diff options
author | Ingo Molnar <mingo@kernel.org> | 2016-09-21 15:01:57 +0200 |
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committer | Ingo Molnar <mingo@kernel.org> | 2016-09-21 15:01:57 +0200 |
commit | 580498a23be1de55be55147eaee20a69249aeb13 (patch) | |
tree | 345f1a280812bf15969ae7097583b7dd59482636 /include/linux/compiler.h | |
parent | 3ec979658e5cc0fab86a42af79a650299e4d7135 (diff) | |
parent | 7d1e042314619115153a0f6f06e4552c09a50e13 (diff) |
Merge branch 'linus' into x86/boot, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/compiler.h')
-rw-r--r-- | include/linux/compiler.h | 7 |
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); \ }) |