livepatch: move x86 specific ftrace handler code to arch/x86

The execution flow redirection related implemention in the livepatch
ftrace handler is depended on the specific architecture. This patch
introduces klp_arch_set_pc(like kgdb_arch_set_pc) interface to change
the pt_regs.

Signed-off-by: Li Bin <huawei.libin@huawei.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/x86/include/asm/livepatch.h b/arch/x86/include/asm/livepatch.h
index d529db1b1edf..b5608d7757fd 100644
--- a/arch/x86/include/asm/livepatch.h
+++ b/arch/x86/include/asm/livepatch.h
@@ -22,6 +22,7 @@
 #define _ASM_X86_LIVEPATCH_H
 
 #include <linux/module.h>
+#include <linux/ftrace.h>
 
 #ifdef CONFIG_LIVE_PATCHING
 #ifndef CC_USING_FENTRY
@@ -30,6 +31,10 @@
 extern int klp_write_module_reloc(struct module *mod, unsigned long type,
                                   unsigned long loc, unsigned long value);
 
+static inline void klp_arch_set_pc(struct pt_regs *regs, unsigned long ip)
+{
+        regs->ip = ip;
+}
 #else
 #error Live patching support is disabled; check CONFIG_LIVE_PATCHING
 #endif