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authorAl Viro <viro@zeniv.linux.org.uk>2016-10-10 23:02:51 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2016-10-10 23:02:51 -0400
commit3873691e5ab34fa26948643d038a2b98c4437298 (patch)
tree5327469194c2167830bce38b56a618b754cdbeea /include/linux/compiler.h
parentfs: Replace current_fs_time() with current_time() (diff)
parentvfs: add note about i_op->rename changes to porting (diff)
downloadlinux-dev-3873691e5ab34fa26948643d038a2b98c4437298.tar.xz
linux-dev-3873691e5ab34fa26948643d038a2b98c4437298.zip
Merge remote-tracking branch 'ovl/rename2' 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 436aa4e42221..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 size_t variable is to validate @p is indeed a pointer
- * type by making sure it can be dereferenced.
+ * 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); \
- size_t __maybe_unused __size_of_ptr = sizeof(*(p)); \
+ typeof(*(p)) *___typecheck_p __maybe_unused; \
smp_read_barrier_depends(); /* Dependency order vs. p above. */ \
(_________p1); \
})