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/*
 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)
31{
32	return __save_address(data, address, 0);
33}
34
35static int save_address_nosched(void *data, unsigned long address)
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);