Am 2022-01-25 um 13:04 schrieb Philip Yang:
SVM ioctls take proper svms->lock to handle race conditions, don't need
take process mutex to serialize ioctls. This also fixes circular locking
warning:
WARNING: possible circular locking dependency detected
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock((work_completion)(&svms->deferred_list_work));
lock(&process->mutex);
lock((work_completion)(&svms->deferred_list_work));
lock(&process->mutex);
*** DEADLOCK ***
Signed-off-by: Philip Yang <Philip.Yang@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
---
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 4 ----
1 file changed, 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 337953af7c2f..70122978bdd0 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1846,13 +1846,9 @@ static int kfd_ioctl_svm(struct file *filep, struct kfd_process *p, void *data)
if (!args->start_addr || !args->size)
return -EINVAL;
- mutex_lock(&p->mutex);
-
r = svm_ioctl(p, args->op, args->start_addr, args->size, args->nattr,
args->attrs);
- mutex_unlock(&p->mutex);
-
return r;
}
#else
