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

 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/sched.h>
10#include <linux/sched/debug.h>
11#include <linux/stacktrace.h>
12#include <linux/kallsyms.h>
13#include <linux/export.h>
14
15static int __save_address(void *data, unsigned long address, int nosched)
16{
17	struct stack_trace *trace = data;
18
19	if (nosched && in_sched_functions(address))
20		return 0;
21	if (trace->skip > 0) {
22		trace->skip--;
23		return 0;
24	}
25	if (trace->nr_entries < trace->max_entries) {
26		trace->entries[trace->nr_entries++] = address;
27		return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
28	}
29	return 1;
30}
31
32static int save_address(void *data, unsigned long address, int reliable)
33{
34	return __save_address(data, address, 0);
35}
36
37static int save_address_nosched(void *data, unsigned long address, int reliable)
38{
39	return __save_address(data, address, 1);
40}
41
42void save_stack_trace(struct stack_trace *trace)
43{
44	unsigned long sp;
 
45
46	sp = current_stack_pointer();
47	dump_trace(save_address, trace, NULL, sp);
48	if (trace->nr_entries < trace->max_entries)
49		trace->entries[trace->nr_entries++] = ULONG_MAX;
 
 
 
 
 
 
 
 
 
 
50}
51EXPORT_SYMBOL_GPL(save_stack_trace);
52
53void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace)
54{
55	unsigned long sp;
56
57	sp = tsk->thread.ksp;
58	if (tsk == current)
59		sp = current_stack_pointer();
60	dump_trace(save_address_nosched, trace, tsk, sp);
61	if (trace->nr_entries < trace->max_entries)
62		trace->entries[trace->nr_entries++] = ULONG_MAX;
63}
64EXPORT_SYMBOL_GPL(save_stack_trace_tsk);
65
66void save_stack_trace_regs(struct pt_regs *regs, struct stack_trace *trace)
67{
68	unsigned long sp;
69
70	sp = kernel_stack_pointer(regs);
71	dump_trace(save_address, trace, NULL, sp);
72	if (trace->nr_entries < trace->max_entries)
73		trace->entries[trace->nr_entries++] = ULONG_MAX;
74}
75EXPORT_SYMBOL_GPL(save_stack_trace_regs);