Hi Ilpo,
On 9/3/24 7:45 AM, Ilpo Järvinen wrote:
The x86 selftests makefile clobbers CFLAGS preventing lib.mk from making the necessary adjustments into CFLAGS. This would lead to a build failure after upcoming change which wants to add -DHAVE_CPUID= into CFLAGS.
Reorder CFLAGS initialization in x86 selftest. Place the constant part of CFLAGS initialization before inclusion of lib.mk but leave adding KHDR_INCLUDES into CFLAGS into the existing position because KHDR_INCLUDES might be generated inside lib.mk.
Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
v4:
New patch
tools/testing/selftests/x86/Makefile | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 5c8757a25998..88a6576de92f 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -1,4 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 +CFLAGS := -O2 -g -std=gnu99 -pthread -Wall
- all:
include ../lib.mk @@ -35,7 +37,7 @@ BINARIES_64 := $(TARGETS_C_64BIT_ALL:%=%_64) BINARIES_32 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_32)) BINARIES_64 := $(patsubst %,$(OUTPUT)/%,$(BINARIES_64)) -CFLAGS := -O2 -g -std=gnu99 -pthread -Wall $(KHDR_INCLUDES) +CFLAGS += $(KHDR_INCLUDES) # call32_from_64 in thunks.S uses absolute addresses. ifeq ($(CAN_BUILD_WITH_NOPIE),1)
These changes are becoming less obvious to me. The first two red flags are: - Most other top level Makefiles assign KHDR_INCLUDES to CFLAGS *before* including lib.mk - What current Makefiles do matches the guidance from Documentation/dev-tools/kselftest.rst as per example (verbatim copy): CFLAGS = $(KHDR_INCLUDES) TEST_GEN_PROGS := close_range_test include ../lib.mk
Looking closer it is not clear to me why lib.mk sets KHDR_INCLUDES. As I understand the usage is intended to be: make TARGETS="target" -C tools/testing/selftests This means that it is tools/testing/selftests/Makefile that will run first and it ensures that KHDR_INCLUDES is set and supports the usage documented in Documentation/dev-tools/kselftest.rst
One usage that a change like in this patch could support is for users to be able to run "make" from within the test directory self ... but considering the current KHDR_INCLUDES custom this does not seem to be supported? (but we cannot know which tests/users rely on this behavior)
Looking further I also noticed that tools/testing/selftests/Makefile even sets ARCH (but does not export it). When considering the next patch it almost looks like what is missing is for tools/testing/selftests/Makefile to "export ARCH" ... but that potentially impacts the Makefiles that do manipulation of ARCH.
I initially started to look at this because of the resctrl impact, but I clearly am not familiar enough with the kselftest build files to understand the impacts nor provide guidance. I do hope the kselftest folks can help here.
Reinette