Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH kcsan 15/29] locking/barriers, kcsan: Support generic instrumentation | Date | Tue, 14 Dec 2021 14:04:25 -0800 |
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From: Marco Elver <elver@google.com>
Thus far only smp_*() barriers had been defined by asm-generic/barrier.h based on __smp_*() barriers, because the !SMP case is usually generic.
With the introduction of instrumentation, it also makes sense to have asm-generic/barrier.h assist in the definition of instrumented versions of mb(), rmb(), wmb(), dma_rmb(), and dma_wmb().
Because there is no requirement to distinguish the !SMP case, the definition can be simpler: we can avoid also providing fallbacks for the __ prefixed cases, and only check if `defined(__<barrier>)`, to finally define the KCSAN-instrumented versions.
This also allows for the compiler to complain if an architecture accidentally defines both the normal and __ prefixed variant.
Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- include/asm-generic/barrier.h | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+)
diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h index 27a9c9edfef66..02c4339c8eebf 100644 --- a/include/asm-generic/barrier.h +++ b/include/asm-generic/barrier.h @@ -21,6 +21,31 @@ #define nop() asm volatile ("nop") #endif +/* + * Architectures that want generic instrumentation can define __ prefixed + * variants of all barriers. + */ + +#ifdef __mb +#define mb() do { kcsan_mb(); __mb(); } while (0) +#endif + +#ifdef __rmb +#define rmb() do { kcsan_rmb(); __rmb(); } while (0) +#endif + +#ifdef __wmb +#define wmb() do { kcsan_wmb(); __wmb(); } while (0) +#endif + +#ifdef __dma_rmb +#define dma_rmb() do { kcsan_rmb(); __dma_rmb(); } while (0) +#endif + +#ifdef __dma_wmb +#define dma_wmb() do { kcsan_wmb(); __dma_wmb(); } while (0) +#endif + /* * Force strict CPU ordering. And yes, this is required on UP too when we're * talking to devices. -- 2.31.1.189.g2e36527f23
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