[4/4] drm/tegra: Use u64_to_user_ptr helper

Message ID 20170818161553.27597-5-mperttunen@nvidia.com
State New
Headers show

Commit Message

Mikko Perttunen Aug. 18, 2017, 4:15 p.m.
Use the u64_to_user_ptr helper macro to cast IOCTL argument u64 values
to user pointers instead of writing out the cast manually.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
 drivers/gpu/drm/tegra/drm.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

Comments

Dmitry Osipenko Aug. 18, 2017, 10:05 p.m. | #1
On 18.08.2017 19:15, Mikko Perttunen wrote:
> Use the u64_to_user_ptr helper macro to cast IOCTL argument u64 values
> to user pointers instead of writing out the cast manually.
> 
> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
> ---
>  drivers/gpu/drm/tegra/drm.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index e3331a2bc082..78c98736b0a5 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -389,11 +389,10 @@ int tegra_drm_submit(struct tegra_drm_context *context,
>  	unsigned int num_relocs = args->num_relocs;
>  	unsigned int num_waitchks = args->num_waitchks;
>  	struct drm_tegra_cmdbuf __user *cmdbufs =
> -		(void __user *)(uintptr_t)args->cmdbufs;
> -	struct drm_tegra_reloc __user *relocs =
> -		(void __user *)(uintptr_t)args->relocs;
> +		u64_to_user_ptr(args->cmdbufs);
> +	struct drm_tegra_reloc __user *relocs = u64_to_user_ptr(args->relocs);
>  	struct drm_tegra_waitchk __user *waitchks =
> -		(void __user *)(uintptr_t)args->waitchks;
> +		u64_to_user_ptr(args->waitchks);

What about to factor out 'u64_to_user_ptr()' assignments to reduce messiness a
tad? Like this:

	struct drm_tegra_waitchk __user *waitchks;
	struct drm_tegra_cmdbuf __user *cmdbufs;
	struct drm_tegra_reloc __user *relocs;
...
	waitchks = u64_to_user_ptr(args->waitchks);
	cmdbufs = u64_to_user_ptr(args->cmdbufs);
	relocs = u64_to_user_ptr(args->relocs);


>  	struct drm_tegra_syncpt syncpt;
>  	struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
>  	struct host1x_syncpt *sp;
> @@ -520,7 +519,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
>  		}
>  	}
>  
> -	if (copy_from_user(&syncpt, (void __user *)(uintptr_t)args->syncpts,
> +	if (copy_from_user(&syncpt, u64_to_user_ptr(args->syncpts),

What about to define and use 'struct drm_tegra_reloc __user *syncpts' for
consistency with other '__user' definitions?

>  			   sizeof(syncpt))) {
>  		err = -EFAULT;
>  		goto fail;
>
Mikko Perttunen Aug. 19, 2017, 8:06 a.m. | #2
On 08/19/2017 01:05 AM, Dmitry Osipenko wrote:
> On 18.08.2017 19:15, Mikko Perttunen wrote:
>> Use the u64_to_user_ptr helper macro to cast IOCTL argument u64 values
>> to user pointers instead of writing out the cast manually.
>>
>> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
>> ---
>>   drivers/gpu/drm/tegra/drm.c | 9 ++++-----
>>   1 file changed, 4 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
>> index e3331a2bc082..78c98736b0a5 100644
>> --- a/drivers/gpu/drm/tegra/drm.c
>> +++ b/drivers/gpu/drm/tegra/drm.c
>> @@ -389,11 +389,10 @@ int tegra_drm_submit(struct tegra_drm_context *context,
>>   	unsigned int num_relocs = args->num_relocs;
>>   	unsigned int num_waitchks = args->num_waitchks;
>>   	struct drm_tegra_cmdbuf __user *cmdbufs =
>> -		(void __user *)(uintptr_t)args->cmdbufs;
>> -	struct drm_tegra_reloc __user *relocs =
>> -		(void __user *)(uintptr_t)args->relocs;
>> +		u64_to_user_ptr(args->cmdbufs);
>> +	struct drm_tegra_reloc __user *relocs = u64_to_user_ptr(args->relocs);
>>   	struct drm_tegra_waitchk __user *waitchks =
>> -		(void __user *)(uintptr_t)args->waitchks;
>> +		u64_to_user_ptr(args->waitchks);
> 
> What about to factor out 'u64_to_user_ptr()' assignments to reduce messiness a
> tad? Like this:
> 
> 	struct drm_tegra_waitchk __user *waitchks;
> 	struct drm_tegra_cmdbuf __user *cmdbufs;
> 	struct drm_tegra_reloc __user *relocs;
> ...
> 	waitchks = u64_to_user_ptr(args->waitchks);
> 	cmdbufs = u64_to_user_ptr(args->cmdbufs);
> 	relocs = u64_to_user_ptr(args->relocs);
> 
> 
>>   	struct drm_tegra_syncpt syncpt;
>>   	struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
>>   	struct host1x_syncpt *sp;
>> @@ -520,7 +519,7 @@ int tegra_drm_submit(struct tegra_drm_context *context,
>>   		}
>>   	}
>>   
>> -	if (copy_from_user(&syncpt, (void __user *)(uintptr_t)args->syncpts,
>> +	if (copy_from_user(&syncpt, u64_to_user_ptr(args->syncpts),
> 
> What about to define and use 'struct drm_tegra_reloc __user *syncpts' for
> consistency with other '__user' definitions?
> 
>>   			   sizeof(syncpt))) {
>>   		err = -EFAULT;
>>   		goto fail;
>>
> 

Yeah, these are good ideas. I'll post a v2 at some point with these 
changes. Thanks!

Mikko
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Patch

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index e3331a2bc082..78c98736b0a5 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -389,11 +389,10 @@  int tegra_drm_submit(struct tegra_drm_context *context,
 	unsigned int num_relocs = args->num_relocs;
 	unsigned int num_waitchks = args->num_waitchks;
 	struct drm_tegra_cmdbuf __user *cmdbufs =
-		(void __user *)(uintptr_t)args->cmdbufs;
-	struct drm_tegra_reloc __user *relocs =
-		(void __user *)(uintptr_t)args->relocs;
+		u64_to_user_ptr(args->cmdbufs);
+	struct drm_tegra_reloc __user *relocs = u64_to_user_ptr(args->relocs);
 	struct drm_tegra_waitchk __user *waitchks =
-		(void __user *)(uintptr_t)args->waitchks;
+		u64_to_user_ptr(args->waitchks);
 	struct drm_tegra_syncpt syncpt;
 	struct host1x *host1x = dev_get_drvdata(drm->dev->parent);
 	struct host1x_syncpt *sp;
@@ -520,7 +519,7 @@  int tegra_drm_submit(struct tegra_drm_context *context,
 		}
 	}
 
-	if (copy_from_user(&syncpt, (void __user *)(uintptr_t)args->syncpts,
+	if (copy_from_user(&syncpt, u64_to_user_ptr(args->syncpts),
 			   sizeof(syncpt))) {
 		err = -EFAULT;
 		goto fail;