[PATCH 1/2] ubsan: allow to disable the null sanitizer
From: Christian Borntraeger <hidden>
Date: 2016-09-12 12:38:05
Also in:
linux-s390, lkml
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), library code, the rest, ubsan · Maintainers:
Nathan Chancellor, Nicolas Schier, Andrew Morton, Linus Torvalds, Kees Cook
Some architectures use a hardware defined struct at address zero. Checking for a null pointer will result in many ubsan reports. Let users disable the null sanitizer. Signed-off-by: Christian Borntraeger <redacted> --- lib/Kconfig.ubsan | 11 +++++++++++ scripts/Makefile.ubsan | 5 ++++- 2 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 39494af..851c3f2 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan@@ -1,6 +1,9 @@ config ARCH_HAS_UBSAN_SANITIZE_ALL bool +config ARCH_WANTS_UBSAN_NO_NULL + def_bool n + config UBSAN bool "Undefined behaviour sanity checker" help
@@ -34,3 +37,11 @@ config UBSAN_ALIGNMENT This option enables detection of unaligned memory accesses. Enabling this option on architectures that support unaligned accesses may produce a lot of false positives. + +config UBSAN_NULL + bool "Enable checking of null pointers" + depends on UBSAN + default y if UBSAN && !ARCH_WANTS_UBSAN_NO_NULL + help + This option enables detection of memory accesses via a + null pointer.
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 77ce538..3b1b138 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan@@ -3,7 +3,6 @@ ifdef CONFIG_UBSAN CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero) CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable) CFLAGS_UBSAN += $(call cc-option, -fsanitize=vla-bound) - CFLAGS_UBSAN += $(call cc-option, -fsanitize=null) CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow) CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds) CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size)
@@ -15,6 +14,10 @@ ifdef CONFIG_UBSAN_ALIGNMENT CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment) endif +ifdef CONFIG_UBSAN_NULL + CFLAGS_UBSAN += $(call cc-option, -fsanitize=null) +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)
--
2.5.5