On 11/30/2017 12:50 AM, Paul Lawrence wrote:
> Use cc-option to figure out whether the compiler's sanitizer uses
> LLVM-style parameters ("-mllvm -asan-foo=bar") or GCC-style parameters
> ("--param asan-foo=bar").
>
> Signed-off-by: Greg Hackmann <ghackmann@xxxxxxxxxx>
> Signed-off-by: Paul Lawrence <paullawrence@xxxxxxxxxx>
>
> ---
> scripts/Makefile.kasan | 39 +++++++++++++++++++++++++++------------
> 1 file changed, 27 insertions(+), 12 deletions(-)
>
It looks rather messy. Try the following patch.
Note, that I didn't add asan-instrument-allocas=1 because it has nothing to do
with LLVM-style params support.
asan-instrument-allocas should probably be in the patch that adds alloca() support.
From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Subject: [PATCH] kasan/Makefile: Support LLVM style asan parameters.
LLVM doesn't understand GCC-style paramters ("--param asan-foo=bar"),
thus we currently we don't use inline/globals/stack instrumentation
when building the kernel with clang.
Add support for LLVM-style parameters ("-mllvm -asan-foo=bar") to
enable all KASAN features.
Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
---
scripts/Makefile.kasan | 29 ++++++++++++++++++-----------
1 file changed, 18 insertions(+), 11 deletions(-)
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1ce7115aa499..2af5977c394d 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -10,10 +10,7 @@ KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
-CFLAGS_KASAN := $(call cc-option, -fsanitize=kernel-address \
- -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET) \
- --param asan-stack=1 --param asan-globals=1 \
- --param asan-instrumentation-with-call-threshold=$(call_threshold))
+cc-param = $(call cc-option, --param $(1)) $(call cc-option, -mllvm -$(1))
ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
ifneq ($(CONFIG_COMPILE_TEST),y)
@@ -21,13 +18,23 @@ ifeq ($(call cc-option, $(CFLAGS_KASAN_MINIMAL) -Werror),)
-fsanitize=kernel-address is not supported by compiler)
endif
else
- ifeq ($(CFLAGS_KASAN),)
- ifneq ($(CONFIG_COMPILE_TEST),y)
- $(warning CONFIG_KASAN: compiler does not support all options.\
- Trying minimal configuration)
- endif
- CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
- endif
+ # -fasan-shadow-offset fails without -fsanitize
+ CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
+ -fasan-shadow-offset=$(KASAN_SHADOW_OFFSET), \
+ $(call cc-option, -fsanitize=kernel-address \
+ -mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))
+
+ ifeq ($(CFLAGS_KASAN_SHADOW),)
+ CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
+ else
+ # Now add all the compiler specific options that are valid standalone
+ CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
+ $(call cc-param,asan-globals=1) \
+ $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
+ $(call cc-param,asan-stack=1) \
+ $(call cc-param,asan-use-after-scope=1)
+ endif
+
endif
CFLAGS_KASAN += $(call cc-option, -fsanitize-address-use-after-scope)
--
2.13.6
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