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selftests/livepatch: Check if CONFIG_LIVEPATCH is enabled

PATCH In review Siddharth Menon 3 participants 4 messages Nov 6, 2024 – Nov 17, 2024

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Siddharth Menon

author
#0 lore raw

PATCH 1/1 selftests/livepatch: Check if CONFIG_LIVEPATCH is enabled

When CONFIG_LIVEPATCH is disabled, compilation fails due to the required structs from the livepatch header file being undefined. This checks for CONFIG_LIVEPATCH in order to verify that it is enabled before compiling livepatch self-tests.

Reviewed-by Shuah Khan <[email protected]>
Signed-off-by Siddharth Menon <[email protected]>
---
 tools/testing/selftests/livepatch/test_modules/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
tools/testing/selftests/livepatch/test_modules/Makefile +7 -1
index e6e638c4bcba..b34b80544709 100644
@@ -1,5 +1,6 @@
 TESTMODS_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
 KDIR ?= /lib/modules/$(shell uname -r)/build
+CONFIG_LIVEPATCH := $(shell cd $(KDIR) && scripts/config --state CONFIG_LIVEPATCH)
 
 obj-m += test_klp_atomic_replace.o \
 	test_klp_callbacks_busy.o \

@@ -13,10 +14,15 @@ obj-m += test_klp_atomic_replace.o \
 	test_klp_shadow_vars.o \
 	test_klp_syscall.o
 
-# Ensure that KDIR exists, otherwise skip the compilation
+
+# Ensure that KDIR exists and CONFIG_LIVEPATCH is enabled, else skip compilation
 modules:
 ifneq ("$(wildcard $(KDIR))", "")
+ifneq ($(filter y m,$(CONFIG_LIVEPATCH)),)
 	$(Q)$(MAKE) -C $(KDIR) modules KBUILD_EXTMOD=$(TESTMODS_DIR)
+else
+    $(warning CONFIG_LIVEPATCH is not enabled in the kernel config file.)
+endif
 endif
 
 # Ensure that KDIR exists, otherwise skip the clean target
Signature · 1 line
2.39.5
maintainer
#1 lore raw

Hi,

Quoted 10 lines · Siddharth Menon

When CONFIG_LIVEPATCH is disabled, compilation fails due to the required structs from the livepatch header file being undefined. This checks for CONFIG_LIVEPATCH in order to verify that it is enabled before compiling livepatch self-tests.

Reviewed-by Shuah Khan <[email protected]>
Signed-off-by Siddharth Menon <[email protected]>
---
 tools/testing/selftests/livepatch/test_modules/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

thank you for the patch.

tools/testing/selftests/livepatch/config contains

CONFIG_LIVEPATCH=y
CONFIG_DYNAMIC_DEBUG=y

I assumed that these prerequisites are respected but apparently not for building the test modules if I understand it correctly.

Is it possible to fix it in the way that the config file is respected? Or how do kselftests work with that?

Regards,
Miroslav

maintainer
#2 lore raw
In reply to Siddharth Menon
Quoted 27 lines · Siddharth Menon

When CONFIG_LIVEPATCH is disabled, compilation fails due to the required structs from the livepatch header file being undefined. This checks for CONFIG_LIVEPATCH in order to verify that it is enabled before compiling livepatch self-tests.

Reviewed-by Shuah Khan <[email protected]>
Signed-off-by Siddharth Menon <[email protected]>
---
 tools/testing/selftests/livepatch/test_modules/Makefile | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)
tools/testing/selftests/livepatch/test_modules/Makefile +1 -1
index e6e638c4bcba..b34b80544709 100644
@@ -1,5 +1,6 @@
 TESTMODS_DIR := $(realpath $(dir $(abspath $(lastword $(MAKEFILE_LIST)))))
 KDIR ?= /lib/modules/$(shell uname -r)/build
+CONFIG_LIVEPATCH := $(shell cd $(KDIR) && scripts/config --state CONFIG_LIVEPATCH)
 
 obj-m += test_klp_atomic_replace.o \
 	test_klp_callbacks_busy.o \

@@ -13,10 +14,15 @@ obj-m += test_klp_atomic_replace.o \
 	test_klp_shadow_vars.o \
 	test_klp_syscall.o
 
-# Ensure that KDIR exists, otherwise skip the compilation

tools/testing/selftests/livepatch/test_modules/Makefile obj-m += test_klp_atomic_replace.o \ · line 26

Quoted 10 lines
tools/testing/selftests/livepatch/test_modules/Makefile +6 -0
+
+# Ensure that KDIR exists and CONFIG_LIVEPATCH is enabled, else skip compilation
 modules:
 ifneq ("$(wildcard $(KDIR))", "")
+ifneq ($(filter y m,$(CONFIG_LIVEPATCH)),)
 	$(Q)$(MAKE) -C $(KDIR) modules KBUILD_EXTMOD=$(TESTMODS_DIR)
+else
+    $(warning CONFIG_LIVEPATCH is not enabled in the kernel config file.)
+endif
 endif

This handles only the build of the modules.

It does not block building the test_klp-call_getpid binary. Also it does not block running the tests, so I get:

tools/testing/selftests/livepatch # make run_tests
CC test_klp-call_getpid
Makefile:24: CONFIG_LIVEPATCH is not enabled in the kernel config file. make[1]: Nothing to be done for 'modules'.
TAP version 13
1..7

# timeout set to 0
# selftests: livepatch: test-livepatch.sh
# TEST: basic function patching ... ERROR: Can't find "test_modules/test_klp_livepatch.ko", try "make"
not ok 1 selftests: livepatch: test-livepatch.sh # exit=1
# timeout set to 0
# selftests: livepatch: test-callbacks.sh
# TEST: target module before livepatch ... ERROR: Can't find "test_modules/test_klp_callbacks_mod.ko", try "make"
not ok 2 selftests: livepatch: test-callbacks.sh # exit=1
...

I like idea mentioned in Miroslav's reply. I wonder if the check could take into account all CONFIG_* variables mentioned in tools/testing/selftests/livepatch/config.

And if it could be generic so that it works for all tools/testing/selftests/<project> directories.

And for both build and run_tests.

Best Regards,
Petr

author
#3 lore raw
Quoted 4 lines · Petr Mladek

I like idea mentioned in Miroslav's reply. I wonder if the check could take into account all CONFIG_* variables mentioned in tools/testing/selftests/livepatch/config.

Thanks for the feedback, I will create a new patch as suggested by Miroslav

Quoted 4 lines

And if it could be generic so that it works for all tools/testing/selftests/<project> directories.

And for both build and run_tests.

I will look into it

Sincerely,
Siddharth Menon