[Xen-devel] [PATCH] powernow: implement struct cpufreq_driver.verify

["Jan Beulich" <jbeulich@xxxxxxxxxx>]

Without this, under rare conditions hypervisor crashes are possible due
to this method being called without checking against NULL.

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxxxx>

Index: 2008-11-20/xen/arch/x86/acpi/cpufreq/powernow.c
===================================================================
--- 2008-11-20.orig/xen/arch/x86/acpi/cpufreq/powernow.c        2008-11-05 
16:54:22.000000000 +0100
+++ 2008-11-20/xen/arch/x86/acpi/cpufreq/powernow.c     2008-12-03 
11:56:27.000000000 +0100
@@ -129,6 +129,16 @@ static int powernow_cpufreq_target(struc
     return result;
 }
 
+static int powernow_cpufreq_verify(struct cpufreq_policy *policy)
+{
+    struct powernow_cpufreq_data *data;
+
+    if (!policy || !(data = drv_data[policy->cpu]))
+        return -EINVAL;
+
+    return cpufreq_frequency_table_verify(policy, data->freq_table);
+}
+
 static int powernow_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
     unsigned int i;
@@ -243,6 +253,7 @@ static int powernow_cpufreq_cpu_exit(str
 }
 
 static struct cpufreq_driver powernow_cpufreq_driver = {
+    .verify = powernow_cpufreq_verify,
     .target = powernow_cpufreq_target,
     .init   = powernow_cpufreq_cpu_init,
     .exit   = powernow_cpufreq_cpu_exit




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