[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>

#include "dumpstack.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, 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)
{
	show_stack_log_lvl(task, NULL, sp, 0, "");
}

/*
 * The architecture-independent dump_stack generator
 */
void dump_stack(void)
{
	unsigned long bp = 0;
	unsigned long stack;

#ifdef CONFIG_FRAME_POINTER
	if (!bp)
		get_bp(bp);
#endif

	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, bp);
}
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;

	/* notify the hw-branch tracer so it may disable tracing and
	   add the last trace to the trace buffer -
	   the earlier this happens, the more useful the trace. */
	trace_hw_branch_oops();

	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;
}

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);
}

void notrace __kprobes
die_nmi(char *str, struct pt_regs *regs, int do_panic)
{
	unsigned long flags;

	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
		return;

	/*
	 * We are in trouble anyway, lets at least try
	 * to get a message out.
	 */
	flags = oops_begin();
	printk(KERN_EMERG "%s", str);
	printk(" on CPU%d, ip %08lx, registers:\n",
		smp_processor_id(), regs->ip);
	show_registers(regs);
	oops_end(flags, regs, 0);
	if (do_panic || panic_on_oops)
		panic("Non maskable interrupt");
	nmi_exit();
	local_irq_enable();
	do_exit(SIGBUS);
}

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
	21	#include "dumpstack.h"
	22
	23	int panic_on_unrecovered_nmi;
5211a242	24	int panic_on_io_nmi;
878719e8 NH	25	unsigned int code_bytes = 64;
	26	int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
	27	static int die_counter;
	28
	29	void printk_address(unsigned long address, int reliable)
	30	{
	31	printk(" [<%p>] %s%pS\n", (void *) address,
	32	reliable ? "" : "? ", (void *) address);
	33	}
	34
7ee991fb SR	35	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	36	static void
	37	print_ftrace_graph_addr(unsigned long addr, void *data,
	38	const struct stacktrace_ops *ops,
	39	struct thread_info tinfo, int graph)
	40	{
	41	struct task_struct *task = tinfo->task;
	42	unsigned long ret_addr;
	43	int index = task->curr_ret_stack;
	44
	45	if (addr != (unsigned long)return_to_handler)
	46	return;
	47
	48	if (!task->ret_stack \|\| index < *graph)
	49	return;
	50
	51	index -= *graph;
	52	ret_addr = task->ret_stack[index].ret;
	53
	54	ops->address(data, ret_addr, 1);
	55
	56	(*graph)++;
	57	}
	58	#else
	59	static inline void
	60	print_ftrace_graph_addr(unsigned long addr, void *data,
	61	const struct stacktrace_ops *ops,
	62	struct thread_info tinfo, int graph)
	63	{ }
	64	#endif
	65
878719e8 NH	66	/*
	67	* x86-64 can have up to three kernel stacks:
	68	* process stack
	69	* interrupt stack
	70	* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
	71	*/
	72
	73	static inline int valid_stack_ptr(struct thread_info *tinfo,
	74	void p, unsigned int size, void end)
	75	{
	76	void *t = tinfo;
	77	if (end) {
	78	if (p < end && p >= (end-THREAD_SIZE))
	79	return 1;
	80	else
	81	return 0;
	82	}
	83	return p > t && p < t + THREAD_SIZE - size;
	84	}
	85
	86	unsigned long
	87	print_context_stack(struct thread_info *tinfo,
	88	unsigned long *stack, unsigned long bp,
	89	const struct stacktrace_ops ops, void data,
7ee991fb	90	unsigned long end, int graph)
878719e8 NH	91	{
	92	struct stack_frame frame = (struct stack_frame )bp;
	93
	94	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
	95	unsigned long addr;
	96
	97	addr = *stack;
	98	if (__kernel_text_address(addr)) {
	99	if ((unsigned long) stack == bp + sizeof(long)) {
	100	ops->address(data, addr, 1);
	101	frame = frame->next_frame;
	102	bp = (unsigned long) frame;
	103	} else {
2c344e9d	104	ops->address(data, addr, 0);
878719e8	105	}
7ee991fb	106	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
878719e8 NH	107	}
	108	stack++;
	109	}
	110	return bp;
	111	}
06d65bda FW	112	EXPORT_SYMBOL_GPL(print_context_stack);
	113
	114	unsigned long
	115	print_context_stack_bp(struct thread_info *tinfo,
	116	unsigned long *stack, unsigned long bp,
	117	const struct stacktrace_ops ops, void data,
	118	unsigned long end, int graph)
	119	{
	120	struct stack_frame frame = (struct stack_frame )bp;
	121	unsigned long *ret_addr = &frame->return_address;
	122
	123	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
	124	unsigned long addr = *ret_addr;
	125
c2c5d45d FW	126	if (!__kernel_text_address(addr))
	127	break;
	128
	129	ops->address(data, addr, 1);
	130	frame = frame->next_frame;
	131	ret_addr = &frame->return_address;
	132	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
06d65bda	133	}
c2c5d45d	134
06d65bda FW	135	return (unsigned long)frame;
	136	}
	137	EXPORT_SYMBOL_GPL(print_context_stack_bp);
878719e8 NH	138
	139
	140	static void
	141	print_trace_warning_symbol(void data, char msg, unsigned long symbol)
	142	{
	143	printk(data);
	144	print_symbol(msg, symbol);
	145	printk("\n");
	146	}
	147
	148	static void print_trace_warning(void data, char msg)
	149	{
	150	printk("%s%s\n", (char *)data, msg);
	151	}
	152
	153	static int print_trace_stack(void data, char name)
	154	{
	155	printk("%s <%s> ", (char *)data, name);
	156	return 0;
	157	}
	158
	159	/*
	160	* Print one address/symbol entries per line.
	161	*/
	162	static void print_trace_address(void *data, unsigned long addr, int reliable)
	163	{
	164	touch_nmi_watchdog();
	165	printk(data);
	166	printk_address(addr, reliable);
	167	}
	168
	169	static const struct stacktrace_ops print_trace_ops = {
61c1917f FW	170	.warning = print_trace_warning,
61c1917f FW	171	.warning_symbol = print_trace_warning_symbol,
06d65bda FW	172	.stack = print_trace_stack,
06d65bda FW	173	.address = print_trace_address,
61c1917f	174	.walk_stack = print_context_stack,
878719e8 NH	175	};
	176
	177	void
	178	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
	179	unsigned long stack, unsigned long bp, char log_lvl)
	180	{
	181	printk("%sCall Trace:\n", log_lvl);
	182	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
	183	}
	184
	185	void show_trace(struct task_struct task, struct pt_regs regs,
	186	unsigned long *stack, unsigned long bp)
	187	{
	188	show_trace_log_lvl(task, regs, stack, bp, "");
	189	}
	190
	191	void show_stack(struct task_struct task, unsigned long sp)
	192	{
	193	show_stack_log_lvl(task, NULL, sp, 0, "");
	194	}
	195
	196	/*
	197	* The architecture-independent dump_stack generator
	198	*/
	199	void dump_stack(void)
	200	{
	201	unsigned long bp = 0;
	202	unsigned long stack;
	203
	204	#ifdef CONFIG_FRAME_POINTER
	205	if (!bp)
	206	get_bp(bp);
	207	#endif
	208
	209	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
	210	current->pid, current->comm, print_tainted(),
	211	init_utsname()->release,
	212	(int)strcspn(init_utsname()->version, " "),
	213	init_utsname()->version);
	214	show_trace(NULL, NULL, &stack, bp);
	215	}
	216	EXPORT_SYMBOL(dump_stack);
	217
edc35bd7	218	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
878719e8 NH	219	static int die_owner = -1;
	220	static unsigned int die_nest_count;
	221
	222	unsigned __kprobes long oops_begin(void)
	223	{
	224	int cpu;
	225	unsigned long flags;
	226
b1818748 MM	227	/* notify the hw-branch tracer so it may disable tracing and
	228	add the last trace to the trace buffer -
	229	the earlier this happens, the more useful the trace. */
	230	trace_hw_branch_oops();
	231
878719e8 NH	232	oops_enter();
	233
	234	/* racy, but better than risking deadlock. */
	235	raw_local_irq_save(flags);
	236	cpu = smp_processor_id();
0199c4e6	237	if (!arch_spin_trylock(&die_lock)) {
878719e8 NH	238	if (cpu == die_owner)
	239	/* nested oops. should stop eventually */;
	240	else
0199c4e6	241	arch_spin_lock(&die_lock);
878719e8 NH	242	}
	243	die_nest_count++;
	244	die_owner = cpu;
	245	console_verbose();
	246	bust_spinlocks(1);
	247	return flags;
	248	}
	249
	250	void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	251	{
	252	if (regs && kexec_should_crash(current))
	253	crash_kexec(regs);
	254
	255	bust_spinlocks(0);
	256	die_owner = -1;
	257	add_taint(TAINT_DIE);
	258	die_nest_count--;
	259	if (!die_nest_count)
	260	/* Nest count reaches zero, release the lock. */
0199c4e6	261	arch_spin_unlock(&die_lock);
878719e8 NH	262	raw_local_irq_restore(flags);
	263	oops_exit();
	264
	265	if (!signr)
	266	return;
	267	if (in_interrupt())
	268	panic("Fatal exception in interrupt");
	269	if (panic_on_oops)
	270	panic("Fatal exception");
	271	do_exit(signr);
	272	}
	273
	274	int __kprobes __die(const char str, struct pt_regs regs, long err)
	275	{
	276	#ifdef CONFIG_X86_32
	277	unsigned short ss;
	278	unsigned long sp;
	279	#endif
	280	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
	281	#ifdef CONFIG_PREEMPT
	282	printk("PREEMPT ");
	283	#endif
	284	#ifdef CONFIG_SMP
	285	printk("SMP ");
	286	#endif
	287	#ifdef CONFIG_DEBUG_PAGEALLOC
	288	printk("DEBUG_PAGEALLOC");
	289	#endif
	290	printk("\n");
	291	sysfs_printk_last_file();
	292	if (notify_die(DIE_OOPS, str, regs, err,
	293	current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
	294	return 1;
	295
	296	show_registers(regs);
	297	#ifdef CONFIG_X86_32
a343c75d	298	if (user_mode_vm(regs)) {
878719e8 NH	299	sp = regs->sp;
878719e8 NH	300	ss = regs->ss & 0xffff;
a343c75d PA	301	} else {
	302	sp = kernel_stack_pointer(regs);
	303	savesegment(ss, ss);
878719e8 NH	304	}
	305	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	306	print_symbol("%s", regs->ip);
	307	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	308	#else
	309	/* Executive summary in case the oops scrolled away */
	310	printk(KERN_ALERT "RIP ");
	311	printk_address(regs->ip, 1);
	312	printk(" RSP <%016lx>\n", regs->sp);
	313	#endif
	314	return 0;
	315	}
	316
	317	/*
	318	* This is gone through when something in the kernel has done something bad
	319	* and is about to be terminated:
	320	*/
	321	void die(const char str, struct pt_regs regs, long err)
	322	{
	323	unsigned long flags = oops_begin();
	324	int sig = SIGSEGV;
	325
	326	if (!user_mode_vm(regs))
	327	report_bug(regs->ip, regs);
	328
	329	if (__die(str, regs, err))
	330	sig = 0;
	331	oops_end(flags, regs, sig);
	332	}
	333
	334	void notrace __kprobes
	335	die_nmi(char str, struct pt_regs regs, int do_panic)
	336	{
	337	unsigned long flags;
	338
	339	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
	340	return;
	341
	342	/*
	343	* We are in trouble anyway, lets at least try
	344	* to get a message out.
	345	*/
	346	flags = oops_begin();
	347	printk(KERN_EMERG "%s", str);
	348	printk(" on CPU%d, ip %08lx, registers:\n",
	349	smp_processor_id(), regs->ip);
	350	show_registers(regs);
	351	oops_end(flags, regs, 0);
	352	if (do_panic \|\| panic_on_oops)
	353	panic("Non maskable interrupt");
	354	nmi_exit();
	355	local_irq_enable();
	356	do_exit(SIGBUS);
	357	}
	358
	359	static int __init oops_setup(char *s)
	360	{
	361	if (!s)
	362	return -EINVAL;
	363	if (!strcmp(s, "panic"))
	364	panic_on_oops = 1;
	365	return 0;
	366	}
	367	early_param("oops", oops_setup);
368
369	static int __init kstack_setup(char *s)
370	{
371	if (!s)
372	return -EINVAL;
373	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
374	return 0;
375	}
376	early_param("kstack", kstack_setup);
377
378	static int __init code_bytes_setup(char *s)
379	{
380	code_bytes = simple_strtoul(s, NULL, 0);
381	if (code_bytes > 8192)
382	code_bytes = 8192;
383
384	return 1;
385	}
386	__setup("code_bytes=", code_bytes_setup);