It turned out that KMSAN instruments READ_ONCE_NOCHECK(), resulting in
false positive reports, because __no_sanitize_or_inline enforced inlining.
Properly declare __no_sanitize_or_inline under __SANITIZE_MEMORY__,
so that it does not __always_inline the annotated function.
Reported-by: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 5de0ce85f5a4 ("kmsan: mark noinstr as __no_sanitize_memory")
Cc: [email protected]
Signed-off-by: Alexander Potapenko <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
---
include/linux/compiler_types.h | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h
index 0caf354cb94b5..a6a28952836cb 100644
--- a/include/linux/compiler_types.h
+++ b/include/linux/compiler_types.h
@@ -278,6 +278,17 @@ struct ftrace_likely_data {
# define __no_kcsan
#endif
+#ifdef __SANITIZE_MEMORY__
+/*
+ * Similarly to KASAN and KCSAN, KMSAN loses function attributes of inlined
+ * functions, therefore disabling KMSAN checks also requires disabling inlining.
+ *
+ * __no_sanitize_or_inline effectively prevents KMSAN from reporting errors
+ * within the function and marks all its outputs as initialized.
+ */
+# define __no_sanitize_or_inline __no_kmsan_checks notrace __maybe_unused
+#endif
+
#ifndef __no_sanitize_or_inline
#define __no_sanitize_or_inline __always_inline
#endif
--
2.44.0.769.g3c40516874-goog