[PATCH 3/7] Disable instrumentation for some code

[Abbott Liu]

From: Andrey Ryabinin <a.ryabi...@samsung.com>

Disable instrumentation for arch/arm/boot/compressed/*
and arch/arm/vdso/* because those code won't linkd with
kernel image.

Disable kasan check in the function unwind_pop_register
because it doesn't matter that kasan checks failed when
unwind_pop_register read stack memory of task.

Reviewed-by: Russell King - ARM Linux <li...@armlinux.org.uk>
Reviewed-by: Florian Fainelli <f.faine...@gmail.com>
Tested-by: Florian Fainelli <f.faine...@gmail.com>
Signed-off-by: Abbott Liu <liuwenli...@huawei.com>
---
 arch/arm/boot/compressed/Makefile | 1 +
 arch/arm/kernel/unwind.c          | 3 ++-
 arch/arm/vdso/Makefile            | 2 ++
 3 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/compressed/Makefile 
b/arch/arm/boot/compressed/Makefile
index 45a6b9b..966103e 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -24,6 +24,7 @@ OBJS          += hyp-stub.o
 endif
 
 GCOV_PROFILE           := n
+KASAN_SANITIZE         := n
 
 #
 # Architecture dependencies
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 0bee233..2e55c7d 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -249,7 +249,8 @@ static int unwind_pop_register(struct unwind_ctrl_block 
*ctrl,
                if (*vsp >= (unsigned long *)ctrl->sp_high)
                        return -URC_FAILURE;
 
-       ctrl->vrs[reg] = *(*vsp)++;
+       ctrl->vrs[reg] = READ_ONCE_NOCHECK(*(*vsp));
+       (*vsp)++;
        return URC_OK;
 }
 
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index bb411821..87abbb7 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -30,6 +30,8 @@ CFLAGS_vgettimeofday.o = -O2
 # Disable gcov profiling for VDSO code
 GCOV_PROFILE := n
 
+KASAN_SANITIZE := n
+
 # Force dependency
 $(obj)/vdso.o : $(obj)/vdso.so
 
-- 
2.9.0