1 /* SPDX-License-Identifier: GPL-2.0 */
2 
3 /*
4  * This file provides wrappers with sanitizer instrumentation for non-atomic
5  * bit operations.
6  *
7  * To use this functionality, an arch's bitops.h file needs to define each of
8  * the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
9  * arch___set_bit(), etc.).
10  */
11 #ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
12 #define _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
13 
14 #include <linux/instrumented.h>
15 
16 /**
17  * __set_bit - Set a bit in memory
18  * @nr: the bit to set
19  * @addr: the address to start counting from
20  *
21  * Unlike set_bit(), this function is non-atomic. If it is called on the same
22  * region of memory concurrently, the effect may be that only one operation
23  * succeeds.
24  */
25 static inline void __set_bit(long nr, volatile unsigned long *addr)
26 {
27 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
28 	arch___set_bit(nr, addr);
29 }
30 
31 /**
32  * __clear_bit - Clears a bit in memory
33  * @nr: the bit to clear
34  * @addr: the address to start counting from
35  *
36  * Unlike clear_bit(), this function is non-atomic. If it is called on the same
37  * region of memory concurrently, the effect may be that only one operation
38  * succeeds.
39  */
40 static inline void __clear_bit(long nr, volatile unsigned long *addr)
41 {
42 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
43 	arch___clear_bit(nr, addr);
44 }
45 
46 /**
47  * __change_bit - Toggle a bit in memory
48  * @nr: the bit to change
49  * @addr: the address to start counting from
50  *
51  * Unlike change_bit(), this function is non-atomic. If it is called on the same
52  * region of memory concurrently, the effect may be that only one operation
53  * succeeds.
54  */
55 static inline void __change_bit(long nr, volatile unsigned long *addr)
56 {
57 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
58 	arch___change_bit(nr, addr);
59 }
60 
61 /**
62  * __test_and_set_bit - Set a bit and return its old value
63  * @nr: Bit to set
64  * @addr: Address to count from
65  *
66  * This operation is non-atomic. If two instances of this operation race, one
67  * can appear to succeed but actually fail.
68  */
69 static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr)
70 {
71 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
72 	return arch___test_and_set_bit(nr, addr);
73 }
74 
75 /**
76  * __test_and_clear_bit - Clear a bit and return its old value
77  * @nr: Bit to clear
78  * @addr: Address to count from
79  *
80  * This operation is non-atomic. If two instances of this operation race, one
81  * can appear to succeed but actually fail.
82  */
83 static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr)
84 {
85 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
86 	return arch___test_and_clear_bit(nr, addr);
87 }
88 
89 /**
90  * __test_and_change_bit - Change a bit and return its old value
91  * @nr: Bit to change
92  * @addr: Address to count from
93  *
94  * This operation is non-atomic. If two instances of this operation race, one
95  * can appear to succeed but actually fail.
96  */
97 static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr)
98 {
99 	instrument_write(addr + BIT_WORD(nr), sizeof(long));
100 	return arch___test_and_change_bit(nr, addr);
101 }
102 
103 /**
104  * test_bit - Determine whether a bit is set
105  * @nr: bit number to test
106  * @addr: Address to start counting from
107  */
108 static inline bool test_bit(long nr, const volatile unsigned long *addr)
109 {
110 	instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long));
111 	return arch_test_bit(nr, addr);
112 }
113 
114 #endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */
115