On Thu, 17 Mar 2022, Lee Jones wrote:
Presently the Client can be freed whilst still in use.
Use the already provided lock to prevent this.
Cc: Felix Kuehling Felix.Kuehling@amd.com Cc: Alex Deucher alexander.deucher@amd.com Cc: "Christian König" christian.koenig@amd.com Cc: "Pan, Xinhui" Xinhui.Pan@amd.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: amd-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Signed-off-by: Lee Jones lee.jones@linaro.org
I should have clarified here, that:
This patch has only been *build* tested.
Since I have no way to run this on real H/W.
Please ensure this is tested on real H/W before it gets applied, since it *may* have some undesired side-effects. For instance, I have no idea if client->lock plays nicely with dev->smi_lock or whether this may well end up in deadlock.
TIA.
drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c index e4beebb1c80a2..3b9ac1e87231f 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c @@ -145,8 +145,11 @@ static int kfd_smi_ev_release(struct inode *inode, struct file *filep) spin_unlock(&dev->smi_lock);
synchronize_rcu();
spin_lock(&client->lock); kfifo_free(&client->fifo); kfree(client);
spin_unlock(&client->lock);
return 0;
} @@ -247,11 +250,13 @@ int kfd_smi_event_open(struct kfd_dev *dev, uint32_t *fd) return ret; }
- spin_lock(&client->lock); ret = anon_inode_getfd(kfd_smi_name, &kfd_smi_ev_fops, (void *)client, O_RDWR); if (ret < 0) { kfifo_free(&client->fifo); kfree(client);
spin_unlock(&client->lock);@@ -264,6 +269,7 @@ int kfd_smi_event_open(struct kfd_dev *dev, uint32_t *fd) spin_lock(&dev->smi_lock); list_add_rcu(&client->list, &dev->smi_clients); spin_unlock(&dev->smi_lock);
spin_unlock(&client->lock);
return 0;
}