From 725c4d22bbc4fcac5779963e0ff9cdf232afbb90 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Mon, 12 Sep 2016 14:37:19 +0200
Subject: [PATCH] ubsan: allow to disable the null sanitizer
Some architectures use a hardware defined structure at address zero.
Checking for a null pointer will result in many ubsan reports.
Allow users to disable the null sanitizer.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
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 39494af9a84ac..bc6e651df68c3 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 !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 8ab68679cfb5b..dd779c40c8e6a 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)
@@ -14,4 +13,8 @@ ifdef CONFIG_UBSAN
ifdef CONFIG_UBSAN_ALIGNMENT
CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
endif
+
+ifdef CONFIG_UBSAN_NULL
+ CFLAGS_UBSAN += $(call cc-option, -fsanitize=null)
+endif
endif
--
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