arch/powerpc/include/asm/livepatch.h

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