On 12/22/2023 9:44 AM, Srinivasan Shanmugam wrote:
Before using list_first_entry, make sure to check that list is not
empty.
Fixes the below:
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1347 kfd_create_indirect_link_prop() warn: can 'gpu_link' even be NULL?
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1428 kfd_add_peer_prop() warn: can 'iolink1' even be NULL?
drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_topology.c:1433 kfd_add_peer_prop() warn: can 'iolink2' even be NULL?
'Fixes: 0f28cca87e9a ("drm/amdkfd: Extend KFD device topology to surface
peer-to-peer links")'
Suggested-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_topology.c | 21 +++++++++------------
1 file changed, 9 insertions(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
index dc7c8312e8c7..a4cc88f08df2 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_topology.c
@@ -1342,10 +1342,9 @@ static int kfd_create_indirect_link_prop(struct kfd_topology_device *kdev, int g
num_cpu++;
}
- gpu_link = list_first_entry(&kdev->io_link_props,
- struct kfd_iolink_properties, list);
- if (!gpu_link)
- return -ENOMEM;
+ if (!list_empty(&kdev->io_link_props))
To match the original code logic, I think it needs to be something like
if (list_empty(&kdev->io_link_props))
return -ENOMEM;
(though the choice of this error code is a matter of another patch).
Otherwise, this will end up in accessing uninitialized gpu_link
variable. Same is the case for other modifications also.
Thanks,
Lijo
+ gpu_link = list_first_entry(&kdev->io_link_props,
+ struct kfd_iolink_properties, list);
for (i = 0; i < num_cpu; i++) {
/* CPU <--> GPU */
@@ -1423,15 +1422,13 @@ static int kfd_add_peer_prop(struct kfd_topology_device *kdev,
peer->gpu->adev))
return ret;
- iolink1 = list_first_entry(&kdev->io_link_props,
- struct kfd_iolink_properties, list);
- if (!iolink1)
- return -ENOMEM;
+ if (!list_empty(&kdev->io_link_props))
+ iolink1 = list_first_entry(&kdev->io_link_props,
+ struct kfd_iolink_properties, list);
- iolink2 = list_first_entry(&peer->io_link_props,
- struct kfd_iolink_properties, list);
- if (!iolink2)
- return -ENOMEM;
+ if (!list_empty(&peer->io_link_props))
+ iolink2 = list_first_entry(&peer->io_link_props,
+ struct kfd_iolink_properties, list);
props = kfd_alloc_struct(props);
if (!props)
