Messages in this thread Patch in this message | | | From | Yannick Fertré <> | Subject | [PATCH] drm/stm: ltdc: limit number of layer to avoid memory overflow | Date | Wed, 3 Apr 2019 11:20:16 +0200 |
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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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