interconnect: qcom: msm8974: Prevent integer overflow in rate

When sync_state support got introduced recently, by default we try to
set the NoCs to run initially at maximum rate. But as these values are
aggregated, we may end with a really big clock rate value, which is
then converted from "u64" to "long" during the clock rate rounding.
But on 32bit platforms this may result an overflow. Fix it by making
sure that the rate is within range.

Reported-by: Luca Weiss <luca@z3ntu.xyz>
Reviewed-by: Brian Masney <masneyb@onstation.org>
Link: https://lore.kernel.org/r/20201106144847.7726-1-georgi.djakov@linaro.org
Signed-off-by: Georgi Djakov <georgi.djakov@linaro.org>

diff --git a/drivers/interconnect/qcom/msm8974.c b/drivers/interconnect/qcom/msm8974.c
index 3a313e1..b6b639d 100644 (file)
--- a/drivers/interconnect/qcom/msm8974.c
+++ b/drivers/interconnect/qcom/msm8974.c
@@ -618,6 +618,8 @@ static int msm8974_icc_set(struct icc_node *src, struct icc_node *dst)
 
        do_div(rate, src_qn->buswidth);
 
+       rate = min_t(u32, rate, INT_MAX);
+
        if (src_qn->rate == rate)
                return 0;
 
@@ -758,6 +760,7 @@ static struct platform_driver msm8974_noc_driver = {
        .driver = {
                .name = "qnoc-msm8974",
                .of_match_table = msm8974_noc_of_match,
+               .sync_state = icc_sync_state,
        },
 };
 module_platform_driver(msm8974_noc_driver);