| Message ID | 20180626174013.GA41617@beast (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 2018-06-26 at 10:40 -0700, Kees Cook wrote: > This is the patch I've got prepared now that fixes for all VLAs have been > sent to maintainers (some are still under review/adjustment, but there > aren't any unexplored cases left). My intention would be to have this land > at the end of the next merge window after all the pending VLA patches > have landed. I just wanted to get any feedback here, since it touches > a couple areas in the process and I didn't want anyone to be surprised. :) [] > diff --git a/Makefile b/Makefile [] > @@ -778,6 +778,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) > # warn about C99 declaration after statement > KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) > > +# VLAs should not be used anywhere in the kernel > +KBUILD_CFLAGS += $(call cc-option,-Wvla) I'd probably spell out what a VLA is here. # VLAs (Variable Length Arrays) should not be used anywhere in the kernel Beyond that, seems sensible, thanks.
On Tue, Jun 26, 2018 at 1:21 PM, Joe Perches <joe@perches.com> wrote: > On Tue, 2018-06-26 at 10:40 -0700, Kees Cook wrote: >> This is the patch I've got prepared now that fixes for all VLAs have been >> sent to maintainers (some are still under review/adjustment, but there >> aren't any unexplored cases left). My intention would be to have this land >> at the end of the next merge window after all the pending VLA patches >> have landed. I just wanted to get any feedback here, since it touches >> a couple areas in the process and I didn't want anyone to be surprised. :) > [] >> diff --git a/Makefile b/Makefile > [] >> @@ -778,6 +778,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) >> # warn about C99 declaration after statement >> KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) >> >> +# VLAs should not be used anywhere in the kernel >> +KBUILD_CFLAGS += $(call cc-option,-Wvla) > > I'd probably spell out what a VLA is here. > # VLAs (Variable Length Arrays) should not be used anywhere in the kernel > > Beyond that, seems sensible, thanks. Ah yes, good idea. I've made that change locally now. Thanks! -Kees
diff --git a/Makefile b/Makefile index c9132594860b..3d5013ec4116 100644 --- a/Makefile +++ b/Makefile @@ -778,6 +778,9 @@ NOSTDINC_FLAGS += -nostdinc -isystem $(shell $(CC) -print-file-name=include) # warn about C99 declaration after statement KBUILD_CFLAGS += $(call cc-option,-Wdeclaration-after-statement,) +# 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) diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile index 4c6adae23e18..289ab5dc5712 100644 --- a/drivers/gpu/drm/i915/Makefile +++ b/drivers/gpu/drm/i915/Makefile @@ -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 += $(call cc-disable-warning, missing-field-initializers) diff --git a/lib/Makefile b/lib/Makefile index 90dc5520b784..4720e276232e 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -52,7 +52,9 @@ obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o obj-$(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 diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn index 8d5357053f86..24b2fb1d1297 100644 --- a/scripts/Makefile.extrawarn +++ b/scripts/Makefile.extrawarn @@ -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)))
This is the patch I've got prepared now that fixes for all VLAs have been sent to maintainers (some are still under review/adjustment, but there aren't any unexplored cases left). My intention would be to have this land at the end of the next merge window after all the pending VLA patches have landed. I just wanted to get any feedback here, since it touches a couple areas in the process and I didn't want anyone to be surprised. :) Thanks! -Kees ---- Now that VLAs have been removed 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. Signed-off-by: Kees Cook <keescook@chromium.org> --- Makefile | 3 +++ drivers/gpu/drm/i915/Makefile | 2 +- lib/Makefile | 2 ++ scripts/Makefile.extrawarn | 1 - 4 files changed, 6 insertions(+), 2 deletions(-)