From: "Yannick Fertré" <yannick.fertre@st.com>
To: Yannick Fertre <yannick.fertre@st.com>,
Philippe Cornu <philippe.cornu@st.com>,
Benjamin Gaignard <benjamin.gaignard@st.com>,
Vincent Abriou <vincent.abriou@st.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Maxime Coquelin <mcoquelin.stm32@gmail.com>,
Alexandre Torgue <alexandre.torgue@st.com>,
dri-devel@lists.freedesktop.org,
linux-stm32@st-md-mailman.stormreply.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] drm/stm: ltdc: limit number of layer to avoid memory overflow
Date: Wed, 3 Apr 2019 11:20:16 +0200 [thread overview]
Message-ID: <1554283216-2700-1-git-send-email-yannick.fertre@st.com> (raw)
If the number of layer is greater than LTDC_MAX_LAYER, we can have
memory overflow when reading plane_fpsi[].
Signed-off-by: Yannick Fertré <yannick.fertre@st.com>
---
drivers/gpu/drm/stm/ltdc.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c
index 32fd6a3..05bd4b6 100644
--- a/drivers/gpu/drm/stm/ltdc.c
+++ b/drivers/gpu/drm/stm/ltdc.c
@@ -1021,10 +1021,13 @@ static int ltdc_get_caps(struct drm_device *ddev)
struct ltdc_device *ldev = ddev->dev_private;
u32 bus_width_log2, lcr, gc2r;
- /* at least 1 layer must be managed */
+ /*
+ * at least 1 layer must be managed & the number of layers
+ * must not exceed LTDC_MAX_LAYER
+ */
lcr = reg_read(ldev->regs, LTDC_LCR);
- ldev->caps.nb_layers = max_t(int, lcr, 1);
+ ldev->caps.nb_layers = clamp((int)lcr, 1, LTDC_MAX_LAYER);
/* set data bus width */
gc2r = reg_read(ldev->regs, LTDC_GC2R);
--
2.7.4
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next reply other threads:[~2019-04-03 9:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-03 9:20 Yannick Fertré [this message]
2019-04-05 16:30 ` [PATCH] drm/stm: ltdc: limit number of layer to avoid memory overflow Philippe CORNU
2019-04-24 12:28 ` Benjamin Gaignard
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