[PATCH 2/2] x86: Disable both KASAN and UBSAN for some booting code

From: Changbin Du
Date: Sat Feb 01 2020 - 01:25:24 EST


Now we have disabled KASAN for some special files properly which might
prevent kernel to boot. We also need to disable UBSAN for some of these
files:
o For code which could operate in one-one mapping mode. In this case,
kernel would crash at accessing data parameter when invoking UBSAN
handlers.
o Since UBSAN handlers are instrumented by KASAN, so invoking UBSAN
handlers before KASAN is initiated also is not allowed.

It is easy to prove such behavior by adding a line of code that triggers
UBSAN report before kasan_early_init().

Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
---
arch/x86/boot/Makefile | 2 +-
arch/x86/boot/compressed/Makefile | 2 +-
arch/x86/entry/vdso/Makefile | 3 +--
arch/x86/kernel/Makefile | 10 +++++-----
arch/x86/lib/Makefile | 2 +-
arch/x86/mm/Makefile | 4 ++--
arch/x86/realmode/Makefile | 2 +-
arch/x86/realmode/rm/Makefile | 2 +-
8 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/arch/x86/boot/Makefile b/arch/x86/boot/Makefile
index 748b6d28a91d..cd1f1ddbd319 100644
--- a/arch/x86/boot/Makefile
+++ b/arch/x86/boot/Makefile
@@ -9,7 +9,7 @@
# Changed by many, many contributors over the years.
#

-KASAN_SANITIZE := n
+SANITIZE := n
OBJECT_FILES_NON_STANDARD := y

# Kernel does not boot with kcov instrumentation here.
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile
index 56aa5fa0a66b..82304ccc1e12 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -17,7 +17,7 @@
# (see scripts/Makefile.lib size_append)
# compressed vmlinux.bin.all + u32 size of vmlinux.bin.all

-KASAN_SANITIZE := n
+SANITIZE := n
OBJECT_FILES_NON_STANDARD := y

# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 2b75e80f6b41..53728b92374b 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -10,8 +10,7 @@ ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
include $(srctree)/lib/vdso/Makefile

KBUILD_CFLAGS += $(DISABLE_LTO)
-KASAN_SANITIZE := n
-UBSAN_SANITIZE := n
+SANITIZE := n
OBJECT_FILES_NON_STANDARD := y

# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 6175e370ee4a..c038ef0fc77c 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -22,11 +22,11 @@ CFLAGS_REMOVE_early_printk.o = -pg
CFLAGS_REMOVE_head64.o = -pg
endif

-KASAN_SANITIZE_head$(BITS).o := n
-KASAN_SANITIZE_dumpstack.o := n
-KASAN_SANITIZE_dumpstack_$(BITS).o := n
-KASAN_SANITIZE_stacktrace.o := n
-KASAN_SANITIZE_paravirt.o := n
+SANITIZE_head$(BITS).o := n
+SANITIZE_dumpstack.o := n
+SANITIZE_dumpstack_$(BITS).o := n
+SANITIZE_stacktrace.o := n
+SANITIZE_paravirt.o := n

OBJECT_FILES_NON_STANDARD_relocate_kernel_$(BITS).o := y
OBJECT_FILES_NON_STANDARD_test_nx.o := y
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index 5246db42de45..f0da5b35e745 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -9,7 +9,7 @@ KCOV_INSTRUMENT_delay.o := n
# Early boot use of cmdline; don't instrument it
ifdef CONFIG_AMD_MEM_ENCRYPT
KCOV_INSTRUMENT_cmdline.o := n
-KASAN_SANITIZE_cmdline.o := n
+SANITIZE_cmdline.o := n

ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_cmdline.o = -pg
diff --git a/arch/x86/mm/Makefile b/arch/x86/mm/Makefile
index 98aecb14fbcc..58d58d9208e9 100644
--- a/arch/x86/mm/Makefile
+++ b/arch/x86/mm/Makefile
@@ -4,8 +4,8 @@ KCOV_INSTRUMENT_tlb.o := n
KCOV_INSTRUMENT_mem_encrypt.o := n
KCOV_INSTRUMENT_mem_encrypt_identity.o := n

-KASAN_SANITIZE_mem_encrypt.o := n
-KASAN_SANITIZE_mem_encrypt_identity.o := n
+SANITIZE_mem_encrypt.o := n
+SANITIZE_mem_encrypt_identity.o := n

ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_mem_encrypt.o = -pg
diff --git a/arch/x86/realmode/Makefile b/arch/x86/realmode/Makefile
index 682c895753d9..db86f4283808 100644
--- a/arch/x86/realmode/Makefile
+++ b/arch/x86/realmode/Makefile
@@ -6,7 +6,7 @@
# for more details.
#
#
-KASAN_SANITIZE := n
+SANITIZE := n
OBJECT_FILES_NON_STANDARD := y

subdir- := rm
diff --git a/arch/x86/realmode/rm/Makefile b/arch/x86/realmode/rm/Makefile
index f60501a384f9..61017575dab1 100644
--- a/arch/x86/realmode/rm/Makefile
+++ b/arch/x86/realmode/rm/Makefile
@@ -6,7 +6,7 @@
# for more details.
#
#
-KASAN_SANITIZE := n
+SANITIZE := n
OBJECT_FILES_NON_STANDARD := y

# Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
--
2.24.0