Commit 8d58f222 authored by Kees Cook's avatar Kees Cook Committed by Linus Torvalds
Browse files

ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST 

The documentation for UBSAN_ALIGNMENT already mentions that it should
not be used on all*config builds (and for efficient-unaligned-access
architectures), so just refactor the Kconfig to correctly implement this
so randconfigs will stop creating insane images that freak out objtool
under CONFIG_UBSAN_TRAP (due to the false positives producing functions
that never return, etc).

Link: http://lkml.kernel.org/r/202005011433.C42EA3E2D@keescook


Fixes: 0887a7eb ("ubsan: add trap instrumentation option")
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Reported-by: default avatarRandy Dunlap <rdunlap@infradead.org>
  Link: https://lore.kernel.org/linux-next/202004231224.D6B3B650@keescook/


Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 17e34526

lib/Kconfig.ubsan

+6 −9
Original line number Diff line number Diff line
@@ -60,18 +60,15 @@ config UBSAN_SANITIZE_ALL 
	  Enabling this option will get kernel image size increased

	  significantly.



config UBSAN_NO_ALIGNMENT

	bool "Disable checking of pointers alignment"

	default y if HAVE_EFFICIENT_UNALIGNED_ACCESS

config UBSAN_ALIGNMENT

	bool "Enable checks for pointers alignment"

	default !HAVE_EFFICIENT_UNALIGNED_ACCESS

	depends on !X86 || !COMPILE_TEST

	help

	  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

	  This option enables the check of unaligned memory accesses.

	  Enabling 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

tools/testing/selftests/wireguard/qemu/debug.config

+0 −1
Original line number Diff line number Diff line
@@ -25,7 +25,6 @@ CONFIG_KASAN=y 
CONFIG_KASAN_INLINE=y

CONFIG_UBSAN=y

CONFIG_UBSAN_SANITIZE_ALL=y

CONFIG_UBSAN_NO_ALIGNMENT=y

CONFIG_UBSAN_NULL=y

CONFIG_DEBUG_KMEMLEAK=y

CONFIG_DEBUG_KMEMLEAK_EARLY_LOG_SIZE=8192

CRA Git | Maintained and supported by SUSTech CRA and CCSE