[PATCH v5 1/5] arch_topology: validate input frequencies to arch_set_freq_scale()

Ionela Voinescu ionela.voinescu at arm.com
Tue Sep 1 16:55:45 EDT 2020

The current frequency passed to arch_set_freq_scale() could end up
being 0, signaling an error in setting a new frequency. Also, if the
maximum frequency in 0, this will result in a division by 0 error.

Therefore, validate these input values before using them for the
setting of the frequency scale factor.

Signed-off-by: Ionela Voinescu <ionela.voinescu at arm.com>
Acked-by: Viresh Kumar <viresh.kumar at linaro.org>
Cc: Sudeep Holla <sudeep.holla at arm.com>
Cc: Rafael J. Wysocki <rjw at rjwysocki.net>
 drivers/base/arch_topology.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/base/arch_topology.c b/drivers/base/arch_topology.c
index 75f72d684294..42a08ef693ae 100644
--- a/drivers/base/arch_topology.c
+++ b/drivers/base/arch_topology.c
@@ -33,6 +33,9 @@ void arch_set_freq_scale(struct cpumask *cpus, unsigned long cur_freq,
 	unsigned long scale;
 	int i;
+	if (WARN_ON_ONCE(!cur_freq || !max_freq))
+		return;
 	 * If the use of counters for FIE is enabled, just return as we don't
 	 * want to update the scale factor with information from CPUFREQ.

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