diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/kcsan/core.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index a73a66cf79df..15f67949d11e 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -790,6 +790,49 @@ void __tsan_write_range(void *ptr, size_t size) EXPORT_SYMBOL(__tsan_write_range); /* + * Use of explicit volatile is generally disallowed [1], however, volatile is + * still used in various concurrent context, whether in low-level + * synchronization primitives or for legacy reasons. + * [1] https://lwn.net/Articles/233479/ + * + * We only consider volatile accesses atomic if they are aligned and would pass + * the size-check of compiletime_assert_rwonce_type(). + */ +#define DEFINE_TSAN_VOLATILE_READ_WRITE(size) \ + void __tsan_volatile_read##size(void *ptr) \ + { \ + const bool is_atomic = size <= sizeof(long long) && \ + IS_ALIGNED((unsigned long)ptr, size); \ + if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS) && is_atomic) \ + return; \ + check_access(ptr, size, is_atomic ? KCSAN_ACCESS_ATOMIC : 0); \ + } \ + EXPORT_SYMBOL(__tsan_volatile_read##size); \ + void __tsan_unaligned_volatile_read##size(void *ptr) \ + __alias(__tsan_volatile_read##size); \ + EXPORT_SYMBOL(__tsan_unaligned_volatile_read##size); \ + void __tsan_volatile_write##size(void *ptr) \ + { \ + const bool is_atomic = size <= sizeof(long long) && \ + IS_ALIGNED((unsigned long)ptr, size); \ + if (IS_ENABLED(CONFIG_KCSAN_IGNORE_ATOMICS) && is_atomic) \ + return; \ + check_access(ptr, size, \ + KCSAN_ACCESS_WRITE | \ + (is_atomic ? KCSAN_ACCESS_ATOMIC : 0)); \ + } \ + EXPORT_SYMBOL(__tsan_volatile_write##size); \ + void __tsan_unaligned_volatile_write##size(void *ptr) \ + __alias(__tsan_volatile_write##size); \ + EXPORT_SYMBOL(__tsan_unaligned_volatile_write##size) + +DEFINE_TSAN_VOLATILE_READ_WRITE(1); +DEFINE_TSAN_VOLATILE_READ_WRITE(2); +DEFINE_TSAN_VOLATILE_READ_WRITE(4); +DEFINE_TSAN_VOLATILE_READ_WRITE(8); +DEFINE_TSAN_VOLATILE_READ_WRITE(16); + +/* * The below are not required by KCSAN, but can still be emitted by the * compiler. */ |