drm/arm/malidp: use drmm_* to allocate driver structures

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@redhat.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221026155934.125294-2-dakr@redhat.com

diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index b734dbd..3ee5d67 100644 (file)
--- 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 @@ query_hw_fail:
                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 cdfddfa..00be369 100644 (file)
--- 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;