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Merge tag 'livepatching-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Petr Mladek: - Add two new selftests * tag 'livepatching-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: selftests/livepatch: add test for module function patching selftests: livepatch: test-ftrace: livepatch a traced function
2 parents 090748e + 448c0f8 commit d3d9443

5 files changed

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‎tools/testing/selftests/livepatch/test-ftrace.sh‎

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@@ -95,4 +95,40 @@ livepatch: '$MOD_LIVEPATCH': completing unpatching transition
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livepatch: '$MOD_LIVEPATCH': unpatching complete
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% rmmod $MOD_LIVEPATCH"
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# - trace a function
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# - verify livepatch can load targgeting on the same traced function
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# - check if the livepatch is in effect
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# - reset trace and unload livepatch
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start_test "livepatch a traced function and check that the live patch remains in effect"
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FUNCTION_NAME="cmdline_proc_show"
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trace_function "$FUNCTION_NAME"
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load_lp $MOD_LIVEPATCH
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if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] ; then
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log "livepatch: ok"
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fi
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check_traced_functions "$FUNCTION_NAME"
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disable_lp $MOD_LIVEPATCH
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unload_lp $MOD_LIVEPATCH
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check_result "% insmod test_modules/$MOD_LIVEPATCH.ko
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livepatch: enabling patch '$MOD_LIVEPATCH'
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livepatch: '$MOD_LIVEPATCH': initializing patching transition
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livepatch: '$MOD_LIVEPATCH': starting patching transition
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livepatch: '$MOD_LIVEPATCH': completing patching transition
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livepatch: '$MOD_LIVEPATCH': patching complete
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livepatch: ok
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% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH/enabled
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livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
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livepatch: '$MOD_LIVEPATCH': starting unpatching transition
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livepatch: '$MOD_LIVEPATCH': completing unpatching transition
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livepatch: '$MOD_LIVEPATCH': unpatching complete
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% rmmod $MOD_LIVEPATCH"
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exit 0

‎tools/testing/selftests/livepatch/test-livepatch.sh‎

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@@ -8,6 +8,8 @@ MOD_LIVEPATCH1=test_klp_livepatch
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MOD_LIVEPATCH2=test_klp_syscall
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MOD_LIVEPATCH3=test_klp_callbacks_demo
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MOD_REPLACE=test_klp_atomic_replace
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MOD_TARGET=test_klp_mod_target
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MOD_TARGET_PATCH=test_klp_mod_patch
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setup_config
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@@ -196,4 +198,102 @@ livepatch: '$MOD_REPLACE': unpatching complete
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% rmmod $MOD_REPLACE"
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# - load a target module that provides /proc/test_klp_mod_target with
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# original output
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# - load a livepatch that patches the target module's show function
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# - verify the proc entry returns livepatched output
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# - disable and unload the livepatch
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# - verify the proc entry returns original output again
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# - unload the target module
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start_test "module function patching"
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load_mod $MOD_TARGET
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if [[ "$(cat /proc/$MOD_TARGET)" != "$MOD_TARGET: original output" ]] ; then
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echo -e "FAIL\n\n"
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die "livepatch kselftest(s) failed"
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fi
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load_lp $MOD_TARGET_PATCH
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if [[ "$(cat /proc/$MOD_TARGET)" != "$MOD_TARGET_PATCH: this has been live patched" ]] ; then
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echo -e "FAIL\n\n"
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die "livepatch kselftest(s) failed"
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fi
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disable_lp $MOD_TARGET_PATCH
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unload_lp $MOD_TARGET_PATCH
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if [[ "$(cat /proc/$MOD_TARGET)" != "$MOD_TARGET: original output" ]] ; then
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echo -e "FAIL\n\n"
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die "livepatch kselftest(s) failed"
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fi
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unload_mod $MOD_TARGET
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check_result "% insmod test_modules/$MOD_TARGET.ko
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$MOD_TARGET: test_klp_mod_target_init
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% insmod test_modules/$MOD_TARGET_PATCH.ko
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livepatch: enabling patch '$MOD_TARGET_PATCH'
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livepatch: '$MOD_TARGET_PATCH': initializing patching transition
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livepatch: '$MOD_TARGET_PATCH': starting patching transition
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livepatch: '$MOD_TARGET_PATCH': completing patching transition
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livepatch: '$MOD_TARGET_PATCH': patching complete
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% echo 0 > $SYSFS_KLP_DIR/$MOD_TARGET_PATCH/enabled
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livepatch: '$MOD_TARGET_PATCH': initializing unpatching transition
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livepatch: '$MOD_TARGET_PATCH': starting unpatching transition
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livepatch: '$MOD_TARGET_PATCH': completing unpatching transition
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livepatch: '$MOD_TARGET_PATCH': unpatching complete
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% rmmod $MOD_TARGET_PATCH
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% rmmod $MOD_TARGET
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$MOD_TARGET: test_klp_mod_target_exit"
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# - load a livepatch that targets a not-yet-loaded module
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# - load the target module: klp_module_coming patches it immediately
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# - verify the proc entry returns livepatched output
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# - disable and unload the livepatch
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# - verify the proc entry returns original output again
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# - unload the target module
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start_test "module function patching (livepatch first)"
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load_lp $MOD_TARGET_PATCH
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load_mod $MOD_TARGET
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if [[ "$(cat /proc/$MOD_TARGET)" != "$MOD_TARGET_PATCH: this has been live patched" ]] ; then
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echo -e "FAIL\n\n"
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die "livepatch kselftest(s) failed"
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fi
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disable_lp $MOD_TARGET_PATCH
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unload_lp $MOD_TARGET_PATCH
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if [[ "$(cat /proc/$MOD_TARGET)" != "$MOD_TARGET: original output" ]] ; then
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echo -e "FAIL\n\n"
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die "livepatch kselftest(s) failed"
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fi
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unload_mod $MOD_TARGET
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check_result "% insmod test_modules/$MOD_TARGET_PATCH.ko
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livepatch: enabling patch '$MOD_TARGET_PATCH'
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livepatch: '$MOD_TARGET_PATCH': initializing patching transition
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livepatch: '$MOD_TARGET_PATCH': starting patching transition
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livepatch: '$MOD_TARGET_PATCH': completing patching transition
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livepatch: '$MOD_TARGET_PATCH': patching complete
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% insmod test_modules/$MOD_TARGET.ko
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livepatch: applying patch '$MOD_TARGET_PATCH' to loading module '$MOD_TARGET'
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$MOD_TARGET: test_klp_mod_target_init
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% echo 0 > $SYSFS_KLP_DIR/$MOD_TARGET_PATCH/enabled
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livepatch: '$MOD_TARGET_PATCH': initializing unpatching transition
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livepatch: '$MOD_TARGET_PATCH': starting unpatching transition
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livepatch: '$MOD_TARGET_PATCH': completing unpatching transition
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livepatch: '$MOD_TARGET_PATCH': unpatching complete
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% rmmod $MOD_TARGET_PATCH
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% rmmod $MOD_TARGET
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$MOD_TARGET: test_klp_mod_target_exit"
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exit 0

‎tools/testing/selftests/livepatch/test_modules/Makefile‎

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@@ -8,6 +8,8 @@ obj-m += test_klp_atomic_replace.o \
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test_klp_callbacks_mod.o \
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test_klp_kprobe.o \
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test_klp_livepatch.o \
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test_klp_mod_patch.o \
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test_klp_mod_target.o \
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test_klp_shadow_vars.o \
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test_klp_state.o \
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test_klp_state2.o \

‎tools/testing/selftests/livepatch/test_modules/test_klp_mod_patch.c‎

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// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2026 Pablo Hugen <phugen@redhat.com>
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/livepatch.h>
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#include <linux/seq_file.h>
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static int livepatch_mod_target_show(struct seq_file *m, void *v)
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{
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seq_printf(m, "%s: %s\n", THIS_MODULE->name,
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"this has been live patched");
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return 0;
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}
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static struct klp_func funcs[] = {
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{
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.old_name = "test_klp_mod_target_show",
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.new_func = livepatch_mod_target_show,
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},
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{},
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};
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static struct klp_object objs[] = {
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{
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.name = "test_klp_mod_target",
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.funcs = funcs,
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},
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{},
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};
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static struct klp_patch patch = {
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.mod = THIS_MODULE,
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.objs = objs,
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};
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static int test_klp_mod_patch_init(void)
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{
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return klp_enable_patch(&patch);
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}
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static void test_klp_mod_patch_exit(void)
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{
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}
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module_init(test_klp_mod_patch_init);
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module_exit(test_klp_mod_patch_exit);
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MODULE_LICENSE("GPL");
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MODULE_INFO(livepatch, "Y");
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MODULE_AUTHOR("Pablo Hugen <phugen@redhat.com>");
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MODULE_DESCRIPTION("Livepatch test: patch for module-provided function");

‎tools/testing/selftests/livepatch/test_modules/test_klp_mod_target.c‎

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// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2026 Pablo Hugen <phugen@redhat.com>
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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static struct proc_dir_entry *pde;
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static noinline int test_klp_mod_target_show(struct seq_file *m, void *v)
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{
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seq_printf(m, "%s: %s\n", THIS_MODULE->name, "original output");
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return 0;
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}
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static int test_klp_mod_target_init(void)
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{
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pr_info("%s\n", __func__);
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pde = proc_create_single("test_klp_mod_target", 0, NULL,
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test_klp_mod_target_show);
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if (!pde)
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return -ENOMEM;
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return 0;
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}
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static void test_klp_mod_target_exit(void)
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{
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pr_info("%s\n", __func__);
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proc_remove(pde);
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}
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module_init(test_klp_mod_target_init);
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module_exit(test_klp_mod_target_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Pablo Hugen <phugen@redhat.com>");
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MODULE_DESCRIPTION("Livepatch test: target module with proc entry");

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