On 29/09/2021 12:08, Colin King wrote:

From: Colin Ian King colin.king@canonical.com

In the case where clock is 2147485 or greater the 32 bit multiplication by 1000 will cause an integer overflow. Fix this by making the constant 1000 a long to ensure a long multiply occurs to avoid the overflow before assigning the result to the long result in variable requested. Most probably a theoretical overflow issue, but worth fixing.

Addresses-Coverity: ("Unintentional integer overflow") Fixes: 3e87599b68e7 ("drm/msm/mdp4: add LVDS panel support") Signed-off-by: Colin Ian King colin.king@canonical.com

---

drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c index 7288041dd86a..deada745d5b9 100644 --- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c +++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_connector.c @@ -64,7 +64,7 @@ static int mdp4_lvds_connector_mode_valid(struct drm_connector *connector, struct drm_encoder *encoder = mdp4_lvds_connector->encoder; long actual, requested;

• requested = 1000 * mode->clock;

• requested = 1000L * mode->clock; actual = mdp4_lcdc_round_pixclk(encoder, requested);

  DBG("requested=%ld, actual=%ld", requested, actual);

NACK: there are a few more occurrences of this in the msm driver, I'll fix them up for a V2.