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Message-id: <1404905415-9046-18-git-send-email-a.ryabinin@samsung.com>
Date: Wed, 09 Jul 2014 15:30:11 +0400
From: Andrey Ryabinin <a.ryabinin@...sung.com>
To: linux-kernel@...r.kernel.org
Cc: Dmitry Vyukov <dvyukov@...gle.com>,
Konstantin Serebryany <kcc@...gle.com>,
Alexey Preobrazhensky <preobr@...gle.com>,
Andrey Konovalov <adech.fo@...il.com>,
Yuri Gribov <tetra2005@...il.com>,
Konstantin Khlebnikov <koct9i@...il.com>,
Sasha Levin <sasha.levin@...cle.com>,
Michal Marek <mmarek@...e.cz>,
Russell King <linux@....linux.org.uk>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
Christoph Lameter <cl@...ux.com>,
Pekka Enberg <penberg@...nel.org>,
David Rientjes <rientjes@...gle.com>,
Joonsoo Kim <iamjoonsoo.kim@....com>,
Andrew Morton <akpm@...ux-foundation.org>,
linux-kbuild@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
x86@...nel.org, linux-mm@...ck.org,
Andrey Ryabinin <a.ryabinin@...sung.com>
Subject: [RFC/PATCH RESEND -next 17/21] arm: add kasan hooks fort
memcpy/memmove/memset functions
Since functions memset, memmove, memcpy are written in assembly,
compiler can't instrument memory accesses inside them.
This patch replaces these functions with our own instrumented
functions (kasan_mem*) for CONFIG_KASAN = y
In rare circumstances you may need to use the original functions,
in such case put #undef KASAN_HOOKS before includes.
Signed-off-by: Andrey Ryabinin <a.ryabinin@...sung.com>
---
arch/arm/include/asm/string.h | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/arch/arm/include/asm/string.h b/arch/arm/include/asm/string.h
index cf4f3aa..3cbe47f 100644
--- a/arch/arm/include/asm/string.h
+++ b/arch/arm/include/asm/string.h
@@ -38,4 +38,34 @@ extern void __memzero(void *ptr, __kernel_size_t n);
(__p); \
})
+
+#if defined(CONFIG_KASAN) && defined(KASAN_HOOKS)
+
+/*
+ * Since some of the following functions (memset, memmove, memcpy)
+ * are written in assembly, compiler can't instrument memory accesses
+ * inside them.
+ *
+ * To solve this issue we replace these functions with our own instrumented
+ * functions (kasan_mem*)
+ *
+ * In case if any of mem*() fucntions are written in C we use our instrumented
+ * functions for perfomance reasons. It's should be faster to check whole
+ * accessed memory range at once, then do a lot of checks at each memory access.
+ *
+ * In rare circumstances you may need to use the original functions,
+ * in such case #undef KASAN_HOOKS before includes.
+ */
+#undef memset
+
+void *kasan_memset(void *ptr, int val, size_t len);
+void *kasan_memcpy(void *dst, const void *src, size_t len);
+void *kasan_memmove(void *dst, const void *src, size_t len);
+
+#define memcpy(dst, src, len) kasan_memcpy((dst), (src), (len))
+#define memset(ptr, val, len) kasan_memset((ptr), (val), (len))
+#define memmove(dst, src, len) kasan_memmove((dst), (src), (len))
+
+#endif /* CONFIG_KASAN && KASAN_HOOKS */
+
#endif
--
1.8.5.5
--
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