ACPI: pdc init related memory leak with physical CPU hotplug

arch_acpi_processor_cleanup_pdc() in x86 and ia64 results in memory allocated
for _PDC objects that is never freed and will cause memory leak in case of
physical CPU remove and add. Patch fixes the memory leak by freeing the
objects soon after _PDC is evaluated.

Reported-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

arch/ia64/kernel/acpi-processor.c

@@ -71,3 +71,15 @@ void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
 }
 
 EXPORT_SYMBOL(arch_acpi_processor_init_pdc);
+
+void arch_acpi_processor_cleanup_pdc(struct acpi_processor *pr)
+{
+	if (pr->pdc) {
+		kfree(pr->pdc->pointer->buffer.pointer);
+		kfree(pr->pdc->pointer);
+		kfree(pr->pdc);
+		pr->pdc = NULL;
+	}
+}
+
+EXPORT_SYMBOL(arch_acpi_processor_cleanup_pdc);

arch/x86/kernel/acpi/processor.c

@@ -72,6 +72,7 @@ static void init_intel_pdc(struct acpi_processor *pr, struct cpuinfo_x86 *c)
 	return;
 }
 
+
 /* Initialize _PDC data based on the CPU vendor */
 void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
 {
@@ -85,3 +86,15 @@ void arch_acpi_processor_init_pdc(struct acpi_processor *pr)
 }
 
 EXPORT_SYMBOL(arch_acpi_processor_init_pdc);
+
+void arch_acpi_processor_cleanup_pdc(struct acpi_processor *pr)
+{
+	if (pr->pdc) {
+		kfree(pr->pdc->pointer->buffer.pointer);
+		kfree(pr->pdc->pointer);
+		kfree(pr->pdc);
+		pr->pdc = NULL;
+	}
+}
+
+EXPORT_SYMBOL(arch_acpi_processor_cleanup_pdc);

drivers/acpi/processor_core.c

@@ -731,6 +731,8 @@ static int __cpuinit acpi_processor_start(struct acpi_device *device)
 	/* _PDC call should be done before doing anything else (if reqd.). */
 	arch_acpi_processor_init_pdc(pr);
 	acpi_processor_set_pdc(pr);
+	arch_acpi_processor_cleanup_pdc(pr);
+
 #ifdef CONFIG_CPU_FREQ
 	acpi_processor_ppc_has_changed(pr);
 #endif

include/acpi/processor.h

@@ -258,6 +258,7 @@ DECLARE_PER_CPU(struct acpi_processor *, processors);
 extern struct acpi_processor_errata errata;
 
 void arch_acpi_processor_init_pdc(struct acpi_processor *pr);
+void arch_acpi_processor_cleanup_pdc(struct acpi_processor *pr);
 
 #ifdef ARCH_HAS_POWER_INIT
 void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,