From: Kalle Valo <kvalo@kernel.org>
To: Manivannan Sadhasivam <mani@kernel.org>
Cc: Qiang Yu <quic_qianyu@quicinc.com>,
quic_hemantk@quicinc.com, loic.poulain@linaro.org,
quic_jhugo@quicinc.com, mhi@lists.linux.dev,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
quic_cang@quicinc.com, ath11k@lists.infradead.org
Subject: Re: [PATCH v3 1/1] bus: mhi: host: Fix up null pointer access in mhi_irq_handler
Date: Tue, 26 Jul 2022 20:53:58 +0300 [thread overview]
Message-ID: <87czdrrc95.fsf@kernel.org> (raw)
In-Reply-To: <20220726080636.GE5522@workstation> (Manivannan Sadhasivam's message of "Tue, 26 Jul 2022 13:36:36 +0530")
Manivannan Sadhasivam <mani@kernel.org> writes:
> +ath11k, Kalle
>
> On Fri, Jul 22, 2022 at 11:17:18AM +0800, Qiang Yu wrote:
>> The irq handler for a shared IRQ ought to be prepared for running
>> even now it's being freed. So let's check the pointer used by
>> mhi_irq_handler to avoid null pointer access since it is probably
>> released before freeing IRQ.
>>
>> Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
This fixes the crash and my regression tests pass now, thanks. But
please see my question below.
Tested-by: Kalle Valo <kvalo@kernel.org>
>> + /*
>> + * If CONFIG_DEBUG_SHIRQ is set, the IRQ handler will get invoked during __free_irq()
>> + * and by that time mhi_ctxt() would've freed. So check for the existence of mhi_ctxt
>> + * before handling the IRQs.
>> + */
>> + if (!mhi_cntrl->mhi_ctxt) {
>> + dev_dbg(&mhi_cntrl->mhi_dev->dev,
>> + "mhi_ctxt has been freed\n");
>> + return IRQ_HANDLED;
>> + }
I don't see any protection accessing mhi_cntrl->mhi_ctxt, is this really
free of race conditions?
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next prev parent reply other threads:[~2022-07-26 17:54 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1658459838-30802-1-git-send-email-quic_qianyu@quicinc.com>
2022-07-26 8:06 ` [PATCH v3 1/1] bus: mhi: host: Fix up null pointer access in mhi_irq_handler Manivannan Sadhasivam
2022-07-26 17:53 ` Kalle Valo [this message]
2022-07-29 14:22 ` Manivannan Sadhasivam
2022-08-29 16:20 ` Kalle Valo
2022-08-29 17:26 ` Manivannan Sadhasivam
2022-08-30 5:25 ` Kalle Valo
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