percpu, module: implement and use is_kernel/module_percpu_address()

lockdep has custom code to check whether a pointer belongs to static
percpu area which is somewhat broken.  Implement proper
is_kernel/module_percpu_address() and replace the custom code.

On UP, percpu variables are regular static variables and can't be
distinguished from them.  Always return %false on UP.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>

1 files changed, 5 insertions, 16 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index c927a549db2c..9bbb9c841e48 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -582,9 +582,6 @@ static int static_obj(void *obj)
         unsigned long start = (unsigned long) &_stext,
                       end   = (unsigned long) &_end,
                       addr  = (unsigned long) obj;
-#ifdef CONFIG_SMP
-        int i;
-#endif
 
         /*
          * static variable?
@@ -595,24 +592,16 @@ static int static_obj(void *obj)
         if (arch_is_kernel_data(addr))
                 return 1;
 
-#ifdef CONFIG_SMP
         /*
-         * percpu var?
+         * in-kernel percpu var?
          */
-        for_each_possible_cpu(i) {
-                start = (unsigned long) &__per_cpu_start + per_cpu_offset(i);
-                end   = (unsigned long) &__per_cpu_start + PERCPU_ENOUGH_ROOM
-                                        + per_cpu_offset(i);
-
-                if ((addr >= start) && (addr < end))
-                        return 1;
-        }
-#endif
+        if (is_kernel_percpu_address(addr))
+                return 1;
 
         /*
-         * module var?
+         * module static or percpu var?
          */
-        return is_module_address(addr);
+        return is_module_address(addr) || is_module_percpu_address(addr);
 }
 
 /*