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Date:   Fri, 24 Jul 2020 09:00:04 +0200
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Subject: [PATCH v2 4/8] kcsan: Add missing CONFIG_KCSAN_IGNORE_ATOMICS checks
From:   Marco Elver <elver@google.com>
To:     elver@google.com, paulmck@kernel.org
Cc:     will@kernel.org, peterz@infradead.org, arnd@arndb.de,
        mark.rutland@arm.com, dvyukov@google.com, glider@google.com,
        kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org
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Add missing CONFIG_KCSAN_IGNORE_ATOMICS checks for the builtin atomics
instrumentation.

Signed-off-by: Marco Elver <elver@google.com>
---
v2:
* Add {} for readability.

Added to this series, as it would otherwise cause patch conflicts.
---
 kernel/kcsan/core.c | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c
index 4633baebf84e..e43a55643e00 100644
--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -892,14 +892,19 @@ EXPORT_SYMBOL(__tsan_init);
 	u##bits __tsan_atomic##bits##_load(const u##bits *ptr, int memorder);                      \
 	u##bits __tsan_atomic##bits##_load(const u##bits *ptr, int memorder)                       \
 	{                                                                                          \
-		check_access(ptr, bits / BITS_PER_BYTE, KCSAN_ACCESS_ATOMIC);                      \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE, KCSAN_ACCESS_ATOMIC);              \
+		}                                                                                  \
 		return __atomic_load_n(ptr, memorder);                                             \
 	}                                                                                          \
 	EXPORT_SYMBOL(__tsan_atomic##bits##_load);                                                 \
 	void __tsan_atomic##bits##_store(u##bits *ptr, u##bits v, int memorder);                   \
 	void __tsan_atomic##bits##_store(u##bits *ptr, u##bits v, int memorder)                    \
 	{                                                                                          \
-		check_access(ptr, bits / BITS_PER_BYTE, KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC); \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC);                    \
+		}                                                                                  \
 		__atomic_store_n(ptr, v, memorder);                                                \
 	}                                                                                          \
 	EXPORT_SYMBOL(__tsan_atomic##bits##_store)
@@ -908,8 +913,11 @@ EXPORT_SYMBOL(__tsan_init);
 	u##bits __tsan_atomic##bits##_##op(u##bits *ptr, u##bits v, int memorder);                 \
 	u##bits __tsan_atomic##bits##_##op(u##bits *ptr, u##bits v, int memorder)                  \
 	{                                                                                          \
-		check_access(ptr, bits / BITS_PER_BYTE,                                            \
-			     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC);    \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
 		return __atomic_##op##suffix(ptr, v, memorder);                                    \
 	}                                                                                          \
 	EXPORT_SYMBOL(__tsan_atomic##bits##_##op)
@@ -937,8 +945,11 @@ EXPORT_SYMBOL(__tsan_init);
 	int __tsan_atomic##bits##_compare_exchange_##strength(u##bits *ptr, u##bits *exp,          \
 							      u##bits val, int mo, int fail_mo)    \
 	{                                                                                          \
-		check_access(ptr, bits / BITS_PER_BYTE,                                            \
-			     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC);    \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
 		return __atomic_compare_exchange_n(ptr, exp, val, weak, mo, fail_mo);              \
 	}                                                                                          \
 	EXPORT_SYMBOL(__tsan_atomic##bits##_compare_exchange_##strength)
@@ -949,8 +960,11 @@ EXPORT_SYMBOL(__tsan_init);
 	u##bits __tsan_atomic##bits##_compare_exchange_val(u##bits *ptr, u##bits exp, u##bits val, \
 							   int mo, int fail_mo)                    \
 	{                                                                                          \
-		check_access(ptr, bits / BITS_PER_BYTE,                                            \
-			     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ATOMIC);    \
+		if (!IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS)) {                                    \
+			check_access(ptr, bits / BITS_PER_BYTE,                                    \
+				     KCSAN_ACCESS_COMPOUND | KCSAN_ACCESS_WRITE |                  \
+					     KCSAN_ACCESS_ATOMIC);                                 \
+		}                                                                                  \
 		__atomic_compare_exchange_n(ptr, &exp, val, 0, mo, fail_mo);                       \
 		return exp;                                                                        \
 	}                                                                                          \
-- 
2.28.0.rc0.142.g3c755180ce-goog