mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 20:51:44 +00:00
7771bdbbfd
Use after scope bugs detector seems to be almost entirely useless for the linux kernel. It exists over two years, but I've seen only one valid bug so far [1]. And the bug was fixed before it has been reported. There were some other use-after-scope reports, but they were false-positives due to different reasons like incompatibility with structleak plugin. This feature significantly increases stack usage, especially with GCC < 9 version, and causes a 32K stack overflow. It probably adds performance penalty too. Given all that, let's remove use-after-scope detector entirely. While preparing this patch I've noticed that we mistakenly enable use-after-scope detection for clang compiler regardless of CONFIG_KASAN_EXTRA setting. This is also fixed now. [1] http://lkml.kernel.org/r/<20171129052106.rhgbjhhis53hkgfn@wfg-t540p.sh.intel.com> Link: http://lkml.kernel.org/r/20190111185842.13978-1-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Will Deacon <will.deacon@arm.com> [arm64] Cc: Qian Cai <cai@lca.pw> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
52 lines
1.4 KiB
Makefile
52 lines
1.4 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
|
|
ifdef CONFIG_KASAN_GENERIC
|
|
|
|
ifdef CONFIG_KASAN_INLINE
|
|
call_threshold := 10000
|
|
else
|
|
call_threshold := 0
|
|
endif
|
|
|
|
KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
|
|
|
|
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
|
|
|
|
cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
|
|
|
|
# -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 ($(strip $(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)) \
|
|
$(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \
|
|
$(call cc-param,asan-instrument-allocas=1)
|
|
endif
|
|
|
|
endif # CONFIG_KASAN_GENERIC
|
|
|
|
ifdef CONFIG_KASAN_SW_TAGS
|
|
|
|
ifdef CONFIG_KASAN_INLINE
|
|
instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
|
|
else
|
|
instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1
|
|
endif
|
|
|
|
CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
|
|
-mllvm -hwasan-instrument-stack=0 \
|
|
$(instrumentation_flags)
|
|
|
|
endif # CONFIG_KASAN_SW_TAGS
|
|
|
|
ifdef CONFIG_KASAN
|
|
CFLAGS_KASAN_NOSANITIZE := -fno-builtin
|
|
endif
|