[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%pB\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 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 = {
	.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;
	unsigned long stack;

	bp = stack_frame(current, NULL);
	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;

	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_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_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 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	{
71f9e598	30	printk(" [<%p>] %s%pB\n", (void *) address,
878719e8 NH	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	137
878719e8 NH	138	static int print_trace_stack(void data, char name)
	139	{
	140	printk("%s <%s> ", (char *)data, name);
	141	return 0;
	142	}
	143
	144	/*
	145	* Print one address/symbol entries per line.
	146	*/
	147	static void print_trace_address(void *data, unsigned long addr, int reliable)
	148	{
	149	touch_nmi_watchdog();
	150	printk(data);
	151	printk_address(addr, reliable);
	152	}
	153
	154	static const struct stacktrace_ops print_trace_ops = {
06d65bda FW	155	.stack = print_trace_stack,
06d65bda FW	156	.address = print_trace_address,
61c1917f	157	.walk_stack = print_context_stack,
878719e8 NH	158	};
	159
	160	void
	161	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
e8e999cf	162	unsigned long stack, unsigned long bp, char log_lvl)
878719e8 NH	163	{
878719e8 NH	164	printk("%sCall Trace:\n", log_lvl);
e8e999cf	165	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
878719e8 NH	166	}
	167
	168	void show_trace(struct task_struct task, struct pt_regs regs,
e8e999cf	169	unsigned long *stack, unsigned long bp)
878719e8	170	{
e8e999cf	171	show_trace_log_lvl(task, regs, stack, bp, "");
878719e8 NH	172	}
	173
	174	void show_stack(struct task_struct task, unsigned long sp)
	175	{
e8e999cf	176	show_stack_log_lvl(task, NULL, sp, 0, "");
878719e8 NH	177	}
	178
	179	/*
	180	* The architecture-independent dump_stack generator
	181	*/
	182	void dump_stack(void)
	183	{
e8e999cf	184	unsigned long bp;
878719e8 NH	185	unsigned long stack;
878719e8 NH	186
e8e999cf	187	bp = stack_frame(current, NULL);
878719e8 NH	188	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
	189	current->pid, current->comm, print_tainted(),
	190	init_utsname()->release,
	191	(int)strcspn(init_utsname()->version, " "),
	192	init_utsname()->version);
e8e999cf	193	show_trace(NULL, NULL, &stack, bp);
878719e8 NH	194	}
	195	EXPORT_SYMBOL(dump_stack);
	196
edc35bd7	197	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
878719e8 NH	198	static int die_owner = -1;
	199	static unsigned int die_nest_count;
	200
	201	unsigned __kprobes long oops_begin(void)
	202	{
	203	int cpu;
	204	unsigned long flags;
	205
	206	oops_enter();
	207
	208	/* racy, but better than risking deadlock. */
	209	raw_local_irq_save(flags);
	210	cpu = smp_processor_id();
0199c4e6	211	if (!arch_spin_trylock(&die_lock)) {
878719e8 NH	212	if (cpu == die_owner)
	213	/* nested oops. should stop eventually */;
	214	else
0199c4e6	215	arch_spin_lock(&die_lock);
878719e8 NH	216	}
	217	die_nest_count++;
	218	die_owner = cpu;
	219	console_verbose();
	220	bust_spinlocks(1);
	221	return flags;
	222	}
81e88fdc	223	EXPORT_SYMBOL_GPL(oops_begin);
878719e8 NH	224
	225	void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	226	{
	227	if (regs && kexec_should_crash(current))
	228	crash_kexec(regs);
	229
	230	bust_spinlocks(0);
	231	die_owner = -1;
	232	add_taint(TAINT_DIE);
	233	die_nest_count--;
	234	if (!die_nest_count)
	235	/* Nest count reaches zero, release the lock. */
0199c4e6	236	arch_spin_unlock(&die_lock);
878719e8 NH	237	raw_local_irq_restore(flags);
	238	oops_exit();
	239
	240	if (!signr)
	241	return;
	242	if (in_interrupt())
	243	panic("Fatal exception in interrupt");
	244	if (panic_on_oops)
	245	panic("Fatal exception");
	246	do_exit(signr);
	247	}
	248
	249	int __kprobes __die(const char str, struct pt_regs regs, long err)
	250	{
	251	#ifdef CONFIG_X86_32
	252	unsigned short ss;
	253	unsigned long sp;
	254	#endif
b0f4c4b3 PB	255	printk(KERN_DEFAULT
b0f4c4b3 PB	256	"%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
878719e8 NH	257	#ifdef CONFIG_PREEMPT
	258	printk("PREEMPT ");
	259	#endif
	260	#ifdef CONFIG_SMP
	261	printk("SMP ");
	262	#endif
	263	#ifdef CONFIG_DEBUG_PAGEALLOC
	264	printk("DEBUG_PAGEALLOC");
	265	#endif
	266	printk("\n");
878719e8 NH	267	if (notify_die(DIE_OOPS, str, regs, err,
	268	current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
	269	return 1;
	270
	271	show_registers(regs);
	272	#ifdef CONFIG_X86_32
a343c75d	273	if (user_mode_vm(regs)) {
878719e8 NH	274	sp = regs->sp;
878719e8 NH	275	ss = regs->ss & 0xffff;
a343c75d PA	276	} else {
	277	sp = kernel_stack_pointer(regs);
	278	savesegment(ss, ss);
878719e8 NH	279	}
	280	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	281	print_symbol("%s", regs->ip);
	282	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	283	#else
	284	/* Executive summary in case the oops scrolled away */
	285	printk(KERN_ALERT "RIP ");
	286	printk_address(regs->ip, 1);
	287	printk(" RSP <%016lx>\n", regs->sp);
	288	#endif
	289	return 0;
	290	}
	291
	292	/*
	293	* This is gone through when something in the kernel has done something bad
	294	* and is about to be terminated:
	295	*/
	296	void die(const char str, struct pt_regs regs, long err)
	297	{
	298	unsigned long flags = oops_begin();
	299	int sig = SIGSEGV;
	300
	301	if (!user_mode_vm(regs))
	302	report_bug(regs->ip, regs);
	303
	304	if (__die(str, regs, err))
	305	sig = 0;
	306	oops_end(flags, regs, sig);
	307	}
	308
878719e8 NH	309	static int __init kstack_setup(char *s)
	310	{
	311	if (!s)
	312	return -EINVAL;
	313	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
	314	return 0;
	315	}
	316	early_param("kstack", kstack_setup);
	317
	318	static int __init code_bytes_setup(char *s)
	319	{
	320	code_bytes = simple_strtoul(s, NULL, 0);
	321	if (code_bytes > 8192)
	322	code_bytes = 8192;
	323
	324	return 1;
	325	}
	326	__setup("code_bytes=", code_bytes_setup);