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/kasan-checks.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 kasan_check_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 kasan_check_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 kasan_check_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 kasan_check_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 kasan_check_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 kasan_check_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 kasan_check_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