[PATCH drm-misc-next 1/8] drm/arm/malidp: use drmm_* to allocate driver structures

Danilo Krummrich dakr at redhat.com
Fri Aug 19 21:20:08 UTC 2022


Use drm managed resources to allocate driver structures and get rid of
the deprecated drm_dev_alloc() call and replace it with
devm_drm_dev_alloc().

This also serves as preparation to get rid of drm_device->dev_private
and to fix use-after-free issues on driver unload.

Signed-off-by: Danilo Krummrich <dakr at redhat.com>
---
 drivers/gpu/drm/arm/malidp_drv.c | 20 +++++++-------------
 drivers/gpu/drm/arm/malidp_drv.h |  1 +
 2 files changed, 8 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index 1d0b0c54ccc7..41c80e905991 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -23,6 +23,7 @@
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem_dma_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_module.h>
 #include <drm/drm_of.h>
@@ -716,11 +717,13 @@ static int malidp_bind(struct device *dev)
 	int ret = 0, i;
 	u32 version, out_depth = 0;
 
-	malidp = devm_kzalloc(dev, sizeof(*malidp), GFP_KERNEL);
-	if (!malidp)
-		return -ENOMEM;
+	malidp = devm_drm_dev_alloc(dev, &malidp_driver, typeof(*malidp), base);
+	if (IS_ERR(malidp))
+		return PTR_ERR(malidp);
+
+	drm = &malidp->base;
 
-	hwdev = devm_kzalloc(dev, sizeof(*hwdev), GFP_KERNEL);
+	hwdev = drmm_kzalloc(drm, sizeof(*hwdev), GFP_KERNEL);
 	if (!hwdev)
 		return -ENOMEM;
 
@@ -753,12 +756,6 @@ static int malidp_bind(struct device *dev)
 	if (ret && ret != -ENODEV)
 		return ret;
 
-	drm = drm_dev_alloc(&malidp_driver, dev);
-	if (IS_ERR(drm)) {
-		ret = PTR_ERR(drm);
-		goto alloc_fail;
-	}
-
 	drm->dev_private = malidp;
 	dev_set_drvdata(dev, drm);
 
@@ -887,8 +884,6 @@ static int malidp_bind(struct device *dev)
 		malidp_runtime_pm_suspend(dev);
 	drm->dev_private = NULL;
 	dev_set_drvdata(dev, NULL);
-	drm_dev_put(drm);
-alloc_fail:
 	of_reserved_mem_device_release(dev);
 
 	return ret;
@@ -917,7 +912,6 @@ static void malidp_unbind(struct device *dev)
 		malidp_runtime_pm_suspend(dev);
 	drm->dev_private = NULL;
 	dev_set_drvdata(dev, NULL);
-	drm_dev_put(drm);
 	of_reserved_mem_device_release(dev);
 }
 
diff --git a/drivers/gpu/drm/arm/malidp_drv.h b/drivers/gpu/drm/arm/malidp_drv.h
index cdfddfabf2d1..00be369b28f1 100644
--- a/drivers/gpu/drm/arm/malidp_drv.h
+++ b/drivers/gpu/drm/arm/malidp_drv.h
@@ -29,6 +29,7 @@ struct malidp_error_stats {
 };
 
 struct malidp_drm {
+	struct drm_device base;
 	struct malidp_hw_device *dev;
 	struct drm_crtc crtc;
 	struct drm_writeback_connector mw_connector;
-- 
2.37.2



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