locking/barriers, kcsan: Support generic instrumentation

[ Upstream commit 2505a51ac6f249956735e0a369e2404f96eebef0 ]

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>
Stable-dep-of: aa6956150f82 ("wifi: ath11k: fix dest ring-buffer corruption when ring is full")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/asm-generic/barrier.h b/include/asm-generic/barrier.h
index 640f09479bdf7984799d7ecdf40d7da17d83e26c..05aae292248563485ed38bce03677adb5b4dadb2 100644 (file)
--- a/include/asm-generic/barrier.h
+++ b/include/asm-generic/barrier.h
@@ -20,6 +20,31 @@
 #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.