From: Jeff McGee <jeff.mc...@intel.com>

We are racing with updates to the timeline. This can cause an inconsistent
snapshot to be dumped, or even worse a NULL pointer dereference.

Signed-off-by: Jeff McGee <jeff.mc...@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 27 ++++++++++-----------------
 1 file changed, 10 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
b/drivers/gpu/drm/i915/i915_debugfs.c
index 0bb6e01121fc..135828fb1904 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -657,33 +657,26 @@ static void print_request(struct seq_file *m,
 static int i915_gem_request_info(struct seq_file *m, void *data)
 {
        struct drm_i915_private *dev_priv = node_to_i915(m->private);
-       struct drm_device *dev = &dev_priv->drm;
        struct drm_i915_gem_request *req;
        struct intel_engine_cs *engine;
        enum intel_engine_id id;
-       int ret, any;
-
-       ret = mutex_lock_interruptible(&dev->struct_mutex);
-       if (ret)
-               return ret;
+       int any = 0;
 
-       any = 0;
        for_each_engine(engine, dev_priv, id) {
-               int count;
+               int count = 0;
 
-               count = 0;
+               spin_lock_irq(&engine->timeline->lock);
                list_for_each_entry(req, &engine->timeline->requests, link)
                        count++;
-               if (count == 0)
-                       continue;
-
-               seq_printf(m, "%s requests: %d\n", engine->name, count);
-               list_for_each_entry(req, &engine->timeline->requests, link)
-                       print_request(m, req, "    ");
 
-               any++;
+               if (count) {
+                       seq_printf(m, "%s requests: %d\n", engine->name, count);
+                       list_for_each_entry(req, &engine->timeline->requests, 
link)
+                               print_request(m, req, "    ");
+                       any++;
+               }
+               spin_unlock_irq(&engine->timeline->lock);
        }
-       mutex_unlock(&dev->struct_mutex);
 
        if (any == 0)
                seq_puts(m, "No requests\n");
-- 
2.14.2

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to