[mirror_ubuntu-artful-kernel.git] / arch / avr32 / kernel / traps.c

/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bug.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/kallsyms.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/sched.h>
#include <linux/uaccess.h>

#include <asm/addrspace.h>
#include <asm/mmu_context.h>
#include <asm/ocd.h>
#include <asm/sysreg.h>
#include <asm/traps.h>

static DEFINE_SPINLOCK(die_lock);

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

	console_verbose();
	spin_lock_irq(&die_lock);
	bust_spinlocks(1);

	printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n",
	       str, err, ++die_counter);

	printk(KERN_EMERG);

#ifdef CONFIG_PREEMPT
	printk(KERN_CONT "PREEMPT ");
#endif
#ifdef CONFIG_FRAME_POINTER
	printk(KERN_CONT "FRAME_POINTER ");
#endif
	if (current_cpu_data.features & AVR32_FEATURE_OCD) {
		unsigned long did = ocd_read(DID);
		printk(KERN_CONT "chip: 0x%03lx:0x%04lx rev %lu\n",
		       (did >> 1) & 0x7ff,
		       (did >> 12) & 0x7fff,
		       (did >> 28) & 0xf);
	} else {
		printk(KERN_CONT "cpu: arch %u r%u / core %u r%u\n",
		       current_cpu_data.arch_type,
		       current_cpu_data.arch_revision,
		       current_cpu_data.cpu_type,
		       current_cpu_data.cpu_revision);
	}

	print_modules();
	show_regs_log_lvl(regs, KERN_EMERG);
	show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
	bust_spinlocks(0);
	add_taint(TAINT_DIE);
	spin_unlock_irq(&die_lock);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	do_exit(err);
}

void _exception(long signr, struct pt_regs *regs, int code,
		unsigned long addr)
{
	siginfo_t info;

	if (!user_mode(regs)) {
		const struct exception_table_entry *fixup;

		/* Are we prepared to handle this kernel fault? */
		fixup = search_exception_tables(regs->pc);
		if (fixup) {
			regs->pc = fixup->fixup;
			return;
		}
		die("Unhandled exception in kernel mode", regs, signr);
	}

	memset(&info, 0, sizeof(info));
	info.si_signo = signr;
	info.si_code = code;
	info.si_addr = (void __user *)addr;
	force_sig_info(signr, &info, current);

	/*
	 * Init gets no signals that it doesn't have a handler for.
	 * That's all very well, but if it has caused a synchronous
	 * exception and we ignore the resulting signal, it will just
	 * generate the same exception over and over again and we get
	 * nowhere.  Better to kill it and let the kernel panic.
	 */
	if (is_global_init(current)) {
		__sighandler_t handler;

		spin_lock_irq(&current->sighand->siglock);
		handler = current->sighand->action[signr-1].sa.sa_handler;
		spin_unlock_irq(&current->sighand->siglock);
		if (handler == SIG_DFL) {
			/* init has generated a synchronous exception
			   and it doesn't have a handler for the signal */
			printk(KERN_CRIT "init has generated signal %ld "
			       "but has no handler for it\n", signr);
			do_exit(signr);
		}
	}
}

asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
{
	int ret;

	nmi_enter();

	ret = notify_die(DIE_NMI, "NMI", regs, 0, ecr, SIGINT);
	switch (ret) {
	case NOTIFY_OK:
	case NOTIFY_STOP:
		break;
	case NOTIFY_BAD:
		die("Fatal Non-Maskable Interrupt", regs, SIGINT);
	default:
		printk(KERN_ALERT "Got NMI, but nobody cared. Disabling...\n");
		nmi_disable();
		break;
	}
	nmi_exit();
}

asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
{
	die("Critical exception", regs, SIGKILL);
}

asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
{
	_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
}

/* This way of handling undefined instructions is stolen from ARM */
static LIST_HEAD(undef_hook);
static DEFINE_SPINLOCK(undef_lock);

void register_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_add(&hook->node, &undef_hook);
	spin_unlock_irq(&undef_lock);
}

void unregister_undef_hook(struct undef_hook *hook)
{
	spin_lock_irq(&undef_lock);
	list_del(&hook->node);
	spin_unlock_irq(&undef_lock);
}

static int do_cop_absent(u32 insn)
{
	int cop_nr;
	u32 cpucr;

	if ((insn & 0xfdf00000) == 0xf1900000)
		/* LDC0 */
		cop_nr = 0;
	else
		cop_nr = (insn >> 13) & 0x7;

	/* Try enabling the coprocessor */
	cpucr = sysreg_read(CPUCR);
	cpucr |= (1 << (24 + cop_nr));
	sysreg_write(CPUCR, cpucr);

	cpucr = sysreg_read(CPUCR);
	if (!(cpucr & (1 << (24 + cop_nr))))
		return -ENODEV;

	return 0;
}

#ifdef CONFIG_BUG
int is_valid_bugaddr(unsigned long pc)
{
	unsigned short opcode;

	if (pc < PAGE_OFFSET)
		return 0;
	if (probe_kernel_address((u16 *)pc, opcode))
		return 0;

	return opcode == AVR32_BUG_OPCODE;
}
#endif

asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
{
	u32 insn;
	struct undef_hook *hook;
	void __user *pc;
	long code;

#ifdef CONFIG_BUG
	if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
		enum bug_trap_type type;

		type = report_bug(regs->pc, regs);
		switch (type) {
		case BUG_TRAP_TYPE_NONE:
			break;
		case BUG_TRAP_TYPE_WARN:
			regs->pc += 2;
			return;
		case BUG_TRAP_TYPE_BUG:
			die("Kernel BUG", regs, SIGKILL);
		}
	}
#endif

	local_irq_enable();

	if (user_mode(regs)) {
		pc = (void __user *)instruction_pointer(regs);
		if (get_user(insn, (u32 __user *)pc))
			goto invalid_area;

		if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
			return;

		spin_lock_irq(&undef_lock);
		list_for_each_entry(hook, &undef_hook, node) {
			if ((insn & hook->insn_mask) == hook->insn_val) {
				if (hook->fn(regs, insn) == 0) {
					spin_unlock_irq(&undef_lock);
					return;
				}
			}
		}
		spin_unlock_irq(&undef_lock);
	}

	switch (ecr) {
	case ECR_PRIVILEGE_VIOLATION:
		code = ILL_PRVOPC;
		break;
	case ECR_COPROC_ABSENT:
		code = ILL_COPROC;
		break;
	default:
		code = ILL_ILLOPC;
		break;
	}

	_exception(SIGILL, regs, code, regs->pc);
	return;

invalid_area:
	_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
}

asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
{
	/* We have no FPU yet */
	_exception(SIGILL, regs, ILL_COPROC, regs->pc);
}


void __init trap_init(void)
{

}
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* Copyright (C) 2004-2006 Atmel Corporation
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*/
623b0355 HS	8
623b0355 HS	9	#include <linux/bug.h>
ba84be23	10	#include <linux/hardirq.h>
5f97f7f9	11	#include <linux/init.h>
5f97f7f9	12	#include <linux/kallsyms.h>
e7ba176b	13	#include <linux/kdebug.h>
623b0355	14	#include <linux/module.h>
5f97f7f9	15	#include <linux/notifier.h>
623b0355 HS	16	#include <linux/sched.h>
623b0355 HS	17	#include <linux/uaccess.h>
5f97f7f9	18
5f97f7f9	19	#include <asm/addrspace.h>
5f97f7f9	20	#include <asm/mmu_context.h>
623b0355 HS	21	#include <asm/ocd.h>
	22	#include <asm/sysreg.h>
	23	#include <asm/traps.h>
5f97f7f9	24
5f97f7f9 HS	25	static DEFINE_SPINLOCK(die_lock);
5f97f7f9 HS	26
623b0355	27	void NORET_TYPE die(const char str, struct pt_regs regs, long err)
5f97f7f9	28	{
5f97f7f9 HS	29	static int die_counter;
	30
	31	console_verbose();
	32	spin_lock_irq(&die_lock);
	33	bust_spinlocks(1);
	34
ad361c98	35	printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n",
623b0355	36	str, err, ++die_counter);
ad361c98 JP	37
	38	printk(KERN_EMERG);
	39
623b0355	40	#ifdef CONFIG_PREEMPT
ad361c98	41	printk(KERN_CONT "PREEMPT ");
623b0355 HS	42	#endif
623b0355 HS	43	#ifdef CONFIG_FRAME_POINTER
ad361c98	44	printk(KERN_CONT "FRAME_POINTER ");
623b0355 HS	45	#endif
623b0355 HS	46	if (current_cpu_data.features & AVR32_FEATURE_OCD) {
8dfe8f29	47	unsigned long did = ocd_read(DID);
ad361c98	48	printk(KERN_CONT "chip: 0x%03lx:0x%04lx rev %lu\n",
623b0355 HS	49	(did >> 1) & 0x7ff,
	50	(did >> 12) & 0x7fff,
	51	(did >> 28) & 0xf);
	52	} else {
ad361c98	53	printk(KERN_CONT "cpu: arch %u r%u / core %u r%u\n",
623b0355 HS	54	current_cpu_data.arch_type,
	55	current_cpu_data.arch_revision,
	56	current_cpu_data.cpu_type,
	57	current_cpu_data.cpu_revision);
5f97f7f9 HS	58	}
5f97f7f9 HS	59
623b0355 HS	60	print_modules();
	61	show_regs_log_lvl(regs, KERN_EMERG);
	62	show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
5f97f7f9	63	bust_spinlocks(0);
bcdcd8e7	64	add_taint(TAINT_DIE);
5f97f7f9	65	spin_unlock_irq(&die_lock);
623b0355 HS	66
	67	if (in_interrupt())
	68	panic("Fatal exception in interrupt");
	69
	70	if (panic_on_oops)
	71	panic("Fatal exception");
	72
	73	do_exit(err);
5f97f7f9 HS	74	}
5f97f7f9 HS	75
623b0355 HS	76	void _exception(long signr, struct pt_regs *regs, int code,
623b0355 HS	77	unsigned long addr)
5f97f7f9	78	{
623b0355 HS	79	siginfo_t info;
623b0355 HS	80
bb6e6470 HS	81	if (!user_mode(regs)) {
	82	const struct exception_table_entry *fixup;
	83
	84	/* Are we prepared to handle this kernel fault? */
	85	fixup = search_exception_tables(regs->pc);
	86	if (fixup) {
	87	regs->pc = fixup->fixup;
	88	return;
	89	}
623b0355	90	die("Unhandled exception in kernel mode", regs, signr);
bb6e6470	91	}
623b0355 HS	92
	93	memset(&info, 0, sizeof(info));
	94	info.si_signo = signr;
	95	info.si_code = code;
	96	info.si_addr = (void __user *)addr;
	97	force_sig_info(signr, &info, current);
5f97f7f9	98
5f97f7f9	99	/*
623b0355 HS	100	* Init gets no signals that it doesn't have a handler for.
	101	* That's all very well, but if it has caused a synchronous
	102	* exception and we ignore the resulting signal, it will just
	103	* generate the same exception over and over again and we get
	104	* nowhere. Better to kill it and let the kernel panic.
5f97f7f9	105	*/
b460cbc5	106	if (is_global_init(current)) {
623b0355 HS	107	__sighandler_t handler;
	108
	109	spin_lock_irq(&current->sighand->siglock);
	110	handler = current->sighand->action[signr-1].sa.sa_handler;
	111	spin_unlock_irq(&current->sighand->siglock);
	112	if (handler == SIG_DFL) {
	113	/* init has generated a synchronous exception
	114	and it doesn't have a handler for the signal */
	115	printk(KERN_CRIT "init has generated signal %ld "
	116	"but has no handler for it\n", signr);
	117	do_exit(signr);
	118	}
	119	}
	120	}
5f97f7f9	121
623b0355 HS	122	asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
623b0355 HS	123	{
e7ba176b HS	124	int ret;
	125
	126	nmi_enter();
	127
	128	ret = notify_die(DIE_NMI, "NMI", regs, 0, ecr, SIGINT);
	129	switch (ret) {
	130	case NOTIFY_OK:
	131	case NOTIFY_STOP:
3d431a74	132	break;
e7ba176b HS	133	case NOTIFY_BAD:
	134	die("Fatal Non-Maskable Interrupt", regs, SIGINT);
	135	default:
3d431a74 MS	136	printk(KERN_ALERT "Got NMI, but nobody cared. Disabling...\n");
3d431a74 MS	137	nmi_disable();
e7ba176b HS	138	break;
e7ba176b HS	139	}
3d431a74	140	nmi_exit();
5f97f7f9 HS	141	}
	142
	143	asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
	144	{
623b0355	145	die("Critical exception", regs, SIGKILL);
5f97f7f9 HS	146	}
	147
	148	asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
	149	{
623b0355	150	_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
5f97f7f9 HS	151	}
	152
	153	/* This way of handling undefined instructions is stolen from ARM */
	154	static LIST_HEAD(undef_hook);
e89b064a	155	static DEFINE_SPINLOCK(undef_lock);
5f97f7f9 HS	156
	157	void register_undef_hook(struct undef_hook *hook)
	158	{
	159	spin_lock_irq(&undef_lock);
	160	list_add(&hook->node, &undef_hook);
	161	spin_unlock_irq(&undef_lock);
	162	}
	163
	164	void unregister_undef_hook(struct undef_hook *hook)
	165	{
	166	spin_lock_irq(&undef_lock);
	167	list_del(&hook->node);
	168	spin_unlock_irq(&undef_lock);
	169	}
	170
	171	static int do_cop_absent(u32 insn)
	172	{
	173	int cop_nr;
	174	u32 cpucr;
623b0355 HS	175
623b0355 HS	176	if ((insn & 0xfdf00000) == 0xf1900000)
5f97f7f9 HS	177	/* LDC0 */
	178	cop_nr = 0;
	179	else
	180	cop_nr = (insn >> 13) & 0x7;
	181
	182	/* Try enabling the coprocessor */
	183	cpucr = sysreg_read(CPUCR);
	184	cpucr \|= (1 << (24 + cop_nr));
	185	sysreg_write(CPUCR, cpucr);
	186
	187	cpucr = sysreg_read(CPUCR);
623b0355 HS	188	if (!(cpucr & (1 << (24 + cop_nr))))
623b0355 HS	189	return -ENODEV;
5f97f7f9 HS	190
	191	return 0;
	192	}
	193
957ecd7d	194	#ifdef CONFIG_BUG
623b0355	195	int is_valid_bugaddr(unsigned long pc)
5f97f7f9	196	{
623b0355 HS	197	unsigned short opcode;
	198
	199	if (pc < PAGE_OFFSET)
	200	return 0;
	201	if (probe_kernel_address((u16 *)pc, opcode))
	202	return 0;
5f97f7f9	203
623b0355	204	return opcode == AVR32_BUG_OPCODE;
5f97f7f9	205	}
957ecd7d	206	#endif
5f97f7f9 HS	207
	208	asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
	209	{
	210	u32 insn;
	211	struct undef_hook *hook;
5f97f7f9	212	void __user *pc;
623b0355	213	long code;
5f97f7f9	214
957ecd7d	215	#ifdef CONFIG_BUG
623b0355 HS	216	if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
	217	enum bug_trap_type type;
	218
608e2619	219	type = report_bug(regs->pc, regs);
623b0355 HS	220	switch (type) {
	221	case BUG_TRAP_TYPE_NONE:
	222	break;
	223	case BUG_TRAP_TYPE_WARN:
	224	regs->pc += 2;
	225	return;
	226	case BUG_TRAP_TYPE_BUG:
	227	die("Kernel BUG", regs, SIGKILL);
	228	}
	229	}
957ecd7d	230	#endif
5f97f7f9 HS	231
	232	local_irq_enable();
	233
623b0355 HS	234	if (user_mode(regs)) {
	235	pc = (void __user *)instruction_pointer(regs);
	236	if (get_user(insn, (u32 __user *)pc))
	237	goto invalid_area;
5f97f7f9	238
623b0355	239	if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
5f97f7f9	240	return;
5f97f7f9	241
623b0355 HS	242	spin_lock_irq(&undef_lock);
	243	list_for_each_entry(hook, &undef_hook, node) {
	244	if ((insn & hook->insn_mask) == hook->insn_val) {
	245	if (hook->fn(regs, insn) == 0) {
	246	spin_unlock_irq(&undef_lock);
	247	return;
	248	}
5f97f7f9 HS	249	}
5f97f7f9 HS	250	}
623b0355	251	spin_unlock_irq(&undef_lock);
5f97f7f9	252	}
5f97f7f9	253
5f97f7f9	254	switch (ecr) {
5f97f7f9	255	case ECR_PRIVILEGE_VIOLATION:
623b0355	256	code = ILL_PRVOPC;
5f97f7f9 HS	257	break;
5f97f7f9 HS	258	case ECR_COPROC_ABSENT:
623b0355	259	code = ILL_COPROC;
5f97f7f9 HS	260	break;
5f97f7f9 HS	261	default:
623b0355 HS	262	code = ILL_ILLOPC;
623b0355 HS	263	break;
5f97f7f9 HS	264	}
5f97f7f9 HS	265
623b0355	266	_exception(SIGILL, regs, code, regs->pc);
5f97f7f9 HS	267	return;
5f97f7f9 HS	268
623b0355 HS	269	invalid_area:
623b0355 HS	270	_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
5f97f7f9 HS	271	}
	272
	273	asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
	274	{
623b0355 HS	275	/* We have no FPU yet */
623b0355 HS	276	_exception(SIGILL, regs, ILL_COPROC, regs->pc);
5f97f7f9 HS	277	}
	278
	279
	280	void __init trap_init(void)
	281	{
	282
	283	}