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authorMarco Elver <elver@google.com>2019-07-12 06:54:03 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-12 21:05:42 +0300
commit7d8ad890dad00f6cd64bfb44d9be4fceb10cf819 (patch)
tree03134a0314ae139e8d92941353e2ef21ef5c0470
parent751ad98d5f881df91ba47e013b82422912381e8e (diff)
downloadlinux-7d8ad890dad00f6cd64bfb44d9be4fceb10cf819.tar.xz
mm/kasan: introduce __kasan_check_{read,write}
Patch series "mm/kasan: Add object validation in ksize()", v3. This patch (of 5): This introduces __kasan_check_{read,write}. __kasan_check functions may be used from anywhere, even compilation units that disable instrumentation selectively. This change eliminates the need for the __KASAN_INTERNAL definition. [elver@google.com: v5] Link: http://lkml.kernel.org/r/20190708170706.174189-2-elver@google.com Link: http://lkml.kernel.org/r/20190626142014.141844-2-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/kasan-checks.h25
-rw-r--r--mm/kasan/common.c10
2 files changed, 26 insertions, 9 deletions
diff --git a/include/linux/kasan-checks.h b/include/linux/kasan-checks.h
index a61dc075e2ce..221f05fbddd7 100644
--- a/include/linux/kasan-checks.h
+++ b/include/linux/kasan-checks.h
@@ -2,9 +2,28 @@
#ifndef _LINUX_KASAN_CHECKS_H
#define _LINUX_KASAN_CHECKS_H
-#if defined(__SANITIZE_ADDRESS__) || defined(__KASAN_INTERNAL)
-void kasan_check_read(const volatile void *p, unsigned int size);
-void kasan_check_write(const volatile void *p, unsigned int size);
+/*
+ * __kasan_check_*: Always available when KASAN is enabled. This may be used
+ * even in compilation units that selectively disable KASAN, but must use KASAN
+ * to validate access to an address. Never use these in header files!
+ */
+#ifdef CONFIG_KASAN
+void __kasan_check_read(const volatile void *p, unsigned int size);
+void __kasan_check_write(const volatile void *p, unsigned int size);
+#else
+static inline void __kasan_check_read(const volatile void *p, unsigned int size)
+{ }
+static inline void __kasan_check_write(const volatile void *p, unsigned int size)
+{ }
+#endif
+
+/*
+ * kasan_check_*: Only available when the particular compilation unit has KASAN
+ * instrumentation enabled. May be used in header files.
+ */
+#ifdef __SANITIZE_ADDRESS__
+#define kasan_check_read __kasan_check_read
+#define kasan_check_write __kasan_check_write
#else
static inline void kasan_check_read(const volatile void *p, unsigned int size)
{ }
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 242fdc01aaa9..6bada42cc152 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -14,8 +14,6 @@
*
*/
-#define __KASAN_INTERNAL
-
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/init.h>
@@ -89,17 +87,17 @@ void kasan_disable_current(void)
current->kasan_depth--;
}
-void kasan_check_read(const volatile void *p, unsigned int size)
+void __kasan_check_read(const volatile void *p, unsigned int size)
{
check_memory_region((unsigned long)p, size, false, _RET_IP_);
}
-EXPORT_SYMBOL(kasan_check_read);
+EXPORT_SYMBOL(__kasan_check_read);
-void kasan_check_write(const volatile void *p, unsigned int size)
+void __kasan_check_write(const volatile void *p, unsigned int size)
{
check_memory_region((unsigned long)p, size, true, _RET_IP_);
}
-EXPORT_SYMBOL(kasan_check_write);
+EXPORT_SYMBOL(__kasan_check_write);
#undef memset
void *memset(void *addr, int c, size_t len)