Yes, I went through the code, found it's a wrong patch, sorry for making the confusion. 

Thanks.

-----邮件原件-----
发件人: Fabien DESSENNE [mailto:fabien.dessenne@st.com] 
发送时间: 2019年12月2日 21:22
收件人: Marc Zyngier [off-list ref]; huangdaode [off-list ref]
抄送: jason@lakedaemon.net; linux-kernel@vger.kernel.org; mcoquelin.stm32@gmail.com; tglx@linutronix.de; linux-stm32@st-md-mailman.stormreply.com; linux-arm-kernel@lists.infradead.org; Alexandre TORGUE [off-list ref]
主题: Re: [PATCH] irqchip/stm32: Fix "WARNING: invalid free of devm_ allocated

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:

quoted

On 2019-11-28 09:04, Daode Huang wrote:

quoted

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 <redacted>
---
 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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