Hi,
I've being trying to understand a problem when adding a new rule to compile
modules on ksefltests:
$ make kselftest TARGETS=livepatch
make[2]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch'
make[3]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules'
make -C /home/mpdesouza/git/linux M=/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules modules
m2c -o scripts/Makefile.build -e scripts/Makefile.build scripts/Makefile.build.mod
make[5]: m2c: No such file or directory
I managed to create a minimal reproducer for the problem here[1]. I'll attach
the patches at the end of the email if you want to inspect the changes without
getting the patches from github.
The curious part is, if I execute the ksefltests using a different target, it
works:
$ make -C tools/testing/selftests run_tests TARGETS=livepatch
make: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests'
make[1]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch'
make -C /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules
make[2]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules'
make -C /home/mpdesouza/git/linux M=/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules modules
CC [M] /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules/mod_test.o
MODPOST /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules/Module.symvers
CC [M] /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules/mod_test.mod.o
LD [M] /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules/mod_test.ko
BTF [M] /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules/mod_test.ko
make[2]: Leaving directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules'
make[1]: Leaving directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch'
make[1]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch'
make -C /home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules
make[2]: Entering directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules'
make -C /home/mpdesouza/git/linux M=/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules modules
make[2]: Leaving directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch/test_modules'
TAP version 13
1..1
# selftests: livepatch: test-true.sh
ok 1 selftests: livepatch: test-true.sh
make[1]: Leaving directory '/home/mpdesouza/git/linux/tools/testing/selftests/livepatch'
make: Leaving directory '/home/mpdesouza/git/linux/tools/testing/selftests'
In the root Makefile, ksefltest is defined as:
PHONY += kselftest
kselftest: headers
$(Q)$(MAKE) -C $(srctree)/tools/testing/selftests run_tests
So, it's quite odd that a "mostly identical" rules being triggered result in
that odd "m2c" command being invoked. Both outputs here were got from a openSUSE
Tumbleweed machine, using make 4.4.1. When executing the kselftest target on a
Ubuntu machine, the error is similar but not the same:
...
make[4]: Entering directory '/root/linux-kbuild'
make -f ./scripts/Makefile.build obj=arch/x86/entry/syscalls all
m2c -o scripts/Makefile.lib -e scripts/Makefile.lib scripts/Makefile.lib.mod
make[5]: m2c: No such file or directory
make[5]: *** [<builtin>: scripts/Makefile.lib] Error 127
make[4]: *** [arch/x86/Makefile:248: archheaders] Error 2
...
So, error is the same, but it failed on Makefile.lib, instead of Makefile.build
from the previous run.
I also tried to change the KDIR from
tools/testing/selftests/livepatch/test_modules/Makefile to point to KDIR ?=
/lib/modules/$(shell uname -r)/build, but it then results in a different
problem, making building_out_of_srctree to be set to false on
/usr/src/linux-6.2.10-1-obj/x86_64/default/Makefile, which then results in
different problems... So I would like to understand this problem first, since
there was no way to stop make from calling "m2c". It was also tested on
linux-kbuild/for-next, but the problem is the same.
I also found some links[2] mentioning "m2c", but the workarounds didn't solved
the issue. At this point any help would be great!
[1]: https://github.com/marcosps/linux/commits/kbuild-next-kselftests
[2]: https://lists.mcs.anl.gov/pipermail/petsc-users/2010-November/007299.html
>From 7fce0614e9399083596415c9e2cd446e46ec5cf8 Mon Sep 17 00:00:00 2001
From: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
Date: Fri, 14 Apr 2023 15:05:08 -0300
Subject: [PATCH 1/2] kselftests: lib.mk: Add TEST_GEN_MODS_DIR variable
This new variable can be set by selftests to point to a directory where
exists modules to be built and tested.
Signed-off-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
---
tools/testing/selftests/lib.mk | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk
index 05400462c779..978d7780cc03 100644
--- a/tools/testing/selftests/lib.mk
+++ b/tools/testing/selftests/lib.mk
@@ -57,8 +57,16 @@ endif
TEST_GEN_PROGS := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS))
TEST_GEN_PROGS_EXTENDED := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_PROGS_EXTENDED))
TEST_GEN_FILES := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_FILES))
+TEST_GEN_MODS_DIR := $(patsubst %,$(OUTPUT)/%,$(TEST_GEN_MODS_DIR))
-all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES)
+gen_mods_dir:
+ $(Q)$(MAKE) -C $(TEST_GEN_MODS_DIR)
+
+clean_mods_dir:
+ $(Q)$(MAKE) -C $(TEST_GEN_MODS_DIR) clean
+
+all: $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) \
+ $(if $TEST_GEN_MODS_DIR, gen_mods_dir)
define RUN_TESTS
BASE_DIR="$(selfdir)"; \
@@ -71,8 +79,8 @@ endef
run_tests: all
ifdef building_out_of_srctree
- @if [ "X$(TEST_PROGS)$(TEST_PROGS_EXTENDED)$(TEST_FILES)" != "X" ]; then \
- rsync -aLq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(OUTPUT); \
+ @if [ "X$(TEST_PROGS)$(TEST_PROGS_EXTENDED)$(TEST_FILES)$(TEST_GEN_MODS_DIR)" != "X" ]; then \
+ rsync -aLq $(TEST_PROGS) $(TEST_PROGS_EXTENDED) $(TEST_FILES) $(TEST_GEN_MODS_DIR) $(OUTPUT); \
fi
@if [ "X$(TEST_PROGS)" != "X" ]; then \
$(call RUN_TESTS, $(TEST_GEN_PROGS) $(TEST_CUSTOM_PROGS) \
@@ -122,7 +130,7 @@ define CLEAN
$(RM) -r $(TEST_GEN_PROGS) $(TEST_GEN_PROGS_EXTENDED) $(TEST_GEN_FILES) $(EXTRA_CLEAN)
endef
-clean:
+clean: $(if $TEST_GEN_MODS_DIR, clean_mods_dir)
$(CLEAN)
# Enables to extend CFLAGS and LDFLAGS from command line, e.g.
@@ -153,4 +161,4 @@ $(OUTPUT)/%:%.S
$(LINK.S) $^ $(LDLIBS) -o $@
endif
-.PHONY: run_tests all clean install emit_tests
+.PHONY: run_tests all clean install emit_tests gen_mods_dir
--
2.40.0
>From 5ac1d2d3e7e66bfe58094f00029fc4ba15555d10 Mon Sep 17 00:00:00 2001
From: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
Date: Thu, 20 Apr 2023 11:51:29 -0300
Subject: [PATCH 2/2] easily test mods building for kselftests
Signed-off-by: Marcos Paulo de Souza <mpdesouza@xxxxxxxx>
---
tools/testing/selftests/livepatch/Makefile | 8 ++------
tools/testing/selftests/livepatch/test-true.sh | 3 +++
.../selftests/livepatch/test_modules/Makefile | 11 +++++++++++
.../selftests/livepatch/test_modules/mod_test.c | 15 +++++++++++++++
4 files changed, 31 insertions(+), 6 deletions(-)
create mode 100755 tools/testing/selftests/livepatch/test-true.sh
create mode 100644 tools/testing/selftests/livepatch/test_modules/Makefile
create mode 100644 tools/testing/selftests/livepatch/test_modules/mod_test.c
diff --git a/tools/testing/selftests/livepatch/Makefile b/tools/testing/selftests/livepatch/Makefile
index 02fadc9d55e0..bfe048f6a65d 100644
--- a/tools/testing/selftests/livepatch/Makefile
+++ b/tools/testing/selftests/livepatch/Makefile
@@ -1,13 +1,9 @@
# SPDX-License-Identifier: GPL-2.0
+TEST_GEN_MODS_DIR := test_modules
TEST_PROGS_EXTENDED := functions.sh
TEST_PROGS := \
- test-livepatch.sh \
- test-callbacks.sh \
- test-shadow-vars.sh \
- test-state.sh \
- test-ftrace.sh \
- test-sysfs.sh
+ test-true.sh
TEST_FILES := settings
diff --git a/tools/testing/selftests/livepatch/test-true.sh b/tools/testing/selftests/livepatch/test-true.sh
new file mode 100755
index 000000000000..8c3cbfc39d94
--- /dev/null
+++ b/tools/testing/selftests/livepatch/test-true.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exit 0
diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile
new file mode 100644
index 000000000000..2975fe21f48c
--- /dev/null
+++ b/tools/testing/selftests/livepatch/test_modules/Makefile
@@ -0,0 +1,11 @@
+LP_TESTMODS_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
+#KDIR ?= /lib/modules/$(shell uname -r)/build
+KDIR ?= $(abspath $(LP_TESTMODS_DIR)/../../../../..)
+
+obj-m += mod_test.o
+
+all:
+ make -C $(KDIR) M=$(LP_TESTMODS_DIR) modules
+
+clean:
+ make -C $(KDIR) M=$(LP_TESTMODS_DIR) clean
diff --git a/tools/testing/selftests/livepatch/test_modules/mod_test.c b/tools/testing/selftests/livepatch/test_modules/mod_test.c
new file mode 100644
index 000000000000..135f5d0b55b0
--- /dev/null
+++ b/tools/testing/selftests/livepatch/test_modules/mod_test.c
@@ -0,0 +1,15 @@
+#include <linux/module.h>
+#include <linux/kernel.h>
+
+static int mod_init(void)
+{
+ return 0;
+}
+
+static void mod_exit(void)
+{
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+MODULE_LICENSE("GPL");
--
2.40.0
