1 files changed, 10 insertions, 34 deletions
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index 51439a71e392..e540b022ceb2 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -261,43 +261,19 @@ void ftrace_arch_code_modify_post_process(void)
 }
 
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-/*
- * Hook the return address and push it in the stack of return addresses
- * in current thread info.
- */
-unsigned long prepare_ftrace_return(unsigned long ra, unsigned long sp,
-				    unsigned long ip)
-{
-	if (unlikely(ftrace_graph_is_dead()))
-		goto out;
-	if (unlikely(atomic_read(&current->tracing_graph_pause)))
-		goto out;
-	ip -= MCOUNT_INSN_SIZE;
-	if (!function_graph_enter(ra, ip, 0, (void *) sp))
-		ra = (unsigned long) return_to_handler;
-out:
-	return ra;
-}
-NOKPROBE_SYMBOL(prepare_ftrace_return);
 
-/*
- * Patch the kernel code at ftrace_graph_caller location. The instruction
- * there is branch relative on condition. To enable the ftrace graph code
- * block, we simply patch the mask field of the instruction to zero and
- * turn the instruction into a nop.
- * To disable the ftrace graph code the mask field will be patched to
- * all ones, which turns the instruction into an unconditional branch.
- */
-int ftrace_enable_ftrace_graph_caller(void)
+void ftrace_graph_func(unsigned long ip, unsigned long parent_ip,
+		       struct ftrace_ops *op, struct ftrace_regs *fregs)
 {
-	/* Expect brc 0xf,... */
-	return ftrace_patch_branch_mask(ftrace_graph_caller, 0xa7f4, false);
-}
+	unsigned long *parent = &arch_ftrace_regs(fregs)->regs.gprs[14];
+	unsigned long sp = arch_ftrace_regs(fregs)->regs.gprs[15];
 
-int ftrace_disable_ftrace_graph_caller(void)
-{
-	/* Expect brc 0x0,... */
-	return ftrace_patch_branch_mask(ftrace_graph_caller, 0xa704, true);
+	if (unlikely(ftrace_graph_is_dead()))
+		return;
+	if (unlikely(atomic_read(&current->tracing_graph_pause)))
+		return;
+	if (!function_graph_enter_regs(*parent, ip, 0, (unsigned long *)sp, fregs))
+		*parent = (unsigned long)&return_to_handler;
 }
 
 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */