Commit 77756ad6 authored by Yannick Fertré's avatar Yannick Fertré Committed by Benjamin Gaignard
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drm/stm: ltdc: limit number of layer to avoid memory overflow 



If the number of layer is greater than LTDC_MAX_LAYER, we can have
memory overflow when reading plane_fpsi[].

Signed-off-by: default avatarYannick Fertré <yannick.fertre@st.com>
Acked-by: default avatarPhilippe Cornu <philippe.cornu@st.com>
Signed-off-by: default avatarBenjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1554283216-2700-1-git-send-email-yannick.fertre@st.com
parent 8ceb8568

drivers/gpu/drm/stm/ltdc.c

+5 −2
Original line number Diff line number Diff line
@@ -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);

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