panthor_vm_get_heap_pool() returns ERR_PTR on failure.
Fixes: 4bdca1150792 ("drm/panthor: Add the driver frontend block")
Signed-off-by: Harshit Mogalapalli <[email protected]>
---
This is spotted by smatch and the patch is only compile tested
---
drivers/gpu/drm/panthor/panthor_drv.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
index 11b3ccd58f85..050b905b0453 100644
--- a/drivers/gpu/drm/panthor/panthor_drv.c
+++ b/drivers/gpu/drm/panthor/panthor_drv.c
@@ -1090,8 +1090,8 @@ static int panthor_ioctl_tiler_heap_destroy(struct drm_device *ddev, void *data,
return -EINVAL;
pool = panthor_vm_get_heap_pool(vm, false);
- if (!pool) {
- ret = -EINVAL;
+ if (IS_ERR(pool)) {
+ ret = PTR_ERR(pool);
goto out_put_vm;
}
--
2.39.3
Hello Harshit,
On Tue, 2 Apr 2024 03:33:58 -0700
Harshit Mogalapalli <[email protected]> wrote:
> panthor_vm_get_heap_pool() returns ERR_PTR on failure.
>
> Fixes: 4bdca1150792 ("drm/panthor: Add the driver frontend block")
> Signed-off-by: Harshit Mogalapalli <[email protected]>
> ---
> This is spotted by smatch and the patch is only compile tested
> ---
> drivers/gpu/drm/panthor/panthor_drv.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> index 11b3ccd58f85..050b905b0453 100644
> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> @@ -1090,8 +1090,8 @@ static int panthor_ioctl_tiler_heap_destroy(struct drm_device *ddev, void *data,
> return -EINVAL;
>
> pool = panthor_vm_get_heap_pool(vm, false);
> - if (!pool) {
> - ret = -EINVAL;
> + if (IS_ERR(pool)) {
> + ret = PTR_ERR(pool);
Actually, panthor_vm_get_heap_pool() will return NULL if there's no
heap pool attached to this VM and create=false, so this was correct.
This being said, I'm fine making that consistent by returning
ERR_PTR(-ENOENT) instead of NULL in that case. This way we don't have
two different semantics based on the 'create' value.
Oh, and please merge everything into a single patch instead of one patch
per call-site.
Regards,
Boris
> goto out_put_vm;
> }
>
Hello Boris,
On 02/04/24 18:03, Boris Brezillon wrote:
> Hello Harshit,
>
> On Tue, 2 Apr 2024 03:33:58 -0700
> Harshit Mogalapalli <[email protected]> wrote:
>
>> panthor_vm_get_heap_pool() returns ERR_PTR on failure.
>>
>> Fixes: 4bdca1150792 ("drm/panthor: Add the driver frontend block")
>> Signed-off-by: Harshit Mogalapalli <[email protected]>
>> ---
>> This is spotted by smatch and the patch is only compile tested
>> ---
>> drivers/gpu/drm/panthor/panthor_drv.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
>> index 11b3ccd58f85..050b905b0453 100644
>> --- a/drivers/gpu/drm/panthor/panthor_drv.c
>> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
>> @@ -1090,8 +1090,8 @@ static int panthor_ioctl_tiler_heap_destroy(struct drm_device *ddev, void *data,
>> return -EINVAL;
>>
>> pool = panthor_vm_get_heap_pool(vm, false);
>> - if (!pool) {
>> - ret = -EINVAL;
>> + if (IS_ERR(pool)) {
>> + ret = PTR_ERR(pool);
>
> Actually, panthor_vm_get_heap_pool() will return NULL if there's no
> heap pool attached to this VM and create=false, so this was correct.
> This being said, I'm fine making that consistent by returning
> ERR_PTR(-ENOENT) instead of NULL in that case. This way we don't have
> two different semantics based on the 'create' value.
>
Thanks for explaining. I missed the case where create is false and there
is no heap pool attached, so panthor_vm_get_heap_pool() can return NULL.
1878 *
1879 * Return: A valid pointer on success, an ERR_PTR() otherwise.
1880 */
1881 struct panthor_heap_pool *panthor_vm_get_heap_pool(struct
panthor_vm *vm, bool create)
The documentation says it returns ERR_PTR() on failure, so is it worth
doing something like:
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
b/drivers/gpu/drm/panthor/panthor_mmu.c
index fdd35249169f..e1285cdb09ff 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -1893,6 +1893,8 @@ struct panthor_heap_pool
*panthor_vm_get_heap_pool(struct panthor_vm *vm, bool c
vm->heaps.pool = panthor_heap_pool_get(pool);
} else {
pool = panthor_heap_pool_get(vm->heaps.pool);
+ if (!pool)
+ pool = ERR_PTR(-ENOENT);
}
mutex_unlock(&vm->heaps.lock);
and change all callers of panthor_vm_get_heap_pool() to only check for
IS_ERR() ?
> Oh, and please merge everything into a single patch instead of one patch
> per call-site.
>
Sure, I noticed one after the other. I will fix them together in v2.
Thanks,
Harshit
> Regards,
>
> Boris
>
>> goto out_put_vm;
>> }
>>
>
On Tue, 2 Apr 2024 18:52:12 +0530
Harshit Mogalapalli <[email protected]> wrote:
> Hello Boris,
>
> On 02/04/24 18:03, Boris Brezillon wrote:
> > Hello Harshit,
> >
> > On Tue, 2 Apr 2024 03:33:58 -0700
> > Harshit Mogalapalli <[email protected]> wrote:
> >
> >> panthor_vm_get_heap_pool() returns ERR_PTR on failure.
> >>
> >> Fixes: 4bdca1150792 ("drm/panthor: Add the driver frontend block")
> >> Signed-off-by: Harshit Mogalapalli <[email protected]>
> >> ---
> >> This is spotted by smatch and the patch is only compile tested
> >> ---
> >> drivers/gpu/drm/panthor/panthor_drv.c | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/panthor/panthor_drv.c b/drivers/gpu/drm/panthor/panthor_drv.c
> >> index 11b3ccd58f85..050b905b0453 100644
> >> --- a/drivers/gpu/drm/panthor/panthor_drv.c
> >> +++ b/drivers/gpu/drm/panthor/panthor_drv.c
> >> @@ -1090,8 +1090,8 @@ static int panthor_ioctl_tiler_heap_destroy(struct drm_device *ddev, void *data,
> >> return -EINVAL;
> >>
> >> pool = panthor_vm_get_heap_pool(vm, false);
> >> - if (!pool) {
> >> - ret = -EINVAL;
> >> + if (IS_ERR(pool)) {
> >> + ret = PTR_ERR(pool);
> >
> > Actually, panthor_vm_get_heap_pool() will return NULL if there's no
> > heap pool attached to this VM and create=false, so this was correct.
> > This being said, I'm fine making that consistent by returning
> > ERR_PTR(-ENOENT) instead of NULL in that case. This way we don't have
> > two different semantics based on the 'create' value.
> >
>
> Thanks for explaining. I missed the case where create is false and there
> is no heap pool attached, so panthor_vm_get_heap_pool() can return NULL.
>
> 1878 *
> 1879 * Return: A valid pointer on success, an ERR_PTR() otherwise.
> 1880 */
> 1881 struct panthor_heap_pool *panthor_vm_get_heap_pool(struct
> panthor_vm *vm, bool create)
>
> The documentation says it returns ERR_PTR() on failure, so is it worth
> doing something like:
>
> diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c
> b/drivers/gpu/drm/panthor/panthor_mmu.c
> index fdd35249169f..e1285cdb09ff 100644
> --- a/drivers/gpu/drm/panthor/panthor_mmu.c
> +++ b/drivers/gpu/drm/panthor/panthor_mmu.c
> @@ -1893,6 +1893,8 @@ struct panthor_heap_pool
> *panthor_vm_get_heap_pool(struct panthor_vm *vm, bool c
> vm->heaps.pool = panthor_heap_pool_get(pool);
> } else {
> pool = panthor_heap_pool_get(vm->heaps.pool);
> + if (!pool)
> + pool = ERR_PTR(-ENOENT);
> }
> mutex_unlock(&vm->heaps.lock);
>
>
> and change all callers of panthor_vm_get_heap_pool() to only check for
> IS_ERR() ?
Yep, that's what I had in mind.
>
>
> > Oh, and please merge everything into a single patch instead of one patch
> > per call-site.
> >
>
> Sure, I noticed one after the other. I will fix them together in v2.
Great!
Thanks,
Boris