[PATCH] dma-buf: use struct_size macro

[PATCH] dma-buf: use struct_size macro

[Christian König]

Instead of manually calculating the structure size.

Signed-off-by: Christian König <christian.koenig@amd.com>
---
 drivers/dma-buf/dma-resv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 1c8f2581cb09..bb5a42b10c29 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -63,7 +63,7 @@ static struct dma_resv_list *dma_resv_list_alloc(unsigned int shared_max)
 {
 	struct dma_resv_list *list;
 
-	list = kmalloc(offsetof(typeof(*list), shared[shared_max]), GFP_KERNEL);
+	list = kmalloc(struct_size(list, shared, shared_max), GFP_KERNEL);
 	if (!list)
 		return NULL;
 
-- 
2.17.1

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Re: [PATCH] dma-buf: use struct_size macro

[Daniel Vetter]

On Thu, Oct 8, 2020 at 10:10 AM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
>
> Instead of manually calculating the structure size.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  drivers/dma-buf/dma-resv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
> index 1c8f2581cb09..bb5a42b10c29 100644
> --- a/drivers/dma-buf/dma-resv.c
> +++ b/drivers/dma-buf/dma-resv.c
> @@ -63,7 +63,7 @@ static struct dma_resv_list *dma_resv_list_alloc(unsigned int shared_max)
>  {
>         struct dma_resv_list *list;
>
> -       list = kmalloc(offsetof(typeof(*list), shared[shared_max]), GFP_KERNEL);
> +       list = kmalloc(struct_size(list, shared, shared_max), GFP_KERNEL);
>         if (!list)
>                 return NULL;
>
> --
> 2.17.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel



-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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Re: [PATCH] dma-buf: use struct_size macro

[Christian König]

Am 08.10.20 um 10:17 schrieb Daniel Vetter:
> On Thu, Oct 8, 2020 at 10:10 AM Christian König
> <ckoenig.leichtzumerken@gmail.com> wrote:
>> Instead of manually calculating the structure size.
>>
>> Signed-off-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Thanks, could anybody (not me) come up with a cocci script for this?

I'm pretty sure we have used this pattern more than once in the kernel.

Thanks,
Christian.

>
>> ---
>>   drivers/dma-buf/dma-resv.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
>> index 1c8f2581cb09..bb5a42b10c29 100644
>> --- a/drivers/dma-buf/dma-resv.c
>> +++ b/drivers/dma-buf/dma-resv.c
>> @@ -63,7 +63,7 @@ static struct dma_resv_list *dma_resv_list_alloc(unsigned int shared_max)
>>   {
>>          struct dma_resv_list *list;
>>
>> -       list = kmalloc(offsetof(typeof(*list), shared[shared_max]), GFP_KERNEL);
>> +       list = kmalloc(struct_size(list, shared, shared_max), GFP_KERNEL);
>>          if (!list)
>>                  return NULL;
>>
>> --
>> 2.17.1
>>
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
>

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Re: [PATCH] dma-buf: use struct_size macro

[Gustavo A. R. Silva]

On Thu, Oct 08, 2020 at 10:40:10AM +0200, Christian König wrote:
> Am 08.10.20 um 10:17 schrieb Daniel Vetter:
> > On Thu, Oct 8, 2020 at 10:10 AM Christian König
> > <ckoenig.leichtzumerken@gmail.com> wrote:
> > > Instead of manually calculating the structure size.
> > > 
> > > Signed-off-by: Christian König <christian.koenig@amd.com>
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

> 
> Thanks, could anybody (not me) come up with a cocci script for this?
> 
> I'm pretty sure we have used this pattern more than once in the kernel.
> 

Sure thing. I'll take care of that. I saw this same pattern, recently[1]:

"
> +       size = offsetof(struct pmt_crashlog_priv, entry[pdev->num_resources]);
> +       priv = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;

struct_size()
"

[1] https://lore.kernel.org/lkml/CAHp75VcP58Ub=gmbRVy0TPJtntKvnQZoi3tOakxE0qsEqzGPVA@mail.gmail.com/

Thanks
--
Gustavo

> 
> > 
> > > ---
> > >   drivers/dma-buf/dma-resv.c | 2 +-
> > >   1 file changed, 1 insertion(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
> > > index 1c8f2581cb09..bb5a42b10c29 100644
> > > --- a/drivers/dma-buf/dma-resv.c
> > > +++ b/drivers/dma-buf/dma-resv.c
> > > @@ -63,7 +63,7 @@ static struct dma_resv_list *dma_resv_list_alloc(unsigned int shared_max)
> > >   {
> > >          struct dma_resv_list *list;
> > > 
> > > -       list = kmalloc(offsetof(typeof(*list), shared[shared_max]), GFP_KERNEL);
> > > +       list = kmalloc(struct_size(list, shared, shared_max), GFP_KERNEL);
> > >          if (!list)
> > >                  return NULL;
> > > 
> > > --
> > > 2.17.1
> > > 
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@lists.freedesktop.org
> > > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> > 
> > 
> 
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