summaryrefslogtreecommitdiff
path: root/include/linux/compiler.h
diff options
context:
space:
mode:
authorRussell King <rmk+kernel@armlinux.org.uk>2016-10-06 08:56:43 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2016-10-06 08:56:43 +0100
commit301a36fa700f9add6e14f5a95c7573e01578343a (patch)
tree6ff94ff3b08b838353b9127eb5f8055b3de6b25f /include/linux/compiler.h
parentb828f960215f02e5d2c88bbd27565c694254a15a (diff)
parentb60752f2b20c167859943e001727f0d4da419b23 (diff)
Merge branches 'misc' and 'sa1111-base' into for-linus
Diffstat (limited to 'include/linux/compiler.h')
-rw-r--r--include/linux/compiler.h7
1 files changed, 4 insertions, 3 deletions
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 1bb954842725..668569844d37 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -527,13 +527,14 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
* 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 *.
+ * The seemingly unused variable ___typecheck_p validates that @p is
+ * indeed a pointer type by using a pointer to typeof(*p) as the type.
+ * Taking a pointer to typeof(*p) again is needed in case p is void *.
*/
#define lockless_dereference(p) \
({ \
typeof(p) _________p1 = READ_ONCE(p); \
- __maybe_unused const void * const _________p2 = _________p1; \
+ typeof(*(p)) *___typecheck_p __maybe_unused; \
smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
(_________p1); \
})