linux_dsm_epyc7002/arch/csky/kernel/ftrace.c
Guo Ren 230c77a5e9 csky: basic ftrace supported
When gcc with -pg, it'll add _mcount stub in every function. We need
implement the _mcount in kernel and ftrace depends on stackstrace.

To do: call-graph, dynamic ftrace

Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2018-12-31 23:16:46 +08:00

25 lines
663 B
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/ftrace.h>
#include <linux/uaccess.h>
extern void (*ftrace_trace_function)(unsigned long, unsigned long,
struct ftrace_ops*, struct pt_regs*);
noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs)
{
asm volatile ("\n");
}
noinline void csky_mcount(unsigned long from_pc, unsigned long self_pc)
{
if (ftrace_trace_function != ftrace_stub)
ftrace_trace_function(self_pc, from_pc, NULL, NULL);
}
/* _mcount is defined in abi's mcount.S */
EXPORT_SYMBOL(_mcount);