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[next] amd/amdgpu_ctx: Use struct_size() helper and kmalloc()

Message ID 20201008143450.GA23077@embeddedor (mailing list archive)
State New, archived
Headers show
Series [next] amd/amdgpu_ctx: Use struct_size() helper and kmalloc() | expand

Commit Message

Gustavo A. R. Silva Oct. 8, 2020, 2:34 p.m. UTC
Make use of the new struct_size() helper instead of the offsetof() idiom.
Also, use kmalloc() instead of kcalloc().

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Alex Deucher Oct. 8, 2020, 5:22 p.m. UTC | #1
Applied.  Thanks!

Alex

On Thu, Oct 8, 2020 at 10:29 AM Gustavo A. R. Silva
<gustavoars@kernel.org> wrote:
>
> Make use of the new struct_size() helper instead of the offsetof() idiom.
> Also, use kmalloc() instead of kcalloc().
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> index c80d8339f58c..5be125f3b92a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> @@ -100,7 +100,7 @@ static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
>         enum drm_sched_priority priority;
>         int r;
>
> -       entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
> +       entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),
>                          GFP_KERNEL);
>         if (!entity)
>                 return  -ENOMEM;
> --
> 2.27.0
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Christian König Oct. 9, 2020, 7:08 a.m. UTC | #2
Am 08.10.20 um 16:34 schrieb Gustavo A. R. Silva:
> Make use of the new struct_size() helper instead of the offsetof() idiom.
> Also, use kmalloc() instead of kcalloc().
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> index c80d8339f58c..5be125f3b92a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> @@ -100,7 +100,7 @@ static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
>   	enum drm_sched_priority priority;
>   	int r;
>   
> -	entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
> +	entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),

NAK. You could use kzalloc() here, but kmalloc won't zero initialize the 
memory which could result in unforeseen consequences.

Christian.

>   			 GFP_KERNEL);
>   	if (!entity)
>   		return  -ENOMEM;
Gustavo A. R. Silva Oct. 9, 2020, 1:54 p.m. UTC | #3
On Fri, Oct 09, 2020 at 09:08:51AM +0200, Christian König wrote:
> Am 08.10.20 um 16:34 schrieb Gustavo A. R. Silva:
> > Make use of the new struct_size() helper instead of the offsetof() idiom.
> > Also, use kmalloc() instead of kcalloc().
> > 
> > Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > index c80d8339f58c..5be125f3b92a 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
> > @@ -100,7 +100,7 @@ static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
> >   	enum drm_sched_priority priority;
> >   	int r;
> > -	entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
> > +	entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),
> 
> NAK. You could use kzalloc() here, but kmalloc won't zero initialize the
> memory which could result in unforeseen consequences.

Oh I see.. I certainly didn't take that into account.

I'll fix that up and respin.

Thanks
--
Gustavo
Christian König Oct. 9, 2020, 2:29 p.m. UTC | #4
Am 09.10.20 um 15:54 schrieb Gustavo A. R. Silva:
> On Fri, Oct 09, 2020 at 09:08:51AM +0200, Christian König wrote:
>> Am 08.10.20 um 16:34 schrieb Gustavo A. R. Silva:
>>> Make use of the new struct_size() helper instead of the offsetof() idiom.
>>> Also, use kmalloc() instead of kcalloc().
>>>
>>> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
>>> ---
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 +-
>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>>> index c80d8339f58c..5be125f3b92a 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>>> @@ -100,7 +100,7 @@ static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
>>>    	enum drm_sched_priority priority;
>>>    	int r;
>>> -	entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
>>> +	entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),
>> NAK. You could use kzalloc() here, but kmalloc won't zero initialize the
>> memory which could result in unforeseen consequences.
> Oh I see.. I certainly didn't take that into account.
>
> I'll fix that up and respin.

Shit happens, we already have a fix for this. Alex merged it and it 
immediately broke our testing systems.

So one of our engineers came up with a fix which should already have 
been applied.

Christian.

>
> Thanks
> --
> Gustavo
Gustavo A. R. Silva Oct. 9, 2020, 2:39 p.m. UTC | #5
On Fri, Oct 09, 2020 at 04:29:55PM +0200, Christian König wrote:
> > > > -	entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
> > > > +	entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),
> > > NAK. You could use kzalloc() here, but kmalloc won't zero initialize the
> > > memory which could result in unforeseen consequences.
> > Oh I see.. I certainly didn't take that into account.
> > 
> > I'll fix that up and respin.
> 
> Shit happens, we already have a fix for this. Alex merged it and it
> immediately broke our testing systems.

:/

> So one of our engineers came up with a fix which should already have been
> applied.

Great. Good to know it's already fixed! :)

Thanks
--
Gustavo
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index c80d8339f58c..5be125f3b92a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -100,7 +100,7 @@  static int amdgpu_ctx_init_entity(struct amdgpu_ctx *ctx, u32 hw_ip,
 	enum drm_sched_priority priority;
 	int r;
 
-	entity = kcalloc(1, offsetof(typeof(*entity), fences[amdgpu_sched_jobs]),
+	entity = kmalloc(struct_size(entity, fences, amdgpu_sched_jobs),
 			 GFP_KERNEL);
 	if (!entity)
 		return  -ENOMEM;