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