diff mbox series

drm/amdgpu: fix warning for overflow check

Message ID 20210927125824.1583474-1-arnd@kernel.org
State New
Headers show
Series drm/amdgpu: fix warning for overflow check | expand

Commit Message

Arnd Bergmann Sept. 27, 2021, 12:58 p.m. UTC
From: Arnd Bergmann <arnd@arndb.de>


The overflow check in amdgpu_bo_list_create() causes a warning with
clang-14 on 64-bit architectures, since the limit can never be
exceeded.

drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c:74:18: error: result of comparison of constant 256204778801521549 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (num_entries > (SIZE_MAX - sizeof(struct amdgpu_bo_list))
            ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The check remains useful for 32-bit architectures, so just avoid the
warning by using size_t as the type for the count.

Fixes: 920990cb080a ("drm/amdgpu: allocate the bo_list array after the list")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

-- 
2.29.2

Comments

Christian König Sept. 27, 2021, 1:07 p.m. UTC | #1
Am 27.09.21 um 14:58 schrieb Arnd Bergmann:
> From: Arnd Bergmann <arnd@arndb.de>

>

> The overflow check in amdgpu_bo_list_create() causes a warning with

> clang-14 on 64-bit architectures, since the limit can never be

> exceeded.

>

> drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c:74:18: error: result of comparison of constant 256204778801521549 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]

>          if (num_entries > (SIZE_MAX - sizeof(struct amdgpu_bo_list))

>              ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

>

> The check remains useful for 32-bit architectures, so just avoid the

> warning by using size_t as the type for the count.

>

> Fixes: 920990cb080a ("drm/amdgpu: allocate the bo_list array after the list")

> Signed-off-by: Arnd Bergmann <arnd@arndb.de>


Reviewed-by: Christian König <christian.koenig@amd.com>


> ---

>   drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 2 +-

>   drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h | 2 +-

>   2 files changed, 2 insertions(+), 2 deletions(-)

>

> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> index 15c45b2a3983..714178f1b6c6 100644

> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> @@ -61,7 +61,7 @@ static void amdgpu_bo_list_free(struct kref *ref)

>   

>   int amdgpu_bo_list_create(struct amdgpu_device *adev, struct drm_file *filp,

>   			  struct drm_amdgpu_bo_list_entry *info,

> -			  unsigned num_entries, struct amdgpu_bo_list **result)

> +			  size_t num_entries, struct amdgpu_bo_list **result)

>   {

>   	unsigned last_entry = 0, first_userptr = num_entries;

>   	struct amdgpu_bo_list_entry *array;

> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> index c905a4cfc173..044b41f0bfd9 100644

> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> @@ -61,7 +61,7 @@ int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in,

>   int amdgpu_bo_list_create(struct amdgpu_device *adev,

>   				 struct drm_file *filp,

>   				 struct drm_amdgpu_bo_list_entry *info,

> -				 unsigned num_entries,

> +				 size_t num_entries,

>   				 struct amdgpu_bo_list **list);

>   

>   static inline struct amdgpu_bo_list_entry *
Alex Deucher Sept. 27, 2021, 7:20 p.m. UTC | #2
Applied.  Thanks!

On Mon, Sep 27, 2021 at 9:07 AM Christian König
<christian.koenig@amd.com> wrote:
>

> Am 27.09.21 um 14:58 schrieb Arnd Bergmann:

> > From: Arnd Bergmann <arnd@arndb.de>

> >

> > The overflow check in amdgpu_bo_list_create() causes a warning with

> > clang-14 on 64-bit architectures, since the limit can never be

> > exceeded.

> >

> > drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c:74:18: error: result of comparison of constant 256204778801521549 with expression of type 'unsigned int' is always false [-Werror,-Wtautological-constant-out-of-range-compare]

> >          if (num_entries > (SIZE_MAX - sizeof(struct amdgpu_bo_list))

> >              ~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

> >

> > The check remains useful for 32-bit architectures, so just avoid the

> > warning by using size_t as the type for the count.

> >

> > Fixes: 920990cb080a ("drm/amdgpu: allocate the bo_list array after the list")

> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>

>

> Reviewed-by: Christian König <christian.koenig@amd.com>

>

> > ---

> >   drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c | 2 +-

> >   drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h | 2 +-

> >   2 files changed, 2 insertions(+), 2 deletions(-)

> >

> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> > index 15c45b2a3983..714178f1b6c6 100644

> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c

> > @@ -61,7 +61,7 @@ static void amdgpu_bo_list_free(struct kref *ref)

> >

> >   int amdgpu_bo_list_create(struct amdgpu_device *adev, struct drm_file *filp,

> >                         struct drm_amdgpu_bo_list_entry *info,

> > -                       unsigned num_entries, struct amdgpu_bo_list **result)

> > +                       size_t num_entries, struct amdgpu_bo_list **result)

> >   {

> >       unsigned last_entry = 0, first_userptr = num_entries;

> >       struct amdgpu_bo_list_entry *array;

> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> > index c905a4cfc173..044b41f0bfd9 100644

> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h

> > @@ -61,7 +61,7 @@ int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in,

> >   int amdgpu_bo_list_create(struct amdgpu_device *adev,

> >                                struct drm_file *filp,

> >                                struct drm_amdgpu_bo_list_entry *info,

> > -                              unsigned num_entries,

> > +                              size_t num_entries,

> >                                struct amdgpu_bo_list **list);

> >

> >   static inline struct amdgpu_bo_list_entry *

>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
index 15c45b2a3983..714178f1b6c6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
@@ -61,7 +61,7 @@  static void amdgpu_bo_list_free(struct kref *ref)
 
 int amdgpu_bo_list_create(struct amdgpu_device *adev, struct drm_file *filp,
 			  struct drm_amdgpu_bo_list_entry *info,
-			  unsigned num_entries, struct amdgpu_bo_list **result)
+			  size_t num_entries, struct amdgpu_bo_list **result)
 {
 	unsigned last_entry = 0, first_userptr = num_entries;
 	struct amdgpu_bo_list_entry *array;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
index c905a4cfc173..044b41f0bfd9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
@@ -61,7 +61,7 @@  int amdgpu_bo_create_list_entry_array(struct drm_amdgpu_bo_list_in *in,
 int amdgpu_bo_list_create(struct amdgpu_device *adev,
 				 struct drm_file *filp,
 				 struct drm_amdgpu_bo_list_entry *info,
-				 unsigned num_entries,
+				 size_t num_entries,
 				 struct amdgpu_bo_list **list);
 
 static inline struct amdgpu_bo_list_entry *