1// SPDX-License-Identifier: GPL-2.0
 2/*
 
 
 3 * Stack trace management functions
 4 *
 5 *  Copyright IBM Corp. 2006
 6 *  Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
 7 */
 8
 
 9#include <linux/stacktrace.h>
10#include <asm/stacktrace.h>
11#include <asm/unwind.h>
12
13void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie,
14		     struct task_struct *task, struct pt_regs *regs)
 
 
 
15{
16	struct unwind_state state;
 
17	unsigned long addr;
18
19	unwind_for_each_frame(&state, task, regs, 0) {
20		addr = unwind_get_return_address(&state);
21		if (!addr || !consume_entry(cookie, addr, false))
22			break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
23	}
24}

 
 1/*
 2 * arch/s390/kernel/stacktrace.c
 3 *
 4 * Stack trace management functions
 5 *
 6 *  Copyright (C) IBM Corp. 2006
 7 *  Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
 8 */
 9
10#include <linux/sched.h>
11#include <linux/stacktrace.h>
12#include <linux/kallsyms.h>
13#include <linux/module.h>
14
15static unsigned long save_context_stack(struct stack_trace *trace,
16					unsigned long sp,
17					unsigned long low,
18					unsigned long high,
19					int savesched)
20{
21	struct stack_frame *sf;
22	struct pt_regs *regs;
23	unsigned long addr;
24
25	while(1) {
26		sp &= PSW_ADDR_INSN;
27		if (sp < low || sp > high)
28			return sp;
29		sf = (struct stack_frame *)sp;
30		while(1) {
31			addr = sf->gprs[8] & PSW_ADDR_INSN;
32			if (!trace->skip)
33				trace->entries[trace->nr_entries++] = addr;
34			else
35				trace->skip--;
36			if (trace->nr_entries >= trace->max_entries)
37				return sp;
38			low = sp;
39			sp = sf->back_chain & PSW_ADDR_INSN;
40			if (!sp)
41				break;
42			if (sp <= low || sp > high - sizeof(*sf))
43				return sp;
44			sf = (struct stack_frame *)sp;
45		}
46		/* Zero backchain detected, check for interrupt frame. */
47		sp = (unsigned long)(sf + 1);
48		if (sp <= low || sp > high - sizeof(*regs))
49			return sp;
50		regs = (struct pt_regs *)sp;
51		addr = regs->psw.addr & PSW_ADDR_INSN;
52		if (savesched || !in_sched_functions(addr)) {
53			if (!trace->skip)
54				trace->entries[trace->nr_entries++] = addr;
55			else
56				trace->skip--;
57		}
58		if (trace->nr_entries >= trace->max_entries)
59			return sp;
60		low = sp;
61		sp = regs->gprs[15];
62	}
63}
64
65void save_stack_trace(struct stack_trace *trace)
66{
67	register unsigned long sp asm ("15");
68	unsigned long orig_sp, new_sp;
69
70	orig_sp = sp & PSW_ADDR_INSN;
71	new_sp = save_context_stack(trace, orig_sp,
72				    S390_lowcore.panic_stack - PAGE_SIZE,
73				    S390_lowcore.panic_stack, 1);
74	if (new_sp != orig_sp)
75		return;
76	new_sp = save_context_stack(trace, new_sp,
77				    S390_lowcore.async_stack - ASYNC_SIZE,
78				    S390_lowcore.async_stack, 1);
79	if (new_sp != orig_sp)
80		return;
81	save_context_stack(trace, new_sp,
82			   S390_lowcore.thread_info,
83			   S390_lowcore.thread_info + THREAD_SIZE, 1);
84}
85EXPORT_SYMBOL_GPL(save_stack_trace);
86
87void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
88{
89	unsigned long sp, low, high;
90
91	sp = tsk->thread.ksp & PSW_ADDR_INSN;
92	low = (unsigned long) task_stack_page(tsk);
93	high = (unsigned long) task_pt_regs(tsk);
94	save_context_stack(trace, sp, low, high, 0);
95	if (trace->nr_entries < trace->max_entries)
96		trace->entries[trace->nr_entries++] = ULONG_MAX;
97}
98EXPORT_SYMBOL_GPL(save_stack_trace_tsk);