diff options
Diffstat (limited to 'include/asm-generic/bitops/instrumented-non-atomic.h')
| -rw-r--r-- | include/asm-generic/bitops/instrumented-non-atomic.h | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/include/asm-generic/bitops/instrumented-non-atomic.h b/include/asm-generic/bitops/instrumented-non-atomic.h index f86234c7c10c..37363d570b9b 100644 --- a/include/asm-generic/bitops/instrumented-non-atomic.h +++ b/include/asm-generic/bitops/instrumented-non-atomic.h @@ -58,6 +58,30 @@ static inline void __change_bit(long nr, volatile unsigned long *addr) arch___change_bit(nr, addr); } +static 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 * @nr: Bit to set @@ -68,7 +92,7 @@ static inline void __change_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr) { - instrument_read_write(addr + BIT_WORD(nr), sizeof(long)); + __instrument_read_write_bitop(nr, addr); return arch___test_and_set_bit(nr, addr); } @@ -82,7 +106,7 @@ static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr) { - instrument_read_write(addr + BIT_WORD(nr), sizeof(long)); + __instrument_read_write_bitop(nr, addr); return arch___test_and_clear_bit(nr, addr); } @@ -96,7 +120,7 @@ static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr) */ static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr) { - instrument_read_write(addr + BIT_WORD(nr), sizeof(long)); + __instrument_read_write_bitop(nr, addr); return arch___test_and_change_bit(nr, addr); } |