Re: [PATCH v3] drm/amdkfd: FORWARD NULL

[Philip Yang]

On 2025-11-18 15:34, Andrew Martin wrote:

This patch fixes issues when the code moves forward with a potential
NULL pointer, without checking.

Signed-off-by: Andrew Martin <andrew.mar...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c | 2 +-
  drivers/gpu/drm/amd/amdkfd/kfd_crat.c            | 2 ++
  drivers/gpu/drm/amd/amdkfd/kfd_debug.c           | 7 ++++++-
  drivers/gpu/drm/amd/amdkfd/kfd_process.c         | 3 ---
  4 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
index 1ef758ac5076..73c5749d4243 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_fence.c
@@ -105,7 +105,7 @@ static const char *amdkfd_fence_get_timeline_name(struct 
dma_fence *f)
  {
        struct amdgpu_amdkfd_fence *fence = to_amdgpu_amdkfd_fence(f);

- return fence->timeline_name;

+       return fence ? fence->timeline_name : NULL;
  }

/**

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
index 4a7180b46b71..c086a9ed8c89 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_crat.c
@@ -2357,6 +2357,8 @@ static int kfd_create_vcrat_image_gpu(void *pcrat_image,
        if (kdev->kfd->hive_id) {
                for (nid = 0; nid < proximity_domain; ++nid) {
                        peer_dev = 
kfd_topology_device_by_proximity_domain_no_lock(nid);
+                       if (!peer_dev)
+                               continue;
                        if (!peer_dev->gpu)
                                continue;

if (!peer_dev || !peer_dev->gpu)
    continue;

                        if (peer_dev->gpu->kfd->hive_id != kdev->kfd->hive_id)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
index ba99e0f258ae..11af0c1cddcd 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_debug.c
@@ -517,7 +517,10 @@ int kfd_dbg_trap_set_flags(struct kfd_process *target, 
uint32_t *flags)

for (i = 0; i < target->n_pdds; i++) {

                struct kfd_topology_device *topo_dev =
-                               
kfd_topology_device_by_id(target->pdds[i]->dev->id);
+                       kfd_topology_device_by_id(target->pdds[i]->dev->id);
+               if (!topo_dev)
+                       return -EINVAL;
+

move this after variable caps definition

                uint32_t caps = topo_dev->node_props.capability;

uin32_t caps;

if (!topo_dev)
    return -EINVAL;

caps = topo_dev->node_props.capability;

                if (!(caps & HSA_CAP_TRAP_DEBUG_PRECISE_MEMORY_OPERATIONS_SUPPORTED) 
&&
@@ -1071,6 +1074,8 @@ int kfd_dbg_trap_device_snapshot(struct kfd_process 
*target,
        for (i = 0; i < tmp_num_devices; i++) {
                struct kfd_process_device *pdd = target->pdds[i];
                struct kfd_topology_device *topo_dev = 
kfd_topology_device_by_id(pdd->dev->id);

add empty line after variable.

+               if (!topo_dev)
+                       return -EINVAL;

break out of the loop to mutex_unlock then return

if (!topo_dev) {
    r = -EINVAL;
    break;
}

Regards,
Philip

                device_info.gpu_id = pdd->dev->id;
                device_info.exception_status = pdd->exception_status;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index f5d173f1ca3b..888b1c24c2a6 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -1685,9 +1685,6 @@ int kfd_process_device_init_vm(struct kfd_process_device 
*pdd,
        struct kfd_node *dev;
        int ret;

- if (!drm_file)

-               return -EINVAL;
-
        if (pdd->drm_priv)
                return -EBUSY;