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From: Danilo Krummrich <dakr@redhat.com>
To: daniel@ffwll.ch, airlied@linux.ie, tzimmermann@suse.de,
	mripard@kernel.org, liviu.dudau@arm.com, brian.starkey@arm.com
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
	Danilo Krummrich <dakr@redhat.com>
Subject: [PATCH drm-misc-next 5/8] drm/arm/malidp: use drm_dev_unplug()
Date: Fri, 19 Aug 2022 23:24:42 +0200	[thread overview]
Message-ID: <20220819212445.559790-3-dakr@redhat.com> (raw)
In-Reply-To: <20220819212015.556220-1-dakr@redhat.com>

When the driver is unbound, there might still be users in userspace
having an open fd and are calling into the driver.

While this is fine for drm managed resources, it is not for resources
bound to the device/driver lifecycle, e.g. clocks or MMIO mappings.

To prevent use-after-free issues we need to protect those resources with
drm_dev_enter() and drm_dev_exit(). This does only work if we indicate
that the drm device was unplugged, hence use drm_dev_unplug() instead of
drm_dev_unregister().

Protecting the particular resources with drm_dev_enter()/drm_dev_exit()
is handled by subsequent patches.

Signed-off-by: Danilo Krummrich <dakr@redhat.com>
---
 drivers/gpu/drm/arm/malidp_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/arm/malidp_drv.c b/drivers/gpu/drm/arm/malidp_drv.c
index 678c5b0d8014..aedd30f5f451 100644
--- a/drivers/gpu/drm/arm/malidp_drv.c
+++ b/drivers/gpu/drm/arm/malidp_drv.c
@@ -893,7 +893,7 @@ static void malidp_unbind(struct device *dev)
 	struct malidp_drm *malidp = drm_to_malidp(drm);
 	struct malidp_hw_device *hwdev = malidp->dev;
 
-	drm_dev_unregister(drm);
+	drm_dev_unplug(drm);
 	drm_kms_helper_poll_fini(drm);
 	pm_runtime_get_sync(dev);
 	drm_atomic_helper_shutdown(drm);
-- 
2.37.2


  parent reply	other threads:[~2022-08-19 21:25 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-19 21:20 [PATCH drm-misc-next 0/8] drm/arm/malidp: use drm managed resources Danilo Krummrich
2022-08-19 21:20 ` [PATCH drm-misc-next 1/8] drm/arm/malidp: use drmm_* to allocate driver structures Danilo Krummrich
2022-08-19 21:20 ` [PATCH drm-misc-next 2/8] drm/arm/malidp: replace drm->dev_private with drm_to_malidp() Danilo Krummrich
2022-08-19 21:24 ` [PATCH drm-misc-next 3/8] drm/arm/malidp: crtc: use drmm_crtc_init_with_planes() Danilo Krummrich
2022-08-19 21:24 ` [PATCH drm-misc-next 4/8] drm/arm/malidp: plane: use drm managed resources Danilo Krummrich
2022-08-19 21:24 ` Danilo Krummrich [this message]
2022-08-19 21:24 ` [PATCH drm-misc-next 6/8] drm/arm/malidp: plane: protect device resources after removal Danilo Krummrich
2022-08-19 21:25 ` [PATCH drm-misc-next 7/8] drm/arm/malidp: crtc: " Danilo Krummrich
2022-08-19 21:25 ` [PATCH drm-misc-next 8/8] drm/arm/malidp: drv: " Danilo Krummrich

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