From 1c6964f9756f7e292c3bc34b0b0c9a4943db1dc4 Mon Sep 17 00:00:00 2001 From: Anders Roxell Date: Wed, 12 Dec 2018 00:05:33 +0100 Subject: [PATCH] lib/ubsan: default UBSAN_ALIGNMENT to not set When booting an allmodconfig kernel, there are a lot of false-positives. With a message like this 'UBSAN: Undefined behaviour in...' with a call trace that follows. Reworked so that when building a allmodconfig kernel that turns everything into '=m' or '=y' will turn off UBSAN_ALIGNMENT. Co-developed-by: Arnd Bergmann Signed-off-by: Arnd Bergmann Signed-off-by: Anders Roxell --- lib/Kconfig.ubsan | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index 98fa559ebd80..a2ae4a8e4fa6 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -27,15 +27,19 @@ config UBSAN_SANITIZE_ALL Enabling this option will get kernel image size increased significantly. -config UBSAN_ALIGNMENT - bool "Enable checking of pointers alignment" +config UBSAN_NO_ALIGNMENT + bool "Disable checking of pointers alignment" depends on UBSAN - default y if !HAVE_EFFICIENT_UNALIGNED_ACCESS + default y if HAVE_EFFICIENT_UNALIGNED_ACCESS help - This option enables detection of unaligned memory accesses. - Enabling this option on architectures that support unaligned + This option disables the check of unaligned memory accesses. + This option should be used when building allmodconfig. + Disabling this option on architectures that support unaligned accesses may produce a lot of false positives. +config UBSAN_ALIGNMENT + def_bool !UBSAN_NO_ALIGNMENT + config TEST_UBSAN tristate "Module for testing for undefined behavior detection" depends on m && UBSAN -- 2.19.2