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>

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 291939de299ee3204e328e7d0a1f51c205cba06f..e587d251c5900cd4532cdbff584d0683131616ed 100644 (file)
--- 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;