On 17/06/2017 12:57, Chris Wilson wrote:
As we walk the obj->vma_list in per_file_stats(), we need to hold
struct_mutex to prevent alteration of that list.
Fixes: 1d2ac403ae3b ("drm: Protect dev->filelist with its own mutex")
Fixes: c84455b4bacc ("drm/i915: Move debug only per-request pid tracking from request to ctx")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101460
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_debugfs.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4577b0af6886..3f44076ec8a0 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -292,6 +292,8 @@ static int per_file_stats(int id, void *ptr, void *data)
struct file_stats *stats = data;
struct i915_vma *vma;
+ lockdep_assert_held(&obj->base.dev->struct_mutex);
+
stats->count++;
stats->total += obj->base.size;
if (!obj->bind_count)
@@ -476,6 +478,8 @@ static int i915_gem_object_info(struct seq_file *m, void *data)
struct drm_i915_gem_request *request;
struct task_struct *task;
+ mutex_lock(&dev->struct_mutex);
Could have put it just before the spin_lock for maximum OCD but doesn't
matter. ;)
+
memset(&stats, 0, sizeof(stats));
stats.file_priv = file->driver_priv;
spin_lock(&file->table_lock);
@@ -487,7 +491,6 @@ static int i915_gem_object_info(struct seq_file *m, void *data)
* still alive (e.g. get_pid(current) => fork() => exit()).
* Therefore, we need to protect this ->comm access using RCU.
*/
- mutex_lock(&dev->struct_mutex);
request = list_first_entry_or_null(&file_priv->mm.request_list,
struct drm_i915_gem_request,
client_link);
@@ -497,6 +500,7 @@ static int i915_gem_object_info(struct seq_file *m, void *data)
PIDTYPE_PID);
print_file_stats(m, task ? task->comm : "<unknown>", stats);
rcu_read_unlock();
+
mutex_unlock(&dev->struct_mutex);
}
mutex_unlock(&dev->filelist_mutex);
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
Regards,
Tvrtko
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
