From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Wesley Cheng <quic_wcheng@quicinc.com>,
srinivas.kandagatla@linaro.org, mathias.nyman@intel.com,
perex@perex.cz, lgirdwood@gmail.com, andersson@kernel.org,
krzysztof.kozlowski+dt@linaro.org, gregkh@linuxfoundation.org,
Thinh.Nguyen@synopsys.com, broonie@kernel.org,
bgoswami@quicinc.com, tiwai@suse.com, robh+dt@kernel.org,
agross@kernel.org
Cc: devicetree@vger.kernel.org, alsa-devel@alsa-project.org,
linux-arm-msm@vger.kernel.org, linux-usb@vger.kernel.org,
linux-kernel@vger.kernel.org, quic_jackp@quicinc.com,
quic_plai@quicinc.com
Subject: Re: [RFC PATCH v2 12/22] sound: usb: card: Introduce USB SND platform op callbacks
Date: Thu, 26 Jan 2023 09:50:14 -0600 [thread overview]
Message-ID: <1013f667-c11f-25a2-ab2b-87b9368ad456@linux.intel.com> (raw)
In-Reply-To: <20230126031424.14582-13-quic_wcheng@quicinc.com>
> +int snd_usb_register_platform_ops(struct snd_usb_platform_ops *ops)
> +{
> + if (platform_ops)
> + return -EEXIST;
> +
> + platform_ops = ops;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(snd_usb_register_platform_ops);
> +
> +int snd_usb_unregister_platform_ops(void)
> +{
> + platform_ops = NULL;
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(snd_usb_unregister_platform_ops);
I find this super-racy.
If the this function is called just before ...
>
> /*
> * disconnect streams
> @@ -910,6 +928,10 @@ static int usb_audio_probe(struct usb_interface *intf,
> usb_set_intfdata(intf, chip);
> atomic_dec(&chip->active);
> mutex_unlock(®ister_mutex);
> +
> + if (platform_ops->connect_cb)
> + platform_ops->connect_cb(intf, chip);
> +
... this, then you have a risk of using a dandling pointer.
You also didn't test that the platform_ops != NULL, so there's a risk of
dereferencing a NULL pointer.
Not so good, eh?
It's a classic (I've had the same sort of issues with SoundWire), when
you export ops from one driver than can be removed, then additional
protection is needed when using those callbacks.
next prev parent reply other threads:[~2023-01-26 16:26 UTC|newest]
Thread overview: 135+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-26 3:14 [RFC PATCH v2 00/22] Introduce QC USB SND audio offloading support Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 01/22] xhci: fix event ring segment table related masks and variables in header Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 02/22] xhci: remove xhci_test_trb_in_td_math early development check Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 7:48 ` Greg KH
2023-01-26 7:48 ` Greg KH
2023-01-26 3:14 ` [RFC PATCH v2 03/22] xhci: Refactor interrupter code for initial multi interrupter support Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 04/22] xhci: Add support to allocate several interrupters Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 05/22] usb: xhci: Add XHCI APIs to support USB offloading Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 06/22] usb: host: xhci-mem: Cleanup pending secondary event ring events Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 07/22] ASoC: Add SOC USB APIs for adding an USB backend Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 15:32 ` Pierre-Louis Bossart
2023-01-30 22:36 ` Wesley Cheng
2023-01-30 22:36 ` Wesley Cheng
2023-01-28 13:26 ` Greg KH
2023-01-28 13:26 ` Greg KH
2023-01-29 6:54 ` Zhou Furong
2023-01-29 6:54 ` Zhou Furong
2023-01-29 7:09 ` Greg KH
2023-01-29 7:09 ` Greg KH
2023-01-30 8:34 ` Zhou Furong
2023-01-30 8:34 ` Zhou Furong
2023-01-30 9:27 ` Greg KH
2023-01-30 9:27 ` Greg KH
2023-02-10 22:46 ` Wesley Cheng
2023-02-10 22:46 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 08/22] ASoC: dt-bindings: Add USB_RX port Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 11:55 ` Krzysztof Kozlowski
2023-01-26 11:55 ` Krzysztof Kozlowski
2023-01-30 21:52 ` Wesley Cheng
2023-01-30 21:52 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 09/22] ASoC: qcom: qdsp6: Introduce USB AFE port to q6dsp Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 15:07 ` Srinivas Kandagatla
2023-01-26 15:07 ` Srinivas Kandagatla
2023-01-26 15:38 ` Pierre-Louis Bossart
2023-01-30 22:54 ` Wesley Cheng
2023-01-30 22:54 ` Wesley Cheng
2023-01-30 23:59 ` Pierre-Louis Bossart
2023-02-01 2:40 ` Wesley Cheng
2023-02-01 2:40 ` Wesley Cheng
2023-02-01 3:02 ` Pierre-Louis Bossart
2023-02-03 1:23 ` Wesley Cheng
2023-02-03 1:23 ` Wesley Cheng
2023-02-03 1:44 ` Wesley Cheng
2023-02-03 1:44 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 10/22] ASoC: qdsp6: q6afe: Increase APR timeout Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 15:09 ` Srinivas Kandagatla
2023-01-26 15:09 ` Srinivas Kandagatla
2023-01-26 3:14 ` [RFC PATCH v2 11/22] ASoC: qcom: Add USB backend ASoC driver for Q6 Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 15:44 ` Pierre-Louis Bossart
2023-01-30 22:59 ` Wesley Cheng
2023-01-30 22:59 ` Wesley Cheng
2023-01-30 23:50 ` Pierre-Louis Bossart
2023-01-26 16:35 ` Srinivas Kandagatla
2023-01-26 16:35 ` Srinivas Kandagatla
2023-01-26 3:14 ` [RFC PATCH v2 12/22] sound: usb: card: Introduce USB SND platform op callbacks Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 15:50 ` Pierre-Louis Bossart [this message]
2023-01-30 23:00 ` Wesley Cheng
2023-01-30 23:00 ` Wesley Cheng
2023-01-28 13:28 ` Greg KH
2023-01-28 13:28 ` Greg KH
2023-02-10 22:49 ` Wesley Cheng
2023-02-10 22:49 ` Wesley Cheng
2023-02-28 2:59 ` Wesley Cheng
2023-02-28 2:59 ` Wesley Cheng
2023-02-28 7:30 ` Greg KH
2023-02-28 7:30 ` Greg KH
2023-02-28 9:19 ` Wesley Cheng
2023-02-28 9:19 ` Wesley Cheng
2023-02-28 15:29 ` Greg KH
2023-02-28 15:29 ` Greg KH
2023-02-20 17:11 ` Albert Wang
2023-02-20 17:11 ` Albert Wang
2023-01-26 3:14 ` [RFC PATCH v2 13/22] sound: usb: Export USB SND APIs for modules Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 14/22] dt-bindings: usb: dwc3: Add snps,num-hc-interrupters definition Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 14/22] dt-bindings: usb: dwc3: Add snps, num-hc-interrupters definition Wesley Cheng
2023-01-26 12:01 ` [RFC PATCH v2 14/22] dt-bindings: usb: dwc3: Add snps,num-hc-interrupters definition Krzysztof Kozlowski
2023-01-26 12:01 ` Krzysztof Kozlowski
2023-01-30 22:02 ` Wesley Cheng
2023-01-30 22:02 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 15/22] usb: dwc3: Add DT parameter to specify maximum number of interrupters Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 16/22] sound: usb: Introduce QC USB SND offloading support Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 16:07 ` Pierre-Louis Bossart
2023-01-28 13:32 ` Greg KH
2023-01-28 13:32 ` Greg KH
2023-02-11 0:03 ` Wesley Cheng
2023-02-11 0:03 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 17/22] sound: usb: card: Check for support for requested audio format Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 18/22] sound: soc: soc-usb: Add PCM format check API for USB backend Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 19/22] sound: soc: qcom: qusb6: Ensure PCM format is supported by USB audio device Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 20/22] sound: usb: Prevent starting of audio stream if in use Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 16:12 ` Pierre-Louis Bossart
2023-02-07 1:15 ` Wesley Cheng
2023-02-07 1:15 ` Wesley Cheng
2023-02-07 13:29 ` Pierre-Louis Bossart
2023-02-07 13:29 ` Pierre-Louis Bossart
2023-02-11 9:52 ` Wesley Cheng
2023-02-11 9:52 ` Wesley Cheng
2023-02-13 15:22 ` Pierre-Louis Bossart
2023-02-13 20:12 ` Wesley Cheng
2023-02-13 20:12 ` Wesley Cheng
2023-01-26 3:14 ` [RFC PATCH v2 21/22] ASoC: dt-bindings: Add Q6USB backend bindings Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 12:03 ` Krzysztof Kozlowski
2023-01-26 12:03 ` Krzysztof Kozlowski
2023-01-26 16:01 ` Srinivas Kandagatla
2023-01-26 16:01 ` Srinivas Kandagatla
2023-01-26 3:14 ` [RFC PATCH v2 22/22] ASoC: dt-bindings: Update example for enabling USB offload on SM8250 Wesley Cheng
2023-01-26 3:14 ` Wesley Cheng
2023-01-26 12:05 ` Krzysztof Kozlowski
2023-01-26 12:05 ` Krzysztof Kozlowski
2023-01-26 9:23 ` [RFC PATCH v2 00/22] Introduce QC USB SND audio offloading support Mathias Nyman
2023-01-26 9:23 ` Mathias Nyman
2023-01-30 21:51 ` Wesley Cheng
2023-01-30 21:51 ` Wesley Cheng
2023-01-26 16:22 ` Pierre-Louis Bossart
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