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);

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