The patch titled Subject: kmsan: compiler_types: declare __no_sanitize_or_inline has been added to the -mm mm-hotfixes-unstable branch. Its filename is kmsan-compiler_types-declare-__no_sanitize_or_inline.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Alexander Potapenko glider@google.com Subject: kmsan: compiler_types: declare __no_sanitize_or_inline Date: Thu, 25 Apr 2024 11:28:59 +0200

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 inline the annotated function.

Link: https://lkml.kernel.org/r/20240425092859.3370297-1-glider@google.com Reported-by: syzbot+355c5bb8c1445c871ee8@syzkaller.appspotmail.com Link: https://lkml.kernel.org/r/000000000000826ac1061675b0e3@google.com Signed-off-by: Alexander Potapenko glider@google.com Reviewed-by: Marco Elver elver@google.com Cc: Dmitry Vyukov dvyukov@google.com Cc: Miguel Ojeda ojeda@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

include/linux/compiler_types.h | 11 +++++++++++ 1 file changed, 11 insertions(+)

--- a/include/linux/compiler_types.h~kmsan-compiler_types-declare-__no_sanitize_or_inline +++ a/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 _

Patches currently in -mm which might be from glider@google.com are

kmsan-compiler_types-declare-__no_sanitize_or_inline.patch mm-kmsan-implement-kmsan_memmove.patch instrumentedh-add-instrument_memcpy_before-instrument_memcpy_after.patch x86-call-instrumentation-hooks-from-copy_mcc.patch