include/asm-generic/bitops/instrumented-non-atomic.h

   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 */