1 files changed, 65 insertions, 22 deletions

diff --git a/include/asm-generic/bitops/instrumented-non-atomic.h b/include/asm-generic/bitops/instrumented-non-atomic.h
index 95ff28d128a1..2b238b161a62 100644
--- a/include/asm-generic/bitops/instrumented-non-atomic.h
+++ b/include/asm-generic/bitops/instrumented-non-atomic.h
@@ -11,10 +11,10 @@
 #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
 #define _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
 
-#include <linux/kasan-checks.h>
+#include <linux/instrumented.h>
 
 /**
- * __set_bit - Set a bit in memory
+ * ___set_bit - Set a bit in memory
  * @nr: the bit to set
  * @addr: the address to start counting from
  *
@@ -22,14 +22,15 @@
  * region of memory concurrently, the effect may be that only one operation
  * succeeds.
  */
-static inline void __set_bit(long nr, volatile unsigned long *addr)
+static __always_inline void
+___set_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	instrument_write(addr + BIT_WORD(nr), sizeof(long));
 	arch___set_bit(nr, addr);
 }
 
 /**
- * __clear_bit - Clears a bit in memory
+ * ___clear_bit - Clears a bit in memory
  * @nr: the bit to clear
  * @addr: the address to start counting from
  *
@@ -37,14 +38,15 @@ static inline void __set_bit(long nr, volatile unsigned long *addr)
  * region of memory concurrently, the effect may be that only one operation
  * succeeds.
  */
-static inline void __clear_bit(long nr, volatile unsigned long *addr)
+static __always_inline void
+___clear_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	instrument_write(addr + BIT_WORD(nr), sizeof(long));
 	arch___clear_bit(nr, addr);
 }
 
 /**
- * __change_bit - Toggle a bit in memory
+ * ___change_bit - Toggle a bit in memory
  * @nr: the bit to change
  * @addr: the address to start counting from
  *
@@ -52,63 +54,104 @@ static inline void __clear_bit(long nr, volatile unsigned long *addr)
  * region of memory concurrently, the effect may be that only one operation
  * succeeds.
  */
-static inline void __change_bit(long nr, volatile unsigned long *addr)
+static __always_inline void
+___change_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	instrument_write(addr + BIT_WORD(nr), sizeof(long));
 	arch___change_bit(nr, addr);
 }
 
+static __always_inline void __instrument_read_write_bitop(long nr, volatile unsigned long *addr)
+{
+	if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC)) {
+		/*
+		 * We treat non-atomic read-write bitops a little more special.
+		 * Given the operations here only modify a single bit, assuming
+		 * non-atomicity of the writer is sufficient may be reasonable
+		 * for certain usage (and follows the permissible nature of the
+		 * assume-plain-writes-atomic rule):
+		 * 1. report read-modify-write races -> check read;
+		 * 2. do not report races with marked readers, but do report
+		 *    races with unmarked readers -> check "atomic" write.
+		 */
+		kcsan_check_read(addr + BIT_WORD(nr), sizeof(long));
+		/*
+		 * Use generic write instrumentation, in case other sanitizers
+		 * or tools are enabled alongside KCSAN.
+		 */
+		instrument_write(addr + BIT_WORD(nr), sizeof(long));
+	} else {
+		instrument_read_write(addr + BIT_WORD(nr), sizeof(long));
+	}
+}
+
 /**
- * __test_and_set_bit - Set a bit and return its old value
+ * ___test_and_set_bit - Set a bit and return its old value
  * @nr: Bit to set
  * @addr: Address to count from
  *
  * This operation is non-atomic. If two instances of this operation race, one
  * can appear to succeed but actually fail.
  */
-static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr)
+static __always_inline bool
+___test_and_set_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	__instrument_read_write_bitop(nr, addr);
 	return arch___test_and_set_bit(nr, addr);
 }
 
 /**
- * __test_and_clear_bit - Clear a bit and return its old value
+ * ___test_and_clear_bit - Clear a bit and return its old value
  * @nr: Bit to clear
  * @addr: Address to count from
  *
  * This operation is non-atomic. If two instances of this operation race, one
  * can appear to succeed but actually fail.
  */
-static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr)
+static __always_inline bool
+___test_and_clear_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	__instrument_read_write_bitop(nr, addr);
 	return arch___test_and_clear_bit(nr, addr);
 }
 
 /**
- * __test_and_change_bit - Change a bit and return its old value
+ * ___test_and_change_bit - Change a bit and return its old value
  * @nr: Bit to change
  * @addr: Address to count from
  *
  * This operation is non-atomic. If two instances of this operation race, one
  * can appear to succeed but actually fail.
  */
-static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr)
+static __always_inline bool
+___test_and_change_bit(unsigned long nr, volatile unsigned long *addr)
 {
-	kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
+	__instrument_read_write_bitop(nr, addr);
 	return arch___test_and_change_bit(nr, addr);
 }
 
 /**
- * test_bit - Determine whether a bit is set
+ * _test_bit - Determine whether a bit is set
  * @nr: bit number to test
  * @addr: Address to start counting from
  */
-static inline bool test_bit(long nr, const volatile unsigned long *addr)
+static __always_inline bool
+_test_bit(unsigned long nr, const volatile unsigned long *addr)
 {
-	kasan_check_read(addr + BIT_WORD(nr), sizeof(long));
+	instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long));
 	return arch_test_bit(nr, addr);
 }
 
+/**
+ * _test_bit_acquire - Determine, with acquire semantics, whether a bit is set
+ * @nr: bit number to test
+ * @addr: Address to start counting from
+ */
+static __always_inline bool
+_test_bit_acquire(unsigned long nr, const volatile unsigned long *addr)
+{
+	instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long));
+	return arch_test_bit_acquire(nr, addr);
+}
+
 #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */