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

From: Danilo Krummrich
Date: Fri Aug 19 2022 - 17:20:46 EST


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@xxxxxxxxxx>
---
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