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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Stephan Gerhold <stephan@gerhold.net>,
        Georgi Djakov <djakov@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.16 0752/1039] interconnect: qcom: rpm: Prevent integer overflow in rate
Date:   Mon, 24 Jan 2022 19:42:21 +0100
Message-Id: <20220124184150.612174636@linuxfoundation.org>
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From: Stephan Gerhold <stephan@gerhold.net>

[ Upstream commit a7d9436a6c85fcb8843c910fd323dcd7f839bf63 ]

Using icc-rpm on ARM32 currently results in clk_set_rate() errors during
boot, e.g. "bus clk_set_rate error: -22". This is very similar to commit
7381e27b1e56 ("interconnect: qcom: msm8974: Prevent integer overflow in rate")
where the u64 is converted to a signed long during clock rate rounding,
resulting in an overflow on 32-bit platforms.

Let's fix it similarly by making sure that the rate does not exceed
LONG_MAX. Such high clock rates will surely result in the maximum
frequency of the bus anyway.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20211206114542.45325-1-stephan@gerhold.net
Signed-off-by: Georgi Djakov <djakov@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/interconnect/qcom/icc-rpm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/interconnect/qcom/icc-rpm.c b/drivers/interconnect/qcom/icc-rpm.c
index ef7999a08c8bf..8114295a83129 100644
--- a/drivers/interconnect/qcom/icc-rpm.c
+++ b/drivers/interconnect/qcom/icc-rpm.c
@@ -239,6 +239,7 @@ static int qcom_icc_set(struct icc_node *src, struct icc_node *dst)
 	rate = max(sum_bw, max_peak_bw);
 
 	do_div(rate, qn->buswidth);
+	rate = min_t(u64, rate, LONG_MAX);
 
 	if (qn->rate == rate)
 		return 0;
-- 
2.34.1