1 files changed, 26 insertions, 14 deletions

diff --git a/mm/percpu.c b/mm/percpu.c
index 60a6488e9e6d..e0aa8ae7bde7 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1284,18 +1284,7 @@ void free_percpu(void __percpu *ptr)
 }
 EXPORT_SYMBOL_GPL(free_percpu);
 
-/**
- * is_kernel_percpu_address - test whether address is from static percpu area
- * @addr: address to test
- *
- * Test whether @addr belongs to in-kernel static percpu area.  Module
- * static percpu areas are not considered.  For those, use
- * is_module_percpu_address().
- *
- * RETURNS:
- * %true if @addr is from in-kernel static percpu area, %false otherwise.
- */
-bool is_kernel_percpu_address(unsigned long addr)
+bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr)
 {
 #ifdef CONFIG_SMP
         const size_t static_size = __per_cpu_end - __per_cpu_start;
@@ -1304,16 +1293,39 @@ bool is_kernel_percpu_address(unsigned long addr)
 
         for_each_possible_cpu(cpu) {
                 void *start = per_cpu_ptr(base, cpu);
+                void *va = (void *)addr;
 
-                if ((void *)addr >= start && (void *)addr < start + static_size)
+                if (va >= start && va < start + static_size) {
+                        if (can_addr) {
+                                *can_addr = (unsigned long) (va - start);
+                                *can_addr += (unsigned long)
+                                        per_cpu_ptr(base, get_boot_cpu_id());
+                        }
                         return true;
-        }
+                }
+        }
 #endif
         /* on UP, can't distinguish from other static vars, always false */
         return false;
 }
 
 /**
+ * is_kernel_percpu_address - test whether address is from static percpu area
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to in-kernel static percpu area.  Module
+ * static percpu areas are not considered.  For those, use
+ * is_module_percpu_address().
+ *
+ * RETURNS:
+ * %true if @addr is from in-kernel static percpu area, %false otherwise.
+ */
+bool is_kernel_percpu_address(unsigned long addr)
+{
+        return __is_kernel_percpu_address(addr, NULL);
+}
+
+/**
  * per_cpu_ptr_to_phys - convert translated percpu address to physical address
  * @addr: the address to be converted to physical address
  *