diff mbox

[v4,6/6] arm: dma-mapping: updates to limit dma_mask and iommu mapping size

Message ID 1422052359-12384-7-git-send-email-m-karicheri2@ti.com (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Murali Karicheri Jan. 23, 2015, 10:32 p.m. UTC
Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.

Also arm_iommu_create_mapping() has size parameter of size_t and
arm_setup_iommu_dma_ops() can take a value higher than that. So
limit the size to SIZE_MAX.

Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
---
 arch/arm/mm/dma-mapping.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Robin Murphy Jan. 27, 2015, 11:12 a.m. UTC | #1
Hi Murali,

On 23/01/15 22:32, Murali Karicheri wrote:
> Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
>
> Also arm_iommu_create_mapping() has size parameter of size_t and
> arm_setup_iommu_dma_ops() can take a value higher than that. So
> limit the size to SIZE_MAX.
>
> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> ---
>   arch/arm/mm/dma-mapping.c |   10 ++++++++++
>   1 file changed, 10 insertions(+)
>
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 7864797..a1f9030 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
>   	if (!iommu)
>   		return false;
>
> +	/*
> +	 * currently arm_iommu_create_mapping() takes a max of size_t
> +	 * for size param. So check this limit for now.
> +	 */
> +	if (size > SIZE_MAX)
> +		return false;
> +
>   	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
>   	if (IS_ERR(mapping)) {
>   		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
> @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>   {
>   	struct dma_map_ops *dma_ops;
>
> +	/* limit dma_mask to the lower of the two values */
> +	*dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
> +

Is there any reason not to do this in of_dma_configure? It seems like 
something everyone could benefit from - I'd cooked up a dodgy workaround 
for the same issue in my arm64 IOMMU code, but handling it generically 
in common code would be much nicer.

Robin.

>   	dev->archdata.dma_coherent = coherent;
>   	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
>   		dma_ops = arm_get_iommu_dma_map_ops(coherent);
>


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Catalin Marinas Jan. 27, 2015, 11:34 a.m. UTC | #2
On Tue, Jan 27, 2015 at 11:12:32AM +0000, Robin Murphy wrote:
> On 23/01/15 22:32, Murali Karicheri wrote:
> > Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
> >
> > Also arm_iommu_create_mapping() has size parameter of size_t and
> > arm_setup_iommu_dma_ops() can take a value higher than that. So
> > limit the size to SIZE_MAX.
> >
> > Signed-off-by: Murali Karicheri <m-karicheri2@ti.com>
> > ---
> >   arch/arm/mm/dma-mapping.c |   10 ++++++++++
> >   1 file changed, 10 insertions(+)
> >
> > diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> > index 7864797..a1f9030 100644
> > --- a/arch/arm/mm/dma-mapping.c
> > +++ b/arch/arm/mm/dma-mapping.c
> > @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
> >   	if (!iommu)
> >   		return false;
> >
> > +	/*
> > +	 * currently arm_iommu_create_mapping() takes a max of size_t
> > +	 * for size param. So check this limit for now.
> > +	 */
> > +	if (size > SIZE_MAX)
> > +		return false;
> > +
> >   	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
> >   	if (IS_ERR(mapping)) {
> >   		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
> > @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
> >   {
> >   	struct dma_map_ops *dma_ops;
> >
> > +	/* limit dma_mask to the lower of the two values */
> > +	*dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
> > +
> 
> Is there any reason not to do this in of_dma_configure? It seems like 
> something everyone could benefit from - I'd cooked up a dodgy workaround 
> for the same issue in my arm64 IOMMU code, but handling it generically 
> in common code would be much nicer.

I agree. I started something here:

http://article.gmane.org/gmane.linux.kernel/1835096

but I don't remember to have got to a clear conclusion.
Murali Karicheri Jan. 27, 2015, 3:19 p.m. UTC | #3
On 01/27/2015 06:34 AM, Catalin Marinas wrote:
> On Tue, Jan 27, 2015 at 11:12:32AM +0000, Robin Murphy wrote:
>> On 23/01/15 22:32, Murali Karicheri wrote:
>>> Limit the dma_mask to minimum of dma_mask and dma_base + size - 1.
>>>
>>> Also arm_iommu_create_mapping() has size parameter of size_t and
>>> arm_setup_iommu_dma_ops() can take a value higher than that. So
>>> limit the size to SIZE_MAX.
>>>
>>> Signed-off-by: Murali Karicheri<m-karicheri2@ti.com>
>>> ---
>>>    arch/arm/mm/dma-mapping.c |   10 ++++++++++
>>>    1 file changed, 10 insertions(+)
>>>
>>> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
>>> index 7864797..a1f9030 100644
>>> --- a/arch/arm/mm/dma-mapping.c
>>> +++ b/arch/arm/mm/dma-mapping.c
>>> @@ -2004,6 +2004,13 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
>>>    	if (!iommu)
>>>    		return false;
>>>
>>> +	/*
>>> +	 * currently arm_iommu_create_mapping() takes a max of size_t
>>> +	 * for size param. So check this limit for now.
>>> +	 */
>>> +	if (size>  SIZE_MAX)
>>> +		return false;
>>> +
>>>    	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
>>>    	if (IS_ERR(mapping)) {
>>>    		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
>>> @@ -2053,6 +2060,9 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
>>>    {
>>>    	struct dma_map_ops *dma_ops;
>>>
>>> +	/* limit dma_mask to the lower of the two values */
>>> +	*dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
>>> +
>>
>> Is there any reason not to do this in of_dma_configure? It seems like
>> something everyone could benefit from - I'd cooked up a dodgy workaround
>> for the same issue in my arm64 IOMMU code, but handling it generically
>> in common code would be much nicer.

Ok Will move this to of_dma_configure().

Murali

>
> I agree. I started something here:
>
> http://article.gmane.org/gmane.linux.kernel/1835096
>
> but I don't remember to have got to a clear conclusion.
>
diff mbox

Patch

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7864797..a1f9030 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -2004,6 +2004,13 @@  static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
 	if (!iommu)
 		return false;
 
+	/*
+	 * currently arm_iommu_create_mapping() takes a max of size_t
+	 * for size param. So check this limit for now.
+	 */
+	if (size > SIZE_MAX)
+		return false;
+
 	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
 	if (IS_ERR(mapping)) {
 		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
@@ -2053,6 +2060,9 @@  void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 {
 	struct dma_map_ops *dma_ops;
 
+	/* limit dma_mask to the lower of the two values */
+	*dev->dma_mask = min((*dev->dma_mask), (dma_base + size - 1));
+
 	dev->archdata.dma_coherent = coherent;
 	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
 		dma_ops = arm_get_iommu_dma_map_ops(coherent);