linux_dsm_epyc7002/kernel/kcsan/atomic.h
Marco Elver 44656d3dc4 kcsan: Add current->state to implicitly atomic accesses
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>
2020-03-25 09:56:00 -07:00

21 lines
608 B
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _KERNEL_KCSAN_ATOMIC_H
#define _KERNEL_KCSAN_ATOMIC_H
#include <linux/jiffies.h>
#include <linux/sched.h>
/*
* Special rules for certain memory where concurrent conflicting accesses are
* common, however, the current convention is to not mark them; returns true if
* access to @ptr should be considered atomic. Called from slow-path.
*/
static bool kcsan_is_atomic_special(const volatile void *ptr)
{
/* volatile globals that have been observed in data races. */
return ptr == &jiffies || ptr == &current->state;
}
#endif /* _KERNEL_KCSAN_ATOMIC_H */