18c2ecf20Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0-only
28c2ecf20Sopenharmony_ci/*
38c2ecf20Sopenharmony_ci * Stack trace management functions
48c2ecf20Sopenharmony_ci *
58c2ecf20Sopenharmony_ci *  Copyright (C) 2009 Helge Deller <deller@gmx.de>
68c2ecf20Sopenharmony_ci *  based on arch/x86/kernel/stacktrace.c by Ingo Molnar <mingo@redhat.com>
78c2ecf20Sopenharmony_ci *  and parisc unwind functions by Randolph Chung <tausq@debian.org>
88c2ecf20Sopenharmony_ci *
98c2ecf20Sopenharmony_ci *  TODO: Userspace stacktrace (CONFIG_USER_STACKTRACE_SUPPORT)
108c2ecf20Sopenharmony_ci */
118c2ecf20Sopenharmony_ci#include <linux/module.h>
128c2ecf20Sopenharmony_ci#include <linux/stacktrace.h>
138c2ecf20Sopenharmony_ci
148c2ecf20Sopenharmony_ci#include <asm/unwind.h>
158c2ecf20Sopenharmony_ci
168c2ecf20Sopenharmony_cistatic void dump_trace(struct task_struct *task, struct stack_trace *trace)
178c2ecf20Sopenharmony_ci{
188c2ecf20Sopenharmony_ci	struct unwind_frame_info info;
198c2ecf20Sopenharmony_ci
208c2ecf20Sopenharmony_ci	unwind_frame_init_task(&info, task, NULL);
218c2ecf20Sopenharmony_ci
228c2ecf20Sopenharmony_ci	/* unwind stack and save entries in stack_trace struct */
238c2ecf20Sopenharmony_ci	trace->nr_entries = 0;
248c2ecf20Sopenharmony_ci	while (trace->nr_entries < trace->max_entries) {
258c2ecf20Sopenharmony_ci		if (unwind_once(&info) < 0 || info.ip == 0)
268c2ecf20Sopenharmony_ci			break;
278c2ecf20Sopenharmony_ci
288c2ecf20Sopenharmony_ci		if (__kernel_text_address(info.ip))
298c2ecf20Sopenharmony_ci			trace->entries[trace->nr_entries++] = info.ip;
308c2ecf20Sopenharmony_ci	}
318c2ecf20Sopenharmony_ci}
328c2ecf20Sopenharmony_ci
338c2ecf20Sopenharmony_ci/*
348c2ecf20Sopenharmony_ci * Save stack-backtrace addresses into a stack_trace buffer.
358c2ecf20Sopenharmony_ci */
368c2ecf20Sopenharmony_civoid save_stack_trace(struct stack_trace *trace)
378c2ecf20Sopenharmony_ci{
388c2ecf20Sopenharmony_ci	dump_trace(current, trace);
398c2ecf20Sopenharmony_ci}
408c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(save_stack_trace);
418c2ecf20Sopenharmony_ci
428c2ecf20Sopenharmony_civoid save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
438c2ecf20Sopenharmony_ci{
448c2ecf20Sopenharmony_ci	dump_trace(tsk, trace);
458c2ecf20Sopenharmony_ci}
468c2ecf20Sopenharmony_ciEXPORT_SYMBOL_GPL(save_stack_trace_tsk);
47