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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-10-15 19:35:20 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-10-16 13:02:45 +0200
commit2d8b39a62a5d386a73f339e46fe05354a3a4895b (patch)
tree278bb10df8488575ff7e8fb9d52cd09ebeda2180 /drivers/acpi/processor_thermal.c
parent65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 (diff)
ACPI: processor: Avoid NULL pointer dereferences at init time
If there are neither processor objects nor processor device objects in the ACPI tables, the per-CPU processors table will not be initialized and attempting to dereference pointers from there will cause the kernel to crash. This happens in acpi_processor_ppc_init() and acpi_thermal_cpufreq_init() after commit d15ce412737a ("ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier") which didn't add the requisite NULL pointer checks in there. Add the NULL pointer checks to acpi_processor_ppc_init() and acpi_thermal_cpufreq_init(), and to the corresponding "exit" routines. While at it, drop redundant return instructions from acpi_processor_ppc_init() and acpi_thermal_cpufreq_init(). Fixes: d15ce412737a ("ACPI: cpufreq: Switch to QoS requests instead of cpufreq notifier") Reported-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Diffstat (limited to 'drivers/acpi/processor_thermal.c')
-rw-r--r--drivers/acpi/processor_thermal.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/acpi/processor_thermal.c b/drivers/acpi/processor_thermal.c
index ec2638f1df4f..8227c7dd75b1 100644
--- a/drivers/acpi/processor_thermal.c
+++ b/drivers/acpi/processor_thermal.c
@@ -130,21 +130,23 @@ void acpi_thermal_cpufreq_init(int cpu)
struct acpi_processor *pr = per_cpu(processors, cpu);
int ret;
+ if (!pr)
+ return;
+
ret = dev_pm_qos_add_request(get_cpu_device(cpu),
&pr->thermal_req, DEV_PM_QOS_MAX_FREQUENCY,
INT_MAX);
- if (ret < 0) {
+ if (ret < 0)
pr_err("Failed to add freq constraint for CPU%d (%d)\n", cpu,
ret);
- return;
- }
}
void acpi_thermal_cpufreq_exit(int cpu)
{
struct acpi_processor *pr = per_cpu(processors, cpu);
- dev_pm_qos_remove_request(&pr->thermal_req);
+ if (pr)
+ dev_pm_qos_remove_request(&pr->thermal_req);
}
#else /* ! CONFIG_CPU_FREQ */
static int cpufreq_get_max_state(unsigned int cpu)