| Message ID | 1574931880-168682-1-git-send-email-huangdaode@hisilicon.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | irqchip/stm32: Fix "WARNING: invalid free of devm_ allocated | expand |
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. M.
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.
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.
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 <maz@kernel.org>; huangdaode <huangdaode@hisilicon.com> 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 <alexandre.torgue@st.com> 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: >> 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.
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; }
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(-)