From 33e53ae1ce413a081254e686d9b27cc1b3585e2f Mon Sep 17 00:00:00 2001
From: Guo Ren <guoren@linux.alibaba.com>
Date: Wed, 1 Apr 2020 09:17:02 +0800
Subject: csky: Add kprobes supported

This patch enable kprobes, kretprobes, ftrace interface. It utilized
software breakpoint and single step debug exceptions, instructions
simulation on csky.

We use USR_BKPT replace origin instruction, and the kprobe handler
prepares an excutable memory slot for out-of-line execution with a
copy of the original instruction being probed. Most of instructions
could be executed by single-step, but some instructions need origin
pc value to execute and we need software simulate these instructions.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 arch/csky/mm/fault.c | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'arch/csky/mm')

diff --git a/arch/csky/mm/fault.c b/arch/csky/mm/fault.c
index 562c7f708749..d3c61b83e195 100644
--- a/arch/csky/mm/fault.c
+++ b/arch/csky/mm/fault.c
@@ -18,6 +18,7 @@
 #include <linux/extable.h>
 #include <linux/uaccess.h>
 #include <linux/perf_event.h>
+#include <linux/kprobes.h>
 
 #include <asm/hardirq.h>
 #include <asm/mmu_context.h>
@@ -53,6 +54,9 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
 	int fault;
 	unsigned long address = mmu_meh & PAGE_MASK;
 
+	if (kprobe_page_fault(regs, tsk->thread.trap_no))
+		return;
+
 	si_code = SEGV_MAPERR;
 
 #ifndef CONFIG_CPU_HAS_TLBI
-- 
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