From nobody Sat Jul 25 15:53:33 2026 Received: from azure-sdnproxy.icoremail.net (azure-sdnproxy.icoremail.net [52.237.72.81]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3A29F3D5C0B; Thu, 16 Jul 2026 11:33:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.237.72.81 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784201624; cv=none; b=B8JIcXVCNq0ZgFES5kFodOOBUxOzhmG0m95oV12Co6g8Jk0IoBLbBU3mhN+It8Sd7zZIeelxN6kJtEXLMKz8X5hG6uR+qsLso/Wol3U7gtZa4EMajsouQ09D03MPF6tqIAxCorzOorHXr9+3HD40IMHSMICjfCdnnU8cxva8uxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784201624; c=relaxed/simple; bh=6fr47kLJuvDzx9THgVPea8JKczKVtXdRPptJqq93sIM=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=CrGTah/3CQ8HX4vQ99lg087HtpuegqnIDHVaIS7anquT7tJTqVRKXRfaNglbydFL+JkQ91oU4xoszU4GjdAOzsS5m3OY80jv5l+dWu/svD91gPzI2i26WD17zNkzZKphRvn0P/l1BwBNTCAmk4jv06KKxrKf0JVZp/nVqq3woyA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn; spf=pass smtp.mailfrom=zju.edu.cn; arc=none smtp.client-ip=52.237.72.81 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=zju.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zju.edu.cn Received: from zju.edu.cn (unknown [10.98.66.117]) by mtasvr (Coremail) with SMTP id _____wDnYfyGwVhqvDJfAA--.24087S3; Thu, 16 Jul 2026 19:33:27 +0800 (CST) Received: from localhost.localdomain (unknown [10.98.66.117]) by mail-app2 (Coremail) with SMTP id zC_KCgDXadCFwVhqsW3wAg--.63253S2; Thu, 16 Jul 2026 19:33:25 +0800 (CST) From: Fan Wu To: mchehab@kernel.org, hverkuil+cisco@kernel.org Cc: y-abhilashchandra@ti.com, bparrot@ti.com, dale@farnsworth.org, dagriego@biglakesoftware.com, sbellary@baylibre.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Fan Wu , stable@vger.kernel.org Subject: [PATCH v4] media: ti: vpe: quiesce overflow recovery before freeing streams Date: Thu, 16 Jul 2026 11:32:30 +0000 Message-Id: <20260716113230.3131086-1-fanwu01@zju.edu.cn> X-Mailer: git-send-email 2.34.1 In-Reply-To: <801025b7-a3b8-4655-af49-f9bb65254170@kernel.org> References: <801025b7-a3b8-4655-af49-f9bb65254170@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: zC_KCgDXadCFwVhqsW3wAg--.63253S2 X-CM-SenderInfo: qrstjiaswqq6lmxovvfxof0/ X-CM-DELIVERINFO: =?B?vBJ5GAXKKxbFmtjJiESix3B1w3vZ3A9ovKVTomAyoQazvoRs/NHSP8GI2EvgeEEW7R sfncGSG+szpQCInt5Y8rbJUI0xPAQCwWO2pVhAwqD+sIzxQW78zoMDftY1wSw0eA+KHkhq coeV5GNxBiZVRkxxB8fN5RPxYw6l01w8CbPzC/8w X-Coremail-Antispam: 1Uk129KBj93XoW3Ary8Jw4kuF4kWF1DKFWxGrX_yoWxuFW5pF Z5t34FkrZ7XF40vF4UAw13tFy5CrWvv3yjyry8u343Aw45tryYvF1xKF10vF97Gryvva42 yrs8J3y7ur45JrXCm3ZEXasCq-sJn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUP0b4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x0267AK xVW0oVCq3wAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc804V CY07AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AK xVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48Icx kI7VAKI48JM4x0Y48IcxkI7VAKI48G6xCjnVAKz4kxM4IIrI8v6xkF7I0E8cxan2IY04v7 MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8CrVAFwI0_Jr 0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0E wIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x0267AKxVWUJV W8JwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAI cVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU85l1PUUUUU== Content-Type: text/plain; charset="utf-8" The VIP overflow recovery worker is armed from the hardirq handler when a FIFO overflow is detected, and the list-complete path looks the stream up through the VPDMA list private pointer. Both keep touching stream, port and device state; the recovery worker also resets the parser and VPDMA, repopulates the descriptor list, and re-enables the per-list IRQs. vip_stop_streaming() masks and clears the per-list IRQs, but it neither synchronizes the hardirq handler nor disables recovery_work. An overflow IRQ that has already queued recovery_work, or a list-complete IRQ in flight when the stream is torn down, can therefore still dereference the stream after its resources are released: the descriptor list is freed by vip_release_stream() on file release, and the stream itself by free_stream() on unbind/remove. Drain the recovery worker and the IRQ handler at both teardown points through a shared vip_quiesce_stream() helper, before any stream-owned resource is released. disable_work_sync() cancels pending recovery_work, drains a running instance, and raises its disable depth, so a subsequent schedule_work() issued by a racing IRQ handler is rejected at the workqueue scheduler: recovery_work cannot be requeued after disable_work_sync() takes effect. The worker may still re-enable the per-list IRQs before disable_work_sync() returns; disable_irqs() then masks those sources and synchronize_irq() waits for any in-flight handler that still dereferences stream state. In vip_stop_streaming() the helper runs before the parser is stopped, since a worker drained by disable_work_sync() may re-enable the parser before exiting and would otherwise undo the stop. recovery_work is created disabled and enabled in vip_start_streaming() before IRQs, pairing the enable with the teardown disable across the streaming lifecycle. This issue was found by an in-house static analysis tool and confirmed by manual code review. Fixes: fc2873aa4a21 ("media: ti: vpe: Add the VIP driver") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.6 Signed-off-by: Fan Wu Reviewed-by: Yemike Abhilash Chandra Tested-by: Yemike Abhilash Chandra (on=20 --- Changes in v4: - Drop the unrelated vpdma_hwlist_release() cleanup from this fix (Hans Verkuil). - In free_stream(), call vip_quiesce_stream() before clearing cap_streams[], so the stream remains published while in-flight IRQ handling is drained (Hans Verkuil). Changes in v3: - Replace the per-stream irq_rearm_allowed flag and the repeated IRQ disable/synchronize_irq() in vip_quiesce_stream() with the workqueue disable-depth API (disable_work_sync/enable_work/disable_work), as suggested by Yemike Abhilash Chandra. This also closes a window the v2 double-drain left open, where its second synchronize_irq() waited for the in-flight handler but did not cancel the recovery_work it had requeued, so that work could run after free. - Create recovery_work disabled and enable it in vip_start_streaming() before IRQs. - In vip_stop_streaming(), quiesce before stopping the parser: a worker drained by disable_work_sync() may re-enable the parser before exiting, so stopping the parser first would be undone. Changes in v2: - Drain the overflow recovery worker at both teardown points through a shared vip_quiesce_stream() helper: vip_stop_streaming() (file release path) and free_stream() (unbind/remove). v1 drained only in free_stream(). - Document how the issue was found and that the patch was prepared with LLM assistance (Assisted-by trailer and body note). Link: https://lore.kernel.org/r/20260708013738.110752-1-fanwu01@zju.edu.cn/ --- drivers/media/platform/ti/vpe/vip.c | 37 +++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 4 deletions(-) diff --git a/drivers/media/platform/ti/vpe/vip.c b/drivers/media/platform/t= i/vpe/vip.c index cb0a5a07a3d4..673f9addfade 100644 --- a/drivers/media/platform/ti/vpe/vip.c +++ b/drivers/media/platform/ti/vpe/vip.c @@ -814,6 +814,22 @@ static void clear_irqs(struct vip_dev *dev, int irq_nu= m, int list_num) vpdma_clear_list_stat(dev->shared->vpdma, irq_num, dev->slice_id); } =20 +/* + * Quiesce recovery work and per-list IRQs before releasing stream resourc= es. + * disable_work_sync() prevents the overflow handler from requeueing recov= ery + * work. Mask and synchronize IRQs afterwards because a running worker may + * have re-enabled them before exiting. + */ +static void vip_quiesce_stream(struct vip_stream *stream) +{ + struct vip_dev *dev =3D stream->port->dev; + + disable_work_sync(&stream->recovery_work); + disable_irqs(dev, dev->slice_id, stream->list_num); + clear_irqs(dev, dev->slice_id, stream->list_num); + synchronize_irq(dev->irq); +} + static void populate_desc_list(struct vip_stream *stream) { struct vip_port *port =3D stream->port; @@ -2428,6 +2444,7 @@ static int vip_start_streaming(struct vb2_queue *vq, = unsigned int count) goto err; =20 stream->num_recovery =3D 0; + enable_work(&stream->recovery_work); =20 clear_irqs(dev, dev->slice_id, stream->list_num); enable_irqs(dev, dev->slice_id, stream->list_num); @@ -2452,13 +2469,17 @@ static void vip_stop_streaming(struct vb2_queue *vq) struct vip_dev *dev =3D port->dev; int ret; =20 + /* + * A running recovery worker may re-enable the parser, so quiesce it + * and its IRQ handler before stopping the parser or releasing the + * descriptor list. + */ + vip_quiesce_stream(stream); + vip_parser_stop_imm(port, true); vip_enable_parser(port, false); unset_fmt_params(stream); =20 - disable_irqs(dev, dev->slice_id, stream->list_num); - clear_irqs(dev, dev->slice_id, stream->list_num); - if (port->subdev) { ret =3D v4l2_subdev_call(port->subdev, video, s_stream, 0); if (ret) @@ -3074,6 +3095,8 @@ static int alloc_stream(struct vip_port *port, int st= ream_id, int vfl_type) goto do_free_hwlist; =20 INIT_WORK(&stream->recovery_work, vip_overflow_recovery_work); + /* Start disabled; vip_start_streaming() enables it before IRQs. */ + disable_work(&stream->recovery_work); =20 INIT_LIST_HEAD(&stream->vidq); =20 @@ -3139,6 +3162,13 @@ static void free_stream(struct vip_stream *stream) return; =20 dev =3D stream->port->dev; + /* + * Quiesce the IRQ handler and recovery worker, then drop the stream + * from cap_streams[], before releasing stream-owned resources. + */ + vip_quiesce_stream(stream); + stream->port->cap_streams[stream->stream_id] =3D NULL; + /* Free up the Drop queue */ list_for_each_safe(pos, q, &stream->dropq) { buf =3D list_entry(pos, @@ -3150,7 +3180,6 @@ static void free_stream(struct vip_stream *stream) =20 video_unregister_device(stream->vfd); vpdma_hwlist_release(dev->shared->vpdma, stream->list_num); - stream->port->cap_streams[stream->stream_id] =3D NULL; kfree(stream); } =20 --=20 2.34.1