Instead of doing if/endif blocks with cc-option calls in the UBSAN
Makefile, move all the tests into Kconfig and use the Makefile to
collect the results.
Suggested-by: Linus Torvalds <[email protected]>
Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
Signed-off-by: Kees Cook <[email protected]>
---
lib/Kconfig.ubsan | 48 +++++++++++++++++++++++++++++++++++++++-
scripts/Makefile.ubsan | 50 ++++++++++++++----------------------------
2 files changed, 64 insertions(+), 34 deletions(-)
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 58f8d03d037b..c0b801871e0b 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan
@@ -36,10 +36,17 @@ config UBSAN_KCOV_BROKEN
See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status
in newer releases.
+config CC_HAS_UBSAN_BOUNDS
+ def_bool $(cc-option,-fsanitize=bounds)
+
+config CC_HAS_UBSAN_ARRAY_BOUNDS
+ def_bool $(cc-option,-fsanitize=array-bounds)
+
config UBSAN_BOUNDS
bool "Perform array index bounds checking"
default UBSAN
depends on !UBSAN_KCOV_BROKEN
+ depends on CC_HAS_UBSAN_ARRAY_BOUNDS || CC_HAS_UBSAN_BOUNDS
help
This option enables detection of directly indexed out of bounds
array accesses, where the array size is known at compile time.
@@ -47,11 +54,17 @@ config UBSAN_BOUNDS
to the {str,mem}*cpy() family of functions (that is addressed
by CONFIG_FORTIFY_SOURCE).
+config CC_ARG_UBSAN_BOUNDS
+ string
+ default "-fsanitize=array-bounds" if CC_HAS_UBSAN_ARRAY_BOUNDS
+ default "-fsanitize=bounds"
+ depends on UBSAN_BOUNDS
+
config UBSAN_LOCAL_BOUNDS
bool "Perform array local bounds checking"
depends on UBSAN_TRAP
- depends on CC_IS_CLANG
depends on !UBSAN_KCOV_BROKEN
+ depends on $(cc-option,-fsanitize=local-bounds)
help
This option enables -fsanitize=local-bounds which traps when an
exception/error is detected. Therefore, it should be enabled only
@@ -69,6 +82,38 @@ config UBSAN_MISC
own Kconfig options. Disable this if you only want to have
individually selected checks.
+config UBSAN_SHIFT
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=shift)
+
+config UBSAN_DIV_ZERO
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=integer-divide-by-zero)
+
+config UBSAN_UNREACHABLE
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=unreachable)
+
+config UBSAN_SIGNED_OVERFLOW
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=signed-integer-overflow)
+
+config UBSAN_UNSIGNED_OVERFLOW
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
+
+config UBSAN_OBJECT_SIZE
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=object-size)
+
+config UBSAN_BOOL
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=bool)
+
+config UBSAN_ENUM
+ def_bool UBSAN_MISC
+ depends on $(cc-option,-fsanitize=enum)
+
config UBSAN_SANITIZE_ALL
bool "Enable instrumentation for the entire kernel"
depends on ARCH_HAS_UBSAN_SANITIZE_ALL
@@ -89,6 +134,7 @@ config UBSAN_ALIGNMENT
bool "Enable checks for pointers alignment"
default !HAVE_EFFICIENT_UNALIGNED_ACCESS
depends on !UBSAN_TRAP
+ depends on $(cc-option,-fsanitize=alignment)
help
This option enables the check of unaligned memory accesses.
Enabling this option on architectures that support unaligned
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 9716dab06bc7..72862da47baf 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -1,37 +1,21 @@
# SPDX-License-Identifier: GPL-2.0
-export CFLAGS_UBSAN :=
+# -fsanitize=* options makes GCC less smart than usual and
+# increases the number of 'maybe-uninitialized' false-positives.
+ubsan-cflags-$(CONFIG_UBSAN) += $(call cc-disable-warning, maybe-uninitialized)
-ifdef CONFIG_UBSAN_ALIGNMENT
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
-endif
+# Enable available and selected UBSAN features.
+ubsan-cflags-$(CONFIG_UBSAN_ALIGNMENT) += -fsanitize=alignment
+ubsan-cflags-$(CONFIG_UBSAN_BOUNDS) += $(CONFIG_CC_ARG_UBSAN_BOUNDS)
+ubsan-cflags-$(CONFIG_UBSAN_LOCAL_BOUNDS) += -fsanitize=local-bounds
+ubsan-cflags-$(CONFIG_UBSAN_SHIFT) += -fsanitize=shift
+ubsan-cflags-$(CONFIG_UBSAN_DIV_ZERO) += -fsanitize=integer-divide-by-zero
+ubsan-cflags-$(CONFIG_UBSAN_UNREACHABLE) += -fsanitize=unreachable
+ubsan-cflags-$(CONFIG_UBSAN_SIGNED_OVERFLOW) += -fsanitize=signed-integer-overflow
+ubsan-cflags-$(CONFIG_UBSAN_UNSIGNED_OVERFLOW) += -fsanitize=unsigned-integer-overflow
+ubsan-cflags-$(CONFIG_UBSAN_OBJECT_SIZE) += -fsanitize=object-size
+ubsan-cflags-$(CONFIG_UBSAN_BOOL) += -fsanitize=bool
+ubsan-cflags-$(CONFIG_UBSAN_ENUM) += -fsanitize=enum
+ubsan-cflags-$(CONFIG_UBSAN_TRAP) += -fsanitize-undefined-trap-on-error
-ifdef CONFIG_UBSAN_BOUNDS
- ifdef CONFIG_CC_IS_CLANG
- CFLAGS_UBSAN += -fsanitize=array-bounds
- else
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
- endif
-endif
-
-ifdef CONFIG_UBSAN_LOCAL_BOUNDS
- CFLAGS_UBSAN += -fsanitize=local-bounds
-endif
-
-ifdef CONFIG_UBSAN_MISC
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
- CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
-endif
-
-ifdef CONFIG_UBSAN_TRAP
- CFLAGS_UBSAN += $(call cc-option, -fsanitize-undefined-trap-on-error)
-endif
-
- # -fsanitize=* options makes GCC less smart than usual and
- # increase number of 'maybe-uninitialized false-positives
- CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized)
+export CFLAGS_UBSAN := $(ubsan-cflags-y)
--
2.25.1
On Fri, Oct 02, 2020 at 03:15:24PM -0700, Kees Cook wrote:
> Instead of doing if/endif blocks with cc-option calls in the UBSAN
> Makefile, move all the tests into Kconfig and use the Makefile to
> collect the results.
>
> Suggested-by: Linus Torvalds <[email protected]>
> Signed-off-by: Kees Cook <[email protected]>
> Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
I tested menuconfig to make sure all the flags when CONFIG_UBSAN_MISC is
flipped.
Reviewed-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
One comment below.
> ---
> lib/Kconfig.ubsan | 48 +++++++++++++++++++++++++++++++++++++++-
> scripts/Makefile.ubsan | 50 ++++++++++++++----------------------------
> 2 files changed, 64 insertions(+), 34 deletions(-)
>
> diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
> index 58f8d03d037b..c0b801871e0b 100644
> --- a/lib/Kconfig.ubsan
> +++ b/lib/Kconfig.ubsan
> @@ -36,10 +36,17 @@ config UBSAN_KCOV_BROKEN
> See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status
> in newer releases.
>
> +config CC_HAS_UBSAN_BOUNDS
> + def_bool $(cc-option,-fsanitize=bounds)
> +
> +config CC_HAS_UBSAN_ARRAY_BOUNDS
> + def_bool $(cc-option,-fsanitize=array-bounds)
> +
> config UBSAN_BOUNDS
> bool "Perform array index bounds checking"
> default UBSAN
> depends on !UBSAN_KCOV_BROKEN
> + depends on CC_HAS_UBSAN_ARRAY_BOUNDS || CC_HAS_UBSAN_BOUNDS
> help
> This option enables detection of directly indexed out of bounds
> array accesses, where the array size is known at compile time.
> @@ -47,11 +54,17 @@ config UBSAN_BOUNDS
> to the {str,mem}*cpy() family of functions (that is addressed
> by CONFIG_FORTIFY_SOURCE).
>
> +config CC_ARG_UBSAN_BOUNDS
> + string
> + default "-fsanitize=array-bounds" if CC_HAS_UBSAN_ARRAY_BOUNDS
> + default "-fsanitize=bounds"
> + depends on UBSAN_BOUNDS
> +
> config UBSAN_LOCAL_BOUNDS
> bool "Perform array local bounds checking"
> depends on UBSAN_TRAP
> - depends on CC_IS_CLANG
> depends on !UBSAN_KCOV_BROKEN
> + depends on $(cc-option,-fsanitize=local-bounds)
> help
> This option enables -fsanitize=local-bounds which traps when an
> exception/error is detected. Therefore, it should be enabled only
> @@ -69,6 +82,38 @@ config UBSAN_MISC
> own Kconfig options. Disable this if you only want to have
> individually selected checks.
>
> +config UBSAN_SHIFT
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=shift)
> +
> +config UBSAN_DIV_ZERO
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=integer-divide-by-zero)
> +
> +config UBSAN_UNREACHABLE
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=unreachable)
> +
> +config UBSAN_SIGNED_OVERFLOW
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=signed-integer-overflow)
> +
> +config UBSAN_UNSIGNED_OVERFLOW
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=unsigned-integer-overflow)
> +
> +config UBSAN_OBJECT_SIZE
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=object-size)
> +
> +config UBSAN_BOOL
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=bool)
> +
> +config UBSAN_ENUM
> + def_bool UBSAN_MISC
> + depends on $(cc-option,-fsanitize=enum)
> +
> config UBSAN_SANITIZE_ALL
> bool "Enable instrumentation for the entire kernel"
> depends on ARCH_HAS_UBSAN_SANITIZE_ALL
> @@ -89,6 +134,7 @@ config UBSAN_ALIGNMENT
> bool "Enable checks for pointers alignment"
> default !HAVE_EFFICIENT_UNALIGNED_ACCESS
> depends on !UBSAN_TRAP
> + depends on $(cc-option,-fsanitize=alignment)
> help
> This option enables the check of unaligned memory accesses.
> Enabling this option on architectures that support unaligned
> diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
> index 9716dab06bc7..72862da47baf 100644
> --- a/scripts/Makefile.ubsan
> +++ b/scripts/Makefile.ubsan
> @@ -1,37 +1,21 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -export CFLAGS_UBSAN :=
> +# -fsanitize=* options makes GCC less smart than usual and
> +# increases the number of 'maybe-uninitialized' false-positives.
> +ubsan-cflags-$(CONFIG_UBSAN) += $(call cc-disable-warning, maybe-uninitialized)
Is this just to force -Wno-maybe-uninitialized even when W=2?
-Wmaybe-uninitialized is already disabled globally after
commit 78a5255ffb6a ("Stop the ad-hoc games with
-Wno-maybe-initialized"). I feel like it might be worth a comment in
case that changes in the future but maybe that is a bit much.
> -ifdef CONFIG_UBSAN_ALIGNMENT
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
> -endif
> +# Enable available and selected UBSAN features.
> +ubsan-cflags-$(CONFIG_UBSAN_ALIGNMENT) += -fsanitize=alignment
> +ubsan-cflags-$(CONFIG_UBSAN_BOUNDS) += $(CONFIG_CC_ARG_UBSAN_BOUNDS)
> +ubsan-cflags-$(CONFIG_UBSAN_LOCAL_BOUNDS) += -fsanitize=local-bounds
> +ubsan-cflags-$(CONFIG_UBSAN_SHIFT) += -fsanitize=shift
> +ubsan-cflags-$(CONFIG_UBSAN_DIV_ZERO) += -fsanitize=integer-divide-by-zero
> +ubsan-cflags-$(CONFIG_UBSAN_UNREACHABLE) += -fsanitize=unreachable
> +ubsan-cflags-$(CONFIG_UBSAN_SIGNED_OVERFLOW) += -fsanitize=signed-integer-overflow
> +ubsan-cflags-$(CONFIG_UBSAN_UNSIGNED_OVERFLOW) += -fsanitize=unsigned-integer-overflow
> +ubsan-cflags-$(CONFIG_UBSAN_OBJECT_SIZE) += -fsanitize=object-size
> +ubsan-cflags-$(CONFIG_UBSAN_BOOL) += -fsanitize=bool
> +ubsan-cflags-$(CONFIG_UBSAN_ENUM) += -fsanitize=enum
> +ubsan-cflags-$(CONFIG_UBSAN_TRAP) += -fsanitize-undefined-trap-on-error
>
> -ifdef CONFIG_UBSAN_BOUNDS
> - ifdef CONFIG_CC_IS_CLANG
> - CFLAGS_UBSAN += -fsanitize=array-bounds
> - else
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds)
> - endif
> -endif
> -
> -ifdef CONFIG_UBSAN_LOCAL_BOUNDS
> - CFLAGS_UBSAN += -fsanitize=local-bounds
> -endif
> -
> -ifdef CONFIG_UBSAN_MISC
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool)
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum)
> -endif
> -
> -ifdef CONFIG_UBSAN_TRAP
> - CFLAGS_UBSAN += $(call cc-option, -fsanitize-undefined-trap-on-error)
> -endif
> -
> - # -fsanitize=* options makes GCC less smart than usual and
> - # increase number of 'maybe-uninitialized false-positives
> - CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized)
> +export CFLAGS_UBSAN := $(ubsan-cflags-y)
> --
> 2.25.1
On Sun, Oct 04, 2020 at 12:08:47AM -0700, Nathan Chancellor wrote:
> On Fri, Oct 02, 2020 at 03:15:24PM -0700, Kees Cook wrote:
> > Instead of doing if/endif blocks with cc-option calls in the UBSAN
> > Makefile, move all the tests into Kconfig and use the Makefile to
> > collect the results.
> >
> > Suggested-by: Linus Torvalds <[email protected]>
> > Signed-off-by: Kees Cook <[email protected]>
> > Link: https://lore.kernel.org/lkml/CAHk-=wjPasyJrDuwDnpHJS2TuQfExwe=px-SzLeN8GFMAQJPmQ@mail.gmail.com/
>
> I tested menuconfig to make sure all the flags when CONFIG_UBSAN_MISC is
> flipped.
>
> Reviewed-by: Nathan Chancellor <[email protected]>
> Tested-by: Nathan Chancellor <[email protected]>
Awesome, thank you!
> One comment below.
>
> > [...]
> > diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
> > index 9716dab06bc7..72862da47baf 100644
> > --- a/scripts/Makefile.ubsan
> > +++ b/scripts/Makefile.ubsan
> > @@ -1,37 +1,21 @@
> > # SPDX-License-Identifier: GPL-2.0
> >
> > -export CFLAGS_UBSAN :=
> > +# -fsanitize=* options makes GCC less smart than usual and
> > +# increases the number of 'maybe-uninitialized' false-positives.
> > +ubsan-cflags-$(CONFIG_UBSAN) += $(call cc-disable-warning, maybe-uninitialized)
>
> Is this just to force -Wno-maybe-uninitialized even when W=2?
> -Wmaybe-uninitialized is already disabled globally after
> commit 78a5255ffb6a ("Stop the ad-hoc games with
> -Wno-maybe-initialized"). I feel like it might be worth a comment in
> case that changes in the future but maybe that is a bit much.
>
> > [...]
> > - # -fsanitize=* options makes GCC less smart than usual and
> > - # increase number of 'maybe-uninitialized false-positives
> > - CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized)
It's just a direct copying of the existing logic, but into the new
"ubsan-cflags-y" style. But yes, AFAICT, that was the intent when it was
added in commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized
warning for "make W=1"").
So for this patch, I kept the logic as it was.
--
Kees Cook