The patch titled
Subject: ubsan: disable UBSAN_ALIGNMENT under COMPILE_TEST
has been added to the -mm tree. Its filename is
ubsan-disable-ubsan_alignment-under-compile_test.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ubsan-disable-ubsan_alignment-under-compile_test.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ubsan-disable-ubsan_alignment-under-compile_test.patch
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------------------------------------------------------
From: Kees Cook <keescook@xxxxxxxxxxxx>
Subject: 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: 0887a7ebc977 ("ubsan: add trap instrumentation option")
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-next/202004231224.D6B3B650@keescook/
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/Kconfig.ubsan | 15 ++++------
tools/testing/selftests/wireguard/qemu/debug.config | 1
2 files changed, 6 insertions(+), 10 deletions(-)
--- a/lib/Kconfig.ubsan~ubsan-disable-ubsan_alignment-under-compile_test
+++ a/lib/Kconfig.ubsan
@@ -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
--- a/tools/testing/selftests/wireguard/qemu/debug.config~ubsan-disable-ubsan_alignment-under-compile_test
+++ a/tools/testing/selftests/wireguard/qemu/debug.config
@@ -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
_
Patches currently in -mm which might be from keescook@xxxxxxxxxxxx are
ubsan-disable-ubsan_alignment-under-compile_test.patch
