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Date:   Tue, 16 Jun 2020 14:36:24 +0200
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Subject: [PATCH 3/4] kcsan: Remove existing special atomic rules
From:   Marco Elver <elver@google.com>
To:     elver@google.com, paulmck@kernel.org
Cc:     dvyukov@google.com, kasan-dev@googlegroups.com,
        linux-kernel@vger.kernel.org
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Sender: linux-kernel-owner@vger.kernel.org
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Remove existing special atomic rules from kcsan_is_atomic_special()
because they are no longer needed. Since we rely on the compiler
emitting instrumentation distinguishing volatile accesses, the rules
have become redundant.

Let's keep kcsan_is_atomic_special() around, so that we have an obvious
place to add special rules should the need arise in future.

Signed-off-by: Marco Elver <elver@google.com>
---
 kernel/kcsan/atomic.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h
index be9e625227f3..75fe701f4127 100644
--- a/kernel/kcsan/atomic.h
+++ b/kernel/kcsan/atomic.h
@@ -3,8 +3,7 @@
 #ifndef _KERNEL_KCSAN_ATOMIC_H
 #define _KERNEL_KCSAN_ATOMIC_H
 
-#include <linux/jiffies.h>
-#include <linux/sched.h>
+#include <linux/types.h>
 
 /*
  * Special rules for certain memory where concurrent conflicting accesses are
@@ -13,8 +12,7 @@
  */
 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;
+	return false;
 }
 
 #endif /* _KERNEL_KCSAN_ATOMIC_H */
-- 
2.27.0.290.gba653c62da-goog