linux/kernel/kcsan/atomic.h
Marco Elver dfd402a4c4 kcsan: Add Kernel Concurrency Sanitizer infrastructure
Kernel Concurrency Sanitizer (KCSAN) is a dynamic data-race detector for
kernel space. KCSAN is a sampling watchpoint-based data-race detector.
See the included Documentation/dev-tools/kcsan.rst for more details.

This patch adds basic infrastructure, but does not yet enable KCSAN for
any architecture.

Signed-off-by: Marco Elver <elver@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
2019-11-16 07:23:13 -08:00

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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _KERNEL_KCSAN_ATOMIC_H
#define _KERNEL_KCSAN_ATOMIC_H
#include <linux/jiffies.h>
/*
* Helper that returns true if access to ptr should be considered as an atomic
* access, even though it is not explicitly atomic.
*
* List all volatile globals that have been observed in races, to suppress
* data race reports between accesses to these variables.
*
* For now, we assume that volatile accesses of globals are as strong as atomic
* accesses (READ_ONCE, WRITE_ONCE cast to volatile). The situation is still not
* entirely clear, as on some architectures (Alpha) READ_ONCE/WRITE_ONCE do more
* than cast to volatile. Eventually, we hope to be able to remove this
* function.
*/
static inline bool kcsan_is_atomic(const volatile void *ptr)
{
/* only jiffies for now */
return ptr == &jiffies;
}
#endif /* _KERNEL_KCSAN_ATOMIC_H */