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: Danilo Krummrich <dakr@redhat.com>, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH RESEND drm-misc-next 7/7] drm/arm/hdlcd: debugfs: protect device resources after removal Date: Mon, 5 Sep 2022 17:27:19 +0200 [thread overview] Message-ID: <20220905152719.128539-8-dakr@redhat.com> (raw) In-Reply-To: <20220905152719.128539-1-dakr@redhat.com> (Hardware) resources which are bound to the driver and device lifecycle must not be accessed after the device and driver are unbound. However, the DRM device isn't freed as long as the last user didn't close it, hence userspace can still call into the driver. Therefore protect the critical sections which are accessing those resources with drm_dev_enter() and drm_dev_exit(). Signed-off-by: Danilo Krummrich <dakr@redhat.com> --- drivers/gpu/drm/arm/hdlcd_drv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c index e41def6d47cc..020c7d0c70a5 100644 --- a/drivers/gpu/drm/arm/hdlcd_drv.c +++ b/drivers/gpu/drm/arm/hdlcd_drv.c @@ -204,11 +204,19 @@ static int hdlcd_show_pxlclock(struct seq_file *m, void *arg) struct drm_info_node *node = (struct drm_info_node *)m->private; struct drm_device *drm = node->minor->dev; struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm); - unsigned long clkrate = clk_get_rate(hdlcd->clk); - unsigned long mode_clock = hdlcd->crtc.mode.crtc_clock * 1000; + unsigned long clkrate, mode_clock; + int idx; + + if (!drm_dev_enter(drm, &idx)) + return -ENODEV; + + clkrate = clk_get_rate(hdlcd->clk); + mode_clock = hdlcd->crtc.mode.crtc_clock * 1000; seq_printf(m, "hw : %lu\n", clkrate); seq_printf(m, "mode: %lu\n", mode_clock); + + drm_dev_exit(idx); return 0; } -- 2.37.2
WARNING: multiple messages have this Message-ID (diff)
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 RESEND drm-misc-next 7/7] drm/arm/hdlcd: debugfs: protect device resources after removal Date: Mon, 5 Sep 2022 17:27:19 +0200 [thread overview] Message-ID: <20220905152719.128539-8-dakr@redhat.com> (raw) In-Reply-To: <20220905152719.128539-1-dakr@redhat.com> (Hardware) resources which are bound to the driver and device lifecycle must not be accessed after the device and driver are unbound. However, the DRM device isn't freed as long as the last user didn't close it, hence userspace can still call into the driver. Therefore protect the critical sections which are accessing those resources with drm_dev_enter() and drm_dev_exit(). Signed-off-by: Danilo Krummrich <dakr@redhat.com> --- drivers/gpu/drm/arm/hdlcd_drv.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/arm/hdlcd_drv.c b/drivers/gpu/drm/arm/hdlcd_drv.c index e41def6d47cc..020c7d0c70a5 100644 --- a/drivers/gpu/drm/arm/hdlcd_drv.c +++ b/drivers/gpu/drm/arm/hdlcd_drv.c @@ -204,11 +204,19 @@ static int hdlcd_show_pxlclock(struct seq_file *m, void *arg) struct drm_info_node *node = (struct drm_info_node *)m->private; struct drm_device *drm = node->minor->dev; struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm); - unsigned long clkrate = clk_get_rate(hdlcd->clk); - unsigned long mode_clock = hdlcd->crtc.mode.crtc_clock * 1000; + unsigned long clkrate, mode_clock; + int idx; + + if (!drm_dev_enter(drm, &idx)) + return -ENODEV; + + clkrate = clk_get_rate(hdlcd->clk); + mode_clock = hdlcd->crtc.mode.crtc_clock * 1000; seq_printf(m, "hw : %lu\n", clkrate); seq_printf(m, "mode: %lu\n", mode_clock); + + drm_dev_exit(idx); return 0; } -- 2.37.2
next prev parent reply other threads:[~2022-09-05 15:28 UTC|newest] Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-09-05 15:27 [PATCH RESEND drm-misc-next 0/7] drm/arm/hdlcd: use drm managed resources Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 1/7] drm/arm/hdlcd: use drmm_* to allocate driver structures Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 2/7] drm/arm/hdlcd: replace drm->dev_private with drm_to_hdlcd_priv() Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 3/7] drm/arm/hdlcd: crtc: use drmm_crtc_init_with_planes() Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 4/7] drm/arm/hdlcd: plane: use drm managed resources Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-12 17:36 ` Liviu Dudau 2022-09-12 17:36 ` Liviu Dudau 2022-09-12 19:50 ` Danilo Krummrich 2022-09-12 19:50 ` Danilo Krummrich 2022-09-13 8:58 ` Liviu Dudau 2022-09-13 8:58 ` Liviu Dudau 2022-09-13 22:03 ` Danilo Krummrich 2022-09-13 22:03 ` Danilo Krummrich 2022-09-26 13:38 ` Liviu Dudau 2022-09-26 13:38 ` Liviu Dudau 2022-09-30 16:56 ` Liviu Dudau 2022-09-30 16:56 ` Liviu Dudau 2022-10-01 1:03 ` Danilo Krummrich 2022-10-01 1:03 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 5/7] drm/arm/hdlcd: use drm_dev_unplug() Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 6/7] drm/arm/hdlcd: crtc: protect device resources after removal Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich 2022-09-05 15:27 ` Danilo Krummrich [this message] 2022-09-05 15:27 ` [PATCH RESEND drm-misc-next 7/7] drm/arm/hdlcd: debugfs: " Danilo Krummrich
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