44656d3dc4
Add volatile current->state to list of implicitly atomic accesses. This is in preparation to eventually enable KCSAN on kernel/sched (which currently still has KCSAN_SANITIZE := n). Since accesses that match the special check in atomic.h are rare, it makes more sense to move this check to the slow-path, avoiding the additional compare in the fast-path. With the microbenchmark, a speedup of ~6% is measured. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
21 lines
608 B
C
21 lines
608 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _KERNEL_KCSAN_ATOMIC_H
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#define _KERNEL_KCSAN_ATOMIC_H
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#include <linux/jiffies.h>
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#include <linux/sched.h>
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/*
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* Special rules for certain memory where concurrent conflicting accesses are
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* common, however, the current convention is to not mark them; returns true if
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* access to @ptr should be considered atomic. Called from slow-path.
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*/
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static bool kcsan_is_atomic_special(const volatile void *ptr)
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{
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/* volatile globals that have been observed in data races. */
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return ptr == &jiffies || ptr == ¤t->state;
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}
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#endif /* _KERNEL_KCSAN_ATOMIC_H */
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