Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tests/liveupdate: add in-kernel liveupdate test
Introduce an in-kernel test module to validate the core logic of the Live
Update Orchestrator's File-Lifecycle-Bound feature. This provides a
low-level, controlled environment to test FLB registration and callback
invocation without requiring userspace interaction or actual kexec
reboots.
The test is enabled by the CONFIG_LIVEUPDATE_TEST Kconfig option.
Link: https://lkml.kernel.org/r/20251218155752.3045808-6-pasha.tatashin@soleen.com
Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: David Gow <davidgow@google.com>
Cc: David Matlack <dmatlack@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kees Cook <kees@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Pratyush Yadav <pratyush@kernel.org>
Cc: Samiullah Khawaja <skhawaja@google.com>
Cc: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
authored by
Pasha Tatashin
and committed by
Andrew Morton
f653ff7a
cab056f2
+203
-1
+1
MAINTAINERS
+1
MAINTAINERS
+5
include/linux/kho/abi/luo.h
+5
include/linux/kho/abi/luo.h
+7
-1
kernel/liveupdate/luo_file.c
+7
-1
kernel/liveupdate/luo_file.c
···
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list_add_tail(&ACCESS_PRIVATE(fh, list), &luo_file_handler_list);
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luo_session_resume();
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+
liveupdate_test_register(fh);
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+
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return 0;
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err_resume:
···
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if (!liveupdate_enabled())
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return -EOPNOTSUPP;
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+
liveupdate_test_unregister(fh);
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+
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if (!luo_session_quiesce())
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-
return -EBUSY;
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+
goto err_register;
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if (!list_empty(&ACCESS_PRIVATE(fh, flb_list)))
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goto err_resume;
···
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err_resume:
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luo_session_resume();
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+
err_register:
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+
liveupdate_test_register(fh);
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return err;
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}
+8
kernel/liveupdate/luo_internal.h
+8
kernel/liveupdate/luo_internal.h
···
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int __init luo_flb_setup_incoming(void *fdt);
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void luo_flb_serialize(void);
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+
#ifdef CONFIG_LIVEUPDATE_TEST
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void liveupdate_test_register(struct liveupdate_file_handler *fh);
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void liveupdate_test_unregister(struct liveupdate_file_handler *fh);
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#else
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static inline void liveupdate_test_register(struct liveupdate_file_handler *fh) { }
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static inline void liveupdate_test_unregister(struct liveupdate_file_handler *fh) { }
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#endif
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+
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#endif /* _LINUX_LUO_INTERNAL_H */
+23
lib/Kconfig.debug
+23
lib/Kconfig.debug
···
2825
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If unsure, say N.
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+
config LIVEUPDATE_TEST
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bool "Live Update Kernel Test"
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default n
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depends on LIVEUPDATE
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help
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Enable a built-in kernel test module for the Live Update
2834
+
Orchestrator.
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+
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+
This module validates the File-Lifecycle-Bound subsystem by
2837
+
registering a set of mock FLB objects with any real file handlers
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+
that support live update (such as the memfd handler).
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+
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When live update operations are performed, this test module will
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output messages to the kernel log (dmesg), confirming that its
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registration and various callback functions (preserve, retrieve,
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finish, etc.) are being invoked correctly.
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This is a debugging and regression testing tool for developers
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working on the Live Update subsystem. It should not be enabled in
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production kernels.
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+
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If unsure, say N
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+
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config CMDLINE_KUNIT_TEST
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tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
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depends on KUNIT
+1
lib/tests/Makefile
+1
lib/tests/Makefile
···
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obj-$(CONFIG_KFIFO_KUNIT_TEST) += kfifo_kunit.o
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obj-$(CONFIG_TEST_LIST_SORT) += test_list_sort.o
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obj-$(CONFIG_LINEAR_RANGES_TEST) += test_linear_ranges.o
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+
obj-$(CONFIG_LIVEUPDATE_TEST) += liveupdate.o
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CFLAGS_longest_symbol_kunit.o += $(call cc-disable-warning, missing-prototypes)
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obj-$(CONFIG_LONGEST_SYM_KUNIT_TEST) += longest_symbol_kunit.o
+158
lib/tests/liveupdate.c
+158
lib/tests/liveupdate.c
···
1
+
// SPDX-License-Identifier: GPL-2.0
2
+
3
+
/*
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+
* Copyright (c) 2025, Google LLC.
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* Pasha Tatashin <pasha.tatashin@soleen.com>
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+
*/
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+
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#define pr_fmt(fmt) KBUILD_MODNAME " test: " fmt
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+
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#include <linux/cleanup.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/liveupdate.h>
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#include <linux/module.h>
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#include "../../kernel/liveupdate/luo_internal.h"
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+
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static const struct liveupdate_flb_ops test_flb_ops;
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#define DEFINE_TEST_FLB(i) { \
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+
.ops = &test_flb_ops, \
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+
.compatible = LIVEUPDATE_TEST_FLB_COMPATIBLE(i), \
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+
}
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+
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/* Number of Test FLBs to register with every file handler */
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#define TEST_NFLBS 3
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static struct liveupdate_flb test_flbs[TEST_NFLBS] = {
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DEFINE_TEST_FLB(0),
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DEFINE_TEST_FLB(1),
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DEFINE_TEST_FLB(2),
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};
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+
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#define TEST_FLB_MAGIC_BASE 0xFEEDF00DCAFEBEE0ULL
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+
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static int test_flb_preserve(struct liveupdate_flb_op_args *argp)
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+
{
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ptrdiff_t index = argp->flb - test_flbs;
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+
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pr_info("%s: preserve was triggered\n", argp->flb->compatible);
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argp->data = TEST_FLB_MAGIC_BASE + index;
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+
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return 0;
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}
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+
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static void test_flb_unpreserve(struct liveupdate_flb_op_args *argp)
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{
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pr_info("%s: unpreserve was triggered\n", argp->flb->compatible);
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+
}
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+
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static int test_flb_retrieve(struct liveupdate_flb_op_args *argp)
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+
{
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ptrdiff_t index = argp->flb - test_flbs;
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+
u64 expected_data = TEST_FLB_MAGIC_BASE + index;
52
+
53
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if (argp->data == expected_data) {
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pr_info("%s: found flb data from the previous boot\n",
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argp->flb->compatible);
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argp->obj = (void *)argp->data;
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+
} else {
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pr_err("%s: ERROR - incorrect data handle: %llx, expected %llx\n",
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+
argp->flb->compatible, argp->data, expected_data);
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+
return -EINVAL;
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}
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+
63
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return 0;
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}
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+
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static void test_flb_finish(struct liveupdate_flb_op_args *argp)
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{
68
+
ptrdiff_t index = argp->flb - test_flbs;
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void *expected_obj = (void *)(TEST_FLB_MAGIC_BASE + index);
70
+
71
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if (argp->obj == expected_obj) {
72
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pr_info("%s: finish was triggered\n", argp->flb->compatible);
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+
} else {
74
+
pr_err("%s: ERROR - finish called with invalid object\n",
75
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argp->flb->compatible);
76
+
}
77
+
}
78
+
79
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static const struct liveupdate_flb_ops test_flb_ops = {
80
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.preserve = test_flb_preserve,
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+
.unpreserve = test_flb_unpreserve,
82
+
.retrieve = test_flb_retrieve,
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+
.finish = test_flb_finish,
84
+
.owner = THIS_MODULE,
85
+
};
86
+
87
+
static void liveupdate_test_init(void)
88
+
{
89
+
static DEFINE_MUTEX(init_lock);
90
+
static bool initialized;
91
+
int i;
92
+
93
+
guard(mutex)(&init_lock);
94
+
95
+
if (initialized)
96
+
return;
97
+
98
+
for (i = 0; i < TEST_NFLBS; i++) {
99
+
struct liveupdate_flb *flb = &test_flbs[i];
100
+
void *obj;
101
+
int err;
102
+
103
+
err = liveupdate_flb_get_incoming(flb, &obj);
104
+
if (err && err != -ENODATA && err != -ENOENT) {
105
+
pr_err("liveupdate_flb_get_incoming for %s failed: %pe\n",
106
+
flb->compatible, ERR_PTR(err));
107
+
}
108
+
}
109
+
initialized = true;
110
+
}
111
+
112
+
void liveupdate_test_register(struct liveupdate_file_handler *fh)
113
+
{
114
+
int err, i;
115
+
116
+
liveupdate_test_init();
117
+
118
+
for (i = 0; i < TEST_NFLBS; i++) {
119
+
struct liveupdate_flb *flb = &test_flbs[i];
120
+
121
+
err = liveupdate_register_flb(fh, flb);
122
+
if (err) {
123
+
pr_err("Failed to register %s %pe\n",
124
+
flb->compatible, ERR_PTR(err));
125
+
}
126
+
}
127
+
128
+
err = liveupdate_register_flb(fh, &test_flbs[0]);
129
+
if (!err || err != -EEXIST) {
130
+
pr_err("Failed: %s should be already registered, but got err: %pe\n",
131
+
test_flbs[0].compatible, ERR_PTR(err));
132
+
}
133
+
134
+
pr_info("Registered %d FLBs with file handler: [%s]\n",
135
+
TEST_NFLBS, fh->compatible);
136
+
}
137
+
138
+
void liveupdate_test_unregister(struct liveupdate_file_handler *fh)
139
+
{
140
+
int err, i;
141
+
142
+
for (i = 0; i < TEST_NFLBS; i++) {
143
+
struct liveupdate_flb *flb = &test_flbs[i];
144
+
145
+
err = liveupdate_unregister_flb(fh, flb);
146
+
if (err) {
147
+
pr_err("Failed to unregister %s %pe\n",
148
+
flb->compatible, ERR_PTR(err));
149
+
}
150
+
}
151
+
152
+
pr_info("Unregistered %d FLBs from file handler: [%s]\n",
153
+
TEST_NFLBS, fh->compatible);
154
+
}
155
+
156
+
MODULE_LICENSE("GPL");
157
+
MODULE_AUTHOR("Pasha Tatashin <pasha.tatashin@soleen.com>");
158
+
MODULE_DESCRIPTION("In-kernel test for LUO mechanism");