Hi Felix,
Quoting Felix Kuehling <felix.kuehling@xxxxxxx>:
Hi Gustavo,
Thanks for catching that. When returning a fault, I think you also need
to srcu_read_unlock(&kfd_processes_srcu, idx).
However, instead of returning an error, I think I'd prefer to skip PDDs
that can't be found with continue statements. That way others would
still suspend and resume successfully. Maybe just print a WARN_ON for
PDDs that aren't found, because that's an unexpected situation,
currently. Maybe in the future it could be normal thing if we ever
support GPU hotplug.
I got it. In that case, what do you think about the following patch instead?
index a22fb071..4ff5f0f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -461,7 +461,8 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
mutex_lock(&p->mutex);
pdd = kfd_get_process_device_data(dev, p);
- if (pdd->bound != PDD_BOUND_SUSPENDED) {
+
+ if (WARN_ON(!pdd) || pdd->bound != PDD_BOUND_SUSPENDED) {
mutex_unlock(&p->mutex);
continue;
}
@@ -501,6 +502,11 @@ void kfd_unbind_processes_from_device(struct
kfd_dev *dev)
mutex_lock(&p->mutex);
pdd = kfd_get_process_device_data(dev, p);
+ if (WARN_ON(!pdd)) {
+ mutex_unlock(&p->mutex);
+ continue;
+ }
+
if (pdd->bound == PDD_BOUND)
pdd->bound = PDD_BOUND_SUSPENDED;
mutex_unlock(&p->mutex);
Thank you for the feedback.
--
Gustavo
Regards,
Felix
On 2018-01-10 11:50 AM, Gustavo A. R. Silva wrote:
In case kfd_get_process_device_data returns null, there are some
null pointer dereferences in functions kfd_bind_processes_to_device
and kfd_unbind_processes_from_device.
Fix this by null checking pdd before dereferencing it.
Addresses-Coverity-ID: 1463794 ("Dereference null return value")
Addresses-Coverity-ID: 1463772 ("Dereference null return value")
Signed-off-by: Gustavo A. R. Silva <garsilva@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index a22fb071..29d51d5 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -461,6 +461,13 @@ int kfd_bind_processes_to_device(struct kfd_dev *dev)
hash_for_each_rcu(kfd_processes_table, temp, p, kfd_processes) {
mutex_lock(&p->mutex);
pdd = kfd_get_process_device_data(dev, p);
+
+ if (!pdd) {
+ pr_err("Process device data doesn't exist\n");
+ mutex_unlock(&p->mutex);
+ return -EFAULT;
+ }
+
if (pdd->bound != PDD_BOUND_SUSPENDED) {
mutex_unlock(&p->mutex);
continue;
@@ -501,6 +508,11 @@ void kfd_unbind_processes_from_device(struct
kfd_dev *dev)
mutex_lock(&p->mutex);
pdd = kfd_get_process_device_data(dev, p);
+ if (!pdd) {
+ mutex_unlock(&p->mutex);
+ return;
+ }
+
if (pdd->bound == PDD_BOUND)
pdd->bound = PDD_BOUND_SUSPENDED;
mutex_unlock(&p->mutex);
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