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Date:   Tue,  5 Oct 2021 12:58:59 +0200
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Subject: [PATCH -rcu/kcsan 17/23] asm-generic/bitops, kcsan: Add
 instrumentation for barriers
From:   Marco Elver <elver@google.com>
To:     elver@google.com, "Paul E . McKenney" <paulmck@kernel.org>
Cc:     Alexander Potapenko <glider@google.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Borislav Petkov <bp@alien8.de>,
        Dmitry Vyukov <dvyukov@google.com>,
        Ingo Molnar <mingo@kernel.org>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Waiman Long <longman@redhat.com>,
        Will Deacon <will@kernel.org>, kasan-dev@googlegroups.com,
        linux-arch@vger.kernel.org, linux-doc@vger.kernel.org,
        linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org, x86@kernel.org
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Adds the required KCSAN instrumentation for barriers of atomic bitops.

Signed-off-by: Marco Elver <elver@google.com>
---
 include/asm-generic/bitops/instrumented-atomic.h | 3 +++
 include/asm-generic/bitops/instrumented-lock.h   | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/include/asm-generic/bitops/instrumented-atomic.h b/include/asm-generic/bitops/instrumented-atomic.h
index 81915dcd4b4e..c90192b1c755 100644
--- a/include/asm-generic/bitops/instrumented-atomic.h
+++ b/include/asm-generic/bitops/instrumented-atomic.h
@@ -67,6 +67,7 @@ static inline void change_bit(long nr, volatile unsigned long *addr)
  */
 static inline bool test_and_set_bit(long nr, volatile unsigned long *addr)
 {
+	kcsan_mb();
 	instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
 	return arch_test_and_set_bit(nr, addr);
 }
@@ -80,6 +81,7 @@ static inline bool test_and_set_bit(long nr, volatile unsigned long *addr)
  */
 static inline bool test_and_clear_bit(long nr, volatile unsigned long *addr)
 {
+	kcsan_mb();
 	instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
 	return arch_test_and_clear_bit(nr, addr);
 }
@@ -93,6 +95,7 @@ static inline bool test_and_clear_bit(long nr, volatile unsigned long *addr)
  */
 static inline bool test_and_change_bit(long nr, volatile unsigned long *addr)
 {
+	kcsan_mb();
 	instrument_atomic_read_write(addr + BIT_WORD(nr), sizeof(long));
 	return arch_test_and_change_bit(nr, addr);
 }
diff --git a/include/asm-generic/bitops/instrumented-lock.h b/include/asm-generic/bitops/instrumented-lock.h
index 75ef606f7145..eb64bd4f11f3 100644
--- a/include/asm-generic/bitops/instrumented-lock.h
+++ b/include/asm-generic/bitops/instrumented-lock.h
@@ -22,6 +22,7 @@
  */
 static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
 {
+	kcsan_release();
 	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
 	arch_clear_bit_unlock(nr, addr);
 }
@@ -37,6 +38,7 @@ static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
  */
 static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
 {
+	kcsan_release();
 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
 	arch___clear_bit_unlock(nr, addr);
 }
@@ -71,6 +73,7 @@ static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
 static inline bool
 clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
 {
+	kcsan_release();
 	instrument_atomic_write(addr + BIT_WORD(nr), sizeof(long));
 	return arch_clear_bit_unlock_is_negative_byte(nr, addr);
 }
-- 
2.33.0.800.g4c38ced690-goog