* [PATCH] ubsan: Disable UBSAN_ALIGNMENT under COMPILE_TEST
@ 2020-05-01 21:42 Kees Cook
0 siblings, 0 replies; only message in thread
From: Kees Cook @ 2020-05-01 21:42 UTC (permalink / raw)
To: Andrew Morton
Cc: Josh Poimboeuf, Randy Dunlap, Stephen Rothwell, Peter Zijlstra,
Andrey Ryabinin, Linux Next Mailing List, linux-kernel
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).
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/linux-next/202004231224.D6B3B650@keescook/
Fixes: 0887a7ebc977 ("ubsan: add trap instrumentation option")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
lib/Kconfig.ubsan | 15 ++++++---------
.../testing/selftests/wireguard/qemu/debug.config | 1 -
2 files changed, 6 insertions(+), 10 deletions(-)
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 48469c95d78e..929211039bac 100644
--- a/lib/Kconfig.ubsan
+++ b/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
diff --git a/tools/testing/selftests/wireguard/qemu/debug.config b/tools/testing/selftests/wireguard/qemu/debug.config
index 807fa7dc60b8..b50c2085c1ac 100644
--- a/tools/testing/selftests/wireguard/qemu/debug.config
+++ b/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
--
2.20.1
--
Kees Cook
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