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From:   Arnd Bergmann <arnd@kernel.org>
To:     Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>
Cc:     Arnd Bergmann <arnd@arndb.de>,
        Alexander Potapenko <glider@google.com>,
        Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Marco Elver <elver@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kbuild@vger.kernel.org, kasan-dev@googlegroups.com,
        linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com
Subject: [PATCH] kasan: fix hwasan build for gcc
Date:   Tue, 23 Mar 2021 13:41:04 +0100
Message-Id: <20210323124112.1229772-1-arnd@kernel.org>
MIME-Version: 1.0
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From: Arnd Bergmann <arnd@arndb.de>

gcc-11 adds support for -fsanitize=kernel-hwaddress, so it becomes
possible to enable CONFIG_KASAN_SW_TAGS.

Unfortunately this fails to build at the moment, because the
corresponding command line arguments use llvm specific syntax.

Change it to use the cc-param macro instead, which works on both
clang and gcc.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 scripts/Makefile.kasan | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1e000cc2e7b4..0a2789783d1b 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -36,14 +36,14 @@ endif # CONFIG_KASAN_GENERIC
 ifdef CONFIG_KASAN_SW_TAGS
 
 ifdef CONFIG_KASAN_INLINE
-    instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
+    instrumentation_flags := $(call cc-param,hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET))
 else
-    instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1
+    instrumentation_flags := $(call cc-param,hwasan-instrument-with-calls=1)
 endif
 
 CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
-		-mllvm -hwasan-instrument-stack=$(CONFIG_KASAN_STACK) \
-		-mllvm -hwasan-use-short-granules=0 \
+		$(call cc-param,hwasan-instrument-stack=$(CONFIG_KASAN_STACK)) \
+		$(call cc-param,hwasan-use-short-granules=0) \
 		$(instrumentation_flags)
 
 endif # CONFIG_KASAN_SW_TAGS
-- 
2.29.2