From: Yafang Shao <laoar.shao@gmail.com>
To: jpoimboe@kernel.org, jikos@kernel.org, mbenes@suse.cz,
pmladek@suse.com, joe.lawrence@redhat.com, song@kernel.org
Cc: live-patching@vger.kernel.org, Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v5 6/9] selftests: livepatch: Adapt atomic replace tests to provides/obsoletes
Date: Sun, 9 Aug 2026 17:19:50 +0800 [thread overview]
Message-ID: <20260809091954.22930-7-laoar.shao@gmail.com> (raw)
In-Reply-To: <20260809091954.22930-1-laoar.shao@gmail.com>
The legacy "replace" field in struct klp_patch was replaced by the
provides/obsoletes mechanism. As a result, the atomic replace
selftests fail to build against kernels that only support
provides/obsoletes.
Adapt the selftests so that they build and run on both old and new
kernels:
- test_modules/Makefile detects whether the kernel header still
declares the "replace" field. If so, it passes KLP_HAS_REPLACE to
the modules via ccflags-y.
- test_klp_atomic_replace.c and other source files using .replace guard
their replace module parameter and .replace assignment with
#ifdef KLP_HAS_REPLACE. The #else branches are left as TODO
placeholders for the upcoming provides/obsoletes based tests.
- functions.sh adds detect_replace_attr(), which loads a temporary
livepatch and checks for the /sys/kernel/livepatch/<patch>/replace
attribute, setting HAS_REPLACE_ATTR accordingly.
- test-livepatch.sh and test-callbacks.sh run the tests that depend
on multiple livepatches coexisting or on the atomic replace
behavior ("multiple livepatches" and "atomic replace") only when
HAS_REPLACE_ATTR is set. These scenarios do not apply to the new
kernel, where provides=0 replaces any other livepatch by default.
The provides/obsoletes based selftests will be added later.
Assisted-by: Comagic:DeepSeek-V4-Flash
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
tools/testing/selftests/livepatch/functions.sh | 15 +++++++++++++++
.../selftests/livepatch/test-callbacks.sh | 6 ++++++
.../selftests/livepatch/test-livepatch.sh | 6 ++++++
.../selftests/livepatch/test_modules/Makefile | 10 ++++++++++
.../test_modules/test_klp_atomic_replace.c | 16 ++++++++++++++++
.../test_modules/test_klp_callbacks_demo2.c | 16 ++++++++++++++++
.../livepatch/test_modules/test_klp_state.c | 7 +++++++
.../livepatch/test_modules/test_klp_state2.c | 7 +++++++
8 files changed, 83 insertions(+)
diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
index 30dc677b2f45..17810521d069 100644
--- a/tools/testing/selftests/livepatch/functions.sh
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -351,6 +351,21 @@ function does_sysfs_exist() {
[[ -f "$SYSFS_KLP_DIR/$mod/$attr" ]]
}
+# detect_replace_attr() - detect whether the running kernel still exposes
+# the legacy "replace" sysfs attribute and set HAS_REPLACE_ATTR
+# accordingly. The atomic replace tests are only run when the attribute
+# is present. The provides/obsoletes based tests will be added later.
+function detect_replace_attr() {
+ HAS_REPLACE_ATTR=0
+
+ load_lp test_klp_livepatch
+ if does_sysfs_exist test_klp_livepatch "replace"; then
+ HAS_REPLACE_ATTR=1
+ fi
+ disable_lp test_klp_livepatch
+ unload_lp test_klp_livepatch
+}
+
# check_sysfs_rights(modname, rel_path, expected_rights) - check sysfs
# path permissions
# modname - livepatch module creating the sysfs interface
diff --git a/tools/testing/selftests/livepatch/test-callbacks.sh b/tools/testing/selftests/livepatch/test-callbacks.sh
index 2a03deb26a12..e9b2dc6ea099 100755
--- a/tools/testing/selftests/livepatch/test-callbacks.sh
+++ b/tools/testing/selftests/livepatch/test-callbacks.sh
@@ -11,6 +11,8 @@ MOD_TARGET_BUSY=test_klp_callbacks_busy
setup_config
+detect_replace_attr
+
# Test a combination of loading a kernel module and a livepatch that
# patches a function in the first module. Load the target module
@@ -451,6 +453,7 @@ $MOD_TARGET_BUSY: busymod_work_func exit
$MOD_TARGET_BUSY: ${MOD_TARGET_BUSY}_exit"
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
# Test loading multiple livepatches. This test-case is mainly for comparing
# with the next test-case.
#
@@ -499,8 +502,10 @@ $MOD_LIVEPATCH: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH2
% rmmod $MOD_LIVEPATCH"
+fi
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
# Load multiple livepatches, but the second as an 'atomic-replace'
# patch. When the latter loads, the original livepatch should be
# disabled and *none* of its pre/post-unpatch callbacks executed. On
@@ -548,6 +553,7 @@ $MOD_LIVEPATCH2: post_unpatch_callback: vmlinux
livepatch: '$MOD_LIVEPATCH2': unpatching complete
% rmmod $MOD_LIVEPATCH2
% rmmod $MOD_LIVEPATCH"
+fi
exit 0
diff --git a/tools/testing/selftests/livepatch/test-livepatch.sh b/tools/testing/selftests/livepatch/test-livepatch.sh
index c44c5341a2f1..b3b7cd81e3d0 100755
--- a/tools/testing/selftests/livepatch/test-livepatch.sh
+++ b/tools/testing/selftests/livepatch/test-livepatch.sh
@@ -13,6 +13,8 @@ MOD_TARGET_PATCH=test_klp_mod_patch
setup_config
+detect_replace_attr
+
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
@@ -49,6 +51,7 @@ livepatch: '$MOD_LIVEPATCH1': unpatching complete
% rmmod $MOD_LIVEPATCH1"
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
# - load another livepatch and verify that both livepatches are active
@@ -107,8 +110,10 @@ livepatch: '$MOD_LIVEPATCH1': starting unpatching transition
livepatch: '$MOD_LIVEPATCH1': completing unpatching transition
livepatch: '$MOD_LIVEPATCH1': unpatching complete
% rmmod $MOD_LIVEPATCH1"
+fi
+if [[ "$HAS_REPLACE_ATTR" == "1" ]]; then
# - load a livepatch that modifies the output from /proc/cmdline and
# verify correct behavior
# - load two additional livepatches and check the number of livepatch modules
@@ -196,6 +201,7 @@ livepatch: '$MOD_REPLACE': starting unpatching transition
livepatch: '$MOD_REPLACE': completing unpatching transition
livepatch: '$MOD_REPLACE': unpatching complete
% rmmod $MOD_REPLACE"
+fi
# - load a target module that provides /proc/test_klp_mod_target with
diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile
index a13d398585dc..29c55df36046 100644
--- a/tools/testing/selftests/livepatch/test_modules/Makefile
+++ b/tools/testing/selftests/livepatch/test_modules/Makefile
@@ -16,6 +16,16 @@ obj-m += test_klp_atomic_replace.o \
test_klp_state3.o \
test_klp_syscall.o
+# The legacy "replace" field was replaced by provides/obsoletes. When the
+# kernel (KDIR) still supports "replace", pass KLP_HAS_REPLACE to the
+# modules so that they can #ifdef the legacy "replace" code. Otherwise
+# the modules are built with the provides/obsoletes based code (to be
+# added later).
+KLP_HAS_REPLACE := $(shell grep -q 'bool replace' $(KDIR)/include/linux/livepatch.h 2>/dev/null && echo y)
+ifeq ($(KLP_HAS_REPLACE),y)
+ccflags-y += -DKLP_HAS_REPLACE
+endif
+
# Ensure that KDIR exists, otherwise skip the compilation
modules:
ifneq ("$(wildcard $(KDIR))", "")
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c b/tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c
index 5af7093ca00c..4b3ed17886e7 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_atomic_replace.c
@@ -7,9 +7,16 @@
#include <linux/kernel.h>
#include <linux/livepatch.h>
+#ifdef KLP_HAS_REPLACE
static int replace;
module_param(replace, int, 0644);
MODULE_PARM_DESC(replace, "replace (default=0)");
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
#include <linux/seq_file.h>
static int livepatch_meminfo_proc_show(struct seq_file *m, void *v)
@@ -36,12 +43,21 @@ static struct klp_object objs[] = {
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
+#ifdef KLP_HAS_REPLACE
/* set .replace in the init function below for demo purposes */
+#endif
};
static int test_klp_atomic_replace_init(void)
{
+#ifdef KLP_HAS_REPLACE
patch.replace = replace;
+#else
+ /*
+ * TODO: Set provides/obsoletes from the module parameters
+ * for the provides/obsoletes based tests (to be added later).
+ */
+#endif
return klp_enable_patch(&patch);
}
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c
index 5417573e80af..135da6d4d882 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_callbacks_demo2.c
@@ -7,9 +7,16 @@
#include <linux/kernel.h>
#include <linux/livepatch.h>
+#ifdef KLP_HAS_REPLACE
static int replace;
module_param(replace, int, 0644);
MODULE_PARM_DESC(replace, "replace (default=0)");
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
static const char *const module_state[] = {
[MODULE_STATE_LIVE] = "[MODULE_STATE_LIVE] Normal state",
@@ -72,12 +79,21 @@ static struct klp_object objs[] = {
static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
+#ifdef KLP_HAS_REPLACE
/* set .replace in the init function below for demo purposes */
+#endif
};
static int test_klp_callbacks_demo2_init(void)
{
+#ifdef KLP_HAS_REPLACE
patch.replace = replace;
+#else
+ /*
+ * TODO: Set provides/obsoletes from the module parameters
+ * for the provides/obsoletes based tests (to be added later).
+ */
+#endif
return klp_enable_patch(&patch);
}
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_state.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state.c
index 57a4253acb01..3492472e5d07 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_state.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_state.c
@@ -142,7 +142,14 @@ static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
.states = states,
+#ifdef KLP_HAS_REPLACE
.replace = true,
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
};
static int test_klp_callbacks_demo_init(void)
diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c b/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c
index c978ea4d5e67..8160b565a659 100644
--- a/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c
+++ b/tools/testing/selftests/livepatch/test_modules/test_klp_state2.c
@@ -171,7 +171,14 @@ static struct klp_patch patch = {
.mod = THIS_MODULE,
.objs = objs,
.states = states,
+#ifdef KLP_HAS_REPLACE
.replace = true,
+#else
+/*
+ * TODO: Add provides/obsoletes module parameters for the
+ * provides/obsoletes based tests (to be added later).
+ */
+#endif
};
static int test_klp_callbacks_demo_init(void)
--
2.52.0
next prev parent reply other threads:[~2026-08-09 9:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-09 9:19 [PATCH v5 0/9] livepatch: Introduce replace set support Yafang Shao
2026-08-09 9:19 ` [PATCH v5 1/9] livepatch: Fix wrong index in funcs cleanup error path Yafang Shao
2026-08-09 9:28 ` sashiko-bot
2026-08-09 9:36 ` Yafang Shao
2026-08-09 9:19 ` [PATCH v5 2/9] livepatch: Make klp_find_func() non static Yafang Shao
2026-08-09 9:32 ` sashiko-bot
2026-08-09 9:39 ` Yafang Shao
2026-08-09 9:19 ` [PATCH v5 3/9] livepatch: Call klp_init_patch_early() earlier Yafang Shao
2026-08-09 9:40 ` sashiko-bot
2026-08-09 9:19 ` [PATCH v5 4/9] livepatch: Implement replace set for scoped atomic replace Yafang Shao
2026-08-09 9:33 ` sashiko-bot
2026-08-09 9:19 ` [PATCH v5 5/9] livepatch: Deprecate stack_order Yafang Shao
2026-08-09 9:19 ` Yafang Shao [this message]
2026-08-09 9:33 ` [PATCH v5 6/9] selftests: livepatch: Adapt atomic replace tests to provides/obsoletes sashiko-bot
2026-08-09 9:45 ` Yafang Shao
2026-08-09 9:19 ` [PATCH v5 7/9] selftests: livepatch: Add provides/obsoletes test scenarios Yafang Shao
2026-08-09 9:31 ` sashiko-bot
2026-08-09 9:19 ` [PATCH v5 8/9] selftests: livepatch: Add test for state ID conflict across provides Yafang Shao
2026-08-09 9:19 ` [PATCH v5 9/9] selftests: livepatch: Add test for function " Yafang Shao
2026-08-09 9:49 ` sashiko-bot
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