Since the integer wrapping sanitizer's behavior depends on its associated
.scl file, we must force a full rebuild if the file changes. If not,
instrumentation may differ between targets based on when they were built.
Generate a new header file, integer-wrap.h, any time the Clang .scl
file changes. Include the header file in compiler-version.h when its
associated feature name, INTEGER_WRAP, is defined. This will be picked
up by fixdep and force rebuilds where needed.
Signed-off-by: Kees Cook <kees@kernel.org>
---
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas.schier@linux.dev>
Cc: Marco Elver <elver@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: <linux-kbuild@vger.kernel.org>
Cc: <kasan-dev@googlegroups.com>
Cc: <linux-hardening@vger.kernel.org>
---
include/linux/compiler-version.h | 3 +++
scripts/Makefile.ubsan | 1 +
scripts/basic/Makefile | 5 +++++
3 files changed, 9 insertions(+)
diff --git a/include/linux/compiler-version.h b/include/linux/compiler-version.h
index 69b29b400ce2..187e749f9e79 100644
--- a/include/linux/compiler-version.h
+++ b/include/linux/compiler-version.h
@@ -19,3 +19,6 @@
#ifdef RANDSTRUCT
#include <generated/randstruct_hash.h>
#endif
+#ifdef INTEGER_WRAP
+#include <generated/integer-wrap.h>
+#endif
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 9e35198edbf0..653f7117819c 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -15,6 +15,7 @@ ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(call cc-option,-fsanitize-trap=undefined
export CFLAGS_UBSAN := $(ubsan-cflags-y)
ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \
+ -DINTEGER_WRAP \
-fsanitize-undefined-ignore-overflow-pattern=all \
-fsanitize=signed-integer-overflow \
-fsanitize=unsigned-integer-overflow \
diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile
index dd289a6725ac..fb8e2c38fbc7 100644
--- a/scripts/basic/Makefile
+++ b/scripts/basic/Makefile
@@ -14,3 +14,8 @@ cmd_create_randstruct_seed = \
$(obj)/randstruct.seed: $(gen-randstruct-seed) FORCE
$(call if_changed,create_randstruct_seed)
always-$(CONFIG_RANDSTRUCT) += randstruct.seed
+
+# integer-wrap: if the .scl file changes, we need to do a full rebuild.
+$(obj)/../../include/generated/integer-wrap.h: $(srctree)/scripts/integer-wrap-ignore.scl FORCE
+ $(call if_changed,touch)
+always-$(CONFIG_UBSAN_INTEGER_WRAP) += ../../include/generated/integer-wrap.h
--
2.34.1On Sat, 03 May 2025, Kees Cook wrote: > Since the integer wrapping sanitizer's behavior depends on its associated > .scl file, we must force a full rebuild if the file changes. If not, > instrumentation may differ between targets based on when they were built. > > Generate a new header file, integer-wrap.h, any time the Clang .scl > file changes. Include the header file in compiler-version.h when its > associated feature name, INTEGER_WRAP, is defined. This will be picked > up by fixdep and force rebuilds where needed. > > Signed-off-by: Kees Cook <kees@kernel.org> > --- > Cc: Masahiro Yamada <masahiroy@kernel.org> > Cc: Justin Stitt <justinstitt@google.com> > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nicolas Schier <nicolas.schier@linux.dev> > Cc: Marco Elver <elver@google.com> > Cc: Andrey Konovalov <andreyknvl@gmail.com> > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > Cc: <linux-kbuild@vger.kernel.org> > Cc: <kasan-dev@googlegroups.com> > Cc: <linux-hardening@vger.kernel.org> > --- > include/linux/compiler-version.h | 3 +++ > scripts/Makefile.ubsan | 1 + > scripts/basic/Makefile | 5 +++++ > 3 files changed, 9 insertions(+) > > diff --git a/include/linux/compiler-version.h b/include/linux/compiler-version.h > index 69b29b400ce2..187e749f9e79 100644 > --- a/include/linux/compiler-version.h > +++ b/include/linux/compiler-version.h > @@ -19,3 +19,6 @@ > #ifdef RANDSTRUCT > #include <generated/randstruct_hash.h> > #endif > +#ifdef INTEGER_WRAP > +#include <generated/integer-wrap.h> > +#endif > diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan > index 9e35198edbf0..653f7117819c 100644 > --- a/scripts/Makefile.ubsan > +++ b/scripts/Makefile.ubsan > @@ -15,6 +15,7 @@ ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(call cc-option,-fsanitize-trap=undefined > export CFLAGS_UBSAN := $(ubsan-cflags-y) > > ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \ > + -DINTEGER_WRAP \ > -fsanitize-undefined-ignore-overflow-pattern=all \ > -fsanitize=signed-integer-overflow \ > -fsanitize=unsigned-integer-overflow \ > diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile > index dd289a6725ac..fb8e2c38fbc7 100644 > --- a/scripts/basic/Makefile > +++ b/scripts/basic/Makefile > @@ -14,3 +14,8 @@ cmd_create_randstruct_seed = \ > $(obj)/randstruct.seed: $(gen-randstruct-seed) FORCE > $(call if_changed,create_randstruct_seed) > always-$(CONFIG_RANDSTRUCT) += randstruct.seed > + > +# integer-wrap: if the .scl file changes, we need to do a full rebuild. > +$(obj)/../../include/generated/integer-wrap.h: $(srctree)/scripts/integer-wrap-ignore.scl FORCE > + $(call if_changed,touch) > +always-$(CONFIG_UBSAN_INTEGER_WRAP) += ../../include/generated/integer-wrap.h > -- > 2.34.1 > Reviewed-by: Nicolas Schier <n.schier@avm.de>
On Sat, May 3, 2025 at 11:46 AM Kees Cook <kees@kernel.org> wrote: > > Since the integer wrapping sanitizer's behavior depends on its associated > .scl file, we must force a full rebuild if the file changes. If not, > instrumentation may differ between targets based on when they were built. > > Generate a new header file, integer-wrap.h, any time the Clang .scl > file changes. Include the header file in compiler-version.h when its > associated feature name, INTEGER_WRAP, is defined. This will be picked > up by fixdep and force rebuilds where needed. > > Signed-off-by: Kees Cook <kees@kernel.org> > --- > Cc: Masahiro Yamada <masahiroy@kernel.org> > Cc: Justin Stitt <justinstitt@google.com> > Cc: Nathan Chancellor <nathan@kernel.org> > Cc: Nicolas Schier <nicolas.schier@linux.dev> > Cc: Marco Elver <elver@google.com> > Cc: Andrey Konovalov <andreyknvl@gmail.com> > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > Cc: <linux-kbuild@vger.kernel.org> > Cc: <kasan-dev@googlegroups.com> > Cc: <linux-hardening@vger.kernel.org> > --- > include/linux/compiler-version.h | 3 +++ > scripts/Makefile.ubsan | 1 + > scripts/basic/Makefile | 5 +++++ > 3 files changed, 9 insertions(+) > > diff --git a/include/linux/compiler-version.h b/include/linux/compiler-version.h > index 69b29b400ce2..187e749f9e79 100644 > --- a/include/linux/compiler-version.h > +++ b/include/linux/compiler-version.h > @@ -19,3 +19,6 @@ > #ifdef RANDSTRUCT > #include <generated/randstruct_hash.h> > #endif > +#ifdef INTEGER_WRAP > +#include <generated/integer-wrap.h> > +#endif > diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan > index 9e35198edbf0..653f7117819c 100644 > --- a/scripts/Makefile.ubsan > +++ b/scripts/Makefile.ubsan > @@ -15,6 +15,7 @@ ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(call cc-option,-fsanitize-trap=undefined > export CFLAGS_UBSAN := $(ubsan-cflags-y) > > ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \ > + -DINTEGER_WRAP \ > -fsanitize-undefined-ignore-overflow-pattern=all \ > -fsanitize=signed-integer-overflow \ > -fsanitize=unsigned-integer-overflow \ > diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile > index dd289a6725ac..fb8e2c38fbc7 100644 > --- a/scripts/basic/Makefile > +++ b/scripts/basic/Makefile > @@ -14,3 +14,8 @@ cmd_create_randstruct_seed = \ > $(obj)/randstruct.seed: $(gen-randstruct-seed) FORCE > $(call if_changed,create_randstruct_seed) > always-$(CONFIG_RANDSTRUCT) += randstruct.seed > + > +# integer-wrap: if the .scl file changes, we need to do a full rebuild. > +$(obj)/../../include/generated/integer-wrap.h: $(srctree)/scripts/integer-wrap-ignore.scl FORCE > + $(call if_changed,touch) > +always-$(CONFIG_UBSAN_INTEGER_WRAP) += ../../include/generated/integer-wrap.h I'm not sure how this fake header stuff works to ensure builds deps are tracked properly but we do need scl files to be considered as part of complete builds, so: Acked-by: Justin Stitt <justinstitt@google.com> > -- > 2.34.1 >
On Mon, May 5, 2025 at 11:16 AM Justin Stitt <justinstitt@google.com> wrote: > > On Sat, May 3, 2025 at 11:46 AM Kees Cook <kees@kernel.org> wrote: > > > > Since the integer wrapping sanitizer's behavior depends on its associated > > .scl file, we must force a full rebuild if the file changes. If not, > > instrumentation may differ between targets based on when they were built. > > > > Generate a new header file, integer-wrap.h, any time the Clang .scl > > file changes. Include the header file in compiler-version.h when its > > associated feature name, INTEGER_WRAP, is defined. This will be picked > > up by fixdep and force rebuilds where needed. > > > > Signed-off-by: Kees Cook <kees@kernel.org> > > --- > > Cc: Masahiro Yamada <masahiroy@kernel.org> > > Cc: Justin Stitt <justinstitt@google.com> > > Cc: Nathan Chancellor <nathan@kernel.org> > > Cc: Nicolas Schier <nicolas.schier@linux.dev> > > Cc: Marco Elver <elver@google.com> > > Cc: Andrey Konovalov <andreyknvl@gmail.com> > > Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> > > Cc: <linux-kbuild@vger.kernel.org> > > Cc: <kasan-dev@googlegroups.com> > > Cc: <linux-hardening@vger.kernel.org> > > --- > > include/linux/compiler-version.h | 3 +++ > > scripts/Makefile.ubsan | 1 + > > scripts/basic/Makefile | 5 +++++ > > 3 files changed, 9 insertions(+) > > > > diff --git a/include/linux/compiler-version.h b/include/linux/compiler-version.h > > index 69b29b400ce2..187e749f9e79 100644 > > --- a/include/linux/compiler-version.h > > +++ b/include/linux/compiler-version.h > > @@ -19,3 +19,6 @@ > > #ifdef RANDSTRUCT > > #include <generated/randstruct_hash.h> > > #endif > > +#ifdef INTEGER_WRAP > > +#include <generated/integer-wrap.h> > > +#endif > > diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan > > index 9e35198edbf0..653f7117819c 100644 > > --- a/scripts/Makefile.ubsan > > +++ b/scripts/Makefile.ubsan > > @@ -15,6 +15,7 @@ ubsan-cflags-$(CONFIG_UBSAN_TRAP) += $(call cc-option,-fsanitize-trap=undefined > > export CFLAGS_UBSAN := $(ubsan-cflags-y) > > > > ubsan-integer-wrap-cflags-$(CONFIG_UBSAN_INTEGER_WRAP) += \ > > + -DINTEGER_WRAP \ > > -fsanitize-undefined-ignore-overflow-pattern=all \ > > -fsanitize=signed-integer-overflow \ > > -fsanitize=unsigned-integer-overflow \ > > diff --git a/scripts/basic/Makefile b/scripts/basic/Makefile > > index dd289a6725ac..fb8e2c38fbc7 100644 > > --- a/scripts/basic/Makefile > > +++ b/scripts/basic/Makefile > > @@ -14,3 +14,8 @@ cmd_create_randstruct_seed = \ > > $(obj)/randstruct.seed: $(gen-randstruct-seed) FORCE > > $(call if_changed,create_randstruct_seed) > > always-$(CONFIG_RANDSTRUCT) += randstruct.seed > > + > > +# integer-wrap: if the .scl file changes, we need to do a full rebuild. > > +$(obj)/../../include/generated/integer-wrap.h: $(srctree)/scripts/integer-wrap-ignore.scl FORCE > > + $(call if_changed,touch) > > +always-$(CONFIG_UBSAN_INTEGER_WRAP) += ../../include/generated/integer-wrap.h > > I'm not sure how this fake header stuff works to ensure builds deps > are tracked properly but we do need scl files to be considered as part > of complete builds, so: As in, I'm sure it works but have personally never written or reviewed a Makefile+generated header snippet like that before :) > > Acked-by: Justin Stitt <justinstitt@google.com> > > > -- > > 2.34.1 > >
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