93862e385d
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 <joe.lawrence@redhat.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
/*
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* Copyright (C) 2017 Joe Lawrence <joe.lawrence@redhat.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* livepatch-callbacks-busymod.c - (un)patching callbacks demo support module
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*
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*
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* Purpose
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* -------
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*
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* Simple module to demonstrate livepatch (un)patching callbacks.
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*
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*
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* Usage
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* -----
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*
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* This module is not intended to be standalone. See the "Usage"
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* section of livepatch-callbacks-mod.c.
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*/
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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/workqueue.h>
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#include <linux/delay.h>
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static int sleep_secs;
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module_param(sleep_secs, int, 0644);
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MODULE_PARM_DESC(sleep_secs, "sleep_secs (default=0)");
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static void busymod_work_func(struct work_struct *work);
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static DECLARE_DELAYED_WORK(work, busymod_work_func);
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static void busymod_work_func(struct work_struct *work)
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{
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pr_info("%s, sleeping %d seconds ...\n", __func__, sleep_secs);
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msleep(sleep_secs * 1000);
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pr_info("%s exit\n", __func__);
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}
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static int livepatch_callbacks_mod_init(void)
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{
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pr_info("%s\n", __func__);
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schedule_delayed_work(&work,
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msecs_to_jiffies(1000 * 0));
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return 0;
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}
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static void livepatch_callbacks_mod_exit(void)
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{
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cancel_delayed_work_sync(&work);
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pr_info("%s\n", __func__);
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}
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module_init(livepatch_callbacks_mod_init);
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module_exit(livepatch_callbacks_mod_exit);
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MODULE_LICENSE("GPL");
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