[deliverable/linux.git] / arch / x86 / kernel / dumpstack.c

/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
 */
#include <linux/kallsyms.h>
#include <linux/kprobes.h>
#include <linux/uaccess.h>
#include <linux/utsname.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/ptrace.h>
#include <linux/ftrace.h>
#include <linux/kexec.h>
#include <linux/bug.h>
#include <linux/nmi.h>
#include <linux/sysfs.h>

#include <asm/stacktrace.h>


int panic_on_unrecovered_nmi;
int panic_on_io_nmi;
unsigned int code_bytes = 64;
int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
static int die_counter;

void printk_address(unsigned long address, int reliable)
{
	printk(" [<%p>] %s%pS\n", (void *) address,
			reliable ? "" : "? ", (void *) address);
}

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
static void
print_ftrace_graph_addr(unsigned long addr, void *data,
			const struct stacktrace_ops *ops,
			struct thread_info *tinfo, int *graph)
{
	struct task_struct *task = tinfo->task;
	unsigned long ret_addr;
	int index = task->curr_ret_stack;

	if (addr != (unsigned long)return_to_handler)
		return;

	if (!task->ret_stack || index < *graph)
		return;

	index -= *graph;
	ret_addr = task->ret_stack[index].ret;

	ops->address(data, ret_addr, 1);

	(*graph)++;
}
#else
static inline void
print_ftrace_graph_addr(unsigned long addr, void *data,
			const struct stacktrace_ops *ops,
			struct thread_info *tinfo, int *graph)
{ }
#endif

/*
 * x86-64 can have up to three kernel stacks:
 * process stack
 * interrupt stack
 * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
 */

static inline int valid_stack_ptr(struct thread_info *tinfo,
			void *p, unsigned int size, void *end)
{
	void *t = tinfo;
	if (end) {
		if (p < end && p >= (end-THREAD_SIZE))
			return 1;
		else
			return 0;
	}
	return p > t && p < t + THREAD_SIZE - size;
}

unsigned long
print_context_stack(struct thread_info *tinfo,
		unsigned long *stack, unsigned long bp,
		const struct stacktrace_ops *ops, void *data,
		unsigned long *end, int *graph)
{
	struct stack_frame *frame = (struct stack_frame *)bp;

	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
		unsigned long addr;

		addr = *stack;
		if (__kernel_text_address(addr)) {
			if ((unsigned long) stack == bp + sizeof(long)) {
				ops->address(data, addr, 1);
				frame = frame->next_frame;
				bp = (unsigned long) frame;
			} else {
				ops->address(data, addr, 0);
			}
			print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
		}
		stack++;
	}
	return bp;
}
EXPORT_SYMBOL_GPL(print_context_stack);

unsigned long
print_context_stack_bp(struct thread_info *tinfo,
		       unsigned long *stack, unsigned long bp,
		       const struct stacktrace_ops *ops, void *data,
		       unsigned long *end, int *graph)
{
	struct stack_frame *frame = (struct stack_frame *)bp;
	unsigned long *ret_addr = &frame->return_address;

	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
		unsigned long addr = *ret_addr;

		if (!__kernel_text_address(addr))
			break;

		ops->address(data, addr, 1);
		frame = frame->next_frame;
		ret_addr = &frame->return_address;
		print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
	}

	return (unsigned long)frame;
}
EXPORT_SYMBOL_GPL(print_context_stack_bp);


static void
print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
{
	printk(data);
	print_symbol(msg, symbol);
	printk("\n");
}

static void print_trace_warning(void *data, char *msg)
{
	printk("%s%s\n", (char *)data, msg);
}

static int print_trace_stack(void *data, char *name)
{
	printk("%s <%s> ", (char *)data, name);
	return 0;
}

/*
 * Print one address/symbol entries per line.
 */
static void print_trace_address(void *data, unsigned long addr, int reliable)
{
	touch_nmi_watchdog();
	printk(data);
	printk_address(addr, reliable);
}

static const struct stacktrace_ops print_trace_ops = {
	.warning		= print_trace_warning,
	.warning_symbol		= print_trace_warning_symbol,
	.stack			= print_trace_stack,
	.address		= print_trace_address,
	.walk_stack		= print_context_stack,
};

void
show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
		unsigned long *stack, char *log_lvl)
{
	printk("%sCall Trace:\n", log_lvl);
	dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
}

void show_trace(struct task_struct *task, struct pt_regs *regs,
		unsigned long *stack)
{
	show_trace_log_lvl(task, regs, stack, "");
}

void show_stack(struct task_struct *task, unsigned long *sp)
{
	show_stack_log_lvl(task, NULL, sp, "");
}

/*
 * The architecture-independent dump_stack generator
 */
void dump_stack(void)
{
	unsigned long stack;

	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
		current->pid, current->comm, print_tainted(),
		init_utsname()->release,
		(int)strcspn(init_utsname()->version, " "),
		init_utsname()->version);
	show_trace(NULL, NULL, &stack);
}
EXPORT_SYMBOL(dump_stack);

static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
static int die_owner = -1;
static unsigned int die_nest_count;

unsigned __kprobes long oops_begin(void)
{
	int cpu;
	unsigned long flags;

	oops_enter();

	/* racy, but better than risking deadlock. */
	raw_local_irq_save(flags);
	cpu = smp_processor_id();
	if (!arch_spin_trylock(&die_lock)) {
		if (cpu == die_owner)
			/* nested oops. should stop eventually */;
		else
			arch_spin_lock(&die_lock);
	}
	die_nest_count++;
	die_owner = cpu;
	console_verbose();
	bust_spinlocks(1);
	return flags;
}
EXPORT_SYMBOL_GPL(oops_begin);

void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
{
	if (regs && kexec_should_crash(current))
		crash_kexec(regs);

	bust_spinlocks(0);
	die_owner = -1;
	add_taint(TAINT_DIE);
	die_nest_count--;
	if (!die_nest_count)
		/* Nest count reaches zero, release the lock. */
		arch_spin_unlock(&die_lock);
	raw_local_irq_restore(flags);
	oops_exit();

	if (!signr)
		return;
	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception");
	do_exit(signr);
}

int __kprobes __die(const char *str, struct pt_regs *regs, long err)
{
#ifdef CONFIG_X86_32
	unsigned short ss;
	unsigned long sp;
#endif
	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
#ifdef CONFIG_PREEMPT
	printk("PREEMPT ");
#endif
#ifdef CONFIG_SMP
	printk("SMP ");
#endif
#ifdef CONFIG_DEBUG_PAGEALLOC
	printk("DEBUG_PAGEALLOC");
#endif
	printk("\n");
	sysfs_printk_last_file();
	if (notify_die(DIE_OOPS, str, regs, err,
			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
		return 1;

	show_registers(regs);
#ifdef CONFIG_X86_32
	if (user_mode_vm(regs)) {
		sp = regs->sp;
		ss = regs->ss & 0xffff;
	} else {
		sp = kernel_stack_pointer(regs);
		savesegment(ss, ss);
	}
	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	print_symbol("%s", regs->ip);
	printk(" SS:ESP %04x:%08lx\n", ss, sp);
#else
	/* Executive summary in case the oops scrolled away */
	printk(KERN_ALERT "RIP ");
	printk_address(regs->ip, 1);
	printk(" RSP <%016lx>\n", regs->sp);
#endif
	return 0;
}

/*
 * This is gone through when something in the kernel has done something bad
 * and is about to be terminated:
 */
void die(const char *str, struct pt_regs *regs, long err)
{
	unsigned long flags = oops_begin();
	int sig = SIGSEGV;

	if (!user_mode_vm(regs))
		report_bug(regs->ip, regs);

	if (__die(str, regs, err))
		sig = 0;
	oops_end(flags, regs, sig);
}

static int __init oops_setup(char *s)
{
	if (!s)
		return -EINVAL;
	if (!strcmp(s, "panic"))
		panic_on_oops = 1;
	return 0;
}
early_param("oops", oops_setup);

static int __init kstack_setup(char *s)
{
	if (!s)
		return -EINVAL;
	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
	return 0;
}
early_param("kstack", kstack_setup);

static int __init code_bytes_setup(char *s)
{
	code_bytes = simple_strtoul(s, NULL, 0);
	if (code_bytes > 8192)
		code_bytes = 8192;

	return 1;
}
__setup("code_bytes=", code_bytes_setup);
Commit	Line	Data
878719e8 NH	1	/*
	2	* Copyright (C) 1991, 1992 Linus Torvalds
	3	* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
	4	*/
	5	#include <linux/kallsyms.h>
	6	#include <linux/kprobes.h>
	7	#include <linux/uaccess.h>
	8	#include <linux/utsname.h>
	9	#include <linux/hardirq.h>
	10	#include <linux/kdebug.h>
	11	#include <linux/module.h>
	12	#include <linux/ptrace.h>
712406a6	13	#include <linux/ftrace.h>
878719e8 NH	14	#include <linux/kexec.h>
	15	#include <linux/bug.h>
	16	#include <linux/nmi.h>
	17	#include <linux/sysfs.h>
	18
	19	#include <asm/stacktrace.h>
	20
878719e8 NH	21
878719e8 NH	22	int panic_on_unrecovered_nmi;
5211a242	23	int panic_on_io_nmi;
878719e8 NH	24	unsigned int code_bytes = 64;
	25	int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
	26	static int die_counter;
	27
	28	void printk_address(unsigned long address, int reliable)
	29	{
	30	printk(" [<%p>] %s%pS\n", (void *) address,
	31	reliable ? "" : "? ", (void *) address);
	32	}
	33
7ee991fb SR	34	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	35	static void
	36	print_ftrace_graph_addr(unsigned long addr, void *data,
	37	const struct stacktrace_ops *ops,
	38	struct thread_info tinfo, int graph)
	39	{
	40	struct task_struct *task = tinfo->task;
	41	unsigned long ret_addr;
	42	int index = task->curr_ret_stack;
	43
	44	if (addr != (unsigned long)return_to_handler)
	45	return;
	46
	47	if (!task->ret_stack \|\| index < *graph)
	48	return;
	49
	50	index -= *graph;
	51	ret_addr = task->ret_stack[index].ret;
	52
	53	ops->address(data, ret_addr, 1);
	54
	55	(*graph)++;
	56	}
	57	#else
	58	static inline void
	59	print_ftrace_graph_addr(unsigned long addr, void *data,
	60	const struct stacktrace_ops *ops,
	61	struct thread_info tinfo, int graph)
	62	{ }
	63	#endif
	64
878719e8 NH	65	/*
	66	* x86-64 can have up to three kernel stacks:
	67	* process stack
	68	* interrupt stack
	69	* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
	70	*/
	71
	72	static inline int valid_stack_ptr(struct thread_info *tinfo,
	73	void p, unsigned int size, void end)
	74	{
	75	void *t = tinfo;
	76	if (end) {
	77	if (p < end && p >= (end-THREAD_SIZE))
	78	return 1;
	79	else
	80	return 0;
	81	}
	82	return p > t && p < t + THREAD_SIZE - size;
	83	}
	84
	85	unsigned long
	86	print_context_stack(struct thread_info *tinfo,
	87	unsigned long *stack, unsigned long bp,
	88	const struct stacktrace_ops ops, void data,
7ee991fb	89	unsigned long end, int graph)
878719e8 NH	90	{
	91	struct stack_frame frame = (struct stack_frame )bp;
	92
	93	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
	94	unsigned long addr;
	95
	96	addr = *stack;
	97	if (__kernel_text_address(addr)) {
	98	if ((unsigned long) stack == bp + sizeof(long)) {
	99	ops->address(data, addr, 1);
	100	frame = frame->next_frame;
	101	bp = (unsigned long) frame;
	102	} else {
2c344e9d	103	ops->address(data, addr, 0);
878719e8	104	}
7ee991fb	105	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
878719e8 NH	106	}
	107	stack++;
	108	}
	109	return bp;
	110	}
06d65bda FW	111	EXPORT_SYMBOL_GPL(print_context_stack);
	112
	113	unsigned long
	114	print_context_stack_bp(struct thread_info *tinfo,
	115	unsigned long *stack, unsigned long bp,
	116	const struct stacktrace_ops ops, void data,
	117	unsigned long end, int graph)
	118	{
	119	struct stack_frame frame = (struct stack_frame )bp;
	120	unsigned long *ret_addr = &frame->return_address;
	121
	122	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
	123	unsigned long addr = *ret_addr;
	124
c2c5d45d FW	125	if (!__kernel_text_address(addr))
	126	break;
	127
	128	ops->address(data, addr, 1);
	129	frame = frame->next_frame;
	130	ret_addr = &frame->return_address;
	131	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
06d65bda	132	}
c2c5d45d	133
06d65bda FW	134	return (unsigned long)frame;
	135	}
	136	EXPORT_SYMBOL_GPL(print_context_stack_bp);
878719e8 NH	137
	138
	139	static void
	140	print_trace_warning_symbol(void data, char msg, unsigned long symbol)
	141	{
	142	printk(data);
	143	print_symbol(msg, symbol);
	144	printk("\n");
	145	}
	146
	147	static void print_trace_warning(void data, char msg)
	148	{
	149	printk("%s%s\n", (char *)data, msg);
	150	}
	151
	152	static int print_trace_stack(void data, char name)
	153	{
	154	printk("%s <%s> ", (char *)data, name);
	155	return 0;
	156	}
	157
	158	/*
	159	* Print one address/symbol entries per line.
	160	*/
	161	static void print_trace_address(void *data, unsigned long addr, int reliable)
	162	{
	163	touch_nmi_watchdog();
	164	printk(data);
	165	printk_address(addr, reliable);
	166	}
	167
	168	static const struct stacktrace_ops print_trace_ops = {
61c1917f FW	169	.warning = print_trace_warning,
61c1917f FW	170	.warning_symbol = print_trace_warning_symbol,
06d65bda FW	171	.stack = print_trace_stack,
06d65bda FW	172	.address = print_trace_address,
61c1917f	173	.walk_stack = print_context_stack,
878719e8 NH	174	};
	175
	176	void
	177	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
9c0729dc	178	unsigned long stack, char log_lvl)
878719e8 NH	179	{
878719e8 NH	180	printk("%sCall Trace:\n", log_lvl);
9c0729dc	181	dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
878719e8 NH	182	}
	183
	184	void show_trace(struct task_struct task, struct pt_regs regs,
9c0729dc	185	unsigned long *stack)
878719e8	186	{
9c0729dc	187	show_trace_log_lvl(task, regs, stack, "");
878719e8 NH	188	}
	189
	190	void show_stack(struct task_struct task, unsigned long sp)
	191	{
9c0729dc	192	show_stack_log_lvl(task, NULL, sp, "");
878719e8 NH	193	}
	194
	195	/*
	196	* The architecture-independent dump_stack generator
	197	*/
	198	void dump_stack(void)
	199	{
878719e8 NH	200	unsigned long stack;
878719e8 NH	201
878719e8 NH	202	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
	203	current->pid, current->comm, print_tainted(),
	204	init_utsname()->release,
	205	(int)strcspn(init_utsname()->version, " "),
	206	init_utsname()->version);
9c0729dc	207	show_trace(NULL, NULL, &stack);
878719e8 NH	208	}
	209	EXPORT_SYMBOL(dump_stack);
	210
edc35bd7	211	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
878719e8 NH	212	static int die_owner = -1;
	213	static unsigned int die_nest_count;
	214
	215	unsigned __kprobes long oops_begin(void)
	216	{
	217	int cpu;
	218	unsigned long flags;
	219
	220	oops_enter();
	221
	222	/* racy, but better than risking deadlock. */
	223	raw_local_irq_save(flags);
	224	cpu = smp_processor_id();
0199c4e6	225	if (!arch_spin_trylock(&die_lock)) {
878719e8 NH	226	if (cpu == die_owner)
	227	/* nested oops. should stop eventually */;
	228	else
0199c4e6	229	arch_spin_lock(&die_lock);
878719e8 NH	230	}
	231	die_nest_count++;
	232	die_owner = cpu;
	233	console_verbose();
	234	bust_spinlocks(1);
	235	return flags;
	236	}
81e88fdc	237	EXPORT_SYMBOL_GPL(oops_begin);
878719e8 NH	238
	239	void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	240	{
	241	if (regs && kexec_should_crash(current))
	242	crash_kexec(regs);
	243
	244	bust_spinlocks(0);
	245	die_owner = -1;
	246	add_taint(TAINT_DIE);
	247	die_nest_count--;
	248	if (!die_nest_count)
	249	/* Nest count reaches zero, release the lock. */
0199c4e6	250	arch_spin_unlock(&die_lock);
878719e8 NH	251	raw_local_irq_restore(flags);
	252	oops_exit();
	253
	254	if (!signr)
	255	return;
	256	if (in_interrupt())
	257	panic("Fatal exception in interrupt");
	258	if (panic_on_oops)
	259	panic("Fatal exception");
	260	do_exit(signr);
	261	}
	262
	263	int __kprobes __die(const char str, struct pt_regs regs, long err)
	264	{
	265	#ifdef CONFIG_X86_32
	266	unsigned short ss;
	267	unsigned long sp;
	268	#endif
	269	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
	270	#ifdef CONFIG_PREEMPT
	271	printk("PREEMPT ");
	272	#endif
	273	#ifdef CONFIG_SMP
	274	printk("SMP ");
	275	#endif
	276	#ifdef CONFIG_DEBUG_PAGEALLOC
	277	printk("DEBUG_PAGEALLOC");
	278	#endif
	279	printk("\n");
	280	sysfs_printk_last_file();
	281	if (notify_die(DIE_OOPS, str, regs, err,
	282	current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
	283	return 1;
	284
	285	show_registers(regs);
	286	#ifdef CONFIG_X86_32
a343c75d	287	if (user_mode_vm(regs)) {
878719e8 NH	288	sp = regs->sp;
878719e8 NH	289	ss = regs->ss & 0xffff;
a343c75d PA	290	} else {
	291	sp = kernel_stack_pointer(regs);
	292	savesegment(ss, ss);
878719e8 NH	293	}
	294	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	295	print_symbol("%s", regs->ip);
	296	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	297	#else
	298	/* Executive summary in case the oops scrolled away */
	299	printk(KERN_ALERT "RIP ");
	300	printk_address(regs->ip, 1);
	301	printk(" RSP <%016lx>\n", regs->sp);
	302	#endif
	303	return 0;
	304	}
	305
	306	/*
	307	* This is gone through when something in the kernel has done something bad
	308	* and is about to be terminated:
	309	*/
	310	void die(const char str, struct pt_regs regs, long err)
	311	{
	312	unsigned long flags = oops_begin();
	313	int sig = SIGSEGV;
	314
	315	if (!user_mode_vm(regs))
	316	report_bug(regs->ip, regs);
	317
	318	if (__die(str, regs, err))
	319	sig = 0;
	320	oops_end(flags, regs, sig);
	321	}
	322
878719e8 NH	323	static int __init oops_setup(char *s)
	324	{
	325	if (!s)
	326	return -EINVAL;
	327	if (!strcmp(s, "panic"))
	328	panic_on_oops = 1;
	329	return 0;
	330	}
	331	early_param("oops", oops_setup);
	332
	333	static int __init kstack_setup(char *s)
	334	{
	335	if (!s)
	336	return -EINVAL;
	337	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
	338	return 0;
	339	}
	340	early_param("kstack", kstack_setup);
	341
	342	static int __init code_bytes_setup(char *s)
	343	{
	344	code_bytes = simple_strtoul(s, NULL, 0);
	345	if (code_bytes > 8192)
	346	code_bytes = 8192;
	347
	348	return 1;
	349	}
	350	__setup("code_bytes=", code_bytes_setup);