Commit 0bb95f80 authored by Kees Cook's avatar Kees Cook
Browse files

Makefile: Globally enable VLA warning 

Now that Variable Length Arrays (VLAs) have been entirely removed[1]
from the kernel, enable the VLA warning globally. The only exceptions
to this are the KASan an UBSan tests which are explicitly checking that
VLAs trigger their respective tests.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com



Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: David Airlie <airlied@linux.ie>
Cc: linux-kbuild@vger.kernel.org
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent 81b45683

Makefile

+3 −0
Original line number Diff line number Diff line
@@ -804,6 +804,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) 
# warn about C99 declaration after statement

KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,)



# Variable Length Arrays (VLAs) should not be used anywhere in the kernel

KBUILD_CFLAGS += $(call cc-option,-Wvla)



# disable pointer signed / unsigned warnings in gcc 4.0

KBUILD_CFLAGS += $(call cc-disable-warning, pointer-sign)

drivers/gpu/drm/i915/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 
# Note the danger in using -Wall -Wextra is that when CI updates gcc we

# will most likely get a sudden build breakage... Hopefully we will fix

# new warnings before CI updates!

subdir-ccflags-y := -Wall -Wextra -Wvla

subdir-ccflags-y := -Wall -Wextra

subdir-ccflags-y += $(call cc-disable-warning, unused-parameter)

subdir-ccflags-y += $(call cc-disable-warning, type-limits)

subdir-ccflags-y += $(call cc-disable-warning, missing-field-initializers)

lib/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -53,7 +53,9 @@ obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o 
obj-$(CONFIG_TEST_IDA) += test_ida.o

obj-$(CONFIG_TEST_KASAN) += test_kasan.o

CFLAGS_test_kasan.o += -fno-builtin

CFLAGS_test_kasan.o += $(call cc-disable-warning, vla)

obj-$(CONFIG_TEST_UBSAN) += test_ubsan.o

CFLAGS_test_ubsan.o += $(call cc-disable-warning, vla)

UBSAN_SANITIZE_test_ubsan.o := y

obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o

obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o

scripts/Makefile.extrawarn

+0 −1
Original line number Diff line number Diff line
@@ -52,7 +52,6 @@ warning-3 += -Wpointer-arith 
warning-3 += -Wredundant-decls

warning-3 += -Wswitch-default

warning-3 += $(call cc-option, -Wpacked-bitfield-compat)

warning-3 += $(call cc-option, -Wvla)



warning := $(warning-$(findstring 1, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))

warning += $(warning-$(findstring 2, $(KBUILD_ENABLE_EXTRA_GCC_CHECKS)))

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