riscv: ftrace: Use ftrace_get_regs helper

Use ftrace_get_regs() helper call to get pt_regs from ftrace_regs struct,
this makes the code simpler.

Signed-off-by: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>

Author: sunnanyong

arch/riscv/kernel/probes/ftrace.c

@@ -4,37 +4,39 @@
 
 /* Ftrace callback handler for kprobes -- called under preepmt disabed */
 void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
-			   struct ftrace_ops *ops, struct ftrace_regs *regs)
+			   struct ftrace_ops *ops, struct ftrace_regs *fregs)
 {
 	struct kprobe *p;
+	struct pt_regs *regs;
 	struct kprobe_ctlblk *kcb;
 
 	p = get_kprobe((kprobe_opcode_t *)ip);
 	if (unlikely(!p) || kprobe_disabled(p))
 		return;
 
+	regs = ftrace_get_regs(fregs);
 	kcb = get_kprobe_ctlblk();
 	if (kprobe_running()) {
 		kprobes_inc_nmissed_count(p);
 	} else {
-		unsigned long orig_ip = instruction_pointer(&(regs->regs));
+		unsigned long orig_ip = instruction_pointer(regs);
 
-		instruction_pointer_set(&(regs->regs), ip);
+		instruction_pointer_set(regs, ip);
 
 		__this_cpu_write(current_kprobe, p);
 		kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-		if (!p->pre_handler || !p->pre_handler(p, &(regs->regs))) {
+		if (!p->pre_handler || !p->pre_handler(p, regs)) {
 			/*
 			 * Emulate singlestep (and also recover regs->pc)
 			 * as if there is a nop
 			 */
-			instruction_pointer_set(&(regs->regs),
+			instruction_pointer_set(regs,
 				(unsigned long)p->addr + MCOUNT_INSN_SIZE);
 			if (unlikely(p->post_handler)) {
 				kcb->kprobe_status = KPROBE_HIT_SSDONE;
-				p->post_handler(p, &(regs->regs), 0);
+				p->post_handler(p, regs, 0);
 			}
-			instruction_pointer_set(&(regs->regs), orig_ip);
+			instruction_pointer_set(regs, orig_ip);
 		}
 
 		/*