CHROMIUM: arm64: Disable asm-operand-width warning for clang

clang raises 'asm-operand-widths' warnings in inline assembly code when
the size of an operand is < 64 bits and the operand width is unspecified.
Most warnings are raised in macros, i.e. the datatype of the operand may
vary. Most of these warnings are fixed in upstream, however we consider it
isn't worth the effort/risk to backport all the necessary changes. On
future CrOS kernels >= v4.13 the warning should be re-enabled.

Change-Id: Ie44748344853f5a394879718ad5d6f610f3c396a
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index a3bda11406e4d0f13019555b981be33b3a7f6673..62274e34d78ed6a4088f8c173c390c1345077bb6 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -95,6 +95,10 @@ else
 TEXT_OFFSET := 0x00080000
 endif
 
+ifeq ($(cc-name),clang)
+KBUILD_CFLAGS += $(call cc-disable-warning, asm-operand-widths)
+endif
+
 # KASAN_SHADOW_OFFSET = VA_START + (1 << (VA_BITS - 3)) - (1 << 61)
 # in 32-bit arithmetic
 KASAN_SHADOW_OFFSET := $(shell printf "0x%08x00000000\n" $$(( \