drm/i915: Hold struct_mutex for per-file stats in debugfs/i915_gem_object

As we walk the obj->vma_list in per_file_stats(), we need to hold
struct_mutex to prevent alteration of that list.

Fixes: 1d2ac403ae ("drm: Protect dev->filelist with its own mutex")
Fixes: c84455b4ba ("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@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170617115744.4452-1-chris@chris-wilson.co.uk
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
(cherry picked from commit 0caf81b5c5)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
This commit is contained in:
Chris Wilson 2017-06-17 12:57:44 +01:00 committed by Daniel Vetter
parent d8462d0ad3
commit 2c73676267

View file

@ -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);
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);