[PATCH v5 1/2] kasan: Add explicit preconditions to kasan_report()

From: Vincenzo Frascino
Date: Tue Jan 26 2021 - 08:45:37 EST


With the introduction of KASAN_HW_TAGS, kasan_report() accesses the
metadata only when addr_has_metadata() succeeds.

Add a comment to make sure that the preconditions to the function are
explicitly clarified.

Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Leon Romanovsky <leonro@xxxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
---
include/linux/kasan.h | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index fe1ae73ff8b5..0aea9e2a2a01 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -333,6 +333,13 @@ static inline void *kasan_reset_tag(const void *addr)
return (void *)arch_kasan_reset_tag(addr);
}

+/**
+ * kasan_report - print a report about a bad memory access detected by KASAN
+ * @addr: address of the bad access
+ * @size: size of the bad access
+ * @is_write: whether the bad access is a write or a read
+ * @ip: instruction pointer for the accessibility check or the bad access itself
+ */
bool kasan_report(unsigned long addr, size_t size,
bool is_write, unsigned long ip);

--
2.30.0