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>

2 files changed, 8 insertions, 0 deletions

diff --git a/include/linux/module.h b/include/linux/module.h
index 87d247ac6761..f0e2659f4e3e 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -395,6 +395,7 @@ static inline int module_is_live(struct module *mod)
 struct module *__module_text_address(unsigned long addr);
 struct module *__module_address(unsigned long addr);
 bool is_module_address(unsigned long addr);
+bool is_module_percpu_address(unsigned long addr);
 bool is_module_text_address(unsigned long addr);
 
 static inline int within_module_core(unsigned long addr, struct module *mod)
diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index a93e5bfdccb8..11d5f834b54a 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -137,6 +137,7 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size,
 extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
 extern void __percpu *__alloc_percpu(size_t size, size_t align);
 extern void free_percpu(void __percpu *__pdata);
+extern bool is_kernel_percpu_address(unsigned long addr);
 extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 
 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
@@ -163,6 +164,12 @@ static inline void free_percpu(void __percpu *p)
         kfree(p);
 }
 
+/* can't distinguish from other static vars, always false */
+static inline bool is_kernel_percpu_address(unsigned long addr)
+{
+        return false;
+}
+
 static inline phys_addr_t per_cpu_ptr_to_phys(void *addr)
 {
         return __pa(addr);