Commit 1e377ae9 authored by Zong Li's avatar Zong Li Committed by Greentime Hu
Browse files

nds32/stack: Get real return address by using ftrace_graph_ret_addr 



Function graph tracer has modified the return address to
'return_to_handler' on stack, and provide the 'ftrace_graph_ret_addr' to
get the real return address.

Signed-off-by: default avatarZong Li <zong@andestech.com>
Acked-by: default avatarGreentime Hu <greentime@andestech.com>
Signed-off-by: default avatarGreentime Hu <greentime@andestech.com>
parent 95cd2f7b

arch/nds32/kernel/stacktrace.c

+4 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#include <linux/sched/debug.h>

#include <linux/sched/task_stack.h>

#include <linux/stacktrace.h>

#include <linux/ftrace.h>



void save_stack_trace(struct stack_trace *trace)

{
@@ -16,6 +17,7 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 
	unsigned long *fpn;

	int skip = trace->skip;

	int savesched;

	int graph_idx = 0;



	if (tsk == current) {

		__asm__ __volatile__("\tori\t%0, $fp, #0\n":"=r"(fpn));
@@ -33,6 +35,8 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) 
		fpp = fpn[FP_OFFSET];

		if (!__kernel_text_address(lpp))

			break;

		else

			lpp = ftrace_graph_ret_addr(tsk, &graph_idx, lpp, NULL);



		if (savesched || !in_sched_functions(lpp)) {

			if (skip) {

arch/nds32/kernel/traps.c

+6 −24
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
#include <linux/kdebug.h>

#include <linux/sched/task_stack.h>

#include <linux/uaccess.h>

#include <linux/ftrace.h>



#include <asm/proc-fns.h>

#include <asm/unistd.h>
@@ -94,28 +95,6 @@ static void dump_instr(struct pt_regs *regs) 
	set_fs(fs);

}



#ifdef CONFIG_FUNCTION_GRAPH_TRACER

#include <linux/ftrace.h>

static void

get_real_ret_addr(unsigned long *addr, struct task_struct *tsk, int *graph)

{

	if (*addr == (unsigned long)return_to_handler) {

		int index = tsk->curr_ret_stack;



		if (tsk->ret_stack && index >= *graph) {

			index -= *graph;

			*addr = tsk->ret_stack[index].ret;

			(*graph)++;

		}

	}

}

#else

static inline void

get_real_ret_addr(unsigned long *addr, struct task_struct *tsk, int *graph)

{

}

#endif



#define LOOP_TIMES (100)

static void __dump(struct task_struct *tsk, unsigned long *base_reg)

{
@@ -126,7 +105,8 @@ static void __dump(struct task_struct *tsk, unsigned long *base_reg) 
		while (!kstack_end(base_reg)) {

			ret_addr = *base_reg++;

			if (__kernel_text_address(ret_addr)) {

				get_real_ret_addr(&ret_addr, tsk, &graph);

				ret_addr = ftrace_graph_ret_addr(

						tsk, &graph, ret_addr, NULL);

				print_ip_sym(ret_addr);

			}

			if (--cnt < 0)
@@ -145,7 +125,9 @@ static void __dump(struct task_struct *tsk, unsigned long *base_reg) 
			next_fp = base_reg[FP_OFFSET];

#endif

			if (__kernel_text_address(ret_addr)) {

				get_real_ret_addr(&ret_addr, tsk, &graph);



				ret_addr = ftrace_graph_ret_addr(

						tsk, &graph, ret_addr, NULL);

				print_ip_sym(ret_addr);

			}

			if (--cnt < 0)