diff options
| author | Peter Zijlstra <[email protected]> | 2016-05-22 12:48:27 +0200 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-06-08 14:22:47 +0200 |
| commit | 331b6d8c7afc2e5b900b9dcd850c265e1ba8d8e7 (patch) | |
| tree | cf3060a9a96357e5f321e5ed28a5165717674f0d | |
| parent | a461d58792d4a46b8b10ae50973ec9b2763b694e (diff) | |
locking/barriers: Validate lockless_dereference() is used on a pointer type
Use the type to validate the argument @p is indeed a pointer type.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Paul McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | include/linux/compiler.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 793c0829e3a3..06f27fd9d760 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -545,10 +545,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s * Similar to rcu_dereference(), but for situations where the pointed-to * object's lifetime is managed by something other than RCU. That * "something other" might be reference counting or simple immortality. + * + * The seemingly unused void * variable is to validate @p is indeed a pointer + * type. All pointer types silently cast to void *. */ #define lockless_dereference(p) \ ({ \ typeof(p) _________p1 = READ_ONCE(p); \ + __maybe_unused const void * const _________p2 = _________p1; \ smp_read_barrier_depends(); /* Dependency order vs. p above. */ \ (_________p1); \ }) |