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/kmsan-compiler_types-declare-__no_sanitize_or_inline.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Alexander Potapenko <glider@xxxxxxxxxx>
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@xxxxxxxxxx
Reported-by: syzbot+355c5bb8c1445c871ee8@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lkml.kernel.org/r/000000000000826ac1061675b0e3@xxxxxxxxxx
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Miguel Ojeda <ojeda@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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@xxxxxxxxxx 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
