// SPDX-License-Identifier: GPL-2.0-only#include <linux/sched.h>#include <linux/sched/debug.h>#include <linux/stacktrace.h>#include <linux/thread_info.h>#include <linux/ftrace.h>#include <linux/export.h>#include <asm/ptrace.h>#include <asm/stacktrace.h> #include "kstack.h" static void __save_stack_trace(struct thread_info *tp,			       struct stack_trace *trace,			       bool skip_sched){	unsigned long ksp, fp;#ifdef CONFIG_FUNCTION_GRAPH_TRACER	struct task_struct *t;	int graph = 0;#endif 	if (tp == current_thread_info()) {		stack_trace_flush();		__asm__ __volatile__("mov %%fp, %0" : "=r" (ksp));	} else {		ksp = tp->ksp;	} 	fp = ksp + STACK_BIAS;#ifdef CONFIG_FUNCTION_GRAPH_TRACER	t = tp->task;#endif	do {		struct sparc_stackf *sf;		struct pt_regs *regs;		unsigned long pc; 		if (!kstack_valid(tp, fp))			break; 		sf = (struct sparc_stackf *) fp;		regs = (struct pt_regs *) (sf + 1); 		if (kstack_is_trap_frame(tp, regs)) {			if (!(regs->tstate & TSTATE_PRIV))				break;			pc = regs->tpc;			fp = regs->u_regs[UREG_I6] + STACK_BIAS;		} else {			pc = sf->callers_pc;			fp = (unsigned long)sf->fp + STACK_BIAS;		} 		if (trace->skip > 0)			trace->skip--;		else if (!skip_sched || !in_sched_functions(pc)) {			trace->entries[trace->nr_entries++] = pc;#ifdef CONFIG_FUNCTION_GRAPH_TRACER			if ((pc + 8UL) == (unsigned long) &return_to_handler) {				struct ftrace_ret_stack *ret_stack;				ret_stack = ftrace_graph_get_ret_stack(t,								       graph);				if (ret_stack) {					pc = ret_stack->ret;					if (trace->nr_entries <					    trace->max_entries)						trace->entries[trace->nr_entries++] = pc;					graph++;				}			}#endif		}	} while (trace->nr_entries < trace->max_entries);} void save_stack_trace(struct stack_trace *trace){	__save_stack_trace(current_thread_info(), trace, false);}EXPORT_SYMBOL_GPL(save_stack_trace); void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace){	struct thread_info *tp = task_thread_info(tsk); 	__save_stack_trace(tp, trace, true);}EXPORT_SYMBOL_GPL(save_stack_trace_tsk);