[mirror_ubuntu-artful-kernel.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;

static void printk_stack_address(unsigned long address, int reliable)
{
	pr_cont(" [<%p>] %s%pB\n",
		(void *)address, reliable ? "" : "? ", (void *)address);
}

void printk_address(unsigned long address)
{
	pr_cont(" [<%p>] %pS\n", (void *)address, (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;
	unsigned long ret_addr;
	int index;

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

	task = tinfo->task;
	index = task->curr_ret_stack;

	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 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_stack_address(addr, reliable);
}

static const struct stacktrace_ops print_trace_ops = {
	.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, unsigned long bp, char *log_lvl)
{
	printk("%sCall Trace:\n", log_lvl);
	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
}

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

void show_stack(struct task_struct *task, unsigned long *sp)
{
	unsigned long bp = 0;
	unsigned long stack;

	/*
	 * Stack frames below this one aren't interesting.  Don't show them
	 * if we're printing for %current.
	 */
	if (!sp && (!task || task == current)) {
		sp = &stack;
		bp = stack_frame(current, NULL);
	}

	show_stack_log_lvl(task, NULL, sp, bp, "");
}

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, LOCKDEP_NOW_UNRELIABLE);
	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_DEFAULT
	       "%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");
	if (notify_die(DIE_OOPS, str, regs, err,
			current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
		return 1;

	print_modules();
	show_regs(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);
	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 kstack_setup(char *s)
{
	ssize_t ret;
	unsigned long val;

	if (!s)
		return -EINVAL;

	ret = kstrtoul(s, 0, &val);
	if (ret)
		return ret;
	kstack_depth_to_print = val;
	return 0;
}
early_param("kstack", kstack_setup);

static int __init code_bytes_setup(char *s)
{
	ssize_t ret;
	unsigned long val;

	if (!s)
		return -EINVAL;

	ret = kstrtoul(s, 0, &val);
	if (ret)
		return ret;

	code_bytes = val;
	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
5f01c988	28	static void printk_stack_address(unsigned long address, int reliable)
878719e8	29	{
c767a54b JP	30	pr_cont(" [<%p>] %s%pB\n",
c767a54b JP	31	(void )address, reliable ? "" : "? ", (void )address);
878719e8 NH	32	}
878719e8 NH	33
5f01c988 JS	34	void printk_address(unsigned long address)
	35	{
	36	pr_cont(" [<%p>] %pS\n", (void )address, (void )address);
	37	}
	38
7ee991fb SR	39	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	40	static void
	41	print_ftrace_graph_addr(unsigned long addr, void *data,
	42	const struct stacktrace_ops *ops,
	43	struct thread_info tinfo, int graph)
	44	{
65c0ff40	45	struct task_struct *task;
7ee991fb	46	unsigned long ret_addr;
65c0ff40	47	int index;
7ee991fb SR	48
	49	if (addr != (unsigned long)return_to_handler)
	50	return;
	51
65c0ff40 HD	52	task = tinfo->task;
	53	index = task->curr_ret_stack;
	54
7ee991fb SR	55	if (!task->ret_stack \|\| index < *graph)
	56	return;
	57
	58	index -= *graph;
	59	ret_addr = task->ret_stack[index].ret;
	60
	61	ops->address(data, ret_addr, 1);
	62
	63	(*graph)++;
	64	}
	65	#else
	66	static inline void
	67	print_ftrace_graph_addr(unsigned long addr, void *data,
	68	const struct stacktrace_ops *ops,
	69	struct thread_info tinfo, int graph)
	70	{ }
	71	#endif
	72
878719e8 NH	73	/*
	74	* x86-64 can have up to three kernel stacks:
	75	* process stack
	76	* interrupt stack
	77	* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
	78	*/
	79
	80	static inline int valid_stack_ptr(struct thread_info *tinfo,
	81	void p, unsigned int size, void end)
	82	{
	83	void *t = tinfo;
	84	if (end) {
	85	if (p < end && p >= (end-THREAD_SIZE))
	86	return 1;
	87	else
	88	return 0;
	89	}
	90	return p > t && p < t + THREAD_SIZE - size;
	91	}
	92
	93	unsigned long
	94	print_context_stack(struct thread_info *tinfo,
	95	unsigned long *stack, unsigned long bp,
	96	const struct stacktrace_ops ops, void data,
7ee991fb	97	unsigned long end, int graph)
878719e8 NH	98	{
	99	struct stack_frame frame = (struct stack_frame )bp;
	100
	101	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
	102	unsigned long addr;
	103
	104	addr = *stack;
	105	if (__kernel_text_address(addr)) {
	106	if ((unsigned long) stack == bp + sizeof(long)) {
	107	ops->address(data, addr, 1);
	108	frame = frame->next_frame;
	109	bp = (unsigned long) frame;
	110	} else {
2c344e9d	111	ops->address(data, addr, 0);
878719e8	112	}
7ee991fb	113	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
878719e8 NH	114	}
	115	stack++;
	116	}
	117	return bp;
	118	}
06d65bda FW	119	EXPORT_SYMBOL_GPL(print_context_stack);
	120
	121	unsigned long
	122	print_context_stack_bp(struct thread_info *tinfo,
	123	unsigned long *stack, unsigned long bp,
	124	const struct stacktrace_ops ops, void data,
	125	unsigned long end, int graph)
	126	{
	127	struct stack_frame frame = (struct stack_frame )bp;
	128	unsigned long *ret_addr = &frame->return_address;
	129
	130	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
	131	unsigned long addr = *ret_addr;
	132
c2c5d45d FW	133	if (!__kernel_text_address(addr))
	134	break;
	135
	136	ops->address(data, addr, 1);
	137	frame = frame->next_frame;
	138	ret_addr = &frame->return_address;
	139	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
06d65bda	140	}
c2c5d45d	141
06d65bda FW	142	return (unsigned long)frame;
	143	}
	144	EXPORT_SYMBOL_GPL(print_context_stack_bp);
878719e8	145
878719e8 NH	146	static int print_trace_stack(void data, char name)
	147	{
	148	printk("%s <%s> ", (char *)data, name);
	149	return 0;
	150	}
	151
	152	/*
	153	* Print one address/symbol entries per line.
	154	*/
	155	static void print_trace_address(void *data, unsigned long addr, int reliable)
	156	{
	157	touch_nmi_watchdog();
	158	printk(data);
5f01c988	159	printk_stack_address(addr, reliable);
878719e8 NH	160	}
	161
	162	static const struct stacktrace_ops print_trace_ops = {
06d65bda FW	163	.stack = print_trace_stack,
06d65bda FW	164	.address = print_trace_address,
61c1917f	165	.walk_stack = print_context_stack,
878719e8 NH	166	};
	167
	168	void
	169	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
e8e999cf	170	unsigned long stack, unsigned long bp, char log_lvl)
878719e8 NH	171	{
878719e8 NH	172	printk("%sCall Trace:\n", log_lvl);
e8e999cf	173	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
878719e8 NH	174	}
	175
	176	void show_trace(struct task_struct task, struct pt_regs regs,
e8e999cf	177	unsigned long *stack, unsigned long bp)
878719e8	178	{
e8e999cf	179	show_trace_log_lvl(task, regs, stack, bp, "");
878719e8 NH	180	}
	181
	182	void show_stack(struct task_struct task, unsigned long sp)
	183	{
a77f2a4e TH	184	unsigned long bp = 0;
	185	unsigned long stack;
	186
	187	/*
	188	* Stack frames below this one aren't interesting. Don't show them
	189	* if we're printing for %current.
	190	*/
	191	if (!sp && (!task \|\| task == current)) {
	192	sp = &stack;
	193	bp = stack_frame(current, NULL);
	194	}
	195
	196	show_stack_log_lvl(task, NULL, sp, bp, "");
878719e8 NH	197	}
878719e8 NH	198
edc35bd7	199	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
878719e8 NH	200	static int die_owner = -1;
	201	static unsigned int die_nest_count;
	202
	203	unsigned __kprobes long oops_begin(void)
	204	{
	205	int cpu;
	206	unsigned long flags;
	207
	208	oops_enter();
	209
	210	/* racy, but better than risking deadlock. */
	211	raw_local_irq_save(flags);
	212	cpu = smp_processor_id();
0199c4e6	213	if (!arch_spin_trylock(&die_lock)) {
878719e8 NH	214	if (cpu == die_owner)
	215	/* nested oops. should stop eventually */;
	216	else
0199c4e6	217	arch_spin_lock(&die_lock);
878719e8 NH	218	}
	219	die_nest_count++;
	220	die_owner = cpu;
	221	console_verbose();
	222	bust_spinlocks(1);
	223	return flags;
	224	}
81e88fdc	225	EXPORT_SYMBOL_GPL(oops_begin);
878719e8 NH	226
	227	void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	228	{
	229	if (regs && kexec_should_crash(current))
	230	crash_kexec(regs);
	231
	232	bust_spinlocks(0);
	233	die_owner = -1;
373d4d09	234	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
878719e8 NH	235	die_nest_count--;
	236	if (!die_nest_count)
	237	/* Nest count reaches zero, release the lock. */
0199c4e6	238	arch_spin_unlock(&die_lock);
878719e8 NH	239	raw_local_irq_restore(flags);
	240	oops_exit();
	241
	242	if (!signr)
	243	return;
	244	if (in_interrupt())
	245	panic("Fatal exception in interrupt");
	246	if (panic_on_oops)
	247	panic("Fatal exception");
	248	do_exit(signr);
	249	}
	250
	251	int __kprobes __die(const char str, struct pt_regs regs, long err)
	252	{
	253	#ifdef CONFIG_X86_32
	254	unsigned short ss;
	255	unsigned long sp;
	256	#endif
b0f4c4b3 PB	257	printk(KERN_DEFAULT
b0f4c4b3 PB	258	"%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
878719e8 NH	259	#ifdef CONFIG_PREEMPT
	260	printk("PREEMPT ");
	261	#endif
	262	#ifdef CONFIG_SMP
	263	printk("SMP ");
	264	#endif
	265	#ifdef CONFIG_DEBUG_PAGEALLOC
	266	printk("DEBUG_PAGEALLOC");
	267	#endif
	268	printk("\n");
878719e8	269	if (notify_die(DIE_OOPS, str, regs, err,
51e7dc70	270	current->thread.trap_nr, SIGSEGV) == NOTIFY_STOP)
878719e8 NH	271	return 1;
878719e8 NH	272
0fa0e2f0	273	print_modules();
57da8b96	274	show_regs(regs);
878719e8	275	#ifdef CONFIG_X86_32
a343c75d	276	if (user_mode_vm(regs)) {
878719e8 NH	277	sp = regs->sp;
878719e8 NH	278	ss = regs->ss & 0xffff;
a343c75d PA	279	} else {
	280	sp = kernel_stack_pointer(regs);
	281	savesegment(ss, ss);
878719e8 NH	282	}
	283	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	284	print_symbol("%s", regs->ip);
	285	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	286	#else
	287	/* Executive summary in case the oops scrolled away */
	288	printk(KERN_ALERT "RIP ");
5f01c988	289	printk_address(regs->ip);
878719e8 NH	290	printk(" RSP <%016lx>\n", regs->sp);
	291	#endif
	292	return 0;
	293	}
	294
	295	/*
	296	* This is gone through when something in the kernel has done something bad
	297	* and is about to be terminated:
	298	*/
	299	void die(const char str, struct pt_regs regs, long err)
	300	{
	301	unsigned long flags = oops_begin();
	302	int sig = SIGSEGV;
	303
	304	if (!user_mode_vm(regs))
	305	report_bug(regs->ip, regs);
	306
	307	if (__die(str, regs, err))
	308	sig = 0;
	309	oops_end(flags, regs, sig);
	310	}
	311
878719e8 NH	312	static int __init kstack_setup(char *s)
878719e8 NH	313	{
363f7ce3 SK	314	ssize_t ret;
	315	unsigned long val;
	316
878719e8 NH	317	if (!s)
878719e8 NH	318	return -EINVAL;
363f7ce3 SK	319
	320	ret = kstrtoul(s, 0, &val);
	321	if (ret)
	322	return ret;
	323	kstack_depth_to_print = val;
878719e8 NH	324	return 0;
	325	}
	326	early_param("kstack", kstack_setup);
	327
	328	static int __init code_bytes_setup(char *s)
	329	{
363f7ce3 SK	330	ssize_t ret;
	331	unsigned long val;
	332
	333	if (!s)
	334	return -EINVAL;
	335
	336	ret = kstrtoul(s, 0, &val);
	337	if (ret)
	338	return ret;
	339
	340	code_bytes = val;
878719e8 NH	341	if (code_bytes > 8192)
	342	code_bytes = 8192;
	343
	344	return 1;
	345	}
	346	__setup("code_bytes=", code_bytes_setup);