From 93862e385ded7c60351e09fcd2a541d273650905 Mon Sep 17 00:00:00 2001 From: Joe Lawrence Date: Fri, 13 Oct 2017 15:08:41 -0400 Subject: livepatch: add (un)patch callbacks Provide livepatch modules a klp_object (un)patching notification mechanism. Pre and post-(un)patch callbacks allow livepatch modules to setup or synchronize changes that would be difficult to support in only patched-or-unpatched code contexts. Callbacks can be registered for target module or vmlinux klp_objects, but each implementation is klp_object specific. - Pre-(un)patch callbacks run before any (un)patching transition starts. - Post-(un)patch callbacks run once an object has been (un)patched and the klp_patch fully transitioned to its target state. Example use cases include modification of global data and registration of newly available services/handlers. See Documentation/livepatch/callbacks.txt for details and samples/livepatch/ for examples. Signed-off-by: Joe Lawrence Acked-by: Josh Poimboeuf Acked-by: Miroslav Benes Signed-off-by: Jiri Kosina --- samples/livepatch/livepatch-callbacks-mod.c | 53 +++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) create mode 100644 samples/livepatch/livepatch-callbacks-mod.c (limited to 'samples/livepatch/livepatch-callbacks-mod.c') diff --git a/samples/livepatch/livepatch-callbacks-mod.c b/samples/livepatch/livepatch-callbacks-mod.c new file mode 100644 index 000000000000..e610ce29ba44 --- /dev/null +++ b/samples/livepatch/livepatch-callbacks-mod.c @@ -0,0 +1,53 @@ +/* + * Copyright (C) 2017 Joe Lawrence + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see . + */ + +/* + * livepatch-callbacks-mod.c - (un)patching callbacks demo support module + * + * + * Purpose + * ------- + * + * Simple module to demonstrate livepatch (un)patching callbacks. + * + * + * Usage + * ----- + * + * This module is not intended to be standalone. See the "Usage" + * section of livepatch-callbacks-demo.c. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include + +static int livepatch_callbacks_mod_init(void) +{ + pr_info("%s\n", __func__); + return 0; +} + +static void livepatch_callbacks_mod_exit(void) +{ + pr_info("%s\n", __func__); +} + +module_init(livepatch_callbacks_mod_init); +module_exit(livepatch_callbacks_mod_exit); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-55-g7522