xref: /linux/arch/powerpc/include/asm/livepatch.h (revision f63e6d89876034c21ecd18bb1cd0d6c5b8da11a5)
1*f63e6d89SMichael Ellerman /*
2*f63e6d89SMichael Ellerman  * livepatch.h - powerpc-specific Kernel Live Patching Core
3*f63e6d89SMichael Ellerman  *
4*f63e6d89SMichael Ellerman  * Copyright (C) 2015-2016, SUSE, IBM Corp.
5*f63e6d89SMichael Ellerman  *
6*f63e6d89SMichael Ellerman  * This program is free software; you can redistribute it and/or
7*f63e6d89SMichael Ellerman  * modify it under the terms of the GNU General Public License
8*f63e6d89SMichael Ellerman  * as published by the Free Software Foundation; either version 2
9*f63e6d89SMichael Ellerman  * of the License, or (at your option) any later version.
10*f63e6d89SMichael Ellerman  *
11*f63e6d89SMichael Ellerman  * This program is distributed in the hope that it will be useful,
12*f63e6d89SMichael Ellerman  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13*f63e6d89SMichael Ellerman  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*f63e6d89SMichael Ellerman  * GNU General Public License for more details.
15*f63e6d89SMichael Ellerman  *
16*f63e6d89SMichael Ellerman  * You should have received a copy of the GNU General Public License
17*f63e6d89SMichael Ellerman  * along with this program; if not, see <http://www.gnu.org/licenses/>.
18*f63e6d89SMichael Ellerman  */
19*f63e6d89SMichael Ellerman #ifndef _ASM_POWERPC_LIVEPATCH_H
20*f63e6d89SMichael Ellerman #define _ASM_POWERPC_LIVEPATCH_H
21*f63e6d89SMichael Ellerman 
22*f63e6d89SMichael Ellerman #include <linux/module.h>
23*f63e6d89SMichael Ellerman #include <linux/ftrace.h>
24*f63e6d89SMichael Ellerman 
25*f63e6d89SMichael Ellerman #ifdef CONFIG_LIVEPATCH
26*f63e6d89SMichael Ellerman static inline int klp_check_compiler_support(void)
27*f63e6d89SMichael Ellerman {
28*f63e6d89SMichael Ellerman 	return 0;
29*f63e6d89SMichael Ellerman }
30*f63e6d89SMichael Ellerman 
31*f63e6d89SMichael Ellerman static inline int klp_write_module_reloc(struct module *mod, unsigned long
32*f63e6d89SMichael Ellerman 		type, unsigned long loc, unsigned long value)
33*f63e6d89SMichael Ellerman {
34*f63e6d89SMichael Ellerman 	/* This requires infrastructure changes; we need the loadinfos. */
35*f63e6d89SMichael Ellerman 	return -ENOSYS;
36*f63e6d89SMichael Ellerman }
37*f63e6d89SMichael Ellerman 
38*f63e6d89SMichael Ellerman static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
39*f63e6d89SMichael Ellerman {
40*f63e6d89SMichael Ellerman 	regs->nip = ip;
41*f63e6d89SMichael Ellerman }
42*f63e6d89SMichael Ellerman 
43*f63e6d89SMichael Ellerman #define klp_get_ftrace_location klp_get_ftrace_location
44*f63e6d89SMichael Ellerman static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
45*f63e6d89SMichael Ellerman {
46*f63e6d89SMichael Ellerman 	/*
47*f63e6d89SMichael Ellerman 	 * Live patch works only with -mprofile-kernel on PPC. In this case,
48*f63e6d89SMichael Ellerman 	 * the ftrace location is always within the first 16 bytes.
49*f63e6d89SMichael Ellerman 	 */
50*f63e6d89SMichael Ellerman 	return ftrace_location_range(faddr, faddr + 16);
51*f63e6d89SMichael Ellerman }
52*f63e6d89SMichael Ellerman #endif /* CONFIG_LIVEPATCH */
53*f63e6d89SMichael Ellerman 
54*f63e6d89SMichael Ellerman #endif /* _ASM_POWERPC_LIVEPATCH_H */
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