[PATCH v6 2/6] ARM: Disable instrumentation for some code

[Florian Fainelli]

From: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>

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

Disable instrumentation for arch/arm/kvm/hyp/*. See commit a6cdf1c08cbf
("kvm: arm64: Disable compiler instrumentation for hypervisor code") for
more details.

Disable instrumentation for arch/arm/mm/physaddr.c. See commit
ec6d06efb0ba ("arm64: Add support for CONFIG_DEBUG_VIRTUAL") for more
details.

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.

Reported-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Reported-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Abbott Liu <liuwenliang@xxxxxxxxxx>
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
 arch/arm/boot/compressed/Makefile | 1 +
 arch/arm/kernel/unwind.c          | 3 ++-
 arch/arm/mm/Makefile              | 1 +
 arch/arm/vdso/Makefile            | 2 ++
 4 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 9219389bbe61..fa4d1fddf1db 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
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
 KCOV_INSTRUMENT		:= n
diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c
index 4574e6aea0a5..b70fb260c28a 100644
--- a/arch/arm/kernel/unwind.c
+++ b/arch/arm/kernel/unwind.c
@@ -236,7 +236,8 @@ 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/mm/Makefile b/arch/arm/mm/Makefile
index 7cb1699fbfc4..432302911d6e 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -16,6 +16,7 @@ endif
 obj-$(CONFIG_ARM_PTDUMP_CORE)	+= dump.o
 obj-$(CONFIG_ARM_PTDUMP_DEBUGFS)	+= ptdump_debugfs.o
 obj-$(CONFIG_MODULES)		+= proc-syms.o
+KASAN_SANITIZE_physaddr.o	:= n
 obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o
 
 obj-$(CONFIG_ALIGNMENT_TRAP)	+= alignment.o
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index fadf554d9391..855fa82bf3ec 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -33,6 +33,8 @@ GCOV_PROFILE := n
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
 KCOV_INSTRUMENT := n
 
+KASAN_SANITIZE := n
+
 # Force dependency
 $(obj)/vdso.o : $(obj)/vdso.so
 
-- 
2.17.1