diff options
| author | Rob Clark <robdclark@chromium.org> | 2021-03-31 18:27:20 -0700 |
|---|---|---|
| committer | Rob Clark <robdclark@chromium.org> | 2021-04-07 11:05:43 -0700 |
| commit | 6ed0897cd800c38b92a33d335d9086c7b092eb15 (patch) | |
| tree | 750784c11ed9a90dba54f4b45761a9558be05c29 /drivers/gpu/drm/msm/msm_gem.c | |
| parent | cc8a4d5a1bd84a37ff1827e2902c459e9b2d4e25 (diff) | |
drm/msm: Fix debugfs deadlock
In normal cases the gem obj lock is acquired first before mm_lock. The
exception is iterating the various object lists. In the shrinker path,
deadlock is avoided by using msm_gem_trylock() and skipping over objects
that cannot be locked. But for debugfs the straightforward thing is to
split things out into a separate list of all objects protected by it's
own lock.
Fixes: d984457b31c4 ("drm/msm: Add priv->mm_lock to protect active/inactive lists")
Signed-off-by: Rob Clark <robdclark@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20210401012722.527712-4-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
Diffstat (limited to 'drivers/gpu/drm/msm/msm_gem.c')
| -rw-r--r-- | drivers/gpu/drm/msm/msm_gem.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c index 156e4ecf9e60..b8dde5332750 100644 --- a/drivers/gpu/drm/msm/msm_gem.c +++ b/drivers/gpu/drm/msm/msm_gem.c @@ -961,7 +961,7 @@ void msm_gem_describe_objects(struct list_head *list, struct seq_file *m) size_t size = 0; seq_puts(m, " flags id ref offset kaddr size madv name\n"); - list_for_each_entry(msm_obj, list, mm_list) { + list_for_each_entry(msm_obj, list, node) { struct drm_gem_object *obj = &msm_obj->base; seq_puts(m, " "); msm_gem_describe(obj, m); @@ -980,6 +980,10 @@ void msm_gem_free_object(struct drm_gem_object *obj) struct drm_device *dev = obj->dev; struct msm_drm_private *priv = dev->dev_private; + mutex_lock(&priv->obj_lock); + list_del(&msm_obj->node); + mutex_unlock(&priv->obj_lock); + mutex_lock(&priv->mm_lock); if (msm_obj->dontneed) mark_unpurgable(msm_obj); @@ -1169,6 +1173,10 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev, list_add_tail(&msm_obj->mm_list, &priv->inactive_willneed); mutex_unlock(&priv->mm_lock); + mutex_lock(&priv->obj_lock); + list_add_tail(&msm_obj->node, &priv->objects); + mutex_unlock(&priv->obj_lock); + return obj; fail: @@ -1239,6 +1247,10 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev, list_add_tail(&msm_obj->mm_list, &priv->inactive_willneed); mutex_unlock(&priv->mm_lock); + mutex_lock(&priv->obj_lock); + list_add_tail(&msm_obj->node, &priv->objects); + mutex_unlock(&priv->obj_lock); + return obj; fail: |