kasan: add CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS

This commit splits the current CONFIG_KASAN config option into two:
1. CONFIG_KASAN_GENERIC, that enables the generic KASAN mode (the one
   that exists now);
2. CONFIG_KASAN_SW_TAGS, that enables the software tag-based KASAN mode.

The name CONFIG_KASAN_SW_TAGS is chosen as in the future we will have
another hardware tag-based KASAN mode, that will rely on hardware memory
tagging support in arm64.

With CONFIG_KASAN_SW_TAGS enabled, compiler options are changed to
instrument kernel files with -fsantize=kernel-hwaddress (except the ones
for which KASAN_SANITIZE := n is set).

Both CONFIG_KASAN_GENERIC and CONFIG_KASAN_SW_TAGS support both
CONFIG_KASAN_INLINE and CONFIG_KASAN_OUTLINE instrumentation modes.

This commit also adds empty placeholder (for now) implementation of
tag-based KASAN specific hooks inserted by the compiler and adjusts
common hooks implementation.

While this commit adds the CONFIG_KASAN_SW_TAGS config option, this option
is not selectable, as it depends on HAVE_ARCH_KASAN_SW_TAGS, which we will
enable once all the infrastracture code has been added.

Link: http://lkml.kernel.org/r/b2550106eb8a68b10fefbabce820910b115aa853.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 13 deletions

diff --git a/include/linux/compiler_attributes.h b/include/linux/compiler_attributes.h
index fe07b680dd4a..19f32b0c29af 100644
--- a/include/linux/compiler_attributes.h
+++ b/include/linux/compiler_attributes.h
@@ -200,19 +200,6 @@
 #define __noreturn                      __attribute__((__noreturn__))
 
 /*
- * Optional: only supported since gcc >= 4.8
- * Optional: not supported by icc
- *
- *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-no_005fsanitize_005faddress-function-attribute
- * clang: https://clang.llvm.org/docs/AttributeReference.html#no-sanitize-address-no-address-safety-analysis
- */
-#if __has_attribute(__no_sanitize_address__)
-# define __no_sanitize_address          __attribute__((__no_sanitize_address__))
-#else
-# define __no_sanitize_address
-#endif
-
-/*
  *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Type-Attributes.html#index-packed-type-attribute
  * clang: https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html#index-packed-variable-attribute
  */