[PATCH v4 3/3] drm/ingenic: Register devm action to cleanup encoders

From: Paul Cercueil
Date: Sat Mar 27 2021 - 07:58:27 EST


Since the encoders have been devm-allocated, they will be freed way
before drm_mode_config_cleanup() is called. To avoid use-after-free
conditions, we then must ensure that drm_encoder_cleanup() is called
before the encoders are freed.

v2: Use the new __drmm_simple_encoder_alloc() function

v3: Use the new drmm_plain_simple_encoder_alloc() macro

v4: Use drmm_plain_encoder_alloc() macro

Fixes: c369cb27c267 ("drm/ingenic: Support multiple panels/bridges")
Cc: <stable@xxxxxxxxxxxxxxx> # 5.8+
Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/ingenic/ingenic-drm-drv.c | 17 +++++++----------
1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
index d60e1eefc9d1..29742ec5ab95 100644
--- a/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
+++ b/drivers/gpu/drm/ingenic/ingenic-drm-drv.c
@@ -24,6 +24,7 @@
#include <drm/drm_crtc.h>
#include <drm/drm_crtc_helper.h>
#include <drm/drm_drv.h>
+#include <drm/drm_encoder.h>
#include <drm/drm_gem_cma_helper.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_fb_helper.h>
@@ -37,7 +38,6 @@
#include <drm/drm_plane.h>
#include <drm/drm_plane_helper.h>
#include <drm/drm_probe_helper.h>
-#include <drm/drm_simple_kms_helper.h>
#include <drm/drm_vblank.h>

struct ingenic_dma_hwdesc {
@@ -1024,20 +1024,17 @@ static int ingenic_drm_bind(struct device *dev, bool has_components)
bridge = devm_drm_panel_bridge_add_typed(dev, panel,
DRM_MODE_CONNECTOR_DPI);

- encoder = devm_kzalloc(dev, sizeof(*encoder), GFP_KERNEL);
- if (!encoder)
- return -ENOMEM;
+ encoder = drmm_plain_encoder_alloc(drm, NULL, DRM_MODE_ENCODER_DPI, NULL);
+ if (IS_ERR(encoder)) {
+ ret = PTR_ERR(encoder);
+ dev_err(dev, "Failed to init encoder: %d\n", ret);
+ return ret;
+ }

encoder->possible_crtcs = 1;

drm_encoder_helper_add(encoder, &ingenic_drm_encoder_helper_funcs);

- ret = drm_simple_encoder_init(drm, encoder, DRM_MODE_ENCODER_DPI);
- if (ret) {
- dev_err(dev, "Failed to init encoder: %d\n", ret);
- return ret;
- }
-
ret = drm_bridge_attach(encoder, bridge, NULL, 0);
if (ret) {
dev_err(dev, "Unable to attach bridge\n");
--
2.30.2