drm/msm: EBUSY status handling in msm_gem_fault()

Subsequent threads returning EBUSY from vm_insert_pfn() was not
handled correctly. As a result concurrent access from new threads
to mmapped data caused SIGBUS.

See e79e0fe3

Signed-off-by: Rob Clark <robdclark@gmail.com>
Acked-by: David Brown <davidb@codeaurora.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 291939de299e..e587d251c590 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -178,6 +178,11 @@ out:
         case 0:
         case -ERESTARTSYS:
         case -EINTR:
+        case -EBUSY:
+                /*
+                 * EBUSY is ok: this just means that another thread
+                 * already did the job.
+                 */
                 return VM_FAULT_NOPAGE;
         case -ENOMEM:
                 return VM_FAULT_OOM;