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 6E4022144C1; Wed, 7 May 2025 19:09:56 +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=1746644996; cv=none; b=OA00gIA3ysycIMhYQPVdHPgOpwi/oeDzBUqZ/GJA8vwIsOgHq30dTpf17K+ci+/koeIAvyg6Bd/Gbf8zNCr6G8vx0fDNCP/u3384KiKzIVEG9s+MtbD/GKUY8rUxGEq5UzRVv/SHapdxmjk++Zu2GeGLlCFSfYKdk5RWxfXComc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746644996; c=relaxed/simple; bh=gizyoxVcXEd7l5YoAeo83HtQ3CXVackkXPPF5G3Z92w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AVKFPh1f/c4OSIToGUp1IvvuBb7JCYaj1B+dL/7xznozP5BPk/Dw1zzUZaXjPBBCdBi0wELmNti6pQce3byo0mD82fh57oQCdSGIrUUowuDYUJKQug58j5Ute/lunb4RflIhGnZHU+P11xCgnTy7KxZ6f8s81zDZbTY+SePRbhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lMTmJiZV; 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="lMTmJiZV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F2E50C4CEE2; Wed, 7 May 2025 19:09:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1746644996; bh=gizyoxVcXEd7l5YoAeo83HtQ3CXVackkXPPF5G3Z92w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lMTmJiZVlELuFVnMTmVtXoRlUykn1L5TBD3HJNOrE+t2LICc/djhDgQ84b37BSVf0 YG2krZafF+yo3gn4A6UCCZQ/gdURcuERDnW7IT2dFou/XrYl3oLt+ZuP2OiQ7ydwq5 tBLLbwth72dhJy429k99VCoMnsE9syOxrRh0o0V0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Louis-Alexis Eyraud , Maxime Chevallier , Bartosz Golaszewski , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 061/129] net: ethernet: mtk-star-emac: fix spinlock recursion issues on rx/tx poll Date: Wed, 7 May 2025 20:39:57 +0200 Message-ID: <20250507183815.999866248@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250507183813.500572371@linuxfoundation.org> References: <20250507183813.500572371@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-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Louis-Alexis Eyraud [ Upstream commit 6fe0866014486736cc3ba1c6fd4606d3dbe55c9c ] Use spin_lock_irqsave and spin_unlock_irqrestore instead of spin_lock and spin_unlock in mtk_star_emac driver to avoid spinlock recursion occurrence that can happen when enabling the DMA interrupts again in rx/tx poll. ``` BUG: spinlock recursion on CPU#0, swapper/0/0 lock: 0xffff00000db9cf20, .magic: dead4ead, .owner: swapper/0/0, .owner_cpu: 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-rc2-next-20250417-00001-gf6a27738686c-dirty #28 PREEMPT Hardware name: MediaTek MT8365 Open Platform EVK (DT) Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0x60/0x80 dump_stack+0x18/0x24 spin_dump+0x78/0x88 do_raw_spin_lock+0x11c/0x120 _raw_spin_lock+0x20/0x2c mtk_star_handle_irq+0xc0/0x22c [mtk_star_emac] __handle_irq_event_percpu+0x48/0x140 handle_irq_event+0x4c/0xb0 handle_fasteoi_irq+0xa0/0x1bc handle_irq_desc+0x34/0x58 generic_handle_domain_irq+0x1c/0x28 gic_handle_irq+0x4c/0x120 do_interrupt_handler+0x50/0x84 el1_interrupt+0x34/0x68 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 regmap_mmio_read32le+0xc/0x20 (P) _regmap_bus_reg_read+0x6c/0xac _regmap_read+0x60/0xdc regmap_read+0x4c/0x80 mtk_star_rx_poll+0x2f4/0x39c [mtk_star_emac] __napi_poll+0x38/0x188 net_rx_action+0x164/0x2c0 handle_softirqs+0x100/0x244 __do_softirq+0x14/0x20 ____do_softirq+0x10/0x20 call_on_irq_stack+0x24/0x64 do_softirq_own_stack+0x1c/0x40 __irq_exit_rcu+0xd4/0x10c irq_exit_rcu+0x10/0x1c el1_interrupt+0x38/0x68 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 cpuidle_enter_state+0xac/0x320 (P) cpuidle_enter+0x38/0x50 do_idle+0x1e4/0x260 cpu_startup_entry+0x34/0x3c rest_init+0xdc/0xe0 console_on_rootfs+0x0/0x6c __primary_switched+0x88/0x90 ``` Fixes: 0a8bd81fd6aa ("net: ethernet: mtk-star-emac: separate tx/rx handling with two NAPIs") Signed-off-by: Louis-Alexis Eyraud Reviewed-by: Maxime Chevallier Acked-by: Bartosz Golaszewski Link: https://patch.msgid.link/20250424-mtk_star_emac-fix-spinlock-recursion-issue-v2-1-f3fde2e529d8@collabora.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/mediatek/mtk_star_emac.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/mediatek/mtk_star_emac.c b/drivers/net/ethernet/mediatek/mtk_star_emac.c index 25989c79c92e6..47a00e02365a2 100644 --- a/drivers/net/ethernet/mediatek/mtk_star_emac.c +++ b/drivers/net/ethernet/mediatek/mtk_star_emac.c @@ -1163,6 +1163,7 @@ static int mtk_star_tx_poll(struct napi_struct *napi, int budget) struct net_device *ndev = priv->ndev; unsigned int head = ring->head; unsigned int entry = ring->tail; + unsigned long flags; while (entry != head && count < (MTK_STAR_RING_NUM_DESCS - 1)) { ret = mtk_star_tx_complete_one(priv); @@ -1182,9 +1183,9 @@ static int mtk_star_tx_poll(struct napi_struct *napi, int budget) netif_wake_queue(ndev); if (napi_complete(napi)) { - spin_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, flags); mtk_star_enable_dma_irq(priv, false, true); - spin_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, flags); } return 0; @@ -1341,6 +1342,7 @@ static int mtk_star_rx(struct mtk_star_priv *priv, int budget) static int mtk_star_rx_poll(struct napi_struct *napi, int budget) { struct mtk_star_priv *priv; + unsigned long flags; int work_done = 0; priv = container_of(napi, struct mtk_star_priv, rx_napi); @@ -1348,9 +1350,9 @@ static int mtk_star_rx_poll(struct napi_struct *napi, int budget) work_done = mtk_star_rx(priv, budget); if (work_done < budget) { napi_complete_done(napi, work_done); - spin_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, flags); mtk_star_enable_dma_irq(priv, true, false); - spin_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, flags); } return work_done; -- 2.39.5