Merge tag 'locking-debug-2021-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull memory model updates from Ingo Molnar:
 "LKMM updates:

   - Update documentation and code example

  KCSAN updates:

   - Introduce CONFIG_KCSAN_STRICT (which RCU uses)

   - Optimize use of get_ctx() by kcsan_found_watchpoint()

   - Rework atomic.h into permissive.h

   - Add the ability to ignore writes that change only one bit of a
     given data-racy variable.

   - Improve comments"

* tag 'locking-debug-2021-09-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools/memory-model: Document data_race(READ_ONCE())
  tools/memory-model: Heuristics using data_race() must handle all values
  tools/memory-model: Add example for heuristic lockless reads
  tools/memory-model: Make read_foo_diagnostic() more clearly diagnostic
  kcsan: Make strict mode imply interruptible watchers
  kcsan: permissive: Ignore data-racy 1-bit value changes
  kcsan: Print if strict or non-strict during init
  kcsan: Rework atomic.h into permissive.h
  kcsan: Reduce get_ctx() uses in kcsan_found_watchpoint()
  kcsan: Introduce CONFIG_KCSAN_STRICT
  kcsan: Remove CONFIG_KCSAN_DEBUG
  kcsan: Improve some Kconfig comments

1 files changed, 0 insertions, 23 deletions

diff --git a/kernel/kcsan/atomic.h b/kernel/kcsan/atomic.h
deleted file mode 100644
index 530ae1bda8e7..000000000000
--- a/kernel/kcsan/atomic.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Rules for implicitly atomic memory accesses.
- *
- * Copyright (C) 2019, Google LLC.
- */
-
-#ifndef _KERNEL_KCSAN_ATOMIC_H
-#define _KERNEL_KCSAN_ATOMIC_H
-
-#include <linux/types.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)
-{
-	return false;
-}
-
-#endif /* _KERNEL_KCSAN_ATOMIC_H */