percpu: add preemption checks to __this_cpu ops

We define a check function in order to avoid trouble with the include
files.  Then the higher level __this_cpu macros are modified to invoke
the preemption check.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Christoph Lameter <cl@linux.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 29 insertions, 10 deletions

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index 4e4d2afcc0c7..e7a0b95ed527 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -173,6 +173,12 @@ extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
 
 extern void __bad_size_call_parameter(void);
 
+#ifdef CONFIG_DEBUG_PREEMPT
+extern void __this_cpu_preempt_check(const char *op);
+#else
+static inline void __this_cpu_preempt_check(const char *op) { }
+#endif
+
 #define __pcpu_size_call_return(stem, variable)				\
 ({	typeof(variable) pscr_ret__;					\
 	__verify_pcpu_ptr(&(variable));					\
@@ -725,18 +731,24 @@ do {									\
 
 /*
  * Generic percpu operations for context that are safe from preemption/interrupts.
- * Checks will be added here soon.
  */
 #ifndef __this_cpu_read
-# define __this_cpu_read(pcp)	__pcpu_size_call_return(raw_cpu_read_, (pcp))
+# define __this_cpu_read(pcp) \
+	(__this_cpu_preempt_check("read"),__pcpu_size_call_return(raw_cpu_read_, (pcp)))
 #endif
 
 #ifndef __this_cpu_write
-# define __this_cpu_write(pcp, val)	__pcpu_size_call(raw_cpu_write_, (pcp), (val))
+# define __this_cpu_write(pcp, val)					\
+do { __this_cpu_preempt_check("write");					\
+     __pcpu_size_call(raw_cpu_write_, (pcp), (val));			\
+} while (0)
 #endif
 
 #ifndef __this_cpu_add
-# define __this_cpu_add(pcp, val)	__pcpu_size_call(raw_cpu_add_, (pcp), (val))
+# define __this_cpu_add(pcp, val)					 \
+do { __this_cpu_preempt_check("add");					\
+	__pcpu_size_call(raw_cpu_add_, (pcp), (val));			\
+} while (0)
 #endif
 
 #ifndef __this_cpu_sub
@@ -752,16 +764,23 @@ do {									\
 #endif
 
 #ifndef __this_cpu_and
-# define __this_cpu_and(pcp, val)	__pcpu_size_call(raw_cpu_and_, (pcp), (val))
+# define __this_cpu_and(pcp, val)					\
+do { __this_cpu_preempt_check("and");					\
+	__pcpu_size_call(raw_cpu_and_, (pcp), (val));			\
+} while (0)
+
 #endif
 
 #ifndef __this_cpu_or
-# define __this_cpu_or(pcp, val)	__pcpu_size_call(raw_cpu_or_, (pcp), (val))
+# define __this_cpu_or(pcp, val)					\
+do { __this_cpu_preempt_check("or");					\
+	__pcpu_size_call(raw_cpu_or_, (pcp), (val));			\
+} while (0)
 #endif
 
 #ifndef __this_cpu_add_return
 # define __this_cpu_add_return(pcp, val)	\
-	__pcpu_size_call_return2(raw_cpu_add_return_, pcp, val)
+	(__this_cpu_preempt_check("add_return"),__pcpu_size_call_return2(raw_cpu_add_return_, pcp, val))
 #endif
 
 #define __this_cpu_sub_return(pcp, val)	__this_cpu_add_return(pcp, -(typeof(pcp))(val))
@@ -770,17 +789,17 @@ do {									\
 
 #ifndef __this_cpu_xchg
 # define __this_cpu_xchg(pcp, nval)	\
-	__pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval)
+	(__this_cpu_preempt_check("xchg"),__pcpu_size_call_return2(raw_cpu_xchg_, (pcp), nval))
 #endif
 
 #ifndef __this_cpu_cmpxchg
 # define __this_cpu_cmpxchg(pcp, oval, nval)	\
-	__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval)
+	(__this_cpu_preempt_check("cmpxchg"),__pcpu_size_call_return2(raw_cpu_cmpxchg_, pcp, oval, nval))
 #endif
 
 #ifndef __this_cpu_cmpxchg_double
 # define __this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)	\
-	__pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2))
+	(__this_cpu_preempt_check("cmpxchg_double"),__pcpu_double_call_return_bool(raw_cpu_cmpxchg_double_, (pcp1), (pcp2), (oval1), (oval2), (nval1), (nval2)))
 #endif
 
 #endif /* __LINUX_PERCPU_H */