summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/dumpstack.c
blob: 829e1c53005c57a81d735fd80e909931b8f9b810 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
/*
 * Stack dumping functions
 *
 *  Copyright IBM Corp. 1999, 2013
 */

#include <linux/kallsyms.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <linux/utsname.h>
#include <linux/export.h>
#include <linux/kdebug.h>
#include <linux/ptrace.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <asm/processor.h>
#include <asm/debug.h>
#include <asm/dis.h>
#include <asm/ipl.h>

/*
 * For dump_trace we have tree different stack to consider:
 *   - the panic stack which is used if the kernel stack has overflown
 *   - the asynchronous interrupt stack (cpu related)
 *   - the synchronous kernel stack (process related)
 * The stack trace can start at any of the three stacks and can potentially
 * touch all of them. The order is: panic stack, async stack, sync stack.
 */
static unsigned long
__dump_trace(dump_trace_func_t func, void *data, unsigned long sp,
	     unsigned long low, unsigned long high)
{
	struct stack_frame *sf;
	struct pt_regs *regs;

	while (1) {
		if (sp < low || sp > high - sizeof(*sf))
			return sp;
		sf = (struct stack_frame *) sp;
		if (func(data, sf->gprs[8], 0))
			return sp;
		/* Follow the backchain. */
		while (1) {
			low = sp;
			sp = sf->back_chain;
			if (!sp)
				break;
			if (sp <= low || sp > high - sizeof(*sf))
				return sp;
			sf = (struct stack_frame *) sp;
			if (func(data, sf->gprs[8], 1))
				return sp;
		}
		/* Zero backchain detected, check for interrupt frame. */
		sp = (unsigned long) (sf + 1);
		if (sp <= low || sp > high - sizeof(*regs))
			return sp;
		regs = (struct pt_regs *) sp;
		if (!user_mode(regs)) {
			if (func(data, regs->psw.addr, 1))
				return sp;
		}
		low = sp;
		sp = regs->gprs[15];
	}
}

void dump_trace(dump_trace_func_t func, void *data, struct task_struct *task,
		unsigned long sp)
{
	unsigned long frame_size;

	frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
#ifdef CONFIG_CHECK_STACK
	sp = __dump_trace(func, data, sp,
			  S390_lowcore.panic_stack + frame_size - 4096,
			  S390_lowcore.panic_stack + frame_size);
#endif
	sp = __dump_trace(func, data, sp,
			  S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
			  S390_lowcore.async_stack + frame_size);
	task = task ?: current;
	__dump_trace(func, data, sp,
		     (unsigned long)task_stack_page(task),
		     (unsigned long)task_stack_page(task) + THREAD_SIZE);
}
EXPORT_SYMBOL_GPL(dump_trace);

static int show_address(void *data, unsigned long address, int reliable)
{
	if (reliable)
		printk(" [<%016lx>] %pSR \n", address, (void *)address);
	else
		printk("([<%016lx>] %pSR)\n", address, (void *)address);
	return 0;
}

static void show_trace(struct task_struct *task, unsigned long sp)
{
	if (!sp)
		sp = task ? task->thread.ksp : current_stack_pointer();
	printk("Call Trace:\n");
	dump_trace(show_address, NULL, task, sp);
	if (!task)
		task = current;
	debug_show_held_locks(task);
}

void show_stack(struct task_struct *task, unsigned long *sp)
{
	unsigned long *stack;
	int i;

	stack = sp;
	if (!stack) {
		if (!task)
			stack = (unsigned long *)current_stack_pointer();
		else
			stack = (unsigned long *)task->thread.ksp;
	}
	printk(KERN_DEFAULT "Stack:\n");
	for (i = 0; i < 20; i++) {
		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
			break;
		if (i % 4 == 0)
			printk(KERN_DEFAULT "       ");
		pr_cont("%016lx%c", *stack++, i % 4 == 3 ? '\n' : ' ');
	}
	show_trace(task, (unsigned long)sp);
}

static void show_last_breaking_event(struct pt_regs *regs)
{
	printk("Last Breaking-Event-Address:\n");
	printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
}

void show_registers(struct pt_regs *regs)
{
	struct psw_bits *psw = &psw_bits(regs->psw);
	char *mode;

	mode = user_mode(regs) ? "User" : "Krnl";
	printk("%s PSW : %p %p", mode, (void *)regs->psw.mask, (void *)regs->psw.addr);
	if (!user_mode(regs))
		pr_cont(" (%pSR)", (void *)regs->psw.addr);
	pr_cont("\n");
	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
	       "P:%x AS:%x CC:%x PM:%x", psw->r, psw->t, psw->i, psw->e,
	       psw->key, psw->m, psw->w, psw->p, psw->as, psw->cc, psw->pm);
	pr_cont(" RI:%x EA:%x\n", psw->ri, psw->eaba);
	printk("%s GPRS: %016lx %016lx %016lx %016lx\n", mode,
	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
	printk("           %016lx %016lx %016lx %016lx\n",
	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
	show_code(regs);
}

void show_regs(struct pt_regs *regs)
{
	show_regs_print_info(KERN_DEFAULT);
	show_registers(regs);
	/* Show stack backtrace if pt_regs is from kernel mode */
	if (!user_mode(regs))
		show_trace(NULL, regs->gprs[15]);
	show_last_breaking_event(regs);
}

static DEFINE_SPINLOCK(die_lock);

void die(struct pt_regs *regs, const char *str)
{
	static int die_counter;

	oops_enter();
	lgr_info_log();
	debug_stop_all();
	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);
	printk("%s: %04x ilc:%d [#%d] ", str, regs->int_code & 0xffff,
	       regs->int_code >> 17, ++die_counter);
#ifdef CONFIG_PREEMPT
	pr_cont("PREEMPT ");
#endif
#ifdef CONFIG_SMP
	pr_cont("SMP ");
#endif
	if (debug_pagealloc_enabled())
		pr_cont("DEBUG_PAGEALLOC");
	pr_cont("\n");
	notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
	print_modules();
	show_regs(regs);
	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	spin_unlock_irq(&die_lock);
	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception: panic_on_oops");
	oops_exit();
	do_exit(SIGSEGV);
}
OpenPOWER on IntegriCloud