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authorAlexander Potapenko <glider@google.com>2024-03-20 11:18:49 +0100
committerAndrew Morton <akpm@linux-foundation.org>2024-04-25 21:07:02 -0700
commit3429055f0451cd3a281f8ed6691335ead626b136 (patch)
treeb9129ba3f2198b5a4c53fe7bf724c4b61d6354db /include/linux/kmsan-checks.h
parent212f863fa8811c780abacc1d0404c573fdc0a2de (diff)
mm: kmsan: implement kmsan_memmove()
Provide a hook that can be used by custom memcpy implementations to tell KMSAN that the metadata needs to be copied. Without that, false positive reports are possible in the cases where KMSAN fails to intercept memory initialization. Link: https://lore.kernel.org/all/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/ Link: https://lkml.kernel.org/r/20240320101851.2589698-1-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/kmsan-checks.h')
-rw-r--r--include/linux/kmsan-checks.h15
1 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/kmsan-checks.h b/include/linux/kmsan-checks.h
index c4cae333deec..e1082dc40abc 100644
--- a/include/linux/kmsan-checks.h
+++ b/include/linux/kmsan-checks.h
@@ -61,6 +61,17 @@ void kmsan_check_memory(const void *address, size_t size);
void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy,
size_t left);
+/**
+ * kmsan_memmove() - Notify KMSAN about a data copy within kernel.
+ * @to: destination address in the kernel.
+ * @from: source address in the kernel.
+ * @size: number of bytes to copy.
+ *
+ * Invoked after non-instrumented version (e.g. implemented using assembly
+ * code) of memmove()/memcpy() is called, in order to copy KMSAN's metadata.
+ */
+void kmsan_memmove(void *to, const void *from, size_t to_copy);
+
#else
static inline void kmsan_poison_memory(const void *address, size_t size,
@@ -78,6 +89,10 @@ static inline void kmsan_copy_to_user(void __user *to, const void *from,
{
}
+static inline void kmsan_memmove(void *to, const void *from, size_t to_copy)
+{
+}
+
#endif
#endif /* _LINUX_KMSAN_CHECKS_H */