[linux-2.6-block.git] / arch / arm64 / kernel / traps.c

/*
 * Based on arch/arm/kernel/traps.c
 *
 * Copyright (C) 1995-2009 Russell King
 * Copyright (C) 2012 ARM Ltd.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/bug.h>
#include <linux/signal.h>
#include <linux/personality.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <linux/kdebug.h>
#include <linux/module.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/syscalls.h>

#include <asm/atomic.h>
#include <asm/bug.h>
#include <asm/debug-monitors.h>
#include <asm/esr.h>
#include <asm/insn.h>
#include <asm/traps.h>
#include <asm/stacktrace.h>
#include <asm/exception.h>
#include <asm/system_misc.h>

static const char *handler[]= {
	"Synchronous Abort",
	"IRQ",
	"FIQ",
	"Error"
};

int show_unhandled_signals = 1;

/*
 * Dump out the contents of some memory nicely...
 */
static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
		     unsigned long top, bool compat)
{
	unsigned long first;
	mm_segment_t fs;
	int i;
	unsigned int width = compat ? 4 : 8;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);

	for (first = bottom & ~31; first < top; first += 32) {
		unsigned long p;
		char str[sizeof(" 12345678") * 8 + 1];

		memset(str, ' ', sizeof(str));
		str[sizeof(str) - 1] = '\0';

		for (p = first, i = 0; i < (32 / width)
					&& p < top; i++, p += width) {
			if (p >= bottom && p < top) {
				unsigned long val;

				if (width == 8) {
					if (__get_user(val, (unsigned long *)p) == 0)
						sprintf(str + i * 17, " %016lx", val);
					else
						sprintf(str + i * 17, " ????????????????");
				} else {
					if (__get_user(val, (unsigned int *)p) == 0)
						sprintf(str + i * 9, " %08lx", val);
					else
						sprintf(str + i * 9, " ????????");
				}
			}
		}
		printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
	}

	set_fs(fs);
}

static void dump_backtrace_entry(unsigned long where)
{
	/*
	 * Note that 'where' can have a physical address, but it's not handled.
	 */
	print_ip_sym(where);
}

static void dump_instr(const char *lvl, struct pt_regs *regs)
{
	unsigned long addr = instruction_pointer(regs);
	mm_segment_t fs;
	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
	int i;

	/*
	 * We need to switch to kernel mode so that we can use __get_user
	 * to safely read from kernel space.  Note that we now dump the
	 * code first, just in case the backtrace kills us.
	 */
	fs = get_fs();
	set_fs(KERNEL_DS);

	for (i = -4; i < 1; i++) {
		unsigned int val, bad;

		bad = __get_user(val, &((u32 *)addr)[i]);

		if (!bad)
			p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
		else {
			p += sprintf(p, "bad PC value");
			break;
		}
	}
	printk("%sCode: %s\n", lvl, str);

	set_fs(fs);
}

static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
{
	struct stackframe frame;
	unsigned long irq_stack_ptr;
	int skip;

	/*
	 * Switching between stacks is valid when tracing current and in
	 * non-preemptible context.
	 */
	if (tsk == current && !preemptible())
		irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
	else
		irq_stack_ptr = 0;

	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);

	if (!tsk)
		tsk = current;

	if (tsk == current) {
		frame.fp = (unsigned long)__builtin_frame_address(0);
		frame.sp = current_stack_pointer;
		frame.pc = (unsigned long)dump_backtrace;
	} else {
		/*
		 * task blocked in __switch_to
		 */
		frame.fp = thread_saved_fp(tsk);
		frame.sp = thread_saved_sp(tsk);
		frame.pc = thread_saved_pc(tsk);
	}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	frame.graph = tsk->curr_ret_stack;
#endif

	skip = !!regs;
	printk("Call trace:\n");
	while (1) {
		unsigned long where = frame.pc;
		unsigned long stack;
		int ret;

		/* skip until specified stack frame */
		if (!skip) {
			dump_backtrace_entry(where);
		} else if (frame.fp == regs->regs[29]) {
			skip = 0;
			/*
			 * Mostly, this is the case where this function is
			 * called in panic/abort. As exception handler's
			 * stack frame does not contain the corresponding pc
			 * at which an exception has taken place, use regs->pc
			 * instead.
			 */
			dump_backtrace_entry(regs->pc);
		}
		ret = unwind_frame(tsk, &frame);
		if (ret < 0)
			break;
		stack = frame.sp;
		if (in_exception_text(where)) {
			/*
			 * If we switched to the irq_stack before calling this
			 * exception handler, then the pt_regs will be on the
			 * task stack. The easiest way to tell is if the large
			 * pt_regs would overlap with the end of the irq_stack.
			 */
			if (stack < irq_stack_ptr &&
			    (stack + sizeof(struct pt_regs)) > irq_stack_ptr)
				stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);

			dump_mem("", "Exception stack", stack,
				 stack + sizeof(struct pt_regs), false);
		}
	}
}

void show_stack(struct task_struct *tsk, unsigned long *sp)
{
	dump_backtrace(NULL, tsk);
	barrier();
}

#ifdef CONFIG_PREEMPT
#define S_PREEMPT " PREEMPT"
#else
#define S_PREEMPT ""
#endif
#define S_SMP " SMP"

static int __die(const char *str, int err, struct thread_info *thread,
		 struct pt_regs *regs)
{
	struct task_struct *tsk = thread->task;
	static int die_counter;
	int ret;

	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
		 str, err, ++die_counter);

	/* trap and error numbers are mostly meaningless on ARM */
	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
	if (ret == NOTIFY_STOP)
		return ret;

	print_modules();
	__show_regs(regs);
	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
		 TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);

	if (!user_mode(regs) || in_interrupt()) {
		dump_mem(KERN_EMERG, "Stack: ", regs->sp,
			 THREAD_SIZE + (unsigned long)task_stack_page(tsk),
			 compat_user_mode(regs));
		dump_backtrace(regs, tsk);
		dump_instr(KERN_EMERG, regs);
	}

	return ret;
}

static DEFINE_RAW_SPINLOCK(die_lock);

/*
 * This function is protected against re-entrancy.
 */
void die(const char *str, struct pt_regs *regs, int err)
{
	struct thread_info *thread = current_thread_info();
	int ret;

	oops_enter();

	raw_spin_lock_irq(&die_lock);
	console_verbose();
	bust_spinlocks(1);
	ret = __die(str, err, thread, regs);

	if (regs && kexec_should_crash(thread->task))
		crash_kexec(regs);

	bust_spinlocks(0);
	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
	raw_spin_unlock_irq(&die_lock);
	oops_exit();

	if (in_interrupt())
		panic("Fatal exception in interrupt");
	if (panic_on_oops)
		panic("Fatal exception");
	if (ret != NOTIFY_STOP)
		do_exit(SIGSEGV);
}

void arm64_notify_die(const char *str, struct pt_regs *regs,
		      struct siginfo *info, int err)
{
	if (user_mode(regs)) {
		current->thread.fault_address = 0;
		current->thread.fault_code = err;
		force_sig_info(info->si_signo, info, current);
	} else {
		die(str, regs, err);
	}
}

static LIST_HEAD(undef_hook);
static DEFINE_RAW_SPINLOCK(undef_lock);

void register_undef_hook(struct undef_hook *hook)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&undef_lock, flags);
	list_add(&hook->node, &undef_hook);
	raw_spin_unlock_irqrestore(&undef_lock, flags);
}

void unregister_undef_hook(struct undef_hook *hook)
{
	unsigned long flags;

	raw_spin_lock_irqsave(&undef_lock, flags);
	list_del(&hook->node);
	raw_spin_unlock_irqrestore(&undef_lock, flags);
}

static int call_undef_hook(struct pt_regs *regs)
{
	struct undef_hook *hook;
	unsigned long flags;
	u32 instr;
	int (*fn)(struct pt_regs *regs, u32 instr) = NULL;
	void __user *pc = (void __user *)instruction_pointer(regs);

	if (!user_mode(regs))
		return 1;

	if (compat_thumb_mode(regs)) {
		/* 16-bit Thumb instruction */
		if (get_user(instr, (u16 __user *)pc))
			goto exit;
		instr = le16_to_cpu(instr);
		if (aarch32_insn_is_wide(instr)) {
			u32 instr2;

			if (get_user(instr2, (u16 __user *)(pc + 2)))
				goto exit;
			instr2 = le16_to_cpu(instr2);
			instr = (instr << 16) | instr2;
		}
	} else {
		/* 32-bit ARM instruction */
		if (get_user(instr, (u32 __user *)pc))
			goto exit;
		instr = le32_to_cpu(instr);
	}

	raw_spin_lock_irqsave(&undef_lock, flags);
	list_for_each_entry(hook, &undef_hook, node)
		if ((instr & hook->instr_mask) == hook->instr_val &&
			(regs->pstate & hook->pstate_mask) == hook->pstate_val)
			fn = hook->fn;

	raw_spin_unlock_irqrestore(&undef_lock, flags);
exit:
	return fn ? fn(regs, instr) : 1;
}

asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
{
	siginfo_t info;
	void __user *pc = (void __user *)instruction_pointer(regs);

	/* check for AArch32 breakpoint instructions */
	if (!aarch32_break_handler(regs))
		return;

	if (call_undef_hook(regs) == 0)
		return;

	if (unhandled_signal(current, SIGILL) && show_unhandled_signals_ratelimited()) {
		pr_info("%s[%d]: undefined instruction: pc=%p\n",
			current->comm, task_pid_nr(current), pc);
		dump_instr(KERN_INFO, regs);
	}

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code  = ILL_ILLOPC;
	info.si_addr  = pc;

	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
}

long compat_arm_syscall(struct pt_regs *regs);

asmlinkage long do_ni_syscall(struct pt_regs *regs)
{
#ifdef CONFIG_COMPAT
	long ret;
	if (is_compat_task()) {
		ret = compat_arm_syscall(regs);
		if (ret != -ENOSYS)
			return ret;
	}
#endif

	if (show_unhandled_signals_ratelimited()) {
		pr_info("%s[%d]: syscall %d\n", current->comm,
			task_pid_nr(current), (int)regs->syscallno);
		dump_instr("", regs);
		if (user_mode(regs))
			__show_regs(regs);
	}

	return sys_ni_syscall();
}

static const char *esr_class_str[] = {
	[0 ... ESR_ELx_EC_MAX]		= "UNRECOGNIZED EC",
	[ESR_ELx_EC_UNKNOWN]		= "Unknown/Uncategorized",
	[ESR_ELx_EC_WFx]		= "WFI/WFE",
	[ESR_ELx_EC_CP15_32]		= "CP15 MCR/MRC",
	[ESR_ELx_EC_CP15_64]		= "CP15 MCRR/MRRC",
	[ESR_ELx_EC_CP14_MR]		= "CP14 MCR/MRC",
	[ESR_ELx_EC_CP14_LS]		= "CP14 LDC/STC",
	[ESR_ELx_EC_FP_ASIMD]		= "ASIMD",
	[ESR_ELx_EC_CP10_ID]		= "CP10 MRC/VMRS",
	[ESR_ELx_EC_CP14_64]		= "CP14 MCRR/MRRC",
	[ESR_ELx_EC_ILL]		= "PSTATE.IL",
	[ESR_ELx_EC_SVC32]		= "SVC (AArch32)",
	[ESR_ELx_EC_HVC32]		= "HVC (AArch32)",
	[ESR_ELx_EC_SMC32]		= "SMC (AArch32)",
	[ESR_ELx_EC_SVC64]		= "SVC (AArch64)",
	[ESR_ELx_EC_HVC64]		= "HVC (AArch64)",
	[ESR_ELx_EC_SMC64]		= "SMC (AArch64)",
	[ESR_ELx_EC_SYS64]		= "MSR/MRS (AArch64)",
	[ESR_ELx_EC_IMP_DEF]		= "EL3 IMP DEF",
	[ESR_ELx_EC_IABT_LOW]		= "IABT (lower EL)",
	[ESR_ELx_EC_IABT_CUR]		= "IABT (current EL)",
	[ESR_ELx_EC_PC_ALIGN]		= "PC Alignment",
	[ESR_ELx_EC_DABT_LOW]		= "DABT (lower EL)",
	[ESR_ELx_EC_DABT_CUR]		= "DABT (current EL)",
	[ESR_ELx_EC_SP_ALIGN]		= "SP Alignment",
	[ESR_ELx_EC_FP_EXC32]		= "FP (AArch32)",
	[ESR_ELx_EC_FP_EXC64]		= "FP (AArch64)",
	[ESR_ELx_EC_SERROR]		= "SError",
	[ESR_ELx_EC_BREAKPT_LOW]	= "Breakpoint (lower EL)",
	[ESR_ELx_EC_BREAKPT_CUR]	= "Breakpoint (current EL)",
	[ESR_ELx_EC_SOFTSTP_LOW]	= "Software Step (lower EL)",
	[ESR_ELx_EC_SOFTSTP_CUR]	= "Software Step (current EL)",
	[ESR_ELx_EC_WATCHPT_LOW]	= "Watchpoint (lower EL)",
	[ESR_ELx_EC_WATCHPT_CUR]	= "Watchpoint (current EL)",
	[ESR_ELx_EC_BKPT32]		= "BKPT (AArch32)",
	[ESR_ELx_EC_VECTOR32]		= "Vector catch (AArch32)",
	[ESR_ELx_EC_BRK64]		= "BRK (AArch64)",
};

const char *esr_get_class_string(u32 esr)
{
	return esr_class_str[esr >> ESR_ELx_EC_SHIFT];
}

/*
 * bad_mode handles the impossible case in the exception vector.
 */
asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
{
	siginfo_t info;
	void __user *pc = (void __user *)instruction_pointer(regs);
	console_verbose();

	pr_crit("Bad mode in %s handler detected, code 0x%08x -- %s\n",
		handler[reason], esr, esr_get_class_string(esr));
	__show_regs(regs);

	info.si_signo = SIGILL;
	info.si_errno = 0;
	info.si_code  = ILL_ILLOPC;
	info.si_addr  = pc;

	arm64_notify_die("Oops - bad mode", regs, &info, 0);
}

void __pte_error(const char *file, int line, unsigned long val)
{
	pr_err("%s:%d: bad pte %016lx.\n", file, line, val);
}

void __pmd_error(const char *file, int line, unsigned long val)
{
	pr_err("%s:%d: bad pmd %016lx.\n", file, line, val);
}

void __pud_error(const char *file, int line, unsigned long val)
{
	pr_err("%s:%d: bad pud %016lx.\n", file, line, val);
}

void __pgd_error(const char *file, int line, unsigned long val)
{
	pr_err("%s:%d: bad pgd %016lx.\n", file, line, val);
}

/* GENERIC_BUG traps */

int is_valid_bugaddr(unsigned long addr)
{
	/*
	 * bug_handler() only called for BRK #BUG_BRK_IMM.
	 * So the answer is trivial -- any spurious instances with no
	 * bug table entry will be rejected by report_bug() and passed
	 * back to the debug-monitors code and handled as a fatal
	 * unexpected debug exception.
	 */
	return 1;
}

static int bug_handler(struct pt_regs *regs, unsigned int esr)
{
	if (user_mode(regs))
		return DBG_HOOK_ERROR;

	switch (report_bug(regs->pc, regs)) {
	case BUG_TRAP_TYPE_BUG:
		die("Oops - BUG", regs, 0);
		break;

	case BUG_TRAP_TYPE_WARN:
		/* Ideally, report_bug() should backtrace for us... but no. */
		dump_backtrace(regs, NULL);
		break;

	default:
		/* unknown/unrecognised bug trap type */
		return DBG_HOOK_ERROR;
	}

	/* If thread survives, skip over the BUG instruction and continue: */
	regs->pc += AARCH64_INSN_SIZE;	/* skip BRK and resume */
	return DBG_HOOK_HANDLED;
}

static struct break_hook bug_break_hook = {
	.esr_val = 0xf2000000 | BUG_BRK_IMM,
	.esr_mask = 0xffffffff,
	.fn = bug_handler,
};

/*
 * Initial handler for AArch64 BRK exceptions
 * This handler only used until debug_traps_init().
 */
int __init early_brk64(unsigned long addr, unsigned int esr,
		struct pt_regs *regs)
{
	return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
}

/* This registration must happen early, before debug_traps_init(). */
void __init trap_init(void)
{
	register_break_hook(&bug_break_hook);
}
Commit	Line	Data
60ffc30d CM	1	/*
	2	* Based on arch/arm/kernel/traps.c
	3	*
	4	* Copyright (C) 1995-2009 Russell King
	5	* Copyright (C) 2012 ARM Ltd.
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
9fb7410f	20	#include <linux/bug.h>
60ffc30d CM	21	#include <linux/signal.h>
	22	#include <linux/personality.h>
	23	#include <linux/kallsyms.h>
	24	#include <linux/spinlock.h>
	25	#include <linux/uaccess.h>
	26	#include <linux/hardirq.h>
	27	#include <linux/kdebug.h>
	28	#include <linux/module.h>
	29	#include <linux/kexec.h>
	30	#include <linux/delay.h>
	31	#include <linux/init.h>
	32	#include <linux/sched.h>
	33	#include <linux/syscalls.h>
	34
	35	#include <asm/atomic.h>
9fb7410f	36	#include <asm/bug.h>
1442b6ed	37	#include <asm/debug-monitors.h>
60a1f02c	38	#include <asm/esr.h>
9fb7410f	39	#include <asm/insn.h>
60ffc30d CM	40	#include <asm/traps.h>
	41	#include <asm/stacktrace.h>
	42	#include <asm/exception.h>
	43	#include <asm/system_misc.h>
	44
	45	static const char *handler[]= {
	46	"Synchronous Abort",
	47	"IRQ",
	48	"FIQ",
	49	"Error"
	50	};
	51
	52	int show_unhandled_signals = 1;
	53
	54	/*
	55	* Dump out the contents of some memory nicely...
	56	*/
	57	static void dump_mem(const char lvl, const char str, unsigned long bottom,
e147ae6d	58	unsigned long top, bool compat)
60ffc30d CM	59	{
	60	unsigned long first;
	61	mm_segment_t fs;
	62	int i;
e147ae6d	63	unsigned int width = compat ? 4 : 8;
60ffc30d CM	64
	65	/*
	66	* We need to switch to kernel mode so that we can use __get_user
	67	* to safely read from kernel space. Note that we now dump the
	68	* code first, just in case the backtrace kills us.
	69	*/
	70	fs = get_fs();
	71	set_fs(KERNEL_DS);
	72
	73	printk("%s%s(0x%016lx to 0x%016lx)\n", lvl, str, bottom, top);
	74
	75	for (first = bottom & ~31; first < top; first += 32) {
	76	unsigned long p;
	77	char str[sizeof(" 12345678") * 8 + 1];
	78
	79	memset(str, ' ', sizeof(str));
	80	str[sizeof(str) - 1] = '\0';
	81
e147ae6d RT	82	for (p = first, i = 0; i < (32 / width)
e147ae6d RT	83	&& p < top; i++, p += width) {
60ffc30d	84	if (p >= bottom && p < top) {
e147ae6d RT	85	unsigned long val;
	86
	87	if (width == 8) {
	88	if (__get_user(val, (unsigned long *)p) == 0)
	89	sprintf(str + i * 17, " %016lx", val);
	90	else
	91	sprintf(str + i * 17, " ????????????????");
	92	} else {
	93	if (__get_user(val, (unsigned int *)p) == 0)
	94	sprintf(str + i * 9, " %08lx", val);
	95	else
	96	sprintf(str + i * 9, " ????????");
	97	}
60ffc30d CM	98	}
	99	}
	100	printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
	101	}
	102
	103	set_fs(fs);
	104	}
	105
9f93f3e9	106	static void dump_backtrace_entry(unsigned long where)
60ffc30d	107	{
9f93f3e9 JL	108	/*
	109	* Note that 'where' can have a physical address, but it's not handled.
	110	*/
60ffc30d	111	print_ip_sym(where);
60ffc30d CM	112	}
	113
	114	static void dump_instr(const char lvl, struct pt_regs regs)
	115	{
	116	unsigned long addr = instruction_pointer(regs);
	117	mm_segment_t fs;
	118	char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
	119	int i;
	120
	121	/*
	122	* We need to switch to kernel mode so that we can use __get_user
	123	* to safely read from kernel space. Note that we now dump the
	124	* code first, just in case the backtrace kills us.
	125	*/
	126	fs = get_fs();
	127	set_fs(KERNEL_DS);
	128
	129	for (i = -4; i < 1; i++) {
	130	unsigned int val, bad;
	131
	132	bad = __get_user(val, &((u32 *)addr)[i]);
	133
	134	if (!bad)
	135	p += sprintf(p, i == 0 ? "(%08x) " : "%08x ", val);
	136	else {
	137	p += sprintf(p, "bad PC value");
	138	break;
	139	}
	140	}
	141	printk("%sCode: %s\n", lvl, str);
	142
	143	set_fs(fs);
	144	}
	145
	146	static void dump_backtrace(struct pt_regs regs, struct task_struct tsk)
	147	{
	148	struct stackframe frame;
a80a0eb7	149	unsigned long irq_stack_ptr;
20380bb3	150	int skip;
60ffc30d	151
a80a0eb7 YS	152	/*
	153	* Switching between stacks is valid when tracing current and in
	154	* non-preemptible context.
	155	*/
	156	if (tsk == current && !preemptible())
	157	irq_stack_ptr = IRQ_STACK_PTR(smp_processor_id());
	158	else
	159	irq_stack_ptr = 0;
	160
60ffc30d CM	161	pr_debug("%s(regs = %p tsk = %p)\n", __func__, regs, tsk);
	162
	163	if (!tsk)
	164	tsk = current;
	165
20380bb3	166	if (tsk == current) {
60ffc30d	167	frame.fp = (unsigned long)__builtin_frame_address(0);
2128df14	168	frame.sp = current_stack_pointer;
60ffc30d CM	169	frame.pc = (unsigned long)dump_backtrace;
	170	} else {
	171	/*
	172	* task blocked in __switch_to
	173	*/
	174	frame.fp = thread_saved_fp(tsk);
	175	frame.sp = thread_saved_sp(tsk);
	176	frame.pc = thread_saved_pc(tsk);
	177	}
20380bb3 AT	178	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	179	frame.graph = tsk->curr_ret_stack;
	180	#endif
60ffc30d	181
20380bb3	182	skip = !!regs;
c9cd0ed9	183	printk("Call trace:\n");
60ffc30d CM	184	while (1) {
60ffc30d CM	185	unsigned long where = frame.pc;
9f93f3e9	186	unsigned long stack;
60ffc30d CM	187	int ret;
60ffc30d CM	188
20380bb3 AT	189	/* skip until specified stack frame */
	190	if (!skip) {
	191	dump_backtrace_entry(where);
	192	} else if (frame.fp == regs->regs[29]) {
	193	skip = 0;
	194	/*
	195	* Mostly, this is the case where this function is
	196	* called in panic/abort. As exception handler's
	197	* stack frame does not contain the corresponding pc
	198	* at which an exception has taken place, use regs->pc
	199	* instead.
	200	*/
	201	dump_backtrace_entry(regs->pc);
	202	}
fe13f95b	203	ret = unwind_frame(tsk, &frame);
60ffc30d CM	204	if (ret < 0)
60ffc30d CM	205	break;
9f93f3e9	206	stack = frame.sp;
132cd887 AT	207	if (in_exception_text(where)) {
	208	/*
	209	* If we switched to the irq_stack before calling this
	210	* exception handler, then the pt_regs will be on the
	211	* task stack. The easiest way to tell is if the large
	212	* pt_regs would overlap with the end of the irq_stack.
	213	*/
	214	if (stack < irq_stack_ptr &&
	215	(stack + sizeof(struct pt_regs)) > irq_stack_ptr)
	216	stack = IRQ_STACK_TO_TASK_STACK(irq_stack_ptr);
	217
9f93f3e9 JL	218	dump_mem("", "Exception stack", stack,
9f93f3e9 JL	219	stack + sizeof(struct pt_regs), false);
132cd887	220	}
60ffc30d CM	221	}
	222	}
	223
60ffc30d CM	224	void show_stack(struct task_struct tsk, unsigned long sp)
	225	{
	226	dump_backtrace(NULL, tsk);
	227	barrier();
	228	}
	229
	230	#ifdef CONFIG_PREEMPT
	231	#define S_PREEMPT " PREEMPT"
	232	#else
	233	#define S_PREEMPT ""
	234	#endif
60ffc30d	235	#define S_SMP " SMP"
60ffc30d CM	236
	237	static int __die(const char str, int err, struct thread_info thread,
	238	struct pt_regs *regs)
	239	{
	240	struct task_struct *tsk = thread->task;
	241	static int die_counter;
	242	int ret;
	243
	244	pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP "\n",
	245	str, err, ++die_counter);
	246
	247	/* trap and error numbers are mostly meaningless on ARM */
	248	ret = notify_die(DIE_OOPS, str, regs, err, 0, SIGSEGV);
	249	if (ret == NOTIFY_STOP)
	250	return ret;
	251
	252	print_modules();
	253	__show_regs(regs);
	254	pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
	255	TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), thread + 1);
	256
	257	if (!user_mode(regs) \|\| in_interrupt()) {
	258	dump_mem(KERN_EMERG, "Stack: ", regs->sp,
e147ae6d RT	259	THREAD_SIZE + (unsigned long)task_stack_page(tsk),
e147ae6d RT	260	compat_user_mode(regs));
60ffc30d CM	261	dump_backtrace(regs, tsk);
	262	dump_instr(KERN_EMERG, regs);
	263	}
	264
	265	return ret;
	266	}
	267
	268	static DEFINE_RAW_SPINLOCK(die_lock);
	269
	270	/*
	271	* This function is protected against re-entrancy.
	272	*/
	273	void die(const char str, struct pt_regs regs, int err)
	274	{
	275	struct thread_info *thread = current_thread_info();
	276	int ret;
	277
	278	oops_enter();
	279
	280	raw_spin_lock_irq(&die_lock);
	281	console_verbose();
	282	bust_spinlocks(1);
	283	ret = __die(str, err, thread, regs);
	284
	285	if (regs && kexec_should_crash(thread->task))
	286	crash_kexec(regs);
	287
	288	bust_spinlocks(0);
373d4d09	289	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
60ffc30d CM	290	raw_spin_unlock_irq(&die_lock);
	291	oops_exit();
	292
	293	if (in_interrupt())
	294	panic("Fatal exception in interrupt");
	295	if (panic_on_oops)
	296	panic("Fatal exception");
	297	if (ret != NOTIFY_STOP)
	298	do_exit(SIGSEGV);
	299	}
	300
	301	void arm64_notify_die(const char str, struct pt_regs regs,
	302	struct siginfo *info, int err)
	303	{
9141300a CM	304	if (user_mode(regs)) {
	305	current->thread.fault_address = 0;
	306	current->thread.fault_code = err;
60ffc30d	307	force_sig_info(info->si_signo, info, current);
9141300a	308	} else {
60ffc30d	309	die(str, regs, err);
9141300a	310	}
60ffc30d CM	311	}
60ffc30d CM	312
9b79f52d PA	313	static LIST_HEAD(undef_hook);
	314	static DEFINE_RAW_SPINLOCK(undef_lock);
	315
	316	void register_undef_hook(struct undef_hook *hook)
	317	{
	318	unsigned long flags;
	319
	320	raw_spin_lock_irqsave(&undef_lock, flags);
	321	list_add(&hook->node, &undef_hook);
	322	raw_spin_unlock_irqrestore(&undef_lock, flags);
	323	}
	324
	325	void unregister_undef_hook(struct undef_hook *hook)
	326	{
	327	unsigned long flags;
	328
	329	raw_spin_lock_irqsave(&undef_lock, flags);
	330	list_del(&hook->node);
	331	raw_spin_unlock_irqrestore(&undef_lock, flags);
	332	}
	333
	334	static int call_undef_hook(struct pt_regs *regs)
	335	{
	336	struct undef_hook *hook;
	337	unsigned long flags;
	338	u32 instr;
	339	int (fn)(struct pt_regs regs, u32 instr) = NULL;
	340	void __user pc = (void __user )instruction_pointer(regs);
	341
	342	if (!user_mode(regs))
	343	return 1;
	344
	345	if (compat_thumb_mode(regs)) {
	346	/* 16-bit Thumb instruction */
	347	if (get_user(instr, (u16 __user *)pc))
	348	goto exit;
	349	instr = le16_to_cpu(instr);
	350	if (aarch32_insn_is_wide(instr)) {
	351	u32 instr2;
	352
	353	if (get_user(instr2, (u16 __user *)(pc + 2)))
	354	goto exit;
	355	instr2 = le16_to_cpu(instr2);
	356	instr = (instr << 16) \| instr2;
	357	}
	358	} else {
	359	/* 32-bit ARM instruction */
	360	if (get_user(instr, (u32 __user *)pc))
	361	goto exit;
	362	instr = le32_to_cpu(instr);
	363	}
	364
	365	raw_spin_lock_irqsave(&undef_lock, flags);
	366	list_for_each_entry(hook, &undef_hook, node)
	367	if ((instr & hook->instr_mask) == hook->instr_val &&
	368	(regs->pstate & hook->pstate_mask) == hook->pstate_val)
	369	fn = hook->fn;
	370
	371	raw_spin_unlock_irqrestore(&undef_lock, flags);
	372	exit:
	373	return fn ? fn(regs, instr) : 1;
	374	}
	375
60ffc30d CM	376	asmlinkage void __exception do_undefinstr(struct pt_regs *regs)
	377	{
	378	siginfo_t info;
	379	void __user pc = (void __user )instruction_pointer(regs);
	380
60ffc30d	381	/* check for AArch32 breakpoint instructions */
1442b6ed	382	if (!aarch32_break_handler(regs))
60ffc30d	383	return;
60ffc30d	384
9b79f52d PA	385	if (call_undef_hook(regs) == 0)
	386	return;
	387
f871d268	388	if (unhandled_signal(current, SIGILL) && show_unhandled_signals_ratelimited()) {
60ffc30d CM	389	pr_info("%s[%d]: undefined instruction: pc=%p\n",
	390	current->comm, task_pid_nr(current), pc);
	391	dump_instr(KERN_INFO, regs);
	392	}
	393
	394	info.si_signo = SIGILL;
	395	info.si_errno = 0;
	396	info.si_code = ILL_ILLOPC;
	397	info.si_addr = pc;
	398
	399	arm64_notify_die("Oops - undefined instruction", regs, &info, 0);
	400	}
	401
	402	long compat_arm_syscall(struct pt_regs *regs);
	403
	404	asmlinkage long do_ni_syscall(struct pt_regs *regs)
	405	{
	406	#ifdef CONFIG_COMPAT
	407	long ret;
	408	if (is_compat_task()) {
	409	ret = compat_arm_syscall(regs);
	410	if (ret != -ENOSYS)
	411	return ret;
	412	}
	413	#endif
	414
86dca36e	415	if (show_unhandled_signals_ratelimited()) {
60ffc30d CM	416	pr_info("%s[%d]: syscall %d\n", current->comm,
	417	task_pid_nr(current), (int)regs->syscallno);
	418	dump_instr("", regs);
	419	if (user_mode(regs))
	420	__show_regs(regs);
	421	}
	422
	423	return sys_ni_syscall();
	424	}
	425
60a1f02c MR	426	static const char *esr_class_str[] = {
	427	[0 ... ESR_ELx_EC_MAX] = "UNRECOGNIZED EC",
	428	[ESR_ELx_EC_UNKNOWN] = "Unknown/Uncategorized",
	429	[ESR_ELx_EC_WFx] = "WFI/WFE",
	430	[ESR_ELx_EC_CP15_32] = "CP15 MCR/MRC",
	431	[ESR_ELx_EC_CP15_64] = "CP15 MCRR/MRRC",
	432	[ESR_ELx_EC_CP14_MR] = "CP14 MCR/MRC",
	433	[ESR_ELx_EC_CP14_LS] = "CP14 LDC/STC",
	434	[ESR_ELx_EC_FP_ASIMD] = "ASIMD",
	435	[ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS",
	436	[ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC",
	437	[ESR_ELx_EC_ILL] = "PSTATE.IL",
	438	[ESR_ELx_EC_SVC32] = "SVC (AArch32)",
	439	[ESR_ELx_EC_HVC32] = "HVC (AArch32)",
	440	[ESR_ELx_EC_SMC32] = "SMC (AArch32)",
	441	[ESR_ELx_EC_SVC64] = "SVC (AArch64)",
	442	[ESR_ELx_EC_HVC64] = "HVC (AArch64)",
	443	[ESR_ELx_EC_SMC64] = "SMC (AArch64)",
	444	[ESR_ELx_EC_SYS64] = "MSR/MRS (AArch64)",
	445	[ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF",
	446	[ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)",
	447	[ESR_ELx_EC_IABT_CUR] = "IABT (current EL)",
	448	[ESR_ELx_EC_PC_ALIGN] = "PC Alignment",
	449	[ESR_ELx_EC_DABT_LOW] = "DABT (lower EL)",
	450	[ESR_ELx_EC_DABT_CUR] = "DABT (current EL)",
	451	[ESR_ELx_EC_SP_ALIGN] = "SP Alignment",
	452	[ESR_ELx_EC_FP_EXC32] = "FP (AArch32)",
	453	[ESR_ELx_EC_FP_EXC64] = "FP (AArch64)",
	454	[ESR_ELx_EC_SERROR] = "SError",
	455	[ESR_ELx_EC_BREAKPT_LOW] = "Breakpoint (lower EL)",
	456	[ESR_ELx_EC_BREAKPT_CUR] = "Breakpoint (current EL)",
	457	[ESR_ELx_EC_SOFTSTP_LOW] = "Software Step (lower EL)",
	458	[ESR_ELx_EC_SOFTSTP_CUR] = "Software Step (current EL)",
	459	[ESR_ELx_EC_WATCHPT_LOW] = "Watchpoint (lower EL)",
	460	[ESR_ELx_EC_WATCHPT_CUR] = "Watchpoint (current EL)",
	461	[ESR_ELx_EC_BKPT32] = "BKPT (AArch32)",
	462	[ESR_ELx_EC_VECTOR32] = "Vector catch (AArch32)",
	463	[ESR_ELx_EC_BRK64] = "BRK (AArch64)",
	464	};
	465
	466	const char *esr_get_class_string(u32 esr)
	467	{
	468	return esr_class_str[esr >> ESR_ELx_EC_SHIFT];
	469	}
	470
60ffc30d CM	471	/*
	472	* bad_mode handles the impossible case in the exception vector.
	473	*/
	474	asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
	475	{
9955ac47 MR	476	siginfo_t info;
9955ac47 MR	477	void __user pc = (void __user )instruction_pointer(regs);
60ffc30d CM	478	console_verbose();
60ffc30d CM	479
60a1f02c MR	480	pr_crit("Bad mode in %s handler detected, code 0x%08x -- %s\n",
60a1f02c MR	481	handler[reason], esr, esr_get_class_string(esr));
9955ac47 MR	482	__show_regs(regs);
	483
	484	info.si_signo = SIGILL;
	485	info.si_errno = 0;
	486	info.si_code = ILL_ILLOPC;
	487	info.si_addr = pc;
60ffc30d	488
9955ac47	489	arm64_notify_die("Oops - bad mode", regs, &info, 0);
60ffc30d CM	490	}
	491
	492	void __pte_error(const char *file, int line, unsigned long val)
	493	{
c9cd0ed9	494	pr_err("%s:%d: bad pte %016lx.\n", file, line, val);
60ffc30d CM	495	}
	496
	497	void __pmd_error(const char *file, int line, unsigned long val)
	498	{
c9cd0ed9	499	pr_err("%s:%d: bad pmd %016lx.\n", file, line, val);
60ffc30d CM	500	}
60ffc30d CM	501
c79b954b JL	502	void __pud_error(const char *file, int line, unsigned long val)
c79b954b JL	503	{
c9cd0ed9	504	pr_err("%s:%d: bad pud %016lx.\n", file, line, val);
c79b954b JL	505	}
c79b954b JL	506
60ffc30d CM	507	void __pgd_error(const char *file, int line, unsigned long val)
60ffc30d CM	508	{
c9cd0ed9	509	pr_err("%s:%d: bad pgd %016lx.\n", file, line, val);
60ffc30d CM	510	}
60ffc30d CM	511
9fb7410f DM	512	/* GENERIC_BUG traps */
	513
	514	int is_valid_bugaddr(unsigned long addr)
	515	{
	516	/*
	517	* bug_handler() only called for BRK #BUG_BRK_IMM.
	518	* So the answer is trivial -- any spurious instances with no
	519	* bug table entry will be rejected by report_bug() and passed
	520	* back to the debug-monitors code and handled as a fatal
	521	* unexpected debug exception.
	522	*/
	523	return 1;
	524	}
	525
	526	static int bug_handler(struct pt_regs *regs, unsigned int esr)
	527	{
	528	if (user_mode(regs))
	529	return DBG_HOOK_ERROR;
	530
	531	switch (report_bug(regs->pc, regs)) {
	532	case BUG_TRAP_TYPE_BUG:
	533	die("Oops - BUG", regs, 0);
	534	break;
	535
	536	case BUG_TRAP_TYPE_WARN:
a4653228 DM	537	/* Ideally, report_bug() should backtrace for us... but no. */
a4653228 DM	538	dump_backtrace(regs, NULL);
9fb7410f DM	539	break;
	540
	541	default:
	542	/* unknown/unrecognised bug trap type */
	543	return DBG_HOOK_ERROR;
	544	}
	545
	546	/* If thread survives, skip over the BUG instruction and continue: */
	547	regs->pc += AARCH64_INSN_SIZE; /* skip BRK and resume */
	548	return DBG_HOOK_HANDLED;
	549	}
	550
	551	static struct break_hook bug_break_hook = {
	552	.esr_val = 0xf2000000 \| BUG_BRK_IMM,
	553	.esr_mask = 0xffffffff,
	554	.fn = bug_handler,
	555	};
	556
	557	/*
	558	* Initial handler for AArch64 BRK exceptions
	559	* This handler only used until debug_traps_init().
	560	*/
	561	int __init early_brk64(unsigned long addr, unsigned int esr,
	562	struct pt_regs *regs)
	563	{
	564	return bug_handler(regs, esr) != DBG_HOOK_HANDLED;
	565	}
	566
	567	/* This registration must happen early, before debug_traps_init(). */
60ffc30d CM	568	void __init trap_init(void)
60ffc30d CM	569	{
9fb7410f	570	register_break_hook(&bug_break_hook);
60ffc30d	571	}