[PATCH v8 08/11] powerpc: disable KASAN instrumentation on early/critical files.

[Christophe Leroy]

All files containing functions run before kasan_early_init() is called
must have KASAN instrumentation disabled.

For those file, branch profiling also have to be disabled otherwise
each if () generates a call to ftrace_likely_update().

Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>
---
 arch/powerpc/kernel/Makefile             | 12 ++++++++++++
 arch/powerpc/lib/Makefile                |  8 ++++++++
 arch/powerpc/mm/Makefile                 |  6 ++++++
 arch/powerpc/platforms/powermac/Makefile |  6 ++++++
 arch/powerpc/purgatory/Makefile          |  3 +++
 arch/powerpc/xmon/Makefile               |  1 +
 6 files changed, 36 insertions(+)

diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 45e47752b692..0ea6c4aa3a20 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -31,6 +31,18 @@ CFLAGS_REMOVE_btext.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_prom.o = $(CC_FLAGS_FTRACE)
 endif
 
+KASAN_SANITIZE_early_32.o := n
+KASAN_SANITIZE_cputable.o := n
+KASAN_SANITIZE_prom_init.o := n
+KASAN_SANITIZE_btext.o := n
+
+ifdef CONFIG_KASAN
+CFLAGS_early_32.o += -DDISABLE_BRANCH_PROFILING
+CFLAGS_cputable.o += -DDISABLE_BRANCH_PROFILING
+CFLAGS_prom_init.o += -DDISABLE_BRANCH_PROFILING
+CFLAGS_btext.o += -DDISABLE_BRANCH_PROFILING
+endif
+
 obj-y				:= cputable.o ptrace.o syscalls.o \
 				   irq.o align.o signal_32.o pmc.o vdso.o \
 				   process.o systbl.o idle.o \
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 47a4de434c22..c55f9c27bf79 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -8,6 +8,14 @@ ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
 
+KASAN_SANITIZE_code-patching.o := n
+KASAN_SANITIZE_feature-fixups.o := n
+
+ifdef CONFIG_KASAN
+CFLAGS_code-patching.o += -DDISABLE_BRANCH_PROFILING
+CFLAGS_feature-fixups.o += -DDISABLE_BRANCH_PROFILING
+endif
+
 obj-y += alloc.o code-patching.o feature-fixups.o
 
 ifndef CONFIG_KASAN
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index d52ec118e09d..240d73dce6bb 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -7,6 +7,12 @@ ccflags-$(CONFIG_PPC64)	:= $(NO_MINIMAL_TOC)
 
 CFLAGS_REMOVE_slb.o = $(CC_FLAGS_FTRACE)
 
+KASAN_SANITIZE_ppc_mmu_32.o := n
+
+ifdef CONFIG_KASAN
+CFLAGS_ppc_mmu_32.o  		+= -DDISABLE_BRANCH_PROFILING
+endif
+
 obj-y				:= fault.o mem.o pgtable.o mmap.o \
 				   init_$(BITS).o pgtable_$(BITS).o \
 				   init-common.o mmu_context.o drmem.o
diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile
index 923bfb340433..859efbacdf06 100644
--- a/arch/powerpc/platforms/powermac/Makefile
+++ b/arch/powerpc/platforms/powermac/Makefile
@@ -2,6 +2,12 @@
 CFLAGS_bootx_init.o  		+= -fPIC
 CFLAGS_bootx_init.o  		+= $(call cc-option, -fno-stack-protector)
 
+KASAN_SANITIZE_bootx_init.o := n
+
+ifdef CONFIG_KASAN
+CFLAGS_bootx_init.o  		+= -DDISABLE_BRANCH_PROFILING
+endif
+
 ifdef CONFIG_FUNCTION_TRACER
 # Do not trace early boot code
 CFLAGS_REMOVE_bootx_init.o = $(CC_FLAGS_FTRACE)
diff --git a/arch/powerpc/purgatory/Makefile b/arch/powerpc/purgatory/Makefile
index 4314ba5baf43..7c6d8b14f440 100644
--- a/arch/powerpc/purgatory/Makefile
+++ b/arch/powerpc/purgatory/Makefile
@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
+
+KASAN_SANITIZE := n
+
 targets += trampoline.o purgatory.ro kexec-purgatory.c
 
 LDFLAGS_purgatory.ro := -e purgatory_start -r --no-undefined
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index 3050f9323254..f142570ad860 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -7,6 +7,7 @@ subdir-ccflags-y := $(call cc-disable-warning, builtin-requires-header)
 GCOV_PROFILE := n
 KCOV_INSTRUMENT := n
 UBSAN_SANITIZE := n
+KASAN_SANITIZE := n
 
 # Disable ftrace for the entire directory
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
-- 
2.13.3