diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-10-15 20:35:20 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-10-16 14:02:45 +0300 |
| commit | 2d8b39a62a5d386a73f339e46fe05354a3a4895b (patch) | |
| tree | 278bb10df8488575ff7e8fb9d52cd09ebeda2180 /drivers/acpi/processor_perflib.c | |
| parent | 65650b35133ff20f0c9ef0abd5c3c66dbce3ae57 (diff) | |
| download | linux-2d8b39a62a5d386a73f339e46fe05354a3a4895b.tar.xz | |
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_perflib.c')
| -rw-r--r-- | drivers/acpi/processor_perflib.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 2261713d1aec..930a49fa4dfc 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -162,21 +162,23 @@ void acpi_processor_ppc_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->perflib_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_processor_ppc_exit(int cpu) { struct acpi_processor *pr = per_cpu(processors, cpu); - dev_pm_qos_remove_request(&pr->perflib_req); + if (pr) + dev_pm_qos_remove_request(&pr->perflib_req); } static int acpi_processor_get_performance_control(struct acpi_processor *pr) |