From: Fabien DESSENNE <fabien.dessenne@st.com>
To: Marc Zyngier <maz@kernel.org>, Daode Huang <huangdaode@hisilicon.com>
Cc: "jason@lakedaemon.net" <jason@lakedaemon.net>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"mcoquelin.stm32@gmail.com" <mcoquelin.stm32@gmail.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"linux-stm32@st-md-mailman.stormreply.com"
<linux-stm32@st-md-mailman.stormreply.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
Alexandre TORGUE <alexandre.torgue@st.com>
Subject: Re: [PATCH] irqchip/stm32: Fix "WARNING: invalid free of devm_ allocated
Date: Mon, 2 Dec 2019 13:22:14 +0000 [thread overview]
Message-ID: <d7a90e49-b847-7fad-d11c-5969050e8d12@st.com> (raw)
In-Reply-To: <028744c349410eb1f74b7e2b18590c75@www.loen.fr>
Hi Daode,
I confirm that this patch is not a good idea, here are some explanations.
irq-stm32-exti.c deals with two different purposes:
- either it is used to probe the "st,stm32mp1-exti" compatible device.
In that case .probe() is invoked and uses devm_kzalloc() to get memory.
No need to free memory.
-either is it used for other stm32 devices. In that case, there is no
probe function, the driver is 'just' init'ed. In that case,
devm_kzalloc() is not used and explicit free memory is required.
As said by Mark, you have just mixed the two paths.
Fabien
On 02/12/2019 1:40 PM, Marc Zyngier wrote:
> On 2019-12-02 12:29, Marc Zyngier wrote:
>> On 2019-11-28 09:04, Daode Huang wrote:
>>> Since devm_ allocated data can be automaitcally released, it's no
>>> need to free it apparently, just remove it.
>>>
>>> Fixes: cfbf9e497094 ("irqchip/stm32: Use a platform driver for
>>> stm32mp1-exti device")
>>> Signed-off-by: Daode Huang <huangdaode@hisilicon.com>
>>> ---
>>> drivers/irqchip/irq-stm32-exti.c | 2 --
>>> 1 file changed, 2 deletions(-)
>>>
>>> diff --git a/drivers/irqchip/irq-stm32-exti.c
>>> b/drivers/irqchip/irq-stm32-exti.c
>>> index e00f2fa..46ec0af 100644
>>> --- a/drivers/irqchip/irq-stm32-exti.c
>>> +++ b/drivers/irqchip/irq-stm32-exti.c
>>> @@ -779,8 +779,6 @@ static int __init stm32_exti_init(const struct
>>> stm32_exti_drv_data *drv_data,
>>> irq_domain_remove(domain);
>>> out_unmap:
>>> iounmap(host_data->base);
>>> - kfree(host_data->chips_data);
>>> - kfree(host_data);
>>> return ret;
>>> }
>>
>> Applied, thanks.
>
> Scratch that. This patch is just wrong, and just reading the code
> makes it obvious. stm32_exti_init() is only called on paths
> that allocate the memory with kmalloc.
>
> Clearly you haven't tried to understand what is going on.
>
> M.
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next prev parent reply other threads:[~2019-12-02 13:22 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-28 9:04 [PATCH] irqchip/stm32: Fix "WARNING: invalid free of devm_ allocated Daode Huang
2019-12-02 12:29 ` Marc Zyngier
2019-12-02 12:40 ` Marc Zyngier
2019-12-02 13:22 ` Fabien DESSENNE [this message]
2019-12-02 13:32 ` 答复: " huangdaode
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