Re: CET/IBT support and live-patches

Ok. And we would need something like the following for the livepatch (not 
even compile tested).

---

diff --git a/arch/powerpc/include/asm/livepatch.h b/arch/powerpc/include/asm/livepatch.h
index 4fe018cc207b..7b9dcd51af32 100644
--- a/arch/powerpc/include/asm/livepatch.h
+++ b/arch/powerpc/include/asm/livepatch.h

@@ -19,16 +19,6 @@ static inline void klp_arch_set_pc(struct ftrace_regs *fregs, unsigned long ip)
 	regs_set_return_ip(regs, ip);
 }
 
-#define klp_get_ftrace_location klp_get_ftrace_location
-static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
-{
-	/*
-	 * Live patch works only with -mprofile-kernel on PPC. In this case,
-	 * the ftrace location is always within the first 16 bytes.
-	 */
-	return ftrace_location_range(faddr, faddr + 16);
-}
-
 static inline void klp_init_thread_info(struct task_struct *p)
 {
 	/* + 1 to account for STACK_END_MAGIC */

diff --git a/kernel/livepatch/patch.c b/kernel/livepatch/patch.c
index fe316c021d73..81cd9235e160 100644
--- a/kernel/livepatch/patch.c
+++ b/kernel/livepatch/patch.c

@@ -127,15 +127,18 @@ static void notrace klp_ftrace_handler(unsigned long ip,
 /*
  * Convert a function address into the appropriate ftrace location.
  *
- * Usually this is just the address of the function, but on some architectures
- * it's more complicated so allow them to provide a custom behaviour.
+ * Usually this is just the address of the function, but there are some
+ * exceptions.
+ *
+ *   * PPC - live patch works only with -mprofile-kernel. In this case,
+ *     the ftrace location is always within the first 16 bytes.
+ *   * x86_64 with CET/IBT enabled - there is ENDBR instruction at +0 offset.
+ *     __fentry__ follows it.
  */
-#ifndef klp_get_ftrace_location
-static unsigned long klp_get_ftrace_location(unsigned long faddr)
+static inline unsigned long klp_get_ftrace_location(unsigned long faddr)
 {
-	return faddr;
+	return ftrace_location_range(faddr, faddr + 16);
 }
-#endif