The patch titled
Subject: instrumented.h: add instrument_memcpy_before, instrument_memcpy_after
has been added to the -mm mm-nonmm-unstable branch. Its filename is
instrumentedh-add-instrument_memcpy_before-instrument_memcpy_after.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/instrumentedh-add-instrument_memcpy_before-instrument_memcpy_after.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Alexander Potapenko <glider@xxxxxxxxxx>
Subject: instrumented.h: add instrument_memcpy_before, instrument_memcpy_after
Date: Wed, 20 Mar 2024 11:18:50 +0100
Bug detection tools based on compiler instrumentation may miss memory
accesses in custom memcpy implementations (such as copy_mc_to_kernel).
Provide instrumentation hooks that tell KASAN, KCSAN, and KMSAN about such
accesses.
Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@xxxxxxxxxxxxxxxxxxx/
Link: https://lkml.kernel.org/r/20240320101851.2589698-2-glider@xxxxxxxxxx
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Reviewed-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/instrumented.h | 35 +++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)
--- a/include/linux/instrumented.h~instrumentedh-add-instrument_memcpy_before-instrument_memcpy_after
+++ a/include/linux/instrumented.h
@@ -148,6 +148,41 @@ instrument_copy_from_user_after(const vo
}
/**
+ * instrument_memcpy_before - add instrumentation before non-instrumented memcpy
+ * @to: destination address
+ * @from: source address
+ * @n: number of bytes to copy
+ *
+ * Instrument memory accesses that happen in custom memcpy implementations. The
+ * instrumentation should be inserted before the memcpy call.
+ */
+static __always_inline void instrument_memcpy_before(void *to, const void *from,
+ unsigned long n)
+{
+ kasan_check_write(to, n);
+ kasan_check_read(from, n);
+ kcsan_check_write(to, n);
+ kcsan_check_read(from, n);
+}
+
+/**
+ * instrument_memcpy_after - add instrumentation after non-instrumented memcpy
+ * @to: destination address
+ * @from: source address
+ * @n: number of bytes to copy
+ * @left: number of bytes not copied (if known)
+ *
+ * Instrument memory accesses that happen in custom memcpy implementations. The
+ * instrumentation should be inserted after the memcpy call.
+ */
+static __always_inline void instrument_memcpy_after(void *to, const void *from,
+ unsigned long n,
+ unsigned long left)
+{
+ kmsan_memmove(to, from, n - left);
+}
+
+/**
* instrument_get_user() - add instrumentation to get_user()-like macros
* @to: destination variable, may not be address-taken
*
_
Patches currently in -mm which might be from glider@xxxxxxxxxx are
mm-kmsan-implement-kmsan_memmove.patch
instrumentedh-add-instrument_memcpy_before-instrument_memcpy_after.patch
x86-call-instrumentation-hooks-from-copy_mcc.patch
