[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;

static void printk_stack_address(unsigned long address, int reliable,
		void *data)
{
	printk("%s [<%p>] %s%pB\n",
		(char *)data, (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;

		if (ops->address(data, addr, 1))
			break;
		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 int print_trace_address(void *data, unsigned long addr, int reliable)
{
	touch_nmi_watchdog();
	printk_stack_address(addr, reliable, data);
	return 0;
}

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 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);
NOKPROBE_SYMBOL(oops_begin);

void 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);
}
NOKPROBE_SYMBOL(oops_end);

int __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]%s%s%s%s\n", str, err & 0xffff, ++die_counter,
	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT"         : "",
	       IS_ENABLED(CONFIG_SMP)     ? " SMP"             : "",
	       debug_pagealloc_enabled()  ? " DEBUG_PAGEALLOC" : "",
	       IS_ENABLED(CONFIG_KASAN)   ? " KASAN"           : "");

	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(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;
}
NOKPROBE_SYMBOL(__die);

/*
 * 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(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
1fc7f61c AS	28	static void printk_stack_address(unsigned long address, int reliable,
1fc7f61c AS	29	void *data)
878719e8	30	{
1fc7f61c AS	31	printk("%s [<%p>] %s%pB\n",
	32	(char )data, (void )address, reliable ? "" : "? ",
	33	(void *)address);
878719e8 NH	34	}
878719e8 NH	35
5f01c988 JS	36	void printk_address(unsigned long address)
	37	{
	38	pr_cont(" [<%p>] %pS\n", (void )address, (void )address);
	39	}
	40
7ee991fb SR	41	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	42	static void
	43	print_ftrace_graph_addr(unsigned long addr, void *data,
	44	const struct stacktrace_ops *ops,
	45	struct thread_info tinfo, int graph)
	46	{
65c0ff40	47	struct task_struct *task;
7ee991fb	48	unsigned long ret_addr;
65c0ff40	49	int index;
7ee991fb SR	50
	51	if (addr != (unsigned long)return_to_handler)
	52	return;
	53
65c0ff40 HD	54	task = tinfo->task;
	55	index = task->curr_ret_stack;
	56
7ee991fb SR	57	if (!task->ret_stack \|\| index < *graph)
	58	return;
	59
	60	index -= *graph;
	61	ret_addr = task->ret_stack[index].ret;
	62
	63	ops->address(data, ret_addr, 1);
	64
	65	(*graph)++;
	66	}
	67	#else
	68	static inline void
	69	print_ftrace_graph_addr(unsigned long addr, void *data,
	70	const struct stacktrace_ops *ops,
	71	struct thread_info tinfo, int graph)
	72	{ }
	73	#endif
	74
878719e8 NH	75	/*
	76	* x86-64 can have up to three kernel stacks:
	77	* process stack
	78	* interrupt stack
	79	* severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
	80	*/
	81
	82	static inline int valid_stack_ptr(struct thread_info *tinfo,
	83	void p, unsigned int size, void end)
	84	{
	85	void *t = tinfo;
	86	if (end) {
	87	if (p < end && p >= (end-THREAD_SIZE))
	88	return 1;
	89	else
	90	return 0;
	91	}
	92	return p > t && p < t + THREAD_SIZE - size;
	93	}
	94
	95	unsigned long
	96	print_context_stack(struct thread_info *tinfo,
	97	unsigned long *stack, unsigned long bp,
	98	const struct stacktrace_ops ops, void data,
7ee991fb	99	unsigned long end, int graph)
878719e8 NH	100	{
	101	struct stack_frame frame = (struct stack_frame )bp;
	102
	103	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
	104	unsigned long addr;
	105
	106	addr = *stack;
	107	if (__kernel_text_address(addr)) {
	108	if ((unsigned long) stack == bp + sizeof(long)) {
	109	ops->address(data, addr, 1);
	110	frame = frame->next_frame;
	111	bp = (unsigned long) frame;
	112	} else {
2c344e9d	113	ops->address(data, addr, 0);
878719e8	114	}
7ee991fb	115	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
878719e8 NH	116	}
	117	stack++;
	118	}
	119	return bp;
	120	}
06d65bda FW	121	EXPORT_SYMBOL_GPL(print_context_stack);
	122
	123	unsigned long
	124	print_context_stack_bp(struct thread_info *tinfo,
	125	unsigned long *stack, unsigned long bp,
	126	const struct stacktrace_ops ops, void data,
	127	unsigned long end, int graph)
	128	{
	129	struct stack_frame frame = (struct stack_frame )bp;
	130	unsigned long *ret_addr = &frame->return_address;
	131
	132	while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) {
	133	unsigned long addr = *ret_addr;
	134
c2c5d45d FW	135	if (!__kernel_text_address(addr))
	136	break;
	137
568b329a AS	138	if (ops->address(data, addr, 1))
568b329a AS	139	break;
c2c5d45d FW	140	frame = frame->next_frame;
	141	ret_addr = &frame->return_address;
	142	print_ftrace_graph_addr(addr, data, ops, tinfo, graph);
06d65bda	143	}
c2c5d45d	144
06d65bda FW	145	return (unsigned long)frame;
	146	}
	147	EXPORT_SYMBOL_GPL(print_context_stack_bp);
878719e8	148
878719e8 NH	149	static int print_trace_stack(void data, char name)
	150	{
	151	printk("%s <%s> ", (char *)data, name);
	152	return 0;
	153	}
	154
	155	/*
	156	* Print one address/symbol entries per line.
	157	*/
568b329a	158	static int print_trace_address(void *data, unsigned long addr, int reliable)
878719e8 NH	159	{
878719e8 NH	160	touch_nmi_watchdog();
1fc7f61c	161	printk_stack_address(addr, reliable, data);
568b329a	162	return 0;
878719e8 NH	163	}
	164
	165	static const struct stacktrace_ops print_trace_ops = {
06d65bda FW	166	.stack = print_trace_stack,
06d65bda FW	167	.address = print_trace_address,
61c1917f	168	.walk_stack = print_context_stack,
878719e8 NH	169	};
	170
	171	void
	172	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
e8e999cf	173	unsigned long stack, unsigned long bp, char log_lvl)
878719e8 NH	174	{
878719e8 NH	175	printk("%sCall Trace:\n", log_lvl);
e8e999cf	176	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
878719e8 NH	177	}
	178
	179	void show_trace(struct task_struct task, struct pt_regs regs,
e8e999cf	180	unsigned long *stack, unsigned long bp)
878719e8	181	{
e8e999cf	182	show_trace_log_lvl(task, regs, stack, bp, "");
878719e8 NH	183	}
	184
	185	void show_stack(struct task_struct task, unsigned long sp)
	186	{
a77f2a4e TH	187	unsigned long bp = 0;
	188	unsigned long stack;
	189
	190	/*
	191	* Stack frames below this one aren't interesting. Don't show them
	192	* if we're printing for %current.
	193	*/
	194	if (!sp && (!task \|\| task == current)) {
	195	sp = &stack;
	196	bp = stack_frame(current, NULL);
	197	}
	198
	199	show_stack_log_lvl(task, NULL, sp, bp, "");
878719e8 NH	200	}
878719e8 NH	201
edc35bd7	202	static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
878719e8 NH	203	static int die_owner = -1;
	204	static unsigned int die_nest_count;
	205
9326638c	206	unsigned long oops_begin(void)
878719e8 NH	207	{
	208	int cpu;
	209	unsigned long flags;
	210
	211	oops_enter();
	212
	213	/* racy, but better than risking deadlock. */
	214	raw_local_irq_save(flags);
	215	cpu = smp_processor_id();
0199c4e6	216	if (!arch_spin_trylock(&die_lock)) {
878719e8 NH	217	if (cpu == die_owner)
	218	/* nested oops. should stop eventually */;
	219	else
0199c4e6	220	arch_spin_lock(&die_lock);
878719e8 NH	221	}
	222	die_nest_count++;
	223	die_owner = cpu;
	224	console_verbose();
	225	bust_spinlocks(1);
	226	return flags;
	227	}
81e88fdc	228	EXPORT_SYMBOL_GPL(oops_begin);
9326638c	229	NOKPROBE_SYMBOL(oops_begin);
878719e8	230
9326638c	231	void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
878719e8 NH	232	{
	233	if (regs && kexec_should_crash(current))
	234	crash_kexec(regs);
	235
	236	bust_spinlocks(0);
	237	die_owner = -1;
373d4d09	238	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
878719e8 NH	239	die_nest_count--;
	240	if (!die_nest_count)
	241	/* Nest count reaches zero, release the lock. */
0199c4e6	242	arch_spin_unlock(&die_lock);
878719e8 NH	243	raw_local_irq_restore(flags);
	244	oops_exit();
	245
	246	if (!signr)
	247	return;
	248	if (in_interrupt())
	249	panic("Fatal exception in interrupt");
	250	if (panic_on_oops)
	251	panic("Fatal exception");
	252	do_exit(signr);
	253	}
9326638c	254	NOKPROBE_SYMBOL(oops_end);
878719e8	255
9326638c	256	int __die(const char str, struct pt_regs regs, long err)
878719e8 NH	257	{
	258	#ifdef CONFIG_X86_32
	259	unsigned short ss;
	260	unsigned long sp;
	261	#endif
b0f4c4b3	262	printk(KERN_DEFAULT
8fad7ec5 RV	263	"%s: %04lx [#%d]%s%s%s%s\n", str, err & 0xffff, ++die_counter,
	264	IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
	265	IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
	266	debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
	267	IS_ENABLED(CONFIG_KASAN) ? " KASAN" : "");
	268
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
f39b6f0e	276	if (user_mode(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	}
9326638c	294	NOKPROBE_SYMBOL(__die);
878719e8 NH	295
	296	/*
	297	* This is gone through when something in the kernel has done something bad
	298	* and is about to be terminated:
	299	*/
	300	void die(const char str, struct pt_regs regs, long err)
	301	{
	302	unsigned long flags = oops_begin();
	303	int sig = SIGSEGV;
	304
f39b6f0e	305	if (!user_mode(regs))
878719e8 NH	306	report_bug(regs->ip, regs);
	307
	308	if (__die(str, regs, err))
	309	sig = 0;
	310	oops_end(flags, regs, sig);
	311	}
	312
878719e8 NH	313	static int __init kstack_setup(char *s)
878719e8 NH	314	{
363f7ce3 SK	315	ssize_t ret;
	316	unsigned long val;
	317
878719e8 NH	318	if (!s)
878719e8 NH	319	return -EINVAL;
363f7ce3 SK	320
	321	ret = kstrtoul(s, 0, &val);
	322	if (ret)
	323	return ret;
	324	kstack_depth_to_print = val;
878719e8 NH	325	return 0;
	326	}
	327	early_param("kstack", kstack_setup);
	328
	329	static int __init code_bytes_setup(char *s)
	330	{
363f7ce3 SK	331	ssize_t ret;
	332	unsigned long val;
	333
	334	if (!s)
	335	return -EINVAL;
	336
	337	ret = kstrtoul(s, 0, &val);
	338	if (ret)
	339	return ret;
	340
	341	code_bytes = val;
878719e8 NH	342	if (code_bytes > 8192)
	343	code_bytes = 8192;
	344
	345	return 1;
	346	}
	347	__setup("code_bytes=", code_bytes_setup);