linux-stable/scripts/Makefile.kasan
Nathan Chancellor 19532869fe kasan: always respect CONFIG_KASAN_STACK
Currently, the asan-stack parameter is only passed along if
CFLAGS_KASAN_SHADOW is not empty, which requires KASAN_SHADOW_OFFSET to
be defined in Kconfig so that the value can be checked.  In RISC-V's
case, KASAN_SHADOW_OFFSET is not defined in Kconfig, which means that
asan-stack does not get disabled with clang even when CONFIG_KASAN_STACK
is disabled, resulting in large stack warnings with allmodconfig:

  drivers/video/fbdev/omap2/omapfb/displays/panel-lgphilips-lb035q02.c:117:12: error: stack frame size (14400) exceeds limit (2048) in function 'lb035q02_connect' [-Werror,-Wframe-larger-than]
  static int lb035q02_connect(struct omap_dss_device *dssdev)
             ^
  1 error generated.

Ensure that the value of CONFIG_KASAN_STACK is always passed along to
the compiler so that these warnings do not happen when
CONFIG_KASAN_STACK is disabled.

Link: https://github.com/ClangBuiltLinux/linux/issues/1453
References: 6baec880d7 ("kasan: turn off asan-stack for clang-8 and earlier")
Link: https://lkml.kernel.org/r/20210922205525.570068-1-nathan@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-24 16:13:35 -07:00

59 lines
1.7 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0
CFLAGS_KASAN_NOSANITIZE := -fno-builtin
KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))
ifdef CONFIG_KASAN_STACK
stack_enable := 1
else
stack_enable := 0
endif
ifdef CONFIG_KASAN_GENERIC
ifdef CONFIG_KASAN_INLINE
call_threshold := 10000
else
call_threshold := 0
endif
CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address
# -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-instrument-allocas=1)
endif
CFLAGS_KASAN += $(call cc-param,asan-stack=$(stack_enable))
endif # CONFIG_KASAN_GENERIC
ifdef CONFIG_KASAN_SW_TAGS
ifdef CONFIG_KASAN_INLINE
instrumentation_flags := $(call cc-param,hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET))
else
instrumentation_flags := $(call cc-param,hwasan-instrument-with-calls=1)
endif
CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
$(call cc-param,hwasan-instrument-stack=$(stack_enable)) \
$(call cc-param,hwasan-use-short-granules=0) \
$(call cc-param,hwasan-inline-all-checks=0) \
$(instrumentation_flags)
endif # CONFIG_KASAN_SW_TAGS
export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE