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
25 #ifdef CONFIG_LIVEPATCH
klp_check_compiler_support(void)26 static inline int klp_check_compiler_support(void)
27 {
28 return 0;
29 }
30
klp_write_module_reloc(struct module * mod,unsigned long type,unsigned long loc,unsigned long value)31 static inline int klp_write_module_reloc(struct module *mod, unsigned long
32 type, unsigned long loc, unsigned long value)
33 {
34 /* This requires infrastructure changes; we need the loadinfos. */
35 return -ENOSYS;
36 }
37
klp_arch_set_pc(struct pt_regs * regs,unsigned long ip)38 static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
39 {
40 regs->nip = ip;
41 }
42
43 #define klp_get_ftrace_location klp_get_ftrace_location
klp_get_ftrace_location(unsigned long faddr)44 static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
45 {
46 /*
47 * Live patch works only with -mprofile-kernel on PPC. In this case,
48 * the ftrace location is always within the first 16 bytes.
49 */
50 return ftrace_location_range(faddr, faddr + 16);
51 }
52
klp_init_thread_info(struct thread_info * ti)53 static inline void klp_init_thread_info(struct thread_info *ti)
54 {
55 /* + 1 to account for STACK_END_MAGIC */
56 ti->livepatch_sp = (unsigned long *)(ti + 1) + 1;
57 }
58 #else
klp_init_thread_info(struct thread_info * ti)59 static void klp_init_thread_info(struct thread_info *ti) { }
60 #endif /* CONFIG_LIVEPATCH */
61
62 #endif /* _ASM_POWERPC_LIVEPATCH_H */
63