1 /*
2  * livepatch.h - powerpc-specific Kernel Live Patching Core
3  *
4  * Copyright (C) 2015-2016, SUSE, IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 #ifndef _ASM_POWERPC_LIVEPATCH_H
20 #define _ASM_POWERPC_LIVEPATCH_H
21 
22 #include <linux/module.h>
23 #include <linux/ftrace.h>
24 #include <linux/sched/task_stack.h>
25 
26 #ifdef CONFIG_LIVEPATCH
27 static inline int klp_check_compiler_support(void)
28 {
29 	return 0;
30 }
31 
32 static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
33 {
34 	regs->nip = ip;
35 }
36 
37 #define klp_get_ftrace_location klp_get_ftrace_location
38 static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
39 {
40 	/*
41 	 * Live patch works only with -mprofile-kernel on PPC. In this case,
42 	 * the ftrace location is always within the first 16 bytes.
43 	 */
44 	return ftrace_location_range(faddr, faddr + 16);
45 }
46 
47 static inline void klp_init_thread_info(struct task_struct *p)
48 {
49 	/* + 1 to account for STACK_END_MAGIC */
50 	task_thread_info(p)->livepatch_sp = end_of_stack(p) + 1;
51 }
52 #else
53 static inline void klp_init_thread_info(struct task_struct *p) { }
54 #endif /* CONFIG_LIVEPATCH */
55 
56 #endif /* _ASM_POWERPC_LIVEPATCH_H */
57