diff options
Diffstat (limited to 'kernel/kcsan')
| -rw-r--r-- | kernel/kcsan/core.c | 17 | ||||
| -rw-r--r-- | kernel/kcsan/kcsan_test.c | 20 |
2 files changed, 19 insertions, 18 deletions
diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c index 54d077e1a2dc..5a60cc52adc0 100644 --- a/kernel/kcsan/core.c +++ b/kernel/kcsan/core.c @@ -337,11 +337,20 @@ static void delay_access(int type) */ static __always_inline u64 read_instrumented_memory(const volatile void *ptr, size_t size) { + /* + * In the below we don't necessarily need the read of the location to + * be atomic, and we don't use READ_ONCE(), since all we need for race + * detection is to observe 2 different values. + * + * Furthermore, on certain architectures (such as arm64), READ_ONCE() + * may turn into more complex instructions than a plain load that cannot + * do unaligned accesses. + */ switch (size) { - case 1: return READ_ONCE(*(const u8 *)ptr); - case 2: return READ_ONCE(*(const u16 *)ptr); - case 4: return READ_ONCE(*(const u32 *)ptr); - case 8: return READ_ONCE(*(const u64 *)ptr); + case 1: return *(const volatile u8 *)ptr; + case 2: return *(const volatile u16 *)ptr; + case 4: return *(const volatile u32 *)ptr; + case 8: return *(const volatile u64 *)ptr; default: return 0; /* Ignore; we do not diff the values. */ } } diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c index a60c561724be..0ddbdab5903d 100644 --- a/kernel/kcsan/kcsan_test.c +++ b/kernel/kcsan/kcsan_test.c @@ -1572,34 +1572,26 @@ static void test_exit(struct kunit *test) } __no_kcsan -static void register_tracepoints(struct tracepoint *tp, void *ignore) +static void register_tracepoints(void) { - check_trace_callback_type_console(probe_console); - if (!strcmp(tp->name, "console")) - WARN_ON(tracepoint_probe_register(tp, probe_console, NULL)); + register_trace_console(probe_console, NULL); } __no_kcsan -static void unregister_tracepoints(struct tracepoint *tp, void *ignore) +static void unregister_tracepoints(void) { - if (!strcmp(tp->name, "console")) - tracepoint_probe_unregister(tp, probe_console, NULL); + unregister_trace_console(probe_console, NULL); } static int kcsan_suite_init(struct kunit_suite *suite) { - /* - * Because we want to be able to build the test as a module, we need to - * iterate through all known tracepoints, since the static registration - * won't work here. - */ - for_each_kernel_tracepoint(register_tracepoints, NULL); + register_tracepoints(); return 0; } static void kcsan_suite_exit(struct kunit_suite *suite) { - for_each_kernel_tracepoint(unregister_tracepoints, NULL); + unregister_tracepoints(); tracepoint_synchronize_unregister(); } |