[PATCH v2] drm/amdkfd: Use memdup_user() rather than duplicating its implementation

[Atul Raut]

To prevent its redundant implementation and streamline
code, use memdup_user.

This fixes warnings reported by Coccinelle:
./drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c:2811:13-20: WARNING 
opportunity for memdup_user

Signed-off-by: Atul Raut 
---
v1 -> v2
  caller checks for errors, hence removed
---
 drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 10 +-
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 2df153828ff4..df9b618756e6 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -2803,19 +2803,11 @@ static void copy_context_work_handler (struct 
work_struct *work)
 static uint32_t *get_queue_ids(uint32_t num_queues, uint32_t 
*usr_queue_id_array)
 {
size_t array_size = num_queues * sizeof(uint32_t);
-   uint32_t *queue_ids = NULL;
 
if (!usr_queue_id_array)
return NULL;
 
-   queue_ids = kzalloc(array_size, GFP_KERNEL);
-   if (!queue_ids)
-   return ERR_PTR(-ENOMEM);
-
-   if (copy_from_user(queue_ids, usr_queue_id_array, array_size))
-   return ERR_PTR(-EFAULT);
-
-   return queue_ids;
+   return memdup_user(usr_queue_id_array, array_size);
 }
 
 int resume_queues(struct kfd_process *p,
-- 
2.34.1

Re: drm/amdkfd: Use memdup_user() rather than duplicating its

[Atul Raut]

Hello Felix,

I appreciate the code review.
Will correct the  typo (seems to have appeared during patch creation 
following compilation).

Shortly as the compilation is successful, V2 will be sent.

-Atul

On 8/8/23 15:47, Felix Kuehling wrote:

On 2023-08-08 16:57, Atul Raut wrote:

To prevent its redundant implementation and streamline
code, use memdup_user.

This fixes warnings reported by Coccinelle:
./drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c:2811:13-20: 
WARNING opportunity for memdup_user


Signed-off-by: Atul Raut 
---
  drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 +++--
  1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c

index 2df153828ff4..51740e007e89 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -2808,12 +2808,9 @@ static uint32_t *get_queue_ids(uint32_t 
num_queues, uint32_t *usr_queue_id_array

  if (!usr_queue_id_array)
  return NULL;
  -    queue_ids = kzalloc(array_size, GFP_KERNEL);
-    if (!queue_ids)
-    return ERR_PTR(-ENOMEM);
-
-    if (copy_from_user(queue_ids, usr_queue_id_array, array_size))
-    return ERR_PTR(-EFAULT);
+    queue_ids = memdup_user(usr_queue_id_array, array_size);
+    if (IS_ERR(Iqueue_ids))


You have a typo in the variable name here. Did you at least 
compile-test the patch?




+    return ERR_PTR(queue_ids);


I think it should just return queue_ids here. That's already an 
ERR_PTR in case of errors. So you don't even need the "if". Just this 
should do the job:


    return memdup_user(usr_queue_id_array, array_size);

The error checking is done by the caller.

Regards,
  Felix



    return queue_ids;
  }

drm/amdkfd: Use memdup_user() rather than duplicating its

[Atul Raut]

To prevent its redundant implementation and streamline
code, use memdup_user.

This fixes warnings reported by Coccinelle:
./drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c:2811:13-20: WARNING 
opportunity for memdup_user

Signed-off-by: Atul Raut 
---
 drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c | 9 +++--
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 2df153828ff4..51740e007e89 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -2808,12 +2808,9 @@ static uint32_t *get_queue_ids(uint32_t num_queues, 
uint32_t *usr_queue_id_array
if (!usr_queue_id_array)
return NULL;
 
-   queue_ids = kzalloc(array_size, GFP_KERNEL);
-   if (!queue_ids)
-   return ERR_PTR(-ENOMEM);
-
-   if (copy_from_user(queue_ids, usr_queue_id_array, array_size))
-   return ERR_PTR(-EFAULT);
+   queue_ids = memdup_user(usr_queue_id_array, array_size);
+   if (IS_ERR(Iqueue_ids))
+   return ERR_PTR(queue_ids);
 
return queue_ids;
 }
-- 
2.34.1