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From:   Vincenzo Frascino <vincenzo.frascino@arm.com>
To:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        kasan-dev@googlegroups.com
Cc:     Vincenzo Frascino <vincenzo.frascino@arm.com>,
        Andrey Ryabinin <aryabinin@virtuozzo.com>,
        Alexander Potapenko <glider@google.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Leon Romanovsky <leonro@mellanox.com>,
        Andrey Konovalov <andreyknvl@google.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        "Paul E . McKenney" <paulmck@kernel.org>,
        Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: [PATCH v4 2/3] kasan: Add explicit preconditions to kasan_report()
Date:   Fri, 22 Jan 2021 15:56:41 +0000
Message-Id: <20210122155642.23187-3-vincenzo.frascino@arm.com>
In-Reply-To: <20210122155642.23187-1-vincenzo.frascino@arm.com>
References: <20210122155642.23187-1-vincenzo.frascino@arm.com>
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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@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Leon Romanovsky <leonro@mellanox.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
 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