From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.215.174 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792541867; b=lvzkSahH/+tqSrQ4Z40zsUSAdgc9hHvi5lN3RYydTljkz0Ynk4TMiU7vlXje31yuVETO XupSFE5WcHIav0fvIske/aTCSei5yRVwetSI4uOLBciqWYSBZXskkQtT0OPX6cPNHUlsB qbxH+EKpJFl3lyZ0Jr8GJYRGyTuxLBWtfcPSmwWbV6c7F1n1mdZ8y+ZTlsX3oqAV3q5Yr 0JjJ3Yw/TL9T7YmCwe9nFeUom8VH7U+B6EGSex3sKnbEcnb0ixwsvb2d1cbG9ra56e6o6 NO7nG9Qn8bHPob7ll+rbIejrpTUdTxU2D92KpWhnA4Pgi2ZYopRRTJUf/wzI23CX2lw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792541867; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Gm-Message-State:X-Gm-Gg:X-Received:Received:From:To:Cc:Subject: Date:Message-ID:X-Mailer:MIME-Version:Content-Transfer-Encoding; bh=lt5khUmxw1gOh/n0LWJhaeEcTc68Du7k7RW7yXiy7Vc=; b=Fx5WLKGWPgdS5evEfDvLMaY9DN6pr8ICKbna5b625OCw8BTD/+HIwvDBgI6OoP2OEOqf YEvk7v5oyPCl6Tp+uEZaBJ/xZ/CuXpmY9Jo093ty3VwLR4Eo9j2pFeqGOaEOQjXe6biP0 xuL27hbQE6QzmOd5NHHUo8rcA5xmXP11jM4GcPac66QWsniRzNzKMacePGYJ6tHGAVSdY AmNVEL/bWUR0aRlG+YkqjJN3sxqUQJzTLPE2yp1fuU7LDS2JXLkoIBXbS9EbvFwq0ODgV uNWgkw2Li4ZkEzCOCj0c9oqzcNrKk+ZvxhGYUQ6M8Nt2Y94BR9e+N+DhQGtm73+fhtg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=cQKJTXtP; arc=none smtp.remote-ip=209.85.215.174 Received: from mail-pg1-f174.google.com (mail-pg1-f174.google.com [209.85.215.174]) (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 D0232606A31A for ; Wed, 21 Oct 2026 00:17:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org D0232606A31A Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=cQKJTXtP Received: by mail-pg1-f174.google.com with SMTP id 41be03b00d2f7-cd69954c755so58355a12.3 for ; Tue, 20 Oct 2026 17:17:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792541866; x=1793146666; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=lt5khUmxw1gOh/n0LWJhaeEcTc68Du7k7RW7yXiy7Vc=; b=cQKJTXtPOqOBfFDsdmTJkZ2OP3TUQ+Y7iAfiMLRmfMLaIqO0Erebw7x2fl65rR0bGh sbjaFbYwRmB6kLa0h0kE2q74WqZs/o3MZgPrRBnZK/rL+g+zM/SRNseY288b/1ROKBxl fNq75cihBGfySJuNAyMTyIGgm0wu65y/Cxiwj+YoX6i8mon51QsSMEGIAdNdpR5WUP3j 1gfAx96eeFXrJCoNlqPqr4aII+X7Qj9c/MobJv8GDGKk9ZbJdkm/pJeMowAnJFViHZ3n hP+vk55GI6uy5SEzGFn0ALTe1QTHOY4KceT31X1uYHu74UsvLASz09PFWJC3ADKKF4R0 yeiQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792541866; x=1793146666; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=lt5khUmxw1gOh/n0LWJhaeEcTc68Du7k7RW7yXiy7Vc=; b=aPLEDGTWZZRIkrCsSfgYFbA/myFd5t61R7AzBo+YPx5ap/Uvdu+c0PYpKKtnK0Di6A 85nCKzLQN6AmB59qXbl3RNR0D77+WyaItazG/rbWwl+loMGwKAncn/w4thtvoa9Dcozt +Xb6JHsjgeud7vSK0a7s+cPbKZFXMPbMsTZfkmV1Rvm16mUgqAdoCFfykp3nyFkNYRmV ri6tlR9FZkFXShpq6AFdZLVczoSC4LrTAQVTm2fyZiVt90kyE23tkkqMOshUiQFdQaQN +B2clamJZiH/xNc9V4e0qCxBzS1PzGL/PQ52wwZaf8lM/xFoeJLPegbnce4p8jemSV9e o4WQ== X-Gm-Message-State: AFq9FYJZmhUK8W/oCHDL2/CwQQRX9K6GY0cyC8MGJjiIOMXK01sld+9g 0PdKNrfz9w/ZLnypZg1ZORCa1+2Eb2RAbfhhUMv8IrFY9AIQJvcGZMPbdXQWqA== X-Gm-Gg: AYBFou2/O+KJ1kPXEJBDg9fhLnxUYjEtfVq3xD4IU+qoHnYCo9b/IH27FszQsFbII5s EhZuDL1lynzcfu/lQXP09sReAE/Ia82y9oJvThS1P40GES5xrwWpJBgGe+gW0++bHsMAcFslW+K j2RQh1cm157ecUZ/i9fUfv4F3mXGb6heIKeDGP2CYzxw2t1tvAo99dnDicLv4ArPqxZ9AbmZZpm ktcvs7mcM9vUffeHuWV2e40az15tbvtWilaJ0jvskYWsk0zxdNA9PISvST/COVVRcA8GkND7Ffl WqqGXC8uVXKL2aIH+rb/j6TQqTNY/ntEU/UYz6/jYWwKyF0/vzFB1+CwU6Qeb7HdKB1o3556hke Jiyo2Q1Ec3QfhXUw4TceHFEdXieZMYeuSVMibUP9og2JWRk3zIrf06SeJryXjHKVCzQz2mbUFL4 7mQvBMHQ5SJP1RgmT4mTSkqO/4E2y0JPiOpm82tzVEPumVxX0Sn4mn/7gqsro1xPyipbSZDb3kn b2NH5Yh70T2h/ex1KN0p23c8R0C/OrN7JtDbuwsTGFhCk8mj5OL+3JeEYgNTbhgThzYjiiU3dO9 v6qwU2t+3WK59h4yTSO25Y0SDhOW1fHBn5QyMFefoK32VU+XCDlRgIwmnw== X-Received: by 2002:a17:90b:2f85:b0:3ac:53e0:4ed5 with SMTP id 98e67ed59e1d1-3ad86f6e8camr387246a91.39.1792541866147; Tue, 20 Oct 2026 17:17:46 -0700 (PDT) Received: from ryzen.lan ([2601:644:8000:37f::e35]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ad85f38df2sm547894a91.2.2026.10.20.17.17.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2026 17:17:45 -0700 (PDT) From: Rosen Penev To: netdev@vger.kernel.org Cc: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Broadcom internal kernel review list , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Felix Fietkau , linux-kernel@vger.kernel.org (open list) Subject: [PATCH net v2] net: bgmac: fix TX DMA unmapping and slot cleanup Date: Tue, 20 Oct 2026 17:17:44 -0700 Message-ID: <20261021001744.2042320-1-rosenp@gmail.com> X-Mailer: git-send-email 2.56.0 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 Content-Transfer-Encoding: 8bit When mapping a fragment fails, bgmac_dma_tx_add() unwinds with the wrong slots. It passes the failed fragment's slot->dma_addr, which holds the mapping error, to dma_unmap_single() for the head. The fragment loop indexes from ring->end instead of ring->end + 1, so it unmaps the head a second time as a page and leaves the last mapped fragment mapped. None of the affected slots get their dma_addr cleared either, which includes the head slot when mapping the head fails. bgmac_dma_tx_ring_free() unmaps every slot with a non-zero dma_addr, so tearing down the ring unmaps these addresses again. It also frees the skbs of pending TX slots but leaves slot->skb and slot->dma_addr set. The slots survive a down/up cycle, and bgmac_dma_tx_add() only sets slot->skb on the last slot of a packet. If a slot with a stale pointer is later used for the head or a fragment of a scatter/gather packet, bgmac_dma_tx_free() frees the old skb a second time when that slot completes. bgmac_dma_tx_ring_free() also picks dma_unmap_single() or dma_unmap_page() by looking at slot->skb, which is set on the last slot of a packet, while the head was mapped with dma_map_single() and the fragments with skb_frag_dma_map(). In the error path, unmap the head and each mapped fragment from their own slots, and clear dma_addr on every slot the failed packet touched. In bgmac_dma_tx_ring_free(), choose the unmap function by the SOF flag of the descriptor like bgmac_dma_tx_free() does, unmap before freeing, and clear both fields. Fixes: 9cde94506eac ("bgmac: implement scatter/gather support") Signed-off-by: Rosen Penev --- v2: merge two patches into one drivers/net/ethernet/broadcom/bgmac.c | 41 ++++++++++++++++----------- 1 file changed, 24 insertions(+), 17 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c index e66856337d33..55d126c7d35c 100644 --- a/drivers/net/ethernet/broadcom/bgmac.c +++ b/drivers/net/ethernet/broadcom/bgmac.c @@ -205,19 +205,24 @@ static netdev_tx_t bgmac_dma_tx_add(struct bgmac *bgmac, return NETDEV_TX_OK; err_dma: - dma_unmap_single(dma_dev, slot->dma_addr, skb_headlen(skb), - DMA_TO_DEVICE); + slot->dma_addr = 0; while (i-- > 0) { - int index = (ring->end + i) % BGMAC_TX_RING_SLOTS; - struct bgmac_slot_info *slot = &ring->slots[index]; - u32 ctl1 = le32_to_cpu(ring->cpu_base[index].ctl1); - int len = ctl1 & BGMAC_DESC_CTL1_LEN; - - dma_unmap_page(dma_dev, slot->dma_addr, len, DMA_TO_DEVICE); + index = (ring->end + 1 + i) % BGMAC_TX_RING_SLOTS; + slot = &ring->slots[index]; + dma_unmap_page(dma_dev, slot->dma_addr, + skb_frag_size(&skb_shinfo(skb)->frags[i]), + DMA_TO_DEVICE); + slot->dma_addr = 0; } + slot = &ring->slots[ring->end % BGMAC_TX_RING_SLOTS]; + dma_unmap_single(dma_dev, slot->dma_addr, skb_headlen(skb), + DMA_TO_DEVICE); + err_dma_head: + slot->dma_addr = 0; + netdev_err(bgmac->net_dev, "Mapping error of skb on ring 0x%X\n", ring->mmio_base); @@ -535,17 +540,19 @@ static void bgmac_dma_tx_ring_free(struct bgmac *bgmac, unsigned int len = ctl1 & BGMAC_DESC_CTL1_LEN; slot = &ring->slots[i]; - dev_kfree_skb(slot->skb); - if (!slot->dma_addr) - continue; + if (slot->dma_addr) { + if (le32_to_cpu(dma_desc[i].ctl0) & BGMAC_DESC_CTL0_SOF) + dma_unmap_single(dma_dev, slot->dma_addr, + len, DMA_TO_DEVICE); + else + dma_unmap_page(dma_dev, slot->dma_addr, + len, DMA_TO_DEVICE); + slot->dma_addr = 0; + } - if (slot->skb) - dma_unmap_single(dma_dev, slot->dma_addr, - len, DMA_TO_DEVICE); - else - dma_unmap_page(dma_dev, slot->dma_addr, - len, DMA_TO_DEVICE); + dev_kfree_skb(slot->skb); + slot->skb = NULL; } } -- 2.56.0