From 57000fe6a60421b35ce51a338cc33caf057f5795 Mon Sep 17 00:00:00 2001 From: Pablo Alessandro Santos Hugen Date: Fri, 20 Mar 2026 17:11:17 -0300 Subject: selftests/livepatch: add test for module function patching Add a target module and livepatch pair that verify module function patching via a proc entry. Two test cases cover both the klp_enable_patch path (target loaded before livepatch) and the klp_module_coming path (livepatch loaded before target). Signed-off-by: Pablo Alessandro Santos Hugen Acked-by: Miroslav Benes Acked-by: Joe Lawrence Reviewed-by: Petr Mladek Tested-by: Petr Mladek Link: https://patch.msgid.link/20260320201135.1203992-1-phugen@redhat.com Signed-off-by: Petr Mladek --- .../selftests/livepatch/test_modules/Makefile | 2 + .../livepatch/test_modules/test_klp_mod_patch.c | 53 ++++++++++++++++++++++ .../livepatch/test_modules/test_klp_mod_target.c | 39 ++++++++++++++++ 3 files changed, 94 insertions(+) create mode 100644 tools/testing/selftests/livepatch/test_modules/test_klp_mod_patch.c create mode 100644 tools/testing/selftests/livepatch/test_modules/test_klp_mod_target.c (limited to 'tools/testing/selftests/livepatch/test_modules') diff --git a/tools/testing/selftests/livepatch/test_modules/Makefile b/tools/testing/selftests/livepatch/test_modules/Makefile index 939230e571f5..a13d398585dc 100644 --- a/tools/testing/selftests/livepatch/test_modules/Makefile +++ b/tools/testing/selftests/livepatch/test_modules/Makefile @@ -8,6 +8,8 @@ obj-m += test_klp_atomic_replace.o \ test_klp_callbacks_mod.o \ test_klp_kprobe.o \ test_klp_livepatch.o \ + test_klp_mod_patch.o \ + test_klp_mod_target.o \ test_klp_shadow_vars.o \ test_klp_state.o \ test_klp_state2.o \ diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_mod_patch.c b/tools/testing/selftests/livepatch/test_modules/test_klp_mod_patch.c new file mode 100644 index 000000000000..6725b4720365 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_mod_patch.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2026 Pablo Hugen + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include + +static int livepatch_mod_target_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%s: %s\n", THIS_MODULE->name, + "this has been live patched"); + return 0; +} + +static struct klp_func funcs[] = { + { + .old_name = "test_klp_mod_target_show", + .new_func = livepatch_mod_target_show, + }, + {}, +}; + +static struct klp_object objs[] = { + { + .name = "test_klp_mod_target", + .funcs = funcs, + }, + {}, +}; + +static struct klp_patch patch = { + .mod = THIS_MODULE, + .objs = objs, +}; + +static int test_klp_mod_patch_init(void) +{ + return klp_enable_patch(&patch); +} + +static void test_klp_mod_patch_exit(void) +{ +} + +module_init(test_klp_mod_patch_init); +module_exit(test_klp_mod_patch_exit); +MODULE_LICENSE("GPL"); +MODULE_INFO(livepatch, "Y"); +MODULE_AUTHOR("Pablo Hugen "); +MODULE_DESCRIPTION("Livepatch test: patch for module-provided function"); diff --git a/tools/testing/selftests/livepatch/test_modules/test_klp_mod_target.c b/tools/testing/selftests/livepatch/test_modules/test_klp_mod_target.c new file mode 100644 index 000000000000..9643984d2402 --- /dev/null +++ b/tools/testing/selftests/livepatch/test_modules/test_klp_mod_target.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2026 Pablo Hugen + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include + +static struct proc_dir_entry *pde; + +static noinline int test_klp_mod_target_show(struct seq_file *m, void *v) +{ + seq_printf(m, "%s: %s\n", THIS_MODULE->name, "original output"); + return 0; +} + +static int test_klp_mod_target_init(void) +{ + pr_info("%s\n", __func__); + pde = proc_create_single("test_klp_mod_target", 0, NULL, + test_klp_mod_target_show); + if (!pde) + return -ENOMEM; + return 0; +} + +static void test_klp_mod_target_exit(void) +{ + pr_info("%s\n", __func__); + proc_remove(pde); +} + +module_init(test_klp_mod_target_init); +module_exit(test_klp_mod_target_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Hugen "); +MODULE_DESCRIPTION("Livepatch test: target module with proc entry"); -- cgit v1.2.3