From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 AE3643BCD34 for ; Wed, 16 Sep 2026 16:06:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789574807; cv=none; b=owIL4sQHzl6f3XpfAxlq8AOniWeIJQy2qWiwua43Of64sf3ktXqyKB/NgD8SDBOmg/0IsJlMTlKkTfvc6PMxJE1MffUlp4vz0ch+yt/LKpowO9RgqYRTWqYUpGHNeNel3o1FF52KjGbTw4uMSGSr0zYbiHNxqev0uNTkn9BWDQY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789574807; c=relaxed/simple; bh=uTKJxERBtip7i62RqZ70PdT45Pji9VnkkPzq0V3eDFQ=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=kLl6q+bFHF+aRjkroaMzjjzrQfW/KCFJSQA2fWjy3NEfX1mUd20Tqjpm8H4WIaxb26Htq8vu3D+K898g2zNxOjlld/n3lQSJDWqmeYnLSQwP42UE8viSUei+s63laKPbuZz7iEkWaMauRW9Zv3zyOXE3woqQ8+VQ1u2aGh93uNY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Lwd6BRKs; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Lwd6BRKs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87B791F000FF; Wed, 16 Sep 2026 16:06:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789574805; bh=4ovQbjAfuge/D1i2VY4zzlmC2/PobHDC314zfjn6hFw=; h=Subject:To:Cc:From:Date; b=Lwd6BRKscWYS9yMqzGZaHAViemw+tcHxoHQVKcBYd12I1mvTQWyvyPdq3JZj422E3 xVKJq/K/0WfPVsWwzPwuwvCxTxboWJwmOmtgNQXzflh6zGcSkqVatcXRMahLxhTH3i KxBHSNDwM6FpoGiIP6MLoNyRzNUZQhD3yf+JVsZM= Subject: FAILED: patch "[PATCH] idpf: disable DIM work before freeing q_vectors" failed to apply to 6.18-stable tree To: mhun512@gmail.com,Samuel.salin@intel.com,ae878000@gmail.com,anthony.l.nguyen@intel.com,stable@vger.kernel.org Cc: From: Date: Wed, 16 Sep 2026 16:43:47 +0100 Message-ID: <2026091647-strum-traverse-cb75@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x 7dd4c829bac2916be98a3e34b41daaba7f42b4c4 # git commit -s git send-email --to '' --in-reply-to '2026091647-strum-traverse-cb75@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7dd4c829bac2916be98a3e34b41daaba7f42b4c4 Mon Sep 17 00:00:00 2001 From: Myeonghun Pak Date: Mon, 20 Jul 2026 22:58:46 +0900 Subject: [PATCH] idpf: disable DIM work before freeing q_vectors idpf never drains the Tx/Rx DIM works before freeing the memory they live in. tx_dim and rx_dim are embedded in struct idpf_q_vector, they are queued from the NAPI poll via net_dim(), and idpf_vport_intr_rel() ends with kfree(rsrc->q_vectors). Nothing in the driver cancels them. idpf_tx_dim_work() and idpf_rx_dim_work() then run on freed memory: idpf_vport_intr_write_itr() writes the ITR register through q_vector->intr_reg.tx_itr / rx_itr, void __iomem pointers loaded out of the freed q_vector. No configuration is needed to get there -- IDPF_ITR_IS_DYNAMIC() is defined as (itr_mode) and idpf_vport_alloc() initialises both modes to IDPF_ITR_DYNAMIC. Draining after idpf_vport_intr_napi_dis_all() is not enough on its own. idpf_net_dim() is called from inside the "if (napi_complete_done(napi, work_done))" branch of the poll, and napi_complete_done() has already cleared NAPIF_STATE_SCHED by then. napi_disable_locked() waits only while (val & (NAPIF_STATE_SCHED | NAPIF_STATE_NPSVC)), so napi_disable() can return while the poll tail is still queueing the work, and a plain cancel_work_sync() would be re-armed behind the drain. Use disable_work_sync(): schedule_work() on a work with a non-zero disable count is dropped by clear_pending_if_disabled() before __queue_work() is reached. Move idpf_init_dim() to idpf_vport_intr_alloc() so the works are initialised on every path that can reach the drain -- the three "goto intr_deinit" sites between idpf_vport_intr_init() and idpf_vport_intr_ena() get there without the enable side having run. Nothing re-enables them: rsrc->q_vectors is freed on every exit from idpf_vport_open() and on every idpf_vport_stop(), so the count dies with the object. It is a race, not a deterministic failure -- net_dim() only schedules once DIM_NEVENTS events have accumulated and the profile index changes. A KASAN ifup/ifdown loop under load is the way to see it. Fixes: c2d548cad150 ("idpf: add TX splitq napi poll support") Fixes: 3a8845af66ed ("idpf: add RX splitq napi poll support") Cc: # see patch description, needs adjustments for <= 6.9 Co-developed-by: Ijae Kim Signed-off-by: Ijae Kim Signed-off-by: Myeonghun Pak Tested-by: Samuel Salin Signed-off-by: Tony Nguyen diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c index 24b91be25676..9ba9c2952d78 100644 --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c @@ -4145,6 +4145,26 @@ static void idpf_vport_intr_ena_irq_all(struct idpf_vport *vport, writel(rsrc->noirq_dyn_ctl_ena, rsrc->noirq_dyn_ctl); } +/** + * idpf_vport_intr_dis_dim_all - Disable DIM work for all q_vectors + * @rsrc: pointer to queue and vector resources + * + * The DIM works are embedded in the q_vector array that + * idpf_vport_intr_rel() frees, and the poll arms them after + * napi_complete_done() has already cleared NAPI_STATE_SCHED. Disable + * rather than just cancel, so that a poll tail still running past + * napi_disable() cannot queue them again behind the drain. + */ +static void idpf_vport_intr_dis_dim_all(struct idpf_q_vec_rsrc *rsrc) +{ + for (u16 v_idx = 0; v_idx < rsrc->num_q_vectors; v_idx++) { + struct idpf_q_vector *q_vector = &rsrc->q_vectors[v_idx]; + + disable_work_sync(&q_vector->tx_dim.work); + disable_work_sync(&q_vector->rx_dim.work); + } +} + /** * idpf_vport_intr_deinit - Release all vector associations for the vport * @vport: main vport structure @@ -4155,6 +4175,7 @@ void idpf_vport_intr_deinit(struct idpf_vport *vport, { idpf_vport_intr_dis_irq_all(rsrc); idpf_vport_intr_napi_dis_all(rsrc); + idpf_vport_intr_dis_dim_all(rsrc); idpf_vport_intr_napi_del_all(rsrc); idpf_vport_intr_rel_irq(vport, rsrc); } @@ -4235,7 +4256,6 @@ static void idpf_vport_intr_napi_ena_all(struct idpf_q_vec_rsrc *rsrc) for (u16 q_idx = 0; q_idx < rsrc->num_q_vectors; q_idx++) { struct idpf_q_vector *q_vector = &rsrc->q_vectors[q_idx]; - idpf_init_dim(q_vector); napi_enable(&q_vector->napi); } } @@ -4578,6 +4598,8 @@ int idpf_vport_intr_alloc(struct idpf_vport *vport, q_coal = &user_config->q_coalesce[v_idx]; q_vector->vport = vport; + idpf_init_dim(q_vector); + q_vector->tx_itr_value = q_coal->tx_coalesce_usecs; q_vector->tx_intr_mode = q_coal->tx_intr_mode; q_vector->tx_itr_idx = VIRTCHNL2_ITR_IDX_1;