY+Xui5l5+h/zLDCCCk1Dh3SDRGtFH5YbvgNv/qnjeCBM4fRiR1XuERyqXcBdDK 4e5K2koBteUHBHDf7PWs0xFS8uLWB1eWQ86z6BpqeBFQdedNmRE5X8I4m9SO6dY+P3kxW y69JjzXec3o5reRN//GDha4MSlfGEqLVszocC19CFvBFoUDEhQjn9Hw8JyOq3xE5h8S0X a92IPmJmogYE3LMLmuxHWx/wQ/GPWaeEFP8qrB6eXOkOtpoZld7m9562QueFdK0VkeWPk wA2uOQHuy7wb8ZEfyE7w7+Q7fXvuZp7od/e3RmjrZoZztJpnWJkweoSS3OYmn1kcPyg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=google.com; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com; dkim=pass header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=Pxi9YUNR; arc=none smtp.remote-ip=74.125.82.70 Received: from mail-dl1-f70.google.com (mail-dl1-f70.google.com [74.125.82.70]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 753DD606A336 for ; Sun, 8 Nov 2026 05:58:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 753DD606A336 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--almasrymina.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20260707 header.b=Pxi9YUNR Received: by mail-dl1-f70.google.com with SMTP id a92af1059eb24-1a71dd190b0so560398c88.1 for ; Sat, 07 Nov 2026 21:58:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20260707; t=1794117496; x=1794722296; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:from:to:cc:subject:date:message-id:reply-to :content-type; bh=7n5mV7LlVJBcizMSVH3942EO35b0cUF5y9HFomTyAB0=; b=Pxi9YUNRYS89eHjvSf17iZ6lWklc3pZv5JlLH6W3szqctgiK4SPSILrcYXe2VFCu05 5ly0qJJCN7uGIWbW2uY+cNmzCQ8IMzn+zfGD6iCp1DhcAWchWCv6O5fLzYHUAozPvX5L IEkkHZtzzwTGP8MMSfFNqSlpS0Wv4qr+Ja5HzYNqNJ+oe+8T2A6Kcfu1pDbtJ77ybC8O iShVsr2D2S5L17/D5ga43y5IGrM21g/uDJlZLXkqMMHTvuV2ndZUTTa0UqGSq1LVn+Vj YKzWDptEN4Ne+KGXazzYgaJyBO6ls2Tyyy3SNStU5AC3z2fJNkXnz7H+WMyi7UuZgdkP 0dcw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794117496; x=1794722296; h=content-type:cc:to:from:subject:message-id:references:mime-version :in-reply-to:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=7n5mV7LlVJBcizMSVH3942EO35b0cUF5y9HFomTyAB0=; b=AuTa2bqiRv7F0ZhxiCpmf871hJOLYxqZHSOTcDcP1Np6ZV+cNwfmqBLPmy09qIgMvU neGN9u8YGYW782PRXQu0y38/dZ5K4vrC6sBLTTq/K7Wg/W6jvarFKi10iFXUjq7fUbTu Vmi4QGq//wGHArl2zWVnD3Txm8zgHQ19yZxt31G8esqyHxBvG/4OVAauJgKCmIot2SgA DzdmCJVeQ9kOoOuxA4jXtSYWEJ/pIUEJ1JHBE2Q672oo9ELNkBDvxu4EwUhJ4ZqN5fsy Wc2HORs8eykmYNEzJhPnrQcyOKopwTOpda2tjVfp/eVqu/HQoerTxmoEeWmaTNBe56WV 8qVw== X-Gm-Message-State: APuU4Z/DwjxFysQoMO0SeFnJhbMH8LyjDsO21RAJbe9H14iFP7PwdZJL VaEkhwXxSDrBKI0iMymArcdeWq603e1wa2+AElgiGvTDkXrSfbqU1r4bIyJ/GMi9cJd517/TZng ua/75KvUMDDWX+jdRMIPH6FG4DWIy9+Yr3LAXiGj4j8PqXxgt/MxC0ARjtjKEqXnXaPdyHjUT40 V42PrLH+BAXrxxDWH7nIam8r7qtmducim0Mq3ii8zw1bElIMzaXIWc5WNWN4gy8fk= X-Received: from dlbtu15.prod.google.com ([2002:a05:7022:3c0f:b0:15d:6b8d:2adc]) (user=almasrymina job=prod-delivery.src-stubby-dispatcher) by 2002:a05:7022:7f01:b0:1b0:f268:3419 with SMTP id a92af1059eb24-1b39fe87bedmr1005367c88.7.1794117495052; Sat, 07 Nov 2026 21:58:15 -0800 (PST) Date: Sun, 8 Nov 2026 05:58:08 +0000 In-Reply-To: <20261108055809.2122934-1-almasrymina@google.com> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list Mime-Version: 1.0 References: <20261108055809.2122934-1-almasrymina@google.com> X-Mailer: git-send-email 2.56.0.455.g6c5a503b38-goog Message-ID: <20261108055809.2122934-6-almasrymina@google.com> Subject: [PATCH net-next v2 5/6] net: devmem: resolve physical map_dev for leased RX bindings From: Mina Almasry To: netdev@vger.kernel.org Cc: Mina Almasry , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Shuah Khan , linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, Daniel Borkmann , Nikolay Aleksandrov , David Wei , Stanislav Fomichev , Bobby Eshleman , Dragos Tatulea Content-Type: text/plain; charset="UTF-8" Previously, netdev_nl_bind_rx_doit() passed netdev as both map_dev and bind_dev to net_devmem_bind_dmabuf(), so leased RX bindings stored the virtual netdev in binding->map_dev without tracking the physical backing netdev at all. Unregistering the physical backing netdev while a leased RX binding was active failed to detach and unmap the dmabuf. Return the physical backing net_device from netdev_nl_get_dma_dev() when the RX queue is leased from another netdev, lock map_dev around net_devmem_bind_dmabuf() when map_dev != netdev (matching netdev_nl_bind_tx_doit()), and assert in net_devmem_bind_dmabuf() that both bind_dev and map_dev are locked. Because a leased map_dev is reached via rxq->lease->dev and locked with raw netdev_lock(map_dev) rather than netdev_get_by_index_lock(), it may already have entered NETREG_UNREGISTERING and completed net_devmem_dev_unregister(map_dev) before cascaded unregistration of bind_dev tears down the lease. Reject binding in net_devmem_bind_dmabuf() if map_dev->reg_state != NETREG_REGISTERED. Signed-off-by: Mina Almasry --- net/core/devmem.c | 12 ++++++++++++ net/core/netdev-genl.c | 19 ++++++++++++++++--- 2 files changed, 28 insertions(+), 3 deletions(-) diff --git a/net/core/devmem.c b/net/core/devmem.c index bb785a871d1c4..2dac581a57e13 100644 --- a/net/core/devmem.c +++ b/net/core/devmem.c @@ -321,6 +321,18 @@ net_devmem_bind_dmabuf(struct net_device *map_dev, size_t i; long err; + netdev_assert_locked(bind_dev); + netdev_assert_locked(map_dev); + + /* When map_dev != bind_dev, map_dev is locked via the queue lease + * rather than netdev_get_by_index_lock(), so it may already be + * unregistering before cascaded bind_dev unregistration runs. + */ + if (map_dev->reg_state != NETREG_REGISTERED) { + NL_SET_ERR_MSG(extack, "Device is being unregistered"); + return ERR_PTR(-ENODEV); + } + if (!dma_dev) { NL_SET_ERR_MSG(extack, "Device doesn't support DMA"); return ERR_PTR(-EOPNOTSUPP); diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c index 9e56c26fc65f9..442362f23fe88 100644 --- a/net/core/netdev-genl.c +++ b/net/core/netdev-genl.c @@ -1005,12 +1005,15 @@ static int netdev_nl_read_rxq_bitmap(struct genl_info *info, static struct device * netdev_nl_get_dma_dev(struct net_device *netdev, unsigned long *rxq_bitmap, + struct net_device **map_dev, struct netlink_ext_ack *extack) { struct device *dma_dev = NULL; u32 rxq_idx, prev_rxq_idx; + *map_dev = netdev; for_each_set_bit(rxq_idx, rxq_bitmap, netdev->real_num_rx_queues) { + struct netdev_rx_queue *rxq; struct device *rxq_dma_dev; rxq_dma_dev = netdev_queue_get_dma_dev(netdev, rxq_idx, @@ -1023,6 +1026,11 @@ netdev_nl_get_dma_dev(struct net_device *netdev, unsigned long *rxq_bitmap, dma_dev = rxq_dma_dev; prev_rxq_idx = rxq_idx; + if (netif_rxq_is_leased(netdev, rxq_idx) && + netif_is_queue_leasee(netdev)) { + rxq = __netif_get_rx_queue(netdev, rxq_idx); + *map_dev = rxq->lease->dev; + } } return dma_dev; @@ -1032,9 +1040,9 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) { struct net_devmem_dmabuf_binding *binding; unsigned int niov_shift = PAGE_SHIFT; + struct net_device *netdev, *map_dev; u32 ifindex, dmabuf_fd, rxq_idx; struct netdev_nl_sock *priv; - struct net_device *netdev; unsigned long *rxq_bitmap; struct device *dma_dev; struct sk_buff *rsp; @@ -1104,16 +1112,21 @@ int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info) if (err) goto err_rxq_bitmap; - dma_dev = netdev_nl_get_dma_dev(netdev, rxq_bitmap, info->extack); + dma_dev = netdev_nl_get_dma_dev(netdev, rxq_bitmap, &map_dev, + info->extack); if (IS_ERR(dma_dev)) { err = PTR_ERR(dma_dev); goto err_rxq_bitmap; } - binding = net_devmem_bind_dmabuf(netdev, netdev, dma_dev, + if (map_dev != netdev) + netdev_lock(map_dev); + binding = net_devmem_bind_dmabuf(map_dev, netdev, dma_dev, DMA_FROM_DEVICE, dmabuf_fd, niov_shift, priv, NETLINK_CB(skb).sk, info->extack); + if (map_dev != netdev) + netdev_unlock(map_dev); if (IS_ERR(binding)) { err = PTR_ERR(binding); goto err_rxq_bitmap; -- 2.56.0.455.g6c5a503b38-goog