#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/stacktrace.h>#include <asm/stacktrace.h> void walk_stackframe(unsigned long sp,		     int (*fn)(unsigned long addr, void *data),		     void *data){	unsigned long high = ALIGN(sp, THREAD_SIZE); 	for (; sp <= high - 4; sp += 4) {		unsigned long addr = *(unsigned long *) sp; 		if (!kernel_text_address(addr))			continue; 		if (fn(addr, data))			break;	}} struct stack_trace_data {	struct stack_trace *trace;	unsigned int no_sched_functions;	unsigned int skip;}; #ifdef CONFIG_STACKTRACE static int save_trace(unsigned long addr, void *d){	struct stack_trace_data *data = d;	struct stack_trace *trace = data->trace; 	if (data->no_sched_functions && in_sched_functions(addr))		return 0; 	if (data->skip) {		data->skip--;		return 0;	} 	trace->entries[trace->nr_entries++] = addr; 	return trace->nr_entries >= trace->max_entries;} void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace){	struct stack_trace_data data;	unsigned long sp; 	data.trace = trace;	data.skip = trace->skip; 	if (tsk != current) {		data.no_sched_functions = 1;		sp = tsk->thread.ksp;	} else {		data.no_sched_functions = 0;		sp = rdsp();	} 	walk_stackframe(sp, save_trace, &data);	if (trace->nr_entries < trace->max_entries)		trace->entries[trace->nr_entries++] = ULONG_MAX;} void save_stack_trace(struct stack_trace *trace){	save_stack_trace_tsk(current, trace);}EXPORT_SYMBOL_GPL(save_stack_trace); #endif /* CONFIG_STACKTRACE */