diff mbox

[1/2] drm: Distinguish no name from ENOMEM in set_unique()

Message ID 20160921145919.13754-1-teg@jklm.no (mailing list archive)
State New, archived
Headers show

Commit Message

Tom Gundersen Sept. 21, 2016, 2:59 p.m. UTC
If passing name == NULL to drm_drv_set_unique() we now get -ENOMEM
as kstrdup() returns NULL. Instead check for this explicitly and
return -EINVAL if no name is provided.

Signed-off-by: Tom Gundersen <teg@jklm.no>
---
 drivers/gpu/drm/drm_drv.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Daniel Vetter Sept. 22, 2016, 6:08 a.m. UTC | #1
On Wed, Sep 21, 2016 at 04:59:18PM +0200, Tom Gundersen wrote:
> If passing name == NULL to drm_drv_set_unique() we now get -ENOMEM
> as kstrdup() returns NULL. Instead check for this explicitly and
> return -EINVAL if no name is provided.
> 
> Signed-off-by: Tom Gundersen <teg@jklm.no>

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

> ---
>  drivers/gpu/drm/drm_drv.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index f2f6429..99e6751 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -338,6 +338,9 @@ void drm_minor_release(struct drm_minor *minor)
>  
>  static int drm_dev_set_unique(struct drm_device *dev, const char *name)
>  {
> +	if (!name)
> +		return -EINVAL;
> +
>  	kfree(dev->unique);
>  	dev->unique = kstrdup(name, GFP_KERNEL);
>  
> -- 
> 2.9.3
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Emil Velikov Sept. 22, 2016, 6:28 a.m. UTC | #2
On 21 September 2016 at 15:59, Tom Gundersen <teg@jklm.no> wrote:
> If passing name == NULL to drm_drv_set_unique() we now get -ENOMEM
> as kstrdup() returns NULL. Instead check for this explicitly and
> return -EINVAL if no name is provided.
>
> Signed-off-by: Tom Gundersen <teg@jklm.no>
> ---
>  drivers/gpu/drm/drm_drv.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index f2f6429..99e6751 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -338,6 +338,9 @@ void drm_minor_release(struct drm_minor *minor)
>
>  static int drm_dev_set_unique(struct drm_device *dev, const char *name)
>  {
> +       if (!name)
> +               return -EINVAL;
> +
From memory there should be no open-source drivers where this happens
today. Either way, having a big WARN/OOPS would be better, imho, since
it will point to the driver bug/issue (?).

Regards,
Emil
Tom Gundersen Sept. 22, 2016, 10:13 a.m. UTC | #3
On Thu, Sep 22, 2016 at 8:28 AM, Emil Velikov <emil.l.velikov@gmail.com> wrote:
> On 21 September 2016 at 15:59, Tom Gundersen <teg@jklm.no> wrote:
>> If passing name == NULL to drm_drv_set_unique() we now get -ENOMEM
>> as kstrdup() returns NULL. Instead check for this explicitly and
>> return -EINVAL if no name is provided.
>>
>> Signed-off-by: Tom Gundersen <teg@jklm.no>
>> ---
>>  drivers/gpu/drm/drm_drv.c | 3 +++
>>  1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
>> index f2f6429..99e6751 100644
>> --- a/drivers/gpu/drm/drm_drv.c
>> +++ b/drivers/gpu/drm/drm_drv.c
>> @@ -338,6 +338,9 @@ void drm_minor_release(struct drm_minor *minor)
>>
>>  static int drm_dev_set_unique(struct drm_device *dev, const char *name)
>>  {
>> +       if (!name)
>> +               return -EINVAL;
>> +
> From memory there should be no open-source drivers where this happens
> today. Either way, having a big WARN/OOPS would be better, imho, since
> it will point to the driver bug/issue (?).

Yeah, I only hit this during development, should not happen with any
upstream drivers afaik. Feel free to drop this patch for now.

Cheers,

Tom
Sean Paul Sept. 22, 2016, 12:07 p.m. UTC | #4
On Wed, Sep 21, 2016 at 7:59 AM, Tom Gundersen <teg@jklm.no> wrote:
> If passing name == NULL to drm_drv_set_unique() we now get -ENOMEM
> as kstrdup() returns NULL. Instead check for this explicitly and
> return -EINVAL if no name is provided.
>
> Signed-off-by: Tom Gundersen <teg@jklm.no>


Thanks, applied to -misc

Sean

> ---
>  drivers/gpu/drm/drm_drv.c | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index f2f6429..99e6751 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -338,6 +338,9 @@ void drm_minor_release(struct drm_minor *minor)
>
>  static int drm_dev_set_unique(struct drm_device *dev, const char *name)
>  {
> +       if (!name)
> +               return -EINVAL;
> +
>         kfree(dev->unique);
>         dev->unique = kstrdup(name, GFP_KERNEL);
>
> --
> 2.9.3
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff mbox

Patch

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index f2f6429..99e6751 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -338,6 +338,9 @@  void drm_minor_release(struct drm_minor *minor)
 
 static int drm_dev_set_unique(struct drm_device *dev, const char *name)
 {
+	if (!name)
+		return -EINVAL;
+
 	kfree(dev->unique);
 	dev->unique = kstrdup(name, GFP_KERNEL);