[linux-block.git] / arch / s390 / kernel / dumpstack.c

/*
 * Stack dumping functions
 *
 *  Copyright IBM Corp. 1999, 2013
 */

#include <linux/kallsyms.h>
#include <linux/hardirq.h>
#include <linux/kprobes.h>
#include <linux/utsname.h>
#include <linux/export.h>
#include <linux/kdebug.h>
#include <linux/ptrace.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <asm/processor.h>
#include <asm/debug.h>
#include <asm/dis.h>
#include <asm/ipl.h>

#ifndef CONFIG_64BIT
#define LONG "%08lx "
#define FOURLONG "%08lx %08lx %08lx %08lx\n"
static int kstack_depth_to_print = 12;
#else /* CONFIG_64BIT */
#define LONG "%016lx "
#define FOURLONG "%016lx %016lx %016lx %016lx\n"
static int kstack_depth_to_print = 20;
#endif /* CONFIG_64BIT */

/*
 * For show_trace we have tree different stack to consider:
 *   - the panic stack which is used if the kernel stack has overflown
 *   - the asynchronous interrupt stack (cpu related)
 *   - the synchronous kernel stack (process related)
 * The stack trace can start at any of the three stack and can potentially
 * touch all of them. The order is: panic stack, async stack, sync stack.
 */
static unsigned long
__show_trace(unsigned long sp, unsigned long low, unsigned long high)
{
	struct stack_frame *sf;
	struct pt_regs *regs;
	unsigned long addr;

	while (1) {
		sp = sp & PSW_ADDR_INSN;
		if (sp < low || sp > high - sizeof(*sf))
			return sp;
		sf = (struct stack_frame *) sp;
		addr = sf->gprs[8] & PSW_ADDR_INSN;
		printk("([<%016lx>] %pSR)\n", addr, (void *)addr);
		/* Follow the backchain. */
		while (1) {
			low = sp;
			sp = sf->back_chain & PSW_ADDR_INSN;
			if (!sp)
				break;
			if (sp <= low || sp > high - sizeof(*sf))
				return sp;
			sf = (struct stack_frame *) sp;
			addr = sf->gprs[8] & PSW_ADDR_INSN;
			printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
		}
		/* Zero backchain detected, check for interrupt frame. */
		sp = (unsigned long) (sf + 1);
		if (sp <= low || sp > high - sizeof(*regs))
			return sp;
		regs = (struct pt_regs *) sp;
		addr = regs->psw.addr & PSW_ADDR_INSN;
		printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
		low = sp;
		sp = regs->gprs[15];
	}
}

static void show_trace(struct task_struct *task, unsigned long *stack)
{
	const unsigned long frame_size =
		STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
	register unsigned long __r15 asm ("15");
	unsigned long sp;

	sp = (unsigned long) stack;
	if (!sp)
		sp = task ? task->thread.ksp : __r15;
	printk("Call Trace:\n");
#ifdef CONFIG_CHECK_STACK
	sp = __show_trace(sp,
			  S390_lowcore.panic_stack + frame_size - 4096,
			  S390_lowcore.panic_stack + frame_size);
#endif
	sp = __show_trace(sp,
			  S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
			  S390_lowcore.async_stack + frame_size);
	if (task)
		__show_trace(sp, (unsigned long) task_stack_page(task),
			     (unsigned long) task_stack_page(task) + THREAD_SIZE);
	else
		__show_trace(sp, S390_lowcore.thread_info,
			     S390_lowcore.thread_info + THREAD_SIZE);
	if (!task)
		task = current;
	debug_show_held_locks(task);
}

void show_stack(struct task_struct *task, unsigned long *sp)
{
	register unsigned long *__r15 asm ("15");
	unsigned long *stack;
	int i;

	if (!sp)
		stack = task ? (unsigned long *) task->thread.ksp : __r15;
	else
		stack = sp;

	for (i = 0; i < kstack_depth_to_print; i++) {
		if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
			break;
		if ((i * sizeof(long) % 32) == 0)
			printk("%s       ", i == 0 ? "" : "\n");
		printk(LONG, *stack++);
	}
	printk("\n");
	show_trace(task, sp);
}

static void show_last_breaking_event(struct pt_regs *regs)
{
#ifdef CONFIG_64BIT
	printk("Last Breaking-Event-Address:\n");
	printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
#endif
}

static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
{
	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
}

void show_registers(struct pt_regs *regs)
{
	char *mode;

	mode = user_mode(regs) ? "User" : "Krnl";
	printk("%s PSW : %p %p (%pSR)\n",
	       mode, (void *) regs->psw.mask,
	       (void *) regs->psw.addr,
	       (void *) regs->psw.addr);
	printk("           R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
	       "P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
	       mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
	       mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
	       mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
	       mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
	       mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
#ifdef CONFIG_64BIT
	printk(" EA:%x", mask_bits(regs, PSW_MASK_EA | PSW_MASK_BA));
#endif
	printk("\n%s GPRS: " FOURLONG, mode,
	       regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
	printk("           " FOURLONG,
	       regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
	printk("           " FOURLONG,
	       regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
	printk("           " FOURLONG,
	       regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
	show_code(regs);
}

void show_regs(struct pt_regs *regs)
{
	show_regs_print_info(KERN_DEFAULT);
	show_registers(regs);
	/* Show stack backtrace if pt_regs is from kernel mode */
	if (!user_mode(regs))
		show_trace(NULL, (unsigned long *) regs->gprs[15]);
	show_last_breaking_event(regs);
}

static DEFINE_SPINLOCK(die_lock);

void die(struct pt_regs *regs, const char *str)
{
	static int die_counter;

	oops_enter();
	lgr_info_log();
	debug_stop_all();
	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);
	printk("%s: %04x [#%d] ", str, regs->int_code & 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");
	notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
	print_modules();
	show_regs(regs);
	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	spin_unlock_irq(&die_lock);
	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception: panic_on_oops");
	oops_exit();
	do_exit(SIGSEGV);
}
Commit	Line	Data
1bca09f7 HC	1	/*
	2	* Stack dumping functions
	3	*
	4	* Copyright IBM Corp. 1999, 2013
	5	*/
	6
	7	#include <linux/kallsyms.h>
	8	#include <linux/hardirq.h>
	9	#include <linux/kprobes.h>
	10	#include <linux/utsname.h>
	11	#include <linux/export.h>
	12	#include <linux/kdebug.h>
	13	#include <linux/ptrace.h>
	14	#include <linux/module.h>
	15	#include <linux/sched.h>
	16	#include <asm/processor.h>
	17	#include <asm/debug.h>
0f20822a	18	#include <asm/dis.h>
1bca09f7 HC	19	#include <asm/ipl.h>
	20
	21	#ifndef CONFIG_64BIT
	22	#define LONG "%08lx "
	23	#define FOURLONG "%08lx %08lx %08lx %08lx\n"
	24	static int kstack_depth_to_print = 12;
	25	#else /* CONFIG_64BIT */
	26	#define LONG "%016lx "
	27	#define FOURLONG "%016lx %016lx %016lx %016lx\n"
	28	static int kstack_depth_to_print = 20;
	29	#endif /* CONFIG_64BIT */
	30
	31	/*
	32	* For show_trace we have tree different stack to consider:
	33	* - the panic stack which is used if the kernel stack has overflown
	34	* - the asynchronous interrupt stack (cpu related)
	35	* - the synchronous kernel stack (process related)
	36	* The stack trace can start at any of the three stack and can potentially
	37	* touch all of them. The order is: panic stack, async stack, sync stack.
	38	*/
	39	static unsigned long
	40	__show_trace(unsigned long sp, unsigned long low, unsigned long high)
	41	{
	42	struct stack_frame *sf;
	43	struct pt_regs *regs;
8237ac3c	44	unsigned long addr;
1bca09f7 HC	45
	46	while (1) {
	47	sp = sp & PSW_ADDR_INSN;
	48	if (sp < low \|\| sp > high - sizeof(*sf))
	49	return sp;
	50	sf = (struct stack_frame *) sp;
8237ac3c HC	51	addr = sf->gprs[8] & PSW_ADDR_INSN;
8237ac3c HC	52	printk("([<%016lx>] %pSR)\n", addr, (void *)addr);
1bca09f7 HC	53	/* Follow the backchain. */
	54	while (1) {
	55	low = sp;
	56	sp = sf->back_chain & PSW_ADDR_INSN;
	57	if (!sp)
	58	break;
	59	if (sp <= low \|\| sp > high - sizeof(*sf))
	60	return sp;
	61	sf = (struct stack_frame *) sp;
8237ac3c HC	62	addr = sf->gprs[8] & PSW_ADDR_INSN;
8237ac3c HC	63	printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
1bca09f7 HC	64	}
	65	/* Zero backchain detected, check for interrupt frame. */
	66	sp = (unsigned long) (sf + 1);
	67	if (sp <= low \|\| sp > high - sizeof(*regs))
	68	return sp;
	69	regs = (struct pt_regs *) sp;
8237ac3c HC	70	addr = regs->psw.addr & PSW_ADDR_INSN;
8237ac3c HC	71	printk(" [<%016lx>] %pSR\n", addr, (void *)addr);
1bca09f7 HC	72	low = sp;
	73	sp = regs->gprs[15];
	74	}
	75	}
	76
	77	static void show_trace(struct task_struct task, unsigned long stack)
	78	{
9cc5c206 MS	79	const unsigned long frame_size =
9cc5c206 MS	80	STACK_FRAME_OVERHEAD + sizeof(struct pt_regs);
1bca09f7 HC	81	register unsigned long __r15 asm ("15");
	82	unsigned long sp;
	83
	84	sp = (unsigned long) stack;
	85	if (!sp)
	86	sp = task ? task->thread.ksp : __r15;
	87	printk("Call Trace:\n");
	88	#ifdef CONFIG_CHECK_STACK
9cc5c206 MS	89	sp = __show_trace(sp,
	90	S390_lowcore.panic_stack + frame_size - 4096,
	91	S390_lowcore.panic_stack + frame_size);
1bca09f7	92	#endif
9cc5c206 MS	93	sp = __show_trace(sp,
	94	S390_lowcore.async_stack + frame_size - ASYNC_SIZE,
	95	S390_lowcore.async_stack + frame_size);
1bca09f7 HC	96	if (task)
	97	__show_trace(sp, (unsigned long) task_stack_page(task),
	98	(unsigned long) task_stack_page(task) + THREAD_SIZE);
	99	else
	100	__show_trace(sp, S390_lowcore.thread_info,
	101	S390_lowcore.thread_info + THREAD_SIZE);
	102	if (!task)
	103	task = current;
	104	debug_show_held_locks(task);
	105	}
	106
	107	void show_stack(struct task_struct task, unsigned long sp)
	108	{
	109	register unsigned long *__r15 asm ("15");
	110	unsigned long *stack;
	111	int i;
	112
	113	if (!sp)
	114	stack = task ? (unsigned long *) task->thread.ksp : __r15;
	115	else
	116	stack = sp;
	117
	118	for (i = 0; i < kstack_depth_to_print; i++) {
	119	if (((addr_t) stack & (THREAD_SIZE-1)) == 0)
	120	break;
	121	if ((i * sizeof(long) % 32) == 0)
	122	printk("%s ", i == 0 ? "" : "\n");
	123	printk(LONG, *stack++);
	124	}
	125	printk("\n");
	126	show_trace(task, sp);
	127	}
	128
	129	static void show_last_breaking_event(struct pt_regs *regs)
	130	{
	131	#ifdef CONFIG_64BIT
	132	printk("Last Breaking-Event-Address:\n");
8237ac3c	133	printk(" [<%016lx>] %pSR\n", regs->args[0], (void *)regs->args[0]);
1bca09f7 HC	134	#endif
	135	}
	136
1bca09f7 HC	137	static inline int mask_bits(struct pt_regs *regs, unsigned long bits)
	138	{
	139	return (regs->psw.mask & bits) / ((~bits + 1) & bits);
	140	}
	141
	142	void show_registers(struct pt_regs *regs)
	143	{
	144	char *mode;
	145
	146	mode = user_mode(regs) ? "User" : "Krnl";
8237ac3c	147	printk("%s PSW : %p %p (%pSR)\n",
1bca09f7	148	mode, (void *) regs->psw.mask,
8237ac3c	149	(void *) regs->psw.addr,
1bca09f7	150	(void *) regs->psw.addr);
1bca09f7 HC	151	printk(" R:%x T:%x IO:%x EX:%x Key:%x M:%x W:%x "
	152	"P:%x AS:%x CC:%x PM:%x", mask_bits(regs, PSW_MASK_PER),
	153	mask_bits(regs, PSW_MASK_DAT), mask_bits(regs, PSW_MASK_IO),
	154	mask_bits(regs, PSW_MASK_EXT), mask_bits(regs, PSW_MASK_KEY),
	155	mask_bits(regs, PSW_MASK_MCHECK), mask_bits(regs, PSW_MASK_WAIT),
	156	mask_bits(regs, PSW_MASK_PSTATE), mask_bits(regs, PSW_MASK_ASC),
	157	mask_bits(regs, PSW_MASK_CC), mask_bits(regs, PSW_MASK_PM));
	158	#ifdef CONFIG_64BIT
	159	printk(" EA:%x", mask_bits(regs, PSW_MASK_EA \| PSW_MASK_BA));
	160	#endif
	161	printk("\n%s GPRS: " FOURLONG, mode,
	162	regs->gprs[0], regs->gprs[1], regs->gprs[2], regs->gprs[3]);
	163	printk(" " FOURLONG,
	164	regs->gprs[4], regs->gprs[5], regs->gprs[6], regs->gprs[7]);
	165	printk(" " FOURLONG,
	166	regs->gprs[8], regs->gprs[9], regs->gprs[10], regs->gprs[11]);
	167	printk(" " FOURLONG,
	168	regs->gprs[12], regs->gprs[13], regs->gprs[14], regs->gprs[15]);
	169	show_code(regs);
	170	}
	171
	172	void show_regs(struct pt_regs *regs)
	173	{
a43cb95d	174	show_regs_print_info(KERN_DEFAULT);
1bca09f7 HC	175	show_registers(regs);
	176	/* Show stack backtrace if pt_regs is from kernel mode */
	177	if (!user_mode(regs))
	178	show_trace(NULL, (unsigned long *) regs->gprs[15]);
	179	show_last_breaking_event(regs);
	180	}
	181
	182	static DEFINE_SPINLOCK(die_lock);
	183
	184	void die(struct pt_regs regs, const char str)
	185	{
	186	static int die_counter;
	187
	188	oops_enter();
	189	lgr_info_log();
	190	debug_stop_all();
	191	console_verbose();
	192	spin_lock_irq(&die_lock);
	193	bust_spinlocks(1);
	194	printk("%s: %04x [#%d] ", str, regs->int_code & 0xffff, ++die_counter);
	195	#ifdef CONFIG_PREEMPT
	196	printk("PREEMPT ");
	197	#endif
	198	#ifdef CONFIG_SMP
	199	printk("SMP ");
	200	#endif
	201	#ifdef CONFIG_DEBUG_PAGEALLOC
	202	printk("DEBUG_PAGEALLOC");
	203	#endif
	204	printk("\n");
	205	notify_die(DIE_OOPS, str, regs, 0, regs->int_code & 0xffff, SIGSEGV);
	206	print_modules();
	207	show_regs(regs);
	208	bust_spinlocks(0);
	209	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	210	spin_unlock_irq(&die_lock);
	211	if (in_interrupt())
	212	panic("Fatal exception in interrupt");
	213	if (panic_on_oops)
	214	panic("Fatal exception: panic_on_oops");
	215	oops_exit();
	216	do_exit(SIGSEGV);
	217	}