Re: [PATCH v3 1/5] arch_topology: validate input frequencies to arch_set_freq_scale()
From: Viresh Kumar <viresh.kumar@linaro.org>
Date: 2020-08-25 05:56:23
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On 24-08-20, 22:02, Ionela Voinescu wrote:
quoted hunk ↗ jump to hunk
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 <redacted> Cc: Sudeep Holla <redacted> Cc: Rafael J. Wysocki <redacted> --- 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..1aca82fcceb8 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 (!cur_freq || !max_freq)
We should probably use unlikely() here. Rafael: Shouldn't this have a WARN_ON_ONCE() as well ?
+ 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. -- 2.17.1
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