| Message ID | 9765491.cFa8AugBjT@kreacher (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | ACPI: processor: Avoid NULL pointer dereferences at init time | expand |
On 15-10-19, 19:35, Rafael J. Wysocki wrote: > rom: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > 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> > --- > drivers/acpi/processor_perflib.c | 10 ++++++---- > drivers/acpi/processor_thermal.c | 10 ++++++---- > 2 files changed, 12 insertions(+), 8 deletions(-) Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Index: linux-pm/drivers/acpi/processor_perflib.c =================================================================== --- linux-pm.orig/drivers/acpi/processor_perflib.c +++ linux-pm/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) Index: linux-pm/drivers/acpi/processor_thermal.c =================================================================== --- linux-pm.orig/drivers/acpi/processor_thermal.c +++ linux-pm/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)
rom: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 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> --- drivers/acpi/processor_perflib.c | 10 ++++++---- drivers/acpi/processor_thermal.c | 10 ++++++---- 2 files changed, 12 insertions(+), 8 deletions(-)