acpi: Validate processor id when mapping the processor

When we want to identify whether the proc_id is unreasonable or not, we
can call the "acpi_processor_validate_proc_id" function. It will search
in the duplicate IDs. If we find the proc_id in the IDs, we return true
to the call function. Conversely, the false represents available.

When we establish all possible cpuid <-> nodeid mapping to handle the
cpu hotplugs, we will use the proc_id from ACPI table.

We do validation when we get the proc_id. If the result is true, we
will stop the mapping.

[ tglx: Mark the new function __init ]
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: mika.j.penttila@gmail.com
Cc: len.brown@intel.com
Cc: rafael@kernel.org
Cc: rjw@rjwysocki.net
Cc: yasu.isimatu@gmail.com
Cc: linux-mm@kvack.org
Cc: linux-acpi@vger.kernel.org
Cc: isimatu.yasuaki@jp.fujitsu.com
Cc: gongzhaogang@inspur.com
Cc: tj@kernel.org
Cc: izumi.taku@jp.fujitsu.com
Cc: cl@linux.com
Cc: chen.tang@easystack.cn
Cc: akpm@linux-foundation.org
Cc: kamezawa.hiroyu@jp.fujitsu.com
Cc: lenb@kernel.org
Link: http://lkml.kernel.org/r/1472114120-3281-8-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

drivers/acpi/acpi_processor.c

@@ -659,6 +659,21 @@ static void __init acpi_processor_check_duplicates(void)
 						NULL, NULL, NULL);
 }
 
+bool __init acpi_processor_validate_proc_id(int proc_id)
+{
+	int i;
+
+	/*
+	 * compare the proc_id with duplicate IDs, if the proc_id is already
+	 * in the duplicate IDs, return true, otherwise, return false.
+	 */
+	for (i = 0; i < nr_duplicate_ids; i++) {
+		if (duplicate_processor_ids[i] == proc_id)
+			return true;
+	}
+	return false;
+}
+
 void __init acpi_processor_init(void)
 {
 	acpi_processor_check_duplicates();

drivers/acpi/processor_core.c

@@ -302,6 +302,10 @@ map_processor(acpi_handle handle, phys_cpuid_t *phys_id, int *cpuid)
 		if (ACPI_FAILURE(status))
 			return false;
 		acpi_id = object.processor.proc_id;
+
+		/* validate the acpi_id */
+		if(acpi_processor_validate_proc_id(acpi_id))
+			return false;
 		break;
 	case ACPI_TYPE_DEVICE:
 		status = acpi_evaluate_integer(handle, "_UID", NULL, &tmp);

include/linux/acpi.h

@@ -267,6 +267,9 @@ static inline bool invalid_phys_cpuid(phys_cpuid_t phys_id)
 	return phys_id == PHYS_CPUID_INVALID;
 }
 
+/* Validate the processor object's proc_id */
+bool acpi_processor_validate_proc_id(int proc_id);
+
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 /* Arch dependent functions for cpu hotplug support */
 int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu);